Sample records for gondwana basin orissa

  1. Alluvial Fan-lacustrine Sedimentation and its Tectonic Implications in the Cretaceous Athgarh Gondwana Basin, Orissa, India

    Microsoft Academic Search

    Banabehari Mishra; Krishna Lal Pandya; Wataru Maejima

    2004-01-01

    The Athgarh Formation is the northernmost extension of the east coast Upper Gondwana sediments of Peninsular India. The formation of the present area is a clastic succession of 700 m thick and was built against an upland scarp along the north and northwestern boundary of the basin marked by an E-W-ENE-WSW boundary fault. A regular variation in the dominant facies

  2. Comparative Study of Cyclicity of Lithofacies in Lower Gondwana Formations of Talchir Basin, Orissa, India: A Statistical Analysis of Subsurface Logs

    Microsoft Academic Search

    Rabindra Nath Hota; Wataru Maejima

    2004-01-01

    Cyclic characters of Karharbari, Barakar and Barren Measures Formations of the Talchir Gondwana basin have been studied in the subsurface logs statistically using first order Markov chain and entropy analyses. Results strongly suggest that the sediments of these formations were deposited by Markovian mechanism and all the three formations represent cyclic sedimentation. The complete cycles of all the three formations

  3. Record of Lower Gondwana megafloral assemblage from Lower Kamthi Formation of Ib River Coalfield, Orissa, India.

    PubMed

    Goswami, Shreerup

    2006-03-01

    Recent investigations carried out in the Ib River Coalfield, Mahanadi Master Basin, Orissa, identified some fossilif-erous beds in the Lower Gondwana deposits. Two exposures of the Lower Kamthi Formation yielded diverse and abundant plant remains, which include Neomariopteris, Vertebraria, and a scale leaf along with 14 Glossopteris species otherwise mapped as Barren Measures and Upper Kamthi formations. Glossopteris indica dominates the flora (22.78%) followed by G. communis (17.72%) and G. browniana (13.92%). Based on megafloral assemblages, different beds exposed at Gopalpur and Laxamanpur Pahar are assigned here to the Lower Kamthi Formation (Late Permian). The floristic composition suggests that a warm and humid climate prevailed during the Late Permian. The status of the Kamthi Formation in the Ib River Coalfield has been redefined in the present study. PMID:16595881

  4. Occurrence of Cordaitales from lower Gondwana sediments of Ib-River Coalfield, Orissa, India: An Indian scenario

    NASA Astrophysics Data System (ADS)

    Singh, Kamal Jeet; Goswami, Shreerup; Chandra, Shaila

    2007-03-01

    The Ib-River Coalfield in Orissa State is a part of Mahanadi Master Basin. Recent extensive investigations were conducted in this Coalfield to locate fossiliferous beds in the Lower Gondwana deposits and as a result a large cache of plant fossils were recovered from Lower Permian sediments (Barakar Formation) exposed in Jurabaga and Lajkura Collieries. The complete flora includes 23 genera representing nine orders viz., Lycopodiales, Equisetales, Sphenophyllales, Filicales, Cordaitales, Coniferales, Ginkgoales, Cycadales and Glossopteridales. Only the Cordaitales, represented by four genera i.e., Noeggerathiopsis, Cordaites, Euryphyllum and Kawizophyllum are discussed in this paper. Cordaitalean leaves are described for the first time from this coalfield; the remaining plant groups will be considered in a subsequent publication. Cordaitalean leaves attributable to Noeggerathiopsis hislopii, Noeggerathiopsis minor, Euryphyllum whittianum, Euryphyllum maithyi, Kawizophyllum dunpathriensis and Cordaites sp. constitute about 13.90% (111 specimens) of the total plant assemblage collected from this Coalfield. Of the cordaitaleans, N. hislopii is most abundant (47.75%; 53 specimens) followed by E. whittianum (40.54%; 45 specimens). A summary of the distribution of Cordaitales throughout the Indian Gondwana is also presented. Floristic composition varies stratigraphically at the two Barakar exposures (Lajkura and Jurabaga Collieries). Cordaitales are preserved only in the lowermost (4th) horizon (lower floral zone). Strata in these collieries have been assigned to the lower and upper Barakar Formation based on floristic content and an Early Permian (Artinskian) age is assigned.

  5. Pteridophytes from Lower Gondwana formations of the Ib River Coalfield, Orissa and their diversity and distribution in the Permian of India

    NASA Astrophysics Data System (ADS)

    Goswami, Shreerup; Jeet Singh, Kamal; Chandra, Shaila

    2006-12-01

    Recent extensive investigations carried out in the Ib River Coalfield, Mahanadi Master Basin, Orissa, identified numerous fossiliferous beds in the lower Gondwana deposits. Six exposures of the Barakar and lower Kamthi formations yielded diverse and abundant plant remains. The flora includes twenty-three genera representing nine groups viz., Lycopodiales, Equisetales, Sphenophyllales, Filicales, Cordaitales, Coniferales, Ginkgoales, Cycadales and Glossopteridales. Systematic descriptions of the pteridophyte taxa namely Cyclodendron (Lycopodiales), Schizoneura, Raniganjia, Bengalia, equisetaceous stems (Equisetales), Trizygia, Benlightfootia (Sphenophyllales), Neomariopteris, and Dichotomopteris (Filicales) are presented in this paper. Pteridophytic leaves comprising nine taxa viz., Cyclodendron leslii, Schizoneura gondwanensis, Raniganjia bengalensis, Bengalia raniganjensis, Trizygia speciosa, Benlightfootia indica, Neomariopteris hughesii, N. talchirensis, and Dichotomopteris sp. together with equisetaceous stems constitute about 7.88% (72 specimens) of the total plant assemblage collected from this coalfield. Among the pteridophytes, equisetaceous stems are most abundant (40.3%; 29 specimens) followed by Schizoneura gondwanensis (20.8%, 15 specimens) and Trizygia speciosa (13.9%, 10 specimens). A summary of the known diversity of pteridophytes in the Indian Permian as a whole is provided. Barakar Formation exposures have been assigned to a lower and upper series based on possession of different floristic assemblages. Pteridophytes do not occur in the lower series. On this basis the beds of Lajkura, Jurabaga collieries, Ratanpur Fireclay Quarry and the locality near Belpahar Railway Station with pteridophyte fossils are assigned to the upper Barakar Formation (late Artinskian). Based on assemblages containing different pteridophytes, beds exposed at Sitaram and Dungri Pahar are assigned to the lower Kamthi Formation (Lopingian). The floristic composition suggests a palaeoclimatic shift from temperate warm moist to warm dry conditions during the late Artinskian and warm and humid during Lopingian. The Permian pteridophytes grew in semi-aquatic conditions, i.e. in marshy places around small ponds, lakes and river-banks.

  6. Palynomorphs of Permian Gondwana coal from borehole GDH-38, Barapukuria Coal Basin, Bangladesh

    USGS Publications Warehouse

    Akhtar, A.; Kosanke, R.M.

    2000-01-01

    Thirty-two core samples of Permian Gondwana coal from three coal beds of borehole GDH-38, Barapukuria Coal Basin, Dinajpur, the north-northwestern part of Bangladesh, have been collected for palynological analysis. All samples except one yielded palynomorphs and some samples contain well-preserved and abundant palynomorphs of the gymnospermal and cryptogamic groups that are considered to be useful for future correlation studies. The lower coal bed (331.6-372.5 m) can easily be differentiated from the upper two coal beds by the presence of Alisporites, Cordaitina, Corisaccites, Hamiapollenites, Leuckisporites, Nuskoisporites, Tumoripollenites, Vestgisporites and Vittatina. It is difficult to palynologically differentiate the middle (198.1-208 m) and upper (162.3-172.9 m) coal beds as they contain a very limited number of specimens by which they can be identified. The middle bed is distinguished by the presence of Microbaculispora and Weylandites and the upper bed by the presence of a single taxon Acanthotriletes. Some of the vesiculate or saccate taxa extracted from these coal beds are typical of those occurring in Permian strata of Gondwana in India, South Africa, South America, Russia, Australia and Antarctica. They are thought to be derived from Glossopteris flora, which is characterised by an abundance of Pteridospermic plants of the gymnosperm group. ?? 2000 Elsevier Science Limited. All rights reserved.

  7. An Interpretation of the Seafloor Spreading History of the West Enderby Basin between Initial Breakup of Gondwana and Anomaly C34

    Microsoft Academic Search

    Yoshifumi Nogi; Kumiko Nishi; Nobukazu Seama; Yoichi Fukuda

    2004-01-01

    The seafloor spreading evolution in the Southern Indian Ocean is key to understanding the initial breakup of Gondwana. We summarize the structural lineaments deduced from the GEOSAT 10?Hz sampled raw altimetry data as well as satellite derived gravity anomaly map and the magnetic anomaly lineation trends from vector magnetic anomalies in the West Enderby Basin, the Southern Indian Ocean. The

  8. Early Callovian ingression in southwestern Gondwana. Palaeoenvironmental evolution of the carbonate ramp (Calabozo Formation) in southwestern Mendoza, Neuquen basin, Argentina

    NASA Astrophysics Data System (ADS)

    Armella, Claudia; Cabaleri, Nora G.; Cagnoni, Mariana C.; Panarello, Héctor O.

    2013-08-01

    The carbonatic sequence of the Calabozo Formation (Lower Callovian) developed in southwestern Gondwana, within the northern area of the Neuquén basin, and is widespread in thin isolated outcrops in southwestern Mendoza province, Argentina. This paper describes the facies, microfacies and geochemical-isotopic analysis carried out in five studied localities, which allowed to define the paleoenvironmental conditions of a homoclinal shallow ramp model, highly influenced by sea level fluctuations, where outer, mid and inner ramp subenvironments were identified. The outer ramp subenvironment was only recognized in the south of the depocenter and is characterized by proximal outer ramp facies with shale levels and interbedded mudstone and packstone layers. The mid ramp subenvironment is formed by low energy facies (wackestone) affected by storms (packstones, grainstones and floatstones). The inner ramp subenvironment is the most predominant and is characterized by tidal flat facies (wackestones, packstones and grainstones) over which a complex of shoals (grainstones and packstones) dissected by tidal channels (packstone, grainstones and floatstones) developed. In the north area, protected environment facies were recorded (bioturbated wackestones and packstones). The vertical distribution of facies indicates that the paleoenvironmental evolution of the Calabozo Formation results from a highstand stage in the depocenter, culminating in a supratidal environment, with stromatolitic levels interbedded with anhydrite originated under restricted water circulation conditions due to a progressive isolation of the basin. ?13C and ?18O values of the carbonates of the Calabozo Formation suggest an isotopic signature influenced by local palaeoenvironmental parameters and diagenetic overprints. The ?13C and ?18O oscillations between the carbonates of the different studied sections are related with lateral facies variations within the carbonate ramp accompanied with dissimilar reactivities in relation to diagenetic fluids. The ?18O values of all sections exhibit a rather broad scatter which may be attributed to diagenesis and recrystallisation while the carbon isotopic composition has been less affected by those processes. Carbon isotope system has best retained the primary isotopic signal and ?13C values (0-3.9‰) are within the Callovian isotope range. The 87Sr/86Sr ratios of the bulk carbonates of El Plomo creek, La Vaina creek and Potimalal River sections are in agreement with the Callovian seawater Sr-isotope curve.

  9. The Chachil Limestone (Pliensbachian-earliest Toarcian) Neuquén Basin, Argentina: U-Pb age calibration and its significance on the Early Jurassic evolution of southwestern Gondwana

    NASA Astrophysics Data System (ADS)

    Leanza, H. A.; Mazzini, A.; Corfu, F.; Llambías, E. J.; Svensen, H.; Planke, S.; Galland, O.

    2013-03-01

    New radiometric U-Pb ages obtained on zircon crystals from Early Jurassic ash layers found within beds of the Chachil Limestone at its type locality in the Chachil depocentre (southern Neuquén Basin) confirm a Pliensbachian age (186.0 ± 0.4 Ma). Additionally, two ash layers found in limestone beds in Chacay Melehue at the Cordillera del Viento depocentre (central Neuquén Basin) gave Early Pliensbachian (185.7 ± 0.4 Ma) and earliest Toarcian (182.3 ± 0.4 Ma) U-Pb zircon ages. Based on these new datings and regional geological observations, we propose that the limestones cropping out at Chacay Melehue are correlatable with the Chachil Limestone. Recent data by other authors from limestones at Serrucho creek in the upper Puesto Araya Formation (Valenciana depocentre, southern Mendoza) reveal ages of 182.16 ± 0.6 Ma. Based on these new evidences, we consider the Chachil Limestone an important Early Jurassic stratigraphic marker, representing an almost instantaneous widespread flooding episode in western Gondwana. The unit marks the initiation in the Neuquén Basin of the Cuyo Group, followed by widespread black shale deposition. Accordingly, these limestones can be regarded as the natural seal of the Late Triassic -earliest Jurassic Precuyano Cycle, which represents the infill of halfgrabens and/or grabens related to a strong extensional regime. Paleontological evidence supports that during Pliensbachian-earliest Toarcian times these limestones were deposited in western Gondwana in marine warm water environments.

  10. Extension of Godavari Gondwana sediments underneath Trap covered region of Satpura basin as evidenced from seismic studies in Deccan Syneclise, India

    NASA Astrophysics Data System (ADS)

    Murty, A. S. N.; Dixit, M. M.; Mandal, B.; Raju, S.; Kumar, Sanjay; Karupannan, P.; Anitha, K.; Sarkar, D.

    2011-11-01

    We present a shallow P-wave velocity structure of the eastern part of Deccan Syneclise, central India, from the refraction and wide-angle reflection data recorded along two ˜100 km long seismic refraction profiles in east-west (E-W) and north-south (N-S) directions using travel time inversion method. In addition to the P-wave velocity model, we have derived S-wave velocity model and estimated Vp/Vs and Poisson's ratios along the east-west profile. Travel time analysis and inversion of the data revealed three layers above the basement. The first layer with a P-wave velocity of 1.4-1.5 km s -1 represents alluvium and the thickness of this layer is varying between 100-400 m in the E-W and 30-100 m in the N-S profile. The Deccan Trap thickness is observed to be varying between 850 and 1250 m constitutes the second layer. P-wave velocity of the Deccan Traps is 4.8-5.2 km s -1. Amplitude decay and travel time skips in the first arrival refraction data in some of the record sections indicate the presence of a velocity inversion i.e. low velocity zone (LVZ) beneath the Traps. Wide-angle reflection phases from top and bottom of the LVZ (top of basement) together with basement refraction phase are identified and modeled to derive LVZ thickness. The LVZ has been interpreted to be the Gondwana sediments sandwiched between Deccan Traps and basement. These sediments are about 200-450 m thick with a P-wave velocity of 3.6 km s -1. The basement lies at about 1.60 km depth near Khandala in the west and Rajola in the north shows an upward trend towards south-east. The P-wave velocity of the basement is about 6.0-6.2 km s -1. The inferred subtrappean sediments could be the possible extension of Gondwana sediments of the Godavari graben towards the Satpura basin.

  11. A Late Jurassic fossil assemblage in Gondwana: Biostratigraphy and correlations of the Tacuarembó Formation, Parana Basin, Uruguay

    NASA Astrophysics Data System (ADS)

    Perea, Daniel; Soto, Matías; Veroslavsky, Gerardo; Martínez, Sergio; Ubilla, Martín

    2009-08-01

    The Tacuarembó Formation has yielded a fossil assemblage that includes the best known body fossils, consisting of isolated scales, teeth, spines, and molds of bones, recovered from thin and patchy bonebeds, from the Botucatu Desert, Parana Basin, South America. The remains are preserved in the sandstones widespread around the city of Tacuarembó. We propose a new formalized nomenclature for the Tacuarembó Formation, naming its "Lower" and "Upper" members as the Batoví (new name) and Rivera (new rank) members, respectively. An assemblage zone is defined for the Batoví Member (fluviolacustrine and aeolian deposits). In this unit, the freshwater hybodontid shark Priohybodusarambourgi D'Erasmo is well represented. This species was previously recorded in Late Jurassic-Early Cretaceous units of the Sahara and the southern Arabian Peninsula. Globally considered, the fossil assemblage of this member ( P. arambourgi, dipnoan fishes, Ceratosaurus-like theropods, and conchostracans) is indicative of a Kimmeridgian-Tithonian age, which in combination with the stratigraphic relationships of the Tacuarembó Formation with the overlying basalts of the Arapey Formation (132 My average absolute age) implies that the latter was deposited during the Kimmeridgian-Hauterivian interval.

  12. Improved Moscovian part of the Gondwana APWP for paleocontinental reconstructions, obtained from a first paleomagnetic pole, age-constrained by a fold test, from In Ezzane area in the Murzuq basin (Algeria, stable Africa)

    NASA Astrophysics Data System (ADS)

    Amenna, M.; Derder, M. E. M.; Henry, B.; Bayou, B.; Maouche, S.; Bouabdallah, H.; Ouabadi, A.; Ayache, M.; Beddiaf, M.

    2014-11-01

    To improve paleocontinental reconstructions, paleomagnetic reference curves (Apparent Polar Wander Path: APWP) feature for large continents have to be continuously refined by adding up new high-quality data. For stable Africa, the Moscovian period was favorable for such aim, with well-dated and widespread geological formations. A new study has been conducted in the Upper “Dembaba” geological formation of Lower Moscovian age outcropping in the western part of the “Murzuq” basin (Saharan platform). Well-defined ChRMs, combined with remagnetization circles data, both constrained in age by a positive fold test, yield a new significant paleomagnetic pole (? = 25.2°S, ? = 59.9°E, K = 55, A95 = 5.4°). When joined with previous African data of the same age, it gives an improved reference pole for Africa (? = 28.9°S, ? = 54.5°E, K = 106, A95 = 3.6°). The Mean Moscovian paleomagnetic pole determined from an updated Gondwana Paleozoic APWP (? = 29.4°S, ? = 51.5°E, K = 11, A95 = 1.8°), associated with the corresponding Laurussia pole (Domeier et al., 2012), yields a more constrained paleocontinental reconstruction for 310 Ma.

  13. The Dispersal of East Gondwana from Continental Breakup to the Start of the Cretaceous Quiet Zone

    NASA Astrophysics Data System (ADS)

    Davis, J. K.; Lawver, L. A.; Norton, I. O.; Gahagan, L.

    2014-12-01

    Existing plate models for the breakup of Africa and East Gondwana (Australia, East Antarctica, India, Madagascar, the Seychelles, and Sri Lanka) are problematic and require revision. Specific problems include the utilization of dubious Gondwana configurations, improbable plate motion, and/or a failure to satisfy the holistic marine magnetic anomaly data. I present here a new model for the breakup of East Gondwana. This new model begins from a constrained, pre-breakup, Gondwana configuration. Out of this initial "tight-fit" configuration, East Gondwana rifts from West Gondwana (Africa & South America) as a cohesive unit. During this breakup and subsequent seafloor spreading, East Gondwana is devoid of any internal compression or anomalous plate motion. The overall motion of East Gondwana is constrained by seafloor spreading in the coeval Somali Basin and Mozambique/Riiser Larsen Basins. Seafloor spreading in these basins is modeled using existing marine magnetic anomaly interpretations and satellite-derived gravity data. Our model is uniquely able to satisfy the magnetic anomaly observations in both of the aforementioned basins without invoking improbable plate motion or configurations. Additionally, our plate model provides valuable insight into the breakup of India and East Antarctica. In this model, we fix India to Madagascar from breakup to 90 Ma, thus eventual separation between India and East Antarctica is an output, not an input of our model. We suggest that this separation occurred diachronously from ~140 Ma in the east to ~120 Ma in the west. This modeled motion between India and East Antarctica agrees well with geophysical observations from the margin of East Antarctica and our preliminary analysis of margin character and variability.

  14. Linking the End of Glaciation in Gondwana to Aridity in the Tropics: Coupled Sr Chemostratigraphy and Cyclostratigraphy From the Permian Basin, Texas

    NASA Astrophysics Data System (ADS)

    Rasbury, E. T.; Hemming, N. G.; Saller, A. H.; Dickson, J.

    2007-05-01

    Crowell (1978) suggested the Earth was poised on the brink of glaciation throughout the Paleozoic and that closure of the low-latitude seaway between North America and Europe was responsible for diversion of moisture- laden currents to the south to feed the long-lived Carboniferous-Permian glaciers. This same diversion of currents also produced dramatic aridity in the tropics. This is seen in changes in paleosol types as well as in widespread loess and erg deposits. It also coincides with a dramatic decline in Sr isotopes across the Carboniferous-Permian boundary. Sr chemostratigraphy from cores taken across this boundary on the Central Basin Platform (CBP) of the Permian Basin in Texas show the same dramatic shift as seen in data from the type sections in the Urals across this boundary. This confirms that the fusulinid based stage boundaries for the Permian Basin are correct. On the CBP, high-frequency high-amplitude cycles end at a major stepback of the shelf margin at Abo/Clearfork time (Sakmarian). We suggest this transgression represents the end of major Gondwanan glaciation. If we assume the decline in 87Sr/86Sr is reflecting the aridity of the topics and calculate the reduction in continental Sr flux to the oceans, we can relate this to decreased silicate weathering and the consequent increase in atmospheric CO2. Assuming crustal values of [Sr] of 350 ppm, congruent weathering, that the total number of moles of Sr in the ocean is the same as today, and that all of the change is due to a change in flux of Sr from the continents, the change from a late Carboniferous 87Sr/86Sr high of 0.7082 to a value of 0.7078 (the end of cyclothems), equates to an increase in the ocean-atmosphere system of approximately 4 * 106 gigatons of carbon. Preindustrial carbon concentration in the atmosphere is estimated at 578 gigatons. Obviously there are feedbacks that will remove some of the carbon from the ocean-atmosphere system, perhaps to the biosphere, but this simple calculation shows that no special circumstances are needed to account for the increase in pCO2 shown by published proxy data. It also demonstrates why a model that only considers tectonic changes might fail to reproduce this part of the Sr curve. However, the 87Sr/86Sr continues to decrease to a late Permian low of 0.7069 without reversal while the proxy data show a decrease in pCO2 in the middle Permian to near Carboniferous values. Nevertheless, the change is coincident with a flattening in the most recently published Permian Sr curve.

  15. INDIGENOUS PHYTOTHERAPY FOR FILARIASIS FROM ORISSA

    PubMed Central

    Girach, R.D.; Brahmam, M.; Misra, M.K.; Ahmed, M.

    1998-01-01

    Filarias is one major health problem in the coastal areas of Orissa including district Bhadrak. Tis article deals with 8 plant species used in native phytotherapy for filariasis in this region with the view to provide clue for further research. PMID:22556846

  16. PLANT CONSERVATION IN TEMPLE YARDS OF ORISSA

    PubMed Central

    Mohanty, R.B; Mohapatra, B.K; Padhy, S.N

    1997-01-01

    This paper is a brief survey of the role of temples and holy places in nurturing the surrounding flora and its habitat. Eightysix kinds of plants in temple yards and gardens of orissa have been enlisted where they are cultivated and preserved for different temple rituals. These plants are seen rarely in wild but are saved from extinction by their association with temple rituals and ceremonies. PMID:22556826

  17. A model of plate kinematics in Gondwana breakup

    NASA Astrophysics Data System (ADS)

    Eagles, Graeme; König, Matthias

    2008-05-01

    An accurate model of relative plate motions in Gondwana breakup is based on visual fitting of seafloor isochrons and fracture zones (FZ) from the Riiser-Larsen Sea and Mozambique Basin. Used predictively, the model precisely locates kinematic markers in the West Somali Basin, which allows the conclusion that the spreading centres in the West Somali and Mozambique basins and the Riiser-Larsen Sea formed parts of the boundary between the same two plates. The locations of FZ and less well-defined isochrons from neighbouring regions are also consistent with their formation on other lengths of this same boundary and with its relocation from the West Somali Basin and northern Natal Valley to the West Enderby Basin and Lazarev Sea during chron M10n. Small independently moving plates thus played no role in the breakup of this core part of Gondwana. In an inversion procedure, the data from these areas yield more precise finite rotations that describe the history of the two plates' separation. Breakup is most simply interpreted to have occurred in coincidence with Karoo volcanism, and a reconstruction based on the rotations shows the Lebombo and Mateke-Sabi monoclines and the Mozambique and Astrid ridges as two sets of conjugate volcanic margins. Madagascar's pre-drift position can be used as a constraint to reassess the positions of India and Sri Lanka in the supercontinent.

  18. Transmed Transect VIII: from Laurussia to Gondwana

    NASA Astrophysics Data System (ADS)

    Stephenson, R. A.; Mart, Y.; Okay, A.; Robertson, A.; Stovba, S.; Khriachtchevskaia, O.

    2003-04-01

    TransMed transect VIII crosses the easternmost Mediterranean Sea. Some 2600 km long, it runs from Laurussia in the north (Ukrainian Shield) to Gondwana in the south (Arabian Shield). The Late Palaeozoic aged intracratonic Dniepr-Donets rift basin lies near the northern end of the transect and the modern intracratonic Red Sea rift lies at the southern end. Intervening tectonic units, north to south, include the Scythian Platform and Crimean Orogen in Ukraine; the Black Sea; the Pontides, Kirsehir Massif, and Taurides in Turkey; Cyprus with the Troodos complex; the Levant Basin and distal parts of the Nile Delta in the eastern Mediterranean; and the Sinai in Egypt. Deep structure, including crustal thickness and affinity, is poorly known along much of the transect. Although all available crustal scale seismic data have been considered, much of the deeper parts of the transect are inferred from the exposed geology and how this can be modelled in terms of regional paleotectonics and are, accordingly, speculative. Palaeozoic and younger sediments of the Scythian Platform overlie basement that is surmised to be younger than the adjoining Archean Ukrainian Shield. The whole of the crust of the Crimean Orogen, underlying thrust nappes emplaced during the early Mesozoic, is speculated to comprise an accretionary complex of mainly Triassic age that is correlated with the Sakarya Zone of northern Turkey. The Black Sea is a back-arc rift basin that opened in Late Cretacous-Tertiary times but the margins of the Black Sea intersected by the transect are not conjugate. The Pontide margin of the Black Sea, in northern Turkey, is formed by the Istanbul Zone, with Proterozoic-aged basement correlative with Moesian crust found in southern Romania and Bulgaria. The Kirsehir Massif is made up of Cretaceous metamorphic and granitic rocks, and represents the deeper parts of a magmatic arc. The Taurides form a south-vergent thrust-stack involving Palaeozoic to Eocene sediments. The Troodos complex represents Late Cretaceous-aged marginal-basin-type oceanic crust, which has been uplifted by the ongoing subduction under Cyprus. The Eratosthenes "seamount", south of Cyprus, is part of an isolated small continental sliver that is in the process of subduction under Cyprus along with the Levant Basin. The Levant Basin comprises Mesozoic and Cenozoic sediments overlying Jurassic-aged oceanic crust of the eastern Mediterranean that adjoins the Precambrian crust of the Sinai across a rifted continental margin.

  19. Some observational aspects and modeling results of the Orissa super cyclone, October 1999

    NASA Astrophysics Data System (ADS)

    Rao, N. J.; Rao, D. B.

    2001-05-01

    The super cyclone that crossed the Orissa coast near Paradeep port (20.3 N, 86.7 E) around 0600 UTC on 29 October 1999, caused enormous damage - death of 10,000 people and 400,000 cattle, property damage worth Ind. Rs. 10,000 crores ( about USD 2 billion), salinization of about 1.8 million hectares of agricultural land, destruction of paddy crop paddy crop worth Ind. Rs.1,500 crores (USD 300 million), and severe damage to transmission lines, power supply, roads and buildings sustained severe damages. This cyclone was identified as a low pressure in the Gulf of Thailand on 24th October 1999. It moved westwards and gradually intensified reaching the intensity of a severe cyclonic storm on 27 October. The cyclone further intensified reaching very high intensity to be called as a super cyclone when it crossed the Orissa coast near Paradeep around 0600 UTC of 29 October. The observational installations on the Orissa coast were severely damaged and failed to record. However rough estimates have been made using the satellite and radar pictures. Average speed of the storm was about 20 km/hour and increased to 30 km/hour while intensifying, but reduced before and after crossing the coast. The central surface pressure is estimated as 912 hPa on 29 October with the T-number as T7; correspondingly the maximum wind speed is estimated as 260 km/hour with the radius of the eye at 15 km. Heavy rainfall was reported on 29, 30 and 31 October with maximum amounts of 955 mm in Bhadrak district of Orissa and 600-800 mm in Mahanadi river basin. A storm surge of 5 to 6m above the astronomical tide is reported at Paradeep on 29 October. All the above parameters, namely, strong winds with gale, torrential rains with heavy rainfall rate and high storm surge, caused the devastation. An attempt has been made to simulate the intensification and movement of the cyclone using a high resolution mesoscale model. The simulation study indicated that the models are capable of predicting the intensification of the storm as well as the movement. However the model errors range below 50 km with respect to the track.

  20. Disintegration of the continental margin of northwestern Gondwana: Late Devonian of the eastern Anti-Atlas (Morocco)

    Microsoft Academic Search

    Jobst Wendt

    1985-01-01

    The Devonian early Carboniferous sequence in the eastern Anti-Atlas represents a complete record of the last stage of the depositional and tectonic evolution along the northwestern margin of Gondwana. As a consequence of early Variscan block faulting, a platform and basin topography was established during the Middle and Late Devonian. Platforms were covered by condensed cephalopod limestones; sedimentation in the

  1. Reservoir Characterization and Modeling of the Glorieta and the Clearfork Formations, Monahans Field, Permian Basin, Texas

    E-print Network

    Yeatman, Ryan Yeatman

    2012-10-19

    Basin and CBP The Permian Basin developed in the foreland basin of the Late Mississippian-Permian (Late Paleozoic) Marathon-Ouachita Orogeny. This orogenic belt was created from the collision of Gondwana with the North American continent (Dorobek...

  2. Supercyclone in Orissa: An Assessment of Psychological Status of Survivors

    Microsoft Academic Search

    Damodar Suar; Manas K. Mandal; R. Khuntia

    2002-01-01

    The study assessed the impact of the Orissa supercyclone on survivors' locus of control, anxiety, depression, and posttraumatic stress. The study was conducted in structured interview sessions 3 months after the supercyclone. The affected people (n = 65) who were close to the epicenter of supercyclone and lost their family members, relatives, and property, experienced more anxiety, depression, and posttraumatic

  3. A Mesozoic bird from Gondwana preserving feathers.

    PubMed

    de Souza Carvalho, Ismar; Novas, Fernando E; Agnolín, Federico L; Isasi, Marcelo P; Freitas, Francisco I; Andrade, José A

    2015-01-01

    The fossil record of birds in the Mesozoic of Gondwana is mostly based on isolated and often poorly preserved specimens, none of which has preserved details on feather anatomy. We provide the description of a fossil bird represented by a skeleton with feathers from the Early Cretaceous of Gondwana (NE Brazil). The specimen sheds light on the homology and 3D structure of the rachis-dominated feathers, previously known from two-dimensional slabs. The rectrices exhibit a row of rounded spots, probably corresponding to some original colour pattern. The specimen supports the identification of the feather scapus as the rachis, which is notably robust and elliptical in cross-section. In spite of its juvenile nature, the tail plumage resembles the feathering of adult individuals of modern birds. Documentation of rachis-dominated tail in South American enantiornithines broadens the paleobiogeographic distribution of basal birds with this tail feather morphotype, up to now only reported from China. PMID:26035285

  4. A Mesozoic bird from Gondwana preserving feathers

    PubMed Central

    de Souza Carvalho, Ismar; Novas, Fernando E.; Agnolín, Federico L.; Isasi, Marcelo P.; Freitas, Francisco I.; Andrade, José A.

    2015-01-01

    The fossil record of birds in the Mesozoic of Gondwana is mostly based on isolated and often poorly preserved specimens, none of which has preserved details on feather anatomy. We provide the description of a fossil bird represented by a skeleton with feathers from the Early Cretaceous of Gondwana (NE Brazil). The specimen sheds light on the homology and 3D structure of the rachis-dominated feathers, previously known from two-dimensional slabs. The rectrices exhibit a row of rounded spots, probably corresponding to some original colour pattern. The specimen supports the identification of the feather scapus as the rachis, which is notably robust and elliptical in cross-section. In spite of its juvenile nature, the tail plumage resembles the feathering of adult individuals of modern birds. Documentation of rachis-dominated tail in South American enantiornithines broadens the paleobiogeographic distribution of basal birds with this tail feather morphotype, up to now only reported from China. PMID:26035285

  5. Geophysical evidence for a causative process for fragmentation in western Gondwana

    SciTech Connect

    Antoine, L.A.G.; Moyes, A.B. (Univ. of Witwatersrand, Johannesburg (South Africa))

    1992-07-01

    The existence and subsequent fragmentation of the Gondwana supercontinent are well established in the geological literature. Debate continues, however, on the exact prefragmentation geometry and the causative process of breakup. The easter Walvis Ridge and the Agulhas and the Mozambique plateaus, which surround southern Africa, exhibit geophysically anomalous oceanic crust and lithosphere. In the vicinity of these aseismic bathymetry highs, the crust is considerably thicker than normal, and the uppermost mantle has lower than normal densities and seismic velocities. Within a Gondwana framework, these anomalies coincide with a highly fragmented region at the triple junction of the three major plates (Africa, South America, and Antarctica). This anomalous oceanic crust and lithosphere, the ubiquitous and contemporaneous magmatism, and the basin and range-type tectonism of the region are consonant with a hot-mantle-upflow tectonic framework as the causative process for fragmentation.

  6. Gondwana dispersion and Asian accretion: Tectonic and palaeogeographic evolution of eastern Tethys

    NASA Astrophysics Data System (ADS)

    Metcalfe, I.

    2013-04-01

    Present-day Asia comprises a heterogeneous collage of continental blocks, derived from the Indian-west Australian margin of eastern Gondwana, and subduction related volcanic arcs assembled by the closure of multiple Tethyan and back-arc ocean basins now represented by suture zones containing ophiolites, accretionary complexes and remnants of ocean island arcs. The Phanerozoic evolution of the region is the result of more than 400 million years of continental dispersion from Gondwana and plate tectonic convergence, collision and accretion. This involved successive dispersion of continental blocks, the northwards translation of these, and their amalgamation and accretion to form present-day Asia. Separation and northwards migration of the various continental terranes/blocks from Gondwana occurred in three phases linked with the successive opening and closure of three intervening Tethyan oceans, the Palaeo-Tethys (Devonian-Triassic), Meso-Tethys (late Early Permian-Late Cretaceous) and Ceno-Tethys (Late Triassic-Late Cretaceous). The first group of continental blocks dispersed from Gondwana in the Devonian, opening the Palaeo-Tethys behind them, and included the North China, Tarim, South China and Indochina blocks (including West Sumatra and West Burma). Remnants of the main Palaeo-Tethys ocean are now preserved within the Longmu Co-Shuanghu, Changning-Menglian, Chiang Mai/Inthanon and Bentong-Raub Suture Zones. During northwards subduction of the Palaeo-Tethys, the Sukhothai Arc was constructed on the margin of South China-Indochina and separated from those terranes by a short-lived back-arc basin now represented by the Jinghong, Nan-Uttaradit and Sra Kaeo Sutures. Concurrently, a second continental sliver or collage of blocks (Cimmerian continent) rifted and separated from northern Gondwana and the Meso-Tethys opened in the late Early Permian between these separating blocks and Gondwana. The eastern Cimmerian continent, including the South Qiangtang block and Sibumasu Terrane (including the Baoshan and Tengchong blocks of Yunnan) collided with the Sukhothai Arc and South China/Indochina in the Triassic, closing the Palaeo-Tethys. A third collage of continental blocks, including the Lhasa block, South West Borneo and East Java-West Sulawesi (now identified as the missing "Banda" and "Argoland" blocks) separated from NW Australia in the Late Triassic-Late Jurassic by opening of the Ceno-Tethys and accreted to SE Sundaland by subduction of the Meso-Tethys in the Cretaceous.

  7. The Mesozoic Continental Magmatism in Brazil: its Role in the Western Gondwana Evolution from Integrated Paleomagnetic and Geochemical Data

    NASA Astrophysics Data System (ADS)

    Ernesto, M.; Marques, L. S.

    2011-12-01

    Most of the Paleozoic era in the South American platform represents a period of tectonic quiescence during which large sedimentary basins evolved. Subsequently an intense magmatic activity took place preceding the disclosure of the Gondwana from Pangea, and later the disruption of the western Gondwana blocks (South America and Africa separation). In Brazil Early Jurassic (~220-180 Ma) tholeiitic basalts erupted mostly in the northern area (Amazonas and Parnaíba basins), whereas the Early Cretaceous (~140-120 Ma) is best represented by the huge magmatism of the Serra Geral Formation (Paraná basin, southeastern Brazil). An intense associated intrusive activity in the form of dykes and sills of both ages is widespread all over the country but tends to concentrate towards the continental margins. The integration of paleomagnetic and geochemical data on the Brazilian Mesozoic magmatism put some constraints on the timing, duration and the mantle sources involved in the generation of the magma products related to the different magmatic events.

  8. Environmental health impact assessment of National Aluminum Company, Orissa.

    PubMed

    Patil, Rajan R

    2011-05-01

    Environmental Health Impact Assessment of industries is an important tool help decision-makers make choices about alternatives and improvements to prevent disease/injury and to actively promote health around industrial sites. A rapid environmental health hazard and vulnerability assessment of National Aluminum Company was undertaken in the villages in the vicinity plant in Angul region of Orissa. Aluminum smelter plant was known to discharge hundreds of tones of fluoride in to the environment contaminating the ecosystem around the plant. The present Environmental health impact assessment was carried out in 2005-06 at the request of officials from Government of Orissa. The findings showed adverse effects on human, veterinary and ecological health. Human health effects manifestations included dental and skeletal fluorosis. Veternary health effects were manifested through skeletal fluorosis. Ecological adverse effects were manifested by damage to paddy fields and crop yield. PMID:22223954

  9. Late paleozoic orogeny in the northwestern Gondwana continental margin, western Argentina and Chile

    NASA Astrophysics Data System (ADS)

    Bonorino, G. González

    During Early Carboniferous-Early Permian time, the segment of the northwestern Gondwana continental margin (western Argentina and Chile) between present-day latitudes 27°S and 50°S was structurally organized into a marginal orogen and a foreland rising into cratonic highlands. Orogenesis and magmatism were governed by subduction of an ancestral Pacific plate under Gondwana. During the Late Devonian-Early Carboniferous, former slope-rise deposits were thickened to form the orogen and were thrust slightly onto the foreland; parts of the orogen emerged above sea level. Following this early diastrophic phase, tectonic uplift in the orogen was regionally checked by erosion until the late Early Permian when uplift rates overcame erosion. The development of this orogen is peculiar in that throughout much of this time: a) the orogenic bett was partly occupied by marine areas; b) there was no reversal of provenance, so that foreland basins were continuously fed from the interior highlands; and c) the orogenic belt did not advance further onto the foreland. Thus the orogen stabilized in position and relief. Magmatism was intense during the period of orogenic stability and was dominated by plutonism; there are no remnants of a well developed volcanic arc. Reconstructions involving Late Devonian-Early Carboniferous collision of crustal masses against Gondwana and a seaward jump of the subduction trench are not entirely substantiated by available data. An alternative suggests that from the Late Devonian to the Early Permian the trench maintained approximately the same position seaward of present-day coastal exposures.

  10. A unified Lower - Middle Cambrian chronostratigraphy for West Gondwana

    Microsoft Academic Search

    GERD GEYER; ED LANDING

    2004-01-01

    Similarities in biotic successions support a unified, composite chronostratigraphy for the Lower-Middle Cambrian of the Iberian and Moroccan margins of West Gondwana. The Cordubian Series (emended from an Iberian stage-level unit) com- prises the sub-trilobitic Lower Cambrian of West Gondwana. This series represents ca. half of the Cambrian (ca. 25 m.y.), has a base defined at the lowest occurrence of

  11. Gondwana's climate history inferred from the palynological record of South Africa's coal deposits: the Early Triassic wet intermezzo

    NASA Astrophysics Data System (ADS)

    Götz, Annette E.

    2013-04-01

    Permian-Triassic coals of the South African Karoo Basin play a central role in the study and interpretation of Gondwana's climate history and related vegetational changes in time and space. The palynological record of the coal-bearing formations reveals major phases of climate amelioration succeeding the Permo-Carboniferous Gondwana glaciations. Subsequent to the melting of the Dwyka ice, cold to cool-temperate climate conditions prevailed during the Early Permian and a continuous change to hot and dry climate conditions of the Late Permian and Triassic was inferred from sedimentological and palaeontological data so far. The here presented new palynological and geochemical data from the Early Triassic Molteno coal (Stormberg Group) point to a short-term switch from dry to wet climate conditions. To date, this wet intermezzo of Gondwana's early Mesozoic climate history has been overlooked in the Molteno coal of the Karoo Basin. The spore/pollen ratios, used as a proxy for humidity changes, indicate a significant climatic change corresponding to a prominent C-isotope excursion. Ongoing studies will provide a detailed palynological inventory of the Early Triassic coal deposits on an intra-Gondwanic scale, contributing to the interpretation of early Mesozoic palaeoclimates.

  12. Early Paleozoic orogenic belt of the Andes in southwestern South America: Result of Laurentia-Gondwana collision?

    NASA Astrophysics Data System (ADS)

    Dalla Salda, Luis; Cingolani, Carlos; Varela, Ricardo

    1992-07-01

    The late Precambrian to early Paleozoic age rock units of the Pampean ranges, the Puna, and the North Patagonian massif of southwestern South America constitute the Famatinian orogenic belt. They are interpreted as an Ordovician collisional belt between the Occidentalia terrane and the Gondwana craton. They include mafic and ultramafic belts of Neoproterozoic to early Paleozoic age. An intense tectonothermal event resulted from the collision; syntectonic granitoids represent crustal melting. In that collision syntectonic to late-tectonic foreland basins developed. The recently proposed juxtaposition of Laurentia and East Antarctica-Australia in the Neoproterozoic raises the possibility that Laurentia and western South America were close together in the early Paleozoic, and therefore that the Famatinian belt resulted from Laurentia-Gondwana collision. Occidentalia, which is bordered by a Cambrian carbonate platform similar to that of eastern North America, may be a sliver detached from Laurentia during Late Ordovician time.

  13. Patterns of Gondwana plant colonisation anddiversification

    NASA Astrophysics Data System (ADS)

    Anderson, J. M.; Anderson, H. M.; Archangelsky, S.; Bamford, M.; Chandra, S.; Dettmann, M.; Hill, R.; McLoughlin, S.; Rösler, O.

    Charting the broad patterns of vascular plant evolution for Gondwana againstthe major global environmental shifts and events is attempted here for the first time. This is based on the analysis of the major vascular plant-bearing formations of the southern continents (plus India) correlated against the standard geological time-scale. Australia, followed closely by South America, are shown to yield by far the most complete sequences of productive strata. Ten seminal turnover pulses in the unfolding evolutionary picture are identified and seen to be linked to continental drift, climate change and mass global extinctions. The rise of vascular plants along the tropical belt, for instance, followed closely after the end-Ordovician warming and extinction. Equally remarkable is that the Late Devonian extinction may have caused both the terrestrialisation of the vertebrates and the origin of the true gymnosperms. The end-Permian extinction, closure of Iapetus, together with warming, appears to have set in motion an unparalleled, explosive, gymnosperm radiation; whilst the Late Triassic extinction dramatically curtailed it. It is suggested that the latitudinal diversity gradient clearly recognised today, where species richness increases towards the tropics, may have been partly reversed during phases of Hot House climate. Evidence hints at this being particularly so at the heyday of the gymnosperms in the Late Triassic super-Hot House world. As for the origin of terrestrial, vascular, plant life, the angiosperms seem closely linked to a phase of marked shift from Ice House to Hot House. Insect and tetrapod evolutionary patterns are discussed in the context of the plants providing the base of the ever-changing ecosystems. Intimate co-evolution is often evident. This isn't always the case, for example the non-linkage between the dominant, giant, long-necked, herbivorous sauropod dinosaurs and the dramatic radiation of the flowering plants in the Mid Cretaceous.

  14. Upper Permian fluviolacustrine deposits of southern Africa and the late Permian climate southern Gondwana

    SciTech Connect

    Yemane, K. (Univ. of Pennsylvania, Philadelphia, PA (United States). Dept. of Geology Bryn Mawr Coll., PA (United States). Dept. of Geology)

    1993-03-01

    Upper Permian-age fluviolacustrine deposits are widespread throughout southern Africa. In the southern part of the subcontinent, where deposition took place in foreland basin settings, the sequences are thicker and fluvial-dominated whereas, lacustrine-dominated deposits accumulated in settings of low relief, broad warping and mild faulting at the northern end. The geographic extent and lateral correlatability of these deposits suggest the existence of concurrent, perhaps interconnected, giant lakes within major fluvial frameworks throughout the subcontinent, thousands of miles inland from the sea. This period of major lake development within fluvial depositional settings suggests climatic conditions that sustained a uniquely wet continental environment, deep in the heart of the Gondwanan supercontinent. Simulations based on various general circulation and energy balance climate models predict extreme seasonal temperatures and aridity for Gondwana at the palaeolatitudes of southern Africa during the Late Permian. On the other hand, distribution of climate-sensitive rocks, palynologic and palaeobotanic data and vertebrate fossils, coroborate the temperature climate documented by sedimentologic studies. The erroneous modeling results may have arisen from the fact that the models do not employ palaeogeographies that accommodate the existence of the vast lakes and rivers of Gondwana. The Late Permian palaeogeography of series of giant lakes within major fluvial frameworks would have had considerable influences on the regional climate. This suggests that it is imperative that numerical modeling studies incorporate accurate palaeogeographies, constructed based on available geological data, in order to recreate past climates with acceptable degree of accuracy.

  15. The Basement of the Andes: the Gondwana-Laurentia Connections Revisited

    NASA Astrophysics Data System (ADS)

    Ramos, V. A.

    2009-05-01

    The research performed in the last decade in the basement of the Andes have shown that the Precambrian and Paleozoic rocks have recorded a series of igneous and metamorphic events through time. These episodes can be grouped in discrete orogenic events, which have different paleogeographic distribution and intensity. The first and most important orogenic event is widely distributed along the margin and correspond to the Sunsas-Grenville orogen. Evidence of metamorphism and associated magmatic rocks are found from Colombia to the southernmost Patagonia. This episode produced the amalgamation of Amazonia, Pampia and Patagonia, among other cratonic blocks, to form Rodinia. The Rodinia break-up leaved several cratonic blocks accreted in the Gondwana side, such as Marañón, Arequipa, and Antofalla, although the generalized extension of this period produced crustal attenuation, rifted basins, and limited oceanic realms during late Proterozoic times. The Brasiliano-Pampean orogeny reamalgamated these blocks against the Gondwana margin. A new episode of break-up produced the dispersal of several Gondwanian blocks, separation along some previous sutures, crustal attenuation and magmatism in Late Cambrian times, until the new amalgamation occurred in Middle Late Ordovician times. These processes led to the Famatinian orogeny when metamorphism and arc magmatism was widely spread along the continental margin, as seen in Chibcha, Marañón, Arequipa and Sierras Pampeanas. Besides the re-accretion of some parautochthonous terranes, new exotic blocks were derived from Laurentia, such as the Cuyania terrane, which finally collided against the Andean proto-margin at ~ 460 Ma to form the Argentine Precordillera and surrounding regions. Late accretion in Early to Middle Devonian times of Chilenia and related terranes formed most of the basement of Central Andes. Final collision between Laurentia and Gondwana in the Late Carboniferous - Early Permian times to form the Alleghanides, left behind some Laurentian pieces like Tahami, Tres Lagunas and Tahuin terranes of Colombia, Ecuador and Perú. This set of rifting episodes and subsequent collisions along the continental margin of western South America were the result of changes of the absolute motion of Gondwana related to global plate reorganizations during Proterozoic to Paleozoic times.

  16. Global deglaciation and the re-appearance of microbial matground-dominated ecosystems in the late Paleozoic of Gondwana.

    PubMed

    Buatois, L A; Netto, R G; Gabriela Mángano, M; Carmona, N B

    2013-07-01

    The extensive matgrounds in Carboniferous-Permian open-marine deposits of western Argentina constitute an anachronistic facies, because with the onset of penetrative bioturbation during the early Paleozoic microbial mats essentially disappeared from these settings. Abundant microbially induced sedimentary structures in the Argentinean deposits are coincident with the disappearance of trace and body fossils in the succession and with a landward facies shift indicative of transgressive conditions. Deposits of the Late Carboniferous-Early Permian glacial event are well developed in adjacent basins in eastern Argentina, Brazil, South Africa and Antarctica, but do not occur in the western Andean basins of Argentina. However, the deglaciation phase is indirectly recorded in the studied region by a rapid rise in sea level referred to as the Stephanian-Asselian transgression. We suggest that an unusual release of meltwater during the final deglaciation episode of the Gondwana Ice Age may have dramatically freshened peri-Gondwanan seas, impacting negatively on coastal and shallow-marine benthic faunas. Suppression of bioturbation was therefore conducive to a brief re-appearance of matground-dominated ecosystems, reminiscent of those in the precambrian. Bioturbation is essential for ecosystem performance and plays a major role in ocean and sediment geochemistry. Accordingly, the decimation of the mixed layer during deglaciation in the Gondwana basins may have altered ecosystem functioning and geochemical cycling. PMID:23621394

  17. The basins on the Argentine continental margin

    SciTech Connect

    Urien, C.M. [Buenos Aires Technological Institute Petroleum School, Buenos Aires (Argentina)

    1996-08-01

    After the stabilization of the central Gondwana Craton, orogenic belts were accreted, as a result of convergence events and an extensive passive margin developed in southwestern Gondwana. Thermal subsidence in Parana, Karoo-Ventania basins and the Late Paleozoic-Early Mesozoic rifts, were modified by the Gondwana breakup and the South Atlantic opening. Early Paleozoic marine transgressions deposited the Table Mountain Group in Ventania. In southwestern Patagonia foreland clastics were deposited. Magmatic arcs and marine units indicate a tectonic trough was formed, alternating with continental sequences, over Late Paleozoic metamorphics and intrusives, resulting from plastered terrains along the Gondwana margin. In Patagonia, Permo-Carboniferous continental and glacio marine clastics infill the basins, while in Ventania, paralic sequences, grade from neritic to continental to the northeast, extending beneath the continental margin. The Triassic-Jurassic rift basins progressed onto regional widespread acid lavas and were infilled by lagoonal organic-rich sequences. Early drift phase built basins transverse to the margin, with fluvio-lacustrine sequences: Salado, Colorado, Valdes-Rawson, San Julian and North Malvinas intracratonic basins, which underwent transtensional faulting. Post-Oxfordian to Neocomian brackish sequences, onlapped the conjugate basins during the margin`s drift, with petroleum systems, as in Austral and Malvinas. In the Valanginian, basic extrusions commenced to form on the continental border, heralding the oceanic phase. Due to thermal subsidence, offlaping sediments prograded onto the remaining half-grabens. Several petroleum systems, proven and hypothetical, are identified in this region.

  18. Anti-Atlas (Morocco) role in Neoproterozoic Western Gondwana reconstruction

    Microsoft Academic Search

    Kevin P Hefferan; Hassan Admou; Jeffrey A Karson; Ali Saquaque

    2000-01-01

    Reconstruction of latest Neoproterozoic Gondwana hinges on the interpretation of the subduction and collision kinematics of Pan-African orogenic belts that rim the West African craton. The Anti-Atlas suture zone of southern Morocco has presented an enigma in this reconstruction as the inferred subduction zone polarity and age of suturing appear to be incongruous with better known West African orogens to

  19. The Karoo basins of south-central Africa

    Microsoft Academic Search

    O. Catuneanu; H. Wopfner; P. G. Eriksson; B. Cairncross; B. S. Rubidge; R. M. H. Smith; P. J. Hancox

    2005-01-01

    The Karoo basins of south-central Africa evolved during the first-order cycle of supercontinent assembly and breakup of Pangea, under the influence of two distinct tectonic regimes sourced from the southern and northern margins of Gondwana. The southern tectonic regime was related to processes of subduction and orogenesis along the Panthalassan (palaeo-Pacific) margin of Gondwana, which resulted in the formation of

  20. Gondwana Research, V. 7, No. 1, pp. 175-183. 2004 International Association for Gondwana Research, Japan.

    E-print Network

    , Japan. ISSN: 1342-937X Gondwana ResearchGR Paleomagnetic Constraints on the Permian-Triassic Boundary in Terrestrial Strata of the Karoo Supergroup, South Africa: Implications for Causes of the End-Permian of the well-described End-Permian mass extinction from known marine successions worldwide. In the present

  1. Learning from self-initiated community forest management in Orissa, India

    Microsoft Academic Search

    Czech Conroy; Abha Mishra; Ajay Rai

    2002-01-01

    There is growing recognition in tropical countries that safeguarding forests requires the active involvement of local communities, but knowledge of how best to do this is limited. Orissa's extensive experience of community forest management (CFM) provides some valuable lessons and insights regarding: (a) how and why communities manage their forests; and (b) the sustainability of CFM initiatives. The paper discusses

  2. Optimal utilisation of natural resources for agricultural sustainability in rainfed hill plateaus of Orissa

    Microsoft Academic Search

    Dwitikrishna Panigrahi; Pradeep Kumar Mohanty; Milu Acharya; Prafulla Chandra Senapati

    2010-01-01

    The climatic data for 17 years from 1988 to 2004 of the rainfed hill plateaus of Kandhamal district of Orissa (India) were analyzed to find out the monthly climatic index from the calculated values of effective rainfall and evapotranspiration. The 80% dependable monthly climatic index was correlated with crop coefficient and suitable cropping period and sequences for the study area

  3. TRIBAL USES OF PLANTS FROM NARAYANAPATNA REGION OF KORAPUT DISTRICT, ORISSA

    PubMed Central

    Dash, Sudhansu S.; Misra, Malaya K

    1996-01-01

    The paper reports the ethnomedicinal uses of 32 plants by the tribals of Narayanapatna area of koraput district, Orissa. Besides, uses of other plants or plant products are also dealt, with. Distribution of plants in the area, their field numbers, local and oriya names are appended. PMID:22556748

  4. Understanding the Dynamics of Food Insecurity and Vulnerability in Orissa, India

    Microsoft Academic Search

    Christian Romer Lovendal

    2007-01-01

    This paper documents the main findings of a study on food insecurity and vulnerability in the Indian state of Orissa in support of promoting interventions for food security and livelihoods at state level. A similar study was undertaken in Himachal Pradesh, India. The paper analyses the main characteristics and causes of food insecurity and vulnerability. It seeks to identify who

  5. National Initiatives, Local Effects: Trade Liberalization, Shrimp Aquaculture, and Coastal Communities in Orissa, India

    Microsoft Academic Search

    Dolagobinda Pradhan; Mark Flaherty

    2007-01-01

    Commercial shrimp farming in India expanded rapidly after trade liberalization initiatives were introduced in the early 1990s. This article examines the social, economic and environmental impacts that have been generated in communities along Orissa's Coast in east India. The results suggest that macro-level policies such as trade liberalization are useful at the national level, but at the local level they

  6. Perceived Gender Role that Shape Youth Sexual Behaviour: Evidence from Rural Orissa, India

    ERIC Educational Resources Information Center

    Pradhan, Manas Ranjan; Ram, Usha

    2010-01-01

    The study attempts to understand the association of perceived gender role with youth sexual behavior using qualitative data such as focus group discussions (N = 8), in-depth interviews (N = 42), and free listing (N = 50) of rural married youths from Orissa, India. Data collection was conducted during July 2006-April 2007. Atlas. ti and ANTHROPAC…

  7. The Cordon del Portillo Permian magmatism, Mendoza, Argentina, plutonic and volcanic sequences at the western margin of Gondwana

    NASA Astrophysics Data System (ADS)

    Gregori, Daniel; Benedini, Leonardo

    2013-03-01

    The Cerro Punta Blanca, Cerro Bayo and Cerro Punta Negra stocks, parts of the Cordillera Frontal Composite Batholith, cropping out in the Cordón del Portillo, records the Gondwana magmatic development of the Cordillera Frontal of Mendoza, in western Argentina. In this area, the San Rafael Orogenic phase, that represents the closure of the Late Carboniferous-Early Permian marine basins, begins at 284 Ma, and ceased before 276 Ma. The Cerro Punta Blanca, Cerro Bayo and Cerro Punta Negra stocks represent a post-orogenic magmatism and are equivalents to the Choiyoi Group. The Gondwana magmatic activity in the Cordón del Portillo area can be divided into two stages. The Cerro Punta Blanca stock (c.a. 276 Ma) represents an early post-orogenic, subduction-related magmatism similar to the basic-intermediate section of the Choiyoi Group (c.a. 277 Ma). The late post-orogenic second event was recorded by the Cerro Bayo (262 Ma) and Cerro Punta Negra stocks which represent a transition between subduction-related and intra-plate magmatism. This event represents the intrusive counterpart of the acidic facies of the upper section of the Choiyoi Group (c.a. 273 Ma). This extensional condition continued during the Triassic when the Cacheuta basin developed.

  8. L'évolution géologique de Madagascar et la dislocation du Gondwana: une introductionThe geological evolution of Madagascar: an introduction

    NASA Astrophysics Data System (ADS)

    Piqué, A.; Groupe campus 'le rifting malgache'

    1999-05-01

    Between eastern Africa and the Indian Ocean, Madagascar was a part of the Gondwana at the end of the Proterozoic. Its evolution, from the Carboniferous through to the present times, displays successive stages of the Gondwana disintegration. The original location of Madagascar, close to present Kenya, is deduced from sedimentological, structural and palæomagnetic data. During Permo-Triassic times, it was submitted to a northeast-southwest regional extension, which resulted in the opening of the Karoo Basins. During the Mid-Late Jurassic, opening of the Somalian and Mozambican Oceanic Basins was accompanied by the translation of Madagascar along a north-south trending transform fault, located along the present Davie Ridge. The Late Cretaceous was characterised in the island by an acceleration of the subsidence in the coastal basins and by an important magmatic, essentially effusive, activity. This marked the beginning of a northeast-southwest extension, opening of the Mascarene Oceanic Basin and separation of India from Madagascar. Since the Neogene up to present times, another extensional regime developed, as in eastern Africa, characterised by a roughly east-west extensional horizontal direction, which results in the opening of faulted basins and the emission of Pliocene-Quaternary alkaline magmas.

  9. Panjal Paleomagnetism: Implications for Early Permian Gondwana break-up

    NASA Astrophysics Data System (ADS)

    Stojanovic, D.; Aitchison, J.; Ali, J. R.; Ahmad, T.; Ahmad Dar, R.; Agarwal, A.; Roeder, T.

    2013-12-01

    The mid-Early Permian represents an important phase in Pangaea's development marking the time when the >13,000 km-long string of terranes that are collectively known as 'Cimmeria' separated from Gondwana's Tethyan margin (northern Africa-NE Arabia-northern India-NW and northern Australia). The ~289 Ma Panjal Traps of NW India (Kashmir) are one of a number of mafic suites (Abor, Sikkim etc.) that were erupted onto the Indian block possibly during the separation of the Lhasa/SE Qiangtang block. Herein, we report data from the first modern paleomagnetic study of the unit. Results from four quarry sections (15 individual cooling units) from a locality close to Srinagar together form a tectonically coherent sequence spanning 2-3 km of stratigraphy. The derived direction and paleopole yield key new information concerning (1) the Early Permian location of India, and by inference that of central Gondwana, and (2) inform debates related to Cimmeria's breakup from eastern Gondwana. Moreover, they provide a new independent control for assessing NW Greater India's extent prior to its collision with Asia and the amount of vertical-axis rotation this sector of the Himalayan range experienced in the mid to late Cenozoic.

  10. Amalgamation and initial break-up of Gondwana along the East African - Antarctic Orogen

    Microsoft Academic Search

    J. Jacobs; B. Emmel

    2003-01-01

    East- and West-Gondwana, or parts thereof, amalgamated along the East African - Antarctic Orogen at c. 550 Ma. The initial Gondwana break-up roughly followed the length of the orogen and reactivated Pan-African suture and shear zones 350 Ma after amalgamation. In Antarctica, the collision of E- and W-Gondwana overprinted wide continental margins but the location of the principle suture zone(s)

  11. Optical remote sensing a potential tool for forecasting malaria in Orissa, India

    NASA Astrophysics Data System (ADS)

    Nizamuddin, Mohammad; Akhand, Kawsar; Roytman, Leonid; Kogan, Felix; Goldberg, Mitch

    2013-05-01

    Information on current and anticipated moisture and thermal condition from satellite data represents a source of affordable yet careful information for malaria forecasters to implement and control of epidemic. During the last decades Orissa state in India suffered from highest level of malaria incidence. This situation requires frequent monitoring of environmental conditions and dynamics of malaria occurrence. During 1985 to 2004 the NOAA AVHRR global vegetation index (GVI) dataset and its vegetation health (VH) have been studied and used as proxy for malaria fluctuation. This paper discusses applications of VH for early detecting and monitoring malaria incidence in Orissa. A significant relationship between satellite data and annual malaria incidences is found at least three months before the major malaria transmission period.

  12. Production potential of plateau agriculture and food sufficiency in the Kandhamal district of Orissa

    Microsoft Academic Search

    Pradeep Kumar Mohanty; Dwitikrishna Panigrahi; Milu Acharya

    2010-01-01

    The requirement for food grains in the rainfed hill plateaus of the Kandhamal district of the State of Orissa, India was calculated\\u000a according to accepted nutritional standards over 14 years from 1993 to 2006 and compared with actual production during this\\u000a time. Owing to the increase in population, the requirement increased from 120?×?103 MT in 1993 to 142?×?103 MT in 2006. Production, however,

  13. Radiogenic heavy minerals in Chhatrapur beach placer deposit of Orissa, southeastern coast of India

    Microsoft Academic Search

    A. K. Mohanty; S. K. Das; K. V. Van; D. Sengupta; S. K. Saha

    2003-01-01

    The beach placer deposit at Chhatrapur coast of Orissa state, southeastern coast of India, has a significant concentration of radiogenic heavy minerals. The average activity concentrations of radioactive elements such as 232Th, 238U and 40K were measured by gamma ray spectrometry using a HPGe detector, and found to be 2650±50, 400±30 and 120±30 Bq\\/kg, respectively, for the bulk sand samples.

  14. Title: Geophysical definition of PARANAPANEMA Proterozoic Block and its importance for the Rodinia to Gondwana evolutionary theories

    NASA Astrophysics Data System (ADS)

    Mantovani, M.; de Brito Neves, B.; Quintas, M.; Shukowsky, W.

    2003-04-01

    For the last decade, only three cratonic blocks (Amazonian, S. Francisco and Rio de LaPlata) were attributed to the South America portion for the Rodinia reconstitution. The probability of existing other blocks has been ignored. Taking into account a large gravity survey, the premise of a considerable Paleoproterozoic fragment as part of the Paraná basin basement is highly probable. After removing the gravity contribution of its sedimentary load, the gravity pattern of the basin basement framework discriminates the boundaries of a high density block (Paranapanema) from other structures, most of which outcrop beyond the limits of the basin itself. The gravity high, bounded by deep gradients is clearly isolated from the other structures, among which the buried segments of Goiás Arch, Ribeira and Brasilia Belts, and Rio de LaPlata Craton, are easily identified through their outcropping portion. The Goiás Arch gravity signature merges with the topographically defined Paraguay Arch. Important faults as Jacutinga and Lancinha-Cubatäo (NE) and Torres-Posadas lineament (NW) are clearly identified through the geophysical signature; these structures define contacts among blocks at East and South of Paranapanema. The geophysical analysis also shows that any liaison between this block and Rio de LaPlata (south), or Luis Alves / Curitiba (east) Proterozoic blocks is improbable. Deep borehole data provided the lithology, thickness and area distribution of each volcano and sedimentary layer, as well as a geochronology age determination for a number of basement samples. Through a back stripping geophysical analysis, based on borehole data, the maximum attenuation distribution was identified for the two main extensional tectonic events that formed the Paraná basin, for a time interval that lasted from the Silurian to the Triassic. Results, based on a thermo-mechanical model, indicate that for both events the maximum attenuation sites are sub-parallel to the Brasiliano faults (NE), while the lineaments Torres-Posadas and Tietê (NW), better denoted for the second event, are parallel to the Early Cretaceous Ponta Grossa Arch. From geological observations, the Apiaí Belt, a continental Atlantic margin to the East, the Goiás Arch, an active margin to the northwest, and the Socorro-Guaxupé Orogen, an active margin with arch formation to the northeast of Paranapanema, assign great importance to this block for describing the western Gondwana evolution and assembly. Therefore, Paranapanema should be taken into account among the lithosphere segments derived from Rodinia, and later from Western Gondwana, after undergoing a series of orogenic events. Samples from deep boreholes prove the existence of a Paleoproterozoic basement buried by volcano-sedimentary Paleo to Mesoproerozoic layers as also been observed for the Amazonian and the S. Francisco craton. Moreover, geological and geochronology studies of the Ribeira Belt infrastructure identify an increase of Mesoproterozoic rocks towards the border of Paranapanema. Shear faults of Late-Brasiliano age developed significant transitional depressions forming the precursor rifts filled with Silurian to Triassic sediments. As for Paranapanema, analogous blocks may exist under the Parnaiba basin and other structures that were activated during the Brasiliano Cycle to form Gondwana. In this light, we consider that a revision is required in order to amend the present theories on the evolutionary process from Rodinia to Gondwana.

  15. Gondwana and Cathaysian blocks, palaeotethys sutures and cenozoic tectonics in South-east Asia

    Microsoft Academic Search

    Charles S. Hutchison

    1994-01-01

    The Triassic Indosinian Orogeny followed extinction of the Palaeotethys Ocean resulting in suturing of Gondwana affinity and Cathaysian blocks. The Gondwana affinity Sinoburmalaya block of Peninsular Malaysia, characterized by Carboniferous---Permian mudstones containing glacial dropstones and sparse fauna and flora, is traced extensively into Sumatra. This mudstone facies is flanked on the east by a sandstone-dominated facies and by carbonate localized

  16. The Neoproterozoic assembly of Gondwana and its relationship to the Ediacaran–Cambrian radiation

    Microsoft Academic Search

    Joseph G. Meert; Bruce S. Lieberman

    2008-01-01

    The assembly of the Gondwana supercontinent during the waning stages of the Proterozoic provides a tectonic backdrop for the myriad biological, climatological, tectonic and geochemical changes leading up to, and including, the Cambrian radiation. A polyphase assembly of Gondwana during the East Africa, Brasiliano, Kuungan and Damaran orogenies resulted in an extensive mountain chain which delivered nutrients into a shifting

  17. Petroleum system of the Gippsland Basin, Australia

    USGS Publications Warehouse

    Bishop, Michele G.

    2000-01-01

    The Gippsland Basin Province 3930, located on the southeastern coast of Australia, is formed from two successive failed rifts that developed into a passive margin during the Cretaceous. Formation of this basin is related to the break up of Gondwana, which resulted in the separation of Antarctica from Australia, and the separation of the New Zealand and Lord Howe Rise continental crust from Australia. Coals and coaly shales of Late Cretaceous through Eocene age are the source rocks for oil and gas that accumulated predominantly in anticlinal traps. The basin was Australia?s major producing basin until 1996 when daily oil/condensate production from the North West Shelf surpassed it.

  18. Origin and Evolution of Limestone Caves of Chhattisgarh and Orissa, India: Role of Geomorphic, Tectonic and Hydrological Processes

    NASA Astrophysics Data System (ADS)

    Gautam, P. K.; Allu, N. C.; Ramesh, R.; Yadava, M. G.; Panigrahi, C. P.

    2014-12-01

    Carbonate rocks undergo karstic process and karst morphology is a key to understand the nature and genesis of caves. The primary energy source for the formation of karst landforms is hydrological cycle. Geomorphic features along with hydrological characteristics provide important information not only on karst formation but also climate and environmental conditions. In this paper, we present the tectonic and geomorphic features that played a role in evolution of caves located in Chhattisgarh and Orissa States of India. The geomorphic and tectonic aspects of Kotumsar, Kailash, and Gupteshwar caves are discussed in relation to the origin and evolution of these caves. Caves are located near the water falls. The area is folded and faulted along the Eastern Ghat Mobile Belt (EGMB) due to tectonic reactivation. Shaly-limestone beds exhibit vertical dipping near Gupteshwar cave, and steeply inclined near Kotumsar and Kailash caves. Indr?vati and Sabari/Kolab tributaries of the Godavari River drain the area. The landscape evolution and the origin of caves in the region is a multistage process, where the lithology, orogeny, fluvial action, and monsoon are the main agents, which is similar to the four state model (Ford and Ewers, 1978). The river basin evolution and regional tectonism also caused the initiation of karstification in the region. The evolution of caves is believed to have taken place in Pre-Pliocene under more humid conditions that coincided with the initiation of monsoon in India. Further, during the Quaternary wet-dry/cold-warm phases altered physical and chemical weathering of limestone rocks. Contrasting relief features of Bastar plateau have also helped the extensive cave formation in the region. The dissolution along weak planes initiated the openings of caves, further enlarged by geomorphic agents. Both monsoon and tectonics have caused fluctuations in water levels along river courses, which acted as active agents in evolution of caves.

  19. Structural framework across the Bastar craton - the Eastern Ghats Granulite Belt interface: Implications for making of eastern Gondwana

    NASA Astrophysics Data System (ADS)

    Patole, Vishal; Nasipuri, Pritam

    2015-04-01

    The transformation of palaeo-continents involve breakup, dispersal and reassembly of cratonic blocks by collisional suturing that develop a network of orogenic (mobile) belts around the periphery of the stable cratons. During the collision, partial melting of the different crustal blocks produces migmatites at the craton-mobile belt interface. Thus, migmatites at the craton-mobile belt contact can provide valuable information regarding the pressure-temperature conditions of the melting of lower crust during supercontinent building processes. In this contribution, we document the structural framework across the Bastar craton- Eastern Ghats Granulite Belt (EGGB) interface that developed during the accretion of EGGB over Bastar craton. Near Bhawanipatna, Orissa, Eastern India, the granulites of the mobile belt are juxtaposed against the granitic rocks of the Bastar craton. Away from the contact domain, the cratonic granite is non-migmatitic and blasto-porphyritic in nature that gradually transforms to migmatitic variety towards the contact domain. In the non-migmatitic variety, the E-W trending stromatic leucozomes and biotite-hornblende rich fabric (S1) wraps around recrystallized K-feldspar augens. In the migmatitic variety towards the contact domain, NNE-SSW trending diatexite leucozomes (S2) are prominent and the intensity of melting and tightness of folding increases towards the contact domain. Structural measurements indicate that the S1 fabric is folded with the development of NNE-SSW axial plane with easterly plunging fold axis (50 -> 050N). To correlate the geological history of EGGB in the context of supercontinent reconstruction, the existence of a cratonic block consisting of India - Madagascar - Sri Lanka - Enderby Land-Kalahari ("IMSLEK") from 3000 Ma upto 750 Ma has been invoked by several authors. The apparent continuity of the Grenvillian metamorphic orogen along the East Antarctica-Australia-India margin has been taken as conclusive evidence for the existence of a single landmass since the time of Grenvillian orogeny (1000 Ma) and it is suggested that the same configuration was preserved up to the formation of East Gondwana. The EGGB orogenic belt is considered as intercontinental high grade domain with no evidence for the closing of Mesoproterozoic oceans and the younger Pan-African metamorphic events are the results of intercontinental reactivation of old crustal weakness during the Gondwana assembly in the late Neoproterozoic-Paleozoic. However, recent palaeomagnetic data from India and Australia indicate that India was at much higher palaeolatitude compared to the Australia-Antarctica block, and the accretion of Eastern Ghats Granulite Belt over Bastar craton should have occurred during the Pan-African orogeny. The presence of NNW-SSW trending melt bands and the increase in the intensity of melting and tightness of folding near the contact indicate that Eastern Ghats Granulite belt collided with the Bastar craton during the Paleozoic.

  20. The evolution of mammal-like crocodyliforms in the Cretaceous Period of Gondwana.

    PubMed

    O'Connor, Patrick M; Sertich, Joseph J W; Stevens, Nancy J; Roberts, Eric M; Gottfried, Michael D; Hieronymus, Tobin L; Jinnah, Zubair A; Ridgely, Ryan; Ngasala, Sifa E; Temba, Jesuit

    2010-08-01

    Fossil crocodyliforms discovered in recent years have revealed a level of morphological and ecological diversity not exhibited by extant members of the group. This diversity is particularly notable among taxa of the Cretaceous Period (144-65 million years ago) recovered from former Gondwanan landmasses. Here we report the discovery of a new species of Cretaceous notosuchian crocodyliform from the Rukwa Rift Basin of southwestern Tanzania. This small-bodied form deviates significantly from more typical crocodyliform craniodental morphologies, having a short, broad skull, robust lower jaw, and a dentition with relatively few teeth that nonetheless show marked heterodonty. The presence of morphologically complex, complementary upper and lower molariform teeth suggests a degree of crown-crown contact during jaw adduction that is unmatched among known crocodyliforms, paralleling the level of occlusal complexity seen in mammals and their extinct relatives. The presence of another small-bodied mammal-like crocodyliform in the Cretaceous of Gondwana indicates that notosuchians probably filled niches and inhabited ecomorphospace that were otherwise occupied by mammals on northern continents. PMID:20686573

  1. Sedimentary history of the Tethyan margins of Eastern Gondwana during the Mesozoic

    NASA Astrophysics Data System (ADS)

    Ogg, James G.; Gradstein, Felix M.; Dumoulin, Julie A.; Sarti, Massimo; Bown, Paul

    A composite Mesozoic geological history for the Gondwana margins to the Eastern Tethys Ocean can be assembled from stratigraphic successions on the Australian and Himalayan margins and from drill sites of Ocean Drilling Program Legs 122 and 123. During the Triassic, this region drifted northwards, entering tropical paleolatitudes during the Late Triassic-Early Jurassic, then returned to mid-latitudes for the Middle Jurassic through Early Cretaceous. Shallow-water carbonates are restricted to the tropical-latitude interval; at other times, the margins are dominated by clastic deposition. Episodes of deltaic sandstone progradation over the shelves are caused by eustatic sealevel fluctuations, by wet climatic conditions within the source regions and by local tectonic activity. A major hiatus between Callovian shallow-water shelf deposits and Oxfordian deep-water sediments is an ubiquitous feature, which may be related to a widespread plate tectonic reorganization and the cascading effects of associated sealevel rise and elevated carbon dioxide levels. Off Northwest Australia, this Callovian/Oxfordian event also coincides with an episode of block faulting. Marginal sediments deposited during the Late Jurassic are mainly marine claystone containing abundant terrigenous organic matter. Shallow depths of carbonate compensation (CCD) during the Late Jurassic through Early Cretaceous prevented the preservation of carbonate over most of the Argo basin off Northwest Australia, and these deep-sea sediments consist mainly of condensed, oxygenated radiolarian-rich claystone. During the late Kimmeridgian-early Tithonian, a downward excursion in the CCD enabled limited preservation of some larger nannofossils and mollusc fragments within the pelagic deposits, a feature also recorded in coeval deposits in the Atlantic. Explosive volcanism accompanied the final stages of rifting between India and Australia during the late Berriasian and Valanginian, producing volcaniclastic debris washing into the deltas and widespread ash deposits. The late Barremian and Aptian sediments indicate a rise in the CCD, accompanied by warming of the region and an increased delivery of organic-rich claystone into the basins.

  2. Micro-continents offshore Western Australia: implications for East Gondwana reconstructions

    NASA Astrophysics Data System (ADS)

    Whittaker, Joanne; Williams, Simon; Halpin, Jacqueline; Daczko, Nathan; Gardner, Robyn

    2014-05-01

    The southern part of the Western Australian margin formed at the nexus of rifting and breakup between the East Gondwanan continents India, Australia and Antarctica in the Early Cretaceous. However, understanding the basin evolution along this margin has been hampered by a lack of data from the offshore Perth Abyssal Plain, and from the conjugate Greater Indian margin, which was highly deformed during collision with Eurasia. The Batavia Knoll and Gulden Draak Knoll are two prominent, previously unsampled, bathymetric features located >1600 km offshore Australia that have typically been assumed to be igneous features. In late 2011, successful dredges on the western flanks of both knolls recovered continental basement rocks, revealing that both knolls are micro-continents. Felsic orthogneiss and granite from Gulden Draak and Batavia knolls yield 2.8 Ga, 1.3-1.2 Ga and 540-510 Ma U-Pb zircon ages. The affinity of these geological samples, coupled with existing geological sampling and geophysical data, allow us to test alternative reconstructions for East Gondwana breakup. A number of alternative models have been proposed for the pre-rift configuration of Australia and Antarctica. Competing models make very different predictions for the kinematics of Mesozoic rifting that produced the basins along the Southern Australian margin; the magnitude of extension during rifting; and how mapped Paleozoic and Proterozoic geological terranes and fault zones can be correlated between Australia and Antarctica. We will present reconstructions that reconcile our new samples from Indian Ocean micro-continents with observations from India, Antarctica, Australia, and the evolution of the Indian Ocean.

  3. Integrated Analysis and Application of Reservoir Models to Early Permian Detrital Carbonate Deposits, Midland Basin, Texas

    E-print Network

    Johnston, Travis Wayne 1987-

    2012-11-01

    of the Paleozoic foreland basins formed as a 4 result of continental collision of Laurentia with the northwestern portion of Gondwana during the Marathon-Ouachita orogenic event. It is structurally subdivided into several sub-basins (Figure 1) by fault...

  4. Paleogeography of Southwest Gondwana Boundary During the Upper Paleozoic

    NASA Astrophysics Data System (ADS)

    Tomezzoli, R. N.

    2005-05-01

    Current results are summarized from the southwest Gondwana boundary, from rocks from La Pampa province, Argentina. This area is the westward part of an orogenic belt, known as Sam Frau geosincline or Cordón de las Gondwánides and may represent the suture zone between the Gondwana and Patagonia terranes. This collision model is still uncertain and there are many controversies related to the age of the deformation of this belt. Paleomagnetism and the exploration of the magnetic fabric signatures (AMS) can be useful to evaluate the regional deformation and a better understanding of the assembly, deformation, and fragmentation of Gondwana / Pangea. A systematic paleomagnetic study was done in the Cerro Centinela: 36/deg S, 67/deg W, belong to the Choiyoi Group and consist of Lower Paleozoic volcanic rocks. In this paleomagnetic study is present results from 19 sites (84 specimens), sampled from the base to the top in different layers. Samples were demagnetized with thermal procedures. A high un¬blocking temperature component carried by hematite was defined between 580° C and 680° C, showing very good within site consistency (alpha 95<15° and k>20). Remanent magnetization ranges around 1500 mA m-1. In all samples it was possible to isolate one component with the same behavior and positive inclination. These stable remanent magnetization were group into two different Population: 1 and 2, clearly separated. Population 1 (from sites 1 to 12) in situ mean direction is: D=146°, I=63.5°, alpha 95=4°, k=104, N=12. Population 2 (from sites 13 to 19) in situ mean direction is: D=164°, I=42°, alpha 95=4°, k=197, N=7. Reversed characteristic remanence magnetization suggesting that the magnetization was acquired during the Kiaman interval, in accordance with their age. Two high quality paleomagnetic poles were computed for each population on the basis of the in situ remanence directions. The corresponding PP are for Population 1: 63° S, 353° E, Alpha 95=7 and K=44 and for Population 2: 71° S, 60° E, Alpha 95=5, K=169. These two poles are consistent with the age of the rocks and with others PP from the Gondwánides, and are reflecting a huge displacement of the continent during the Permian, before the final assembly of the Pangea.

  5. Early breakup of Gondwana: constraints from global plate motion models

    NASA Astrophysics Data System (ADS)

    Seton, Maria; Zahirovic, Sabin; Williams, Simon; Whittaker, Joanne; Gibbons, Ana; Muller, Dietmar; Brune, Sascha; Heine, Christian

    2015-04-01

    Supercontinent break-up and amalgamation is a fundamental Earth cycle, contributing to long-term sea-level fluctuations, species diversity and extinction events, long-term greenhouse-icehouse cycles and changes in the long-wavelength density structure of the mantle. The most recent and best-constrained example involves the fragmentation of Gondwana, starting with rifting between Africa/Madagascar and Antarctica in the Early Jurassic and ending with the separation of the Lord Howe microcontinental blocks east of Australia in the Late Cretaceous. Although the first order configuration of Gondwana within modern reconstructions appears similar to that first proposed by Wegener a century ago, recent studies utilising a wealth of new geophysical and geological data provide a much more detailed picture of relative plate motions both during rifting and subsequent seafloor spreading. We present our latest global plate motion model that includes extensive, new regional analyses. These include: South Atlantic rifting, which started at 150 Ma and propagated into cratonic Africa by 145 Ma (Heine et al., 2013); rifting and early seafloor spreading between Australia, India and Antarctica, which reconciles the fit between Broken Ridge-Kergulean Plateau and the eastern Tasman region (Whittaker et al., 2013); rifting of continental material from northeastern Gondwana and its accretion onto Eurasia and SE Asia including a new model of microcontinent formation and early seafloor spreading in the eastern Indian Ocean (Gibbons et al., 2012; 2013; in review; Williams et al., 2013; Zahirovic et al., 2014); and a new model for the isolation of Zealandia east of Australia, with rifting initiating at 100 Ma until the start of seafloor spreading in the Tasman Sea at ~85 Ma (Williams et al., in prep). Using these reconstructions within the open-source GPlates software, accompanied by a set of evolving plates and plate boundaries, we can explore the factors that govern the behavior of plate motions during supercontinent break-up and subsequent dispersal. For example, a global analysis of absolute plate velocities over the past 200 million years shows that plates dominated by continental material and bounded by transforms and mid-ocean ridge segments, as is characteristic of plates involved in Gondwana break-up, have average speeds of ~2.6-2.8 cm/yr RMS. In contrast, oceanic plates surrounded by subduction have average speeds of ~8.5 cm/yr RMS. An exception, however, is the rapid motion of India (~18 cm/yr RMS) in the Paleocene preceding its collision with Eurasia, which suggests that plates with continental and cratonic keels can exhibit short-lived (~10 Myr) accelerations resulting from a combination of plume head arrival effects and other complementary plate boundary forces (i.e., slab pull and ridge push). In another example, our reconstructions illustrate that a spectrum of rifting styles from orthogonal to oblique is present during rifting, rather than dominantly orthogonal as often assumed. Although our approach has so far been limited to one supercontinent cycle, these types of models can be extended to cover the entire Phanerozoic, capturing continental rifting and plate behavior over several supercontinent cycles.

  6. Fishes of District Sundargarh, Orissa, with special reference to their potential in mosquito control.

    PubMed

    Yadav, R S; Padhan, K; Sharma, V P

    1992-12-01

    An extensive fish fauna survey was carried out in Sundargarh, a malaria-endemic district in Orissa, during 1988 to 1990 to identify and evaluate the indigenous larvivorous fishes for mosquito control. In all, 57 species belonging to 19 families under 6 orders were found in the local water bodies. On laboratory evaluation against anopheline and culicine larvae, six potential larvivorous fishes, viz. Aplocheilus panchax, Oryzias melastigma, Oreochromis mossambicus, Gambusia affinis, Danio (B.) rerio and Esomus danricus were selected. Feasibility of mass multiplication of these fishes in village ponds for operational use is being studied. PMID:1363317

  7. Palynological records of Gondwana's mid-Permian climate amelioration: New insights from black shale deposits (Collingham Formation, South Africa)

    NASA Astrophysics Data System (ADS)

    Götz, Annette E.

    2015-04-01

    Permian black shale deposits of the southern Karoo Basin were studied with respect to palynostratigraphy, palaeoenvironment, and palaeoclimate signatures recorded in palynomorph assemblages. The 28 m thick black shales of the Collingham Formation, exposed along road cuttings of the Ecca Pass north of Grahamstown (Eastern Cape Province, South Africa), are rich in sedimentary organic matter with a high content of amorphous organic matter and prasinophytes, characteristic of a deep, stratified marine basin. Moderately preserved pollen grains of the lower part of the formation reveal a mid-Permian (Roadian) age, corresponding to the stratigraphic position of the Collingham Formation in the Namibian part of the Karoo with an absolute age of 270 Ma obtained from a tuff (Stollhofen et al., 2000). The samples from the lower Collingham Formation show a very similar composition as samples from coal seams of the upper Vryheid Formation in the northeastern part of the Karoo Basin. Additionally, a similar stratigraphic trend in changes of palynomorph assemblages was detected, showing a striking increase in taeniate bissacate pollen grains up section. This signature points to a warm-temperate bisaccate-producing plant community in the hinterland, replacing cool-temperate floras of the underlying Whitehill Formation (Ruckwied et al., 2014). The detected palaeoclimate signatures document Gondwana's mid-Permian climate amelioration and have proved to be a powerful tool for high-resolution basin-wide correlation of marine and non-marine successions. References Ruckwied, K., Götz, A.E., Jones, P. 2014. Palynological records of the Permian Ecca Group (South Africa): Utilizing climatic icehouse-greenhouse signals for cross basin correlations. Palaeogeography, Palaeoclimatology, Palaeoecology 413, 167-172. Stollhofen, H., Stanistreet, I.G., Bangert, B., Grill, H. 2000. Tuffs, tectonism and glacially related sea-level changes, Carboniferous-Permian, southern Namibia. Palaeogeography, Palaeoclimatology, Palaeoecology 161, 127-150.

  8. Gondwana and Cathaysian blocks, palaeotethys sutures and cenozoic tectonics in South-east Asia

    Microsoft Academic Search

    Charles S. Hutchison

    1994-01-01

    The Triassic Indosinian Orogeny followed extinction of the Palaeotethys Ocean resulting in suturing of Gondwana affinity and Cathaysian blocks.The Gondwana affinity Sinoburmalaya block of Peninsular Malaysia, characterized by Carboniferous—Permian mudstones containing glacial dropstones and sparse fauna and flora, is traced extensively into Sumatra. This mudstone facies is flanked on the east by a sandstone-dominated facies and by carbonate localized in

  9. Indonesian Permian brachiopod fauna and Gondwana-South-East Asia relationships

    Microsoft Academic Search

    N. W. Archbold; C. J. Pigram; N. Ratman; S. Hakim

    1982-01-01

    The island of New Guinea, geologically and structurally part of the Indian-Australian plate1,2, is shown on continental reconstructions of the Permian globe as forming the northeastern part of the supercontinent of Gondwana3,4, facing a large Tethys Ocean to the north. The existence of an ocean separating South-East Asia from Gondwana by some 45° of latitude during the Permian has been

  10. Arabian Shield magmatic cycles and their relationship with Gondwana assembly: Insights from zircon U-Pb and Hf isotopes

    NASA Astrophysics Data System (ADS)

    Robinson, F. A.; Foden, J. D.; Collins, A. S.; Payne, J. L.

    2014-12-01

    The Arabian Shield preserves a protracted magmatic record of amalgamated juvenile terranes that host a diverse range of early Neoproterozoic to Cambrian granitoids intruding volcanosedimentary basin assemblages that have corollaries in other parts of the East African Orogen. New zircon U-Pb geochronology of 19 granitoids intruding eight Arabian Shield terranes, define four discrete magmatic events: island arc (?845 Ma), syncollisional (?710 Ma), post-tectonic (?620 Ma) and anorogenic (?525 Ma). Zircon Lu-Hf isotopic analyses indicate that all studied granitoids are juvenile with typical ?Hf values of >+5 to +10 and Stenian-Tonian (?1100-900 Ma) model ages, regardless of their precise intrusive ages or spatial relationship. Subtle changes in isotopic signatures between ?850 and 600 Ma, suggest the result from changes in granite source materials brought about by; basaltic underplating, limited crustal interaction with Palaeoproterozoic basement and a change to lithospheric delamination/subduction roll-back processes driving juvenile ANS crustal growth. The cycle of granite intrusion reflects accretionary cycles initiated during Mozambique Ocean closure and during Gondwana amalgamation and final assembly. Post-tectonic magmatism is divided into a ?636-600 Ma phase and post 600 Ma event that reflects first subduction and then within-plate related processes. The identification of magmatism at ?525 Ma is now the youngest granitoid identified so far in the Saudi Arabian Shield and may change the identified age of the regional, basal Palaeozoic unconformity. This late magmatism may be generated by the Najd Fault reactivation correlating with the Malagasy/Kunnga Orogeny that marked the final stages of Gondwana assembly.

  11. Genetic Structure and Wolbachia Genotyping in Naturally Occurring Populations of Aedes albopictus across Contiguous Landscapes of Orissa, India

    PubMed Central

    Das, Biswadeep; Satapathy, Truptimayee; Kar, Santanu K.; Hazra, Rupenangshu K.

    2014-01-01

    Background Aedes albopictus has recently been implicated as a major vector in the emergence of dengue and chikungunya in several parts of India, like Orissa, which is gradually gaining endemicity for arboviral diseases. Ae. albopictus is further known to be naturally infected with Wolbachia (maternally inherited bacterium), which causes cytoplasmic incompatibility (CI) in mosquitoes leading to sperm-egg incompatibility inducing the death of embryo. Knowledge of genetic diversity of Ae. albopictus, along with revealing the type of Wolbachia infection in Ae. albopictus is important to explore the genetic and biological characteristics of Ae. albopictus, prior to exploring the uses of CI-based vector control strategies. In this study, we assessed the population genetic structure and the pattern of Wolbachia infection in Ae. albopictus mosquitoes of Orissa. Methods and Results Ae. albopictus mosquitoes were collected from 15 districts representing the four physiographical regions of Orissa from 2010–2012, analyzed for genetic variability at seven microsatellite loci and genotyped for Wolbachia strain detection using wsp gene primers. Most microsatellite markers were successfully amplified and were polymorphic, showing moderate genetic structure among all geographic populations (FST?=?0.088). Genetic diversity was high (FST?=?0.168) in Coastal Plains populations when compared with other populations, which was also evident from cluster analyses that showed most Coastal Plains populations consisted of a separate genetic cluster. Genotyping analyses revealed that Wolbachia-infected Ae. albopictus field populations of Orissa were mostly superinfected with wAlbA and wAlbB strains. Wolbachia superinfection was more pronounced in the Coastal Plain populations. Conclusion High genetic structure and Wolbachia superinfection, observed in the Coastal Plain populations of Orissa suggested it to be genetically and biologically more unique than other populations, and hence could influence their vectorial attributes. Such high genetic diversity observed among Coastal Plains populations could be attributed to multiple introductions of Ae. albopictus in this region. PMID:24714653

  12. A re-examination of the paleo-position of Africa's eastern neighbours in Gondwana

    NASA Astrophysics Data System (ADS)

    Reeves, C. V.; Sahu, B. K.; de Wit, M.

    2002-05-01

    We propose a tight fit at 200 Ma for India, Madagascar, Sri Lanka and Antarctica against the east coast of Africa that avoids the difficulty of accounting for the gaps between continents required by looser fits. We have followed three lines of argument: (1) A credible animation for the modes of dispersal of these fragments is necessary that is consistent with new ocean-floor topographic data ( http://kartoweb.itc.nl/gondwana); (2) Pre-drift rifting has also to be `undone' and we argue for a separation of only 50-100 km between extant (but now widely separated) rift shoulders that mark the boundaries of the rigid plates of ancient crust that has not been distended by rifting; (3) The margins of plates concealed by younger cover formations are defined through interpretation of aeromagnetic anomaly data. Our new fit is substantiated by the integrity of the (largely pre-200 Ma) Karoo rift basins of Tanzania, Kenya and Madagascar and by the co-linearity of a zone of shears, interpreted from aeromagnetics in northern Mozambique, with the line of rupture between India and Madagascar. Even tighter fits for earlier times would follow, logically, the undoing of Karoo rifting (˜300-200 Ma) but this requires further work. Three published reassemblies that compared Precambrian geology across present plate boundaries are presented as figures in their original form and with the fragments reassembled to our new template. They present no real difficulties for our model. Euler rotation parameters for our reassembly are listed to allow others to test our model on their own data.

  13. Amalgamating eastern Gondwana: The evolution of the Circum-Indian Orogens

    NASA Astrophysics Data System (ADS)

    Collins, Alan S.; Pisarevsky, Sergei A.

    2005-08-01

    The Neoproterozoic global reorganisation that saw the demise of Rodinia and the amalgamation of Gondwana took place during an incredibly dynamic period of Earth evolution. To better understand the palaeogeography of these times, and hence help quantify the interrelations between tectonics and other Earth systems, we here integrate Neoproterozoic palaeomagnetic solutions from the various blocks that made up eastern Gondwana, with the large amount of recent geological data available from the orogenic belts that formed as eastern Gondwana amalgamated. From this study, we have: (1) identified large regions of pre-Neoproterozoic crust within late Neoproterozoic/Cambrian orogenic belts that significantly modify the geometry and number of continental blocks present in the Neoproterozoic world; (2) suggested that one of these blocks, Azania, which consists of Archaean and Palaeoproterozoic crust within the East African Orogen of Madagascar, Somalia, Ethiopia and Arabia, collided with the Congo/Tanzania/Bangweulu Block at ˜ 650-630 Ma to form the East African Orogeny; (3) postulated that India did not amalgamate with any of the Gondwana blocks until the latest Neoproterozoic/Cambrian forming the Kuunga Orogeny between it and Australia/Mawson and coeval orogenesis between India and the previously amalgamated Congo/Tanzania/Bangweulu-Azania Block (we suggest the name 'Malagasy Orogeny' for this event); and, (4) produced a palaeomagnetically and geologically permissive model for Neoproterozoic palaeogeography between 750 and 530 Ma, from the detritus of Rodinia to an amalgamated Gondwana.

  14. Dust accumulation and leaf pigment content in vegetation near the national highway at Sambalpur, Orissa, India.

    PubMed

    Prusty, B A K; Mishra, P C; Azeez, P A

    2005-02-01

    An investigation on the seasonal variation in dust accumulation on leaves and leaf pigment content of six plant species of mixed habits was carried out at the side of the National Highway (NH 6) at Sambalpur, Orissa, India. The plants selected for study were Pongamia pinnata, Tabernaemontana divaricata, Ipomea carnea, Ficus relogiosa, Ficus benghalensis, and Quisqualis indica. The observed trend of dust accumulation was in the order T. divaricata>I. carnea>P. pinnata>F. religiosa>F. benghalensis>Q. indica. One-way analysis of variance showed significant difference in dust accumulation among plant species (F1 = 4.674, P < 0.01) and between seasons (F2 = 9.240, P < 0.01). It was seen that dust load increases with increasing number of vehicles using the highway (major emission source). The result shows significant correlation (negative) between dust load and pigment content in summer and rainy season. PMID:15546639

  15. Metal biomonitoring in water resources of Eastern Ghats, Koraput (Orissa), India by aquatic plants.

    PubMed

    Rai, U N; Sinha, S; Chandra, P

    1996-11-01

    Biomonitoring of toxic metals in the water resources used by indigenous tribal communities in Koraput district, Orissa, India was carried out under the National Technology Mission Project. Most of the water bodies catering for the day-to-day needs of the local inhabitants were found to contain high concentrations of Fe and Mn in addition to Cr, Cd, Pb and Cu. The water bodies supported by a great number of phytodiversity and the plants growing therein accumulated significantly high amounts of these toxic metals, submerged plants being more efficient than floating ones. The species like Chara corallina and Spirogyra spp. showed significant potential to magnify Cd and Pb in their tissue several times more than the concentrations in surrounding water. The levels of metals in the plants occurring at places where the metal content is very high could be used for indicating the status of water. PMID:24193821

  16. Neoproterozoic to Lower Palaeozoic successions of the Tandilia System in Argentina: implication for the palaeotectonic framework of southwest Gondwana

    NASA Astrophysics Data System (ADS)

    Zimmermann, Udo; Poiré, Daniel G.; Peral, Lucía Gómez

    2011-04-01

    The Cryogenian to Uppermost Ediacaran successions of the Tandilia System (Sierras Bayas Group and Cerro Negro Formation) in central-eastern Argentina is exceptional because of its unmetamorphosed and nearly undeformed character, its sediment provenance trend and the absence of any identified glacial deposit and the deposition of warm water carbonates. We decipher a dramatic change in the basin evolution from small-scale depositional areas during the Neoproterozoic to a larger basin related to an active continental margin throughout the Uppermost Ediacaran. The base of the succession is represented by immature detritus of alkaline composition (Villa Mónica Formation), but towards the top of this formation, the material is sorted and reworked, nonetheless still reflecting in its detritus the local rocks. The clastic deposition is interrupted by diagenetic overprinted dolomites. The unconformable overlying quartz-arenitic Ediacaran Cerro Largo Formation reworked the Cryogenian Villa Mónica Formation and contains mainly felsic granitic and metamorphic basement material of slightly wider variety, while the dominant alkaline geochemical signature in rocks of the Villa Mónica Formation disappears. Based on diagenetic, petrographic and sedimentological data, we can interpret the unconformity representing a longer time of erosion. The Cerro Largo Formation shows a transition to mudstones and the heterolithic facies of the Olavarría Formation. The top of the Sierras Bayas Group is represented by limestones (Loma Negra Formation), which are discordantly overlain by the Uppermost Ediacaran Cerro Negro Formation. The latter displays detrital material derived from a continental arc, mafic and felsic sources. Several arc-related geochemical proxies (Th/Sc < 0.8; Zr/Sc < 10; La/Sc < 2; Ti/Zr > 20) are recorded in the sediment detritus, as are syn-depositional pyroclastites. The absence of volcanic material in the underlying rocks allows proposing that the Cerro Negro Formation is related to an active continental margin fringing Gondwana ("Terra Australis Orogen") as a retro-arc or retro-arc foreland basin.

  17. World bank EMCP malaria project in Orissa, India — A field reality

    PubMed Central

    Patil, Rajan R; Kumar, Ravi K

    2011-01-01

    Background: Under the National Vector Borne Disease Control Program, the Enhanced Malaria Control Project (EMCP) with World Bank assistance was implemented in India, in the eastern state of Orissa. Aims: This article tries to analyze the possible reasons for the poor performance of EMCP in a few states of India. Settings and Design: The eastern state of India is taken as a case study for looking into systemic, human resource, and logistics related issues that could explain the poor performance of EMCP in a few states of India. Materials and Methods: Field visits were made to some selected EMCP areas in the state of Orissa. Operational issues-related implementation of various components of the project were scrutinized. Statistical analysis: Not Applicable. Results: While the project was highly successful in a few states of India, it had limited success in some states. It was learnt that the honorarium meant for Fever Treatment depot [FTD] work was divided among all the malaria workers. In high-risk areas, presumptive radical treatment was being carried on by malaria workers for every case of fever. Using Rapid Diagnostic Tests (RDTs) in such areas seemed to have no relevance. The laboratory technician ignored malaria work, due to a high work load and no additional incentive. In the Primary Health Centers (PHCs) the Medical officers had either not visited the village under indoor residual spray or symbolically visited only five to six houses. Cement tanks had to be built for larvivorus fish breeding. However, they had not been mad. Conclusions: The success of a public health program is dependent more on project implementation, management, monitoring, and evaluation of project activities than the volume of financial resource allocation. PMID:23507915

  18. Sedimentary basin analysis constrained by 3d seismic and subsidence modelling: the case of the Phanerozoic evolution of the Dampier Subbasin, North West Shelf of Australia

    Microsoft Academic Search

    L. Langhi; G. D. Borel

    2003-01-01

    The North West Shelf of Australia has been a long term passive margin, which underwent a polyphased tectonic history associated with the disintegration of Eastern Gondwana. Several Phanerozoic sedimentary basins like the Northern Carnarvon Basin developed during the rifting phases culminating in the opening of the NeoTethys during the Late Paleozoic and the abyssal plains during the Mesozoic. In order

  19. Sergentomyia (Parrotomyia) jerighatiansis, a new species of sand fly (Diptera: Psychodidae: Phlebotominae) from Kandhamal district, Orissa, India.

    PubMed

    Srinivasan, R; Jambulingam, P

    2013-12-01

    Sergentomyia (Parrotomyia) jerighatiansis a new species of sand fly (Diptera: Psychodidae: Phlebotominae) from the villages of Kandhamal district, Orissa, located on the east coast of India is described. Descriptive morphology, character measurements, and illustrations of males and females are provided and its taxonomic position within the genus is also defined. Voucher specimens of the new species have been deposited at the museum, Vector Control Research Centre (Indian Council of Medical Research), Puducherry, India and Zoological Survey of India, India. PMID:24076324

  20. Coal microscopy as a tool to understand the beneficiation problems of Indian Gondwana coals

    Microsoft Academic Search

    Prakash K Singh

    The present paper intends to demonstrate the occurrence of mineral matter as a deterrent in coal beneficiation as evidenced through coal microscopy. The Indian Gondwana coals are known for their high ash content due to the presence of inorganic mineral matter occurring in high concentration. These minerals have been found to occur as 'deep intergrowth', 'massive impregnation', 'superficial mounting', 'filling

  1. The Saint-Georges-sur-Loire olistostrome, a key zone to understand the Gondwana-Armorica

    E-print Network

    Paris-Sud XI, Université de

    ;Introduction The West European Variscan Belt results of the collision of two main continental masses, Gondwana these two continental masses. Amongst the different structural units constituting the Ligerian domain-Armorican Shear-Zone divide the Armorican massif into the Mid-North Armorican, Ligerian and South Armorican

  2. Important Ayurv?da literatures from the manuscripts available from Orissa (Cikits?rnava).

    PubMed

    Padhi, M M; Das, B; Audichya, K C; Rao, M M

    2005-01-01

    In the treasure of Ayurv?dic literature, many texts are missing or partially available. Only references or few verses from many such texts are mentioned in later texts. Unfortunately, a large number of Ayurv?dic texts are unexplored till today are likely to exist in palm-leaf manuscripts, which are decaying or undergoing permanent annihilation. As such many unique and valuable information contained in these texts are being lost. Though several Institutions have taken up work on literary Research, only few texts have been published during past decades. The present paper highlights the salient features of the text 'Cikits?rnava' authored by Vi?van?th Sena of 16th century of Orissa. Though his text on Pathy?pathya has already been published, which has got a place in the pages of history of Ayurv?da, a very little is known about this important text on therapeutics. Various aspects of this text and its author have been discussed to bring it in to the knowledge of fraternity of Ayurvedic physicians and Sanskrit scholars. PMID:17333660

  3. The felsic magmatic province in East Gondwana: implications for Pan-African tectonics

    NASA Astrophysics Data System (ADS)

    Rajesh, H. M.; Santosh, M.; Yoshida, M.

    The East Gondwana crustal fragments, namely southern India, Sri Lanka, Madagascar, East Antarctica and Western Australia, preserve evidence for a prominent Pan-African felsic magmatic event represented by feldspathoidal syenites, alkali granites and syenites emplaced proximal to fault lineaments. In Peninsular India, late or post-kinematic alkaline plutons ranging in age from 864 to 600 Ma characterize the Eastern Ghats belt, whereas a strong Pan-African imprint is provided by 550-750 Ma alkali granites and syenites in the southern granulite segment. In Sri Lanka, alkali granites occur in all major geologic units, with radiometric ages in the range of 550-760 Ma. In Madagascar, alkali granites and syenites with late Proterozoic to Palaeozoic ages are reported. Felsic magmatic activity in East Antarctica is characterized by post-tectonic granitic and syenitic plutons in Enderby Land and Queen Maud Land, showing an age range of 550-770 Ma. Pan-African felsic plutons in Western Australia define ages of 550-570 Ma. This paper summarizes the petrologic, geochemical and geochronologic characteristics of felsic plutons in the various East Gondwana fragments. Many of the intrusives represent anorogenic A-type magmas generated in rift-related environments of high heat flow and abundant volatile activity, correlative with an extensional tectonic regime and probably including melts generated from both upper mantle and lower crustal sources. This paper identifies a major Pan-African felsic magmatic province in East Gondwana, which, in association with their petrogenetic significance, is considered to be suggestive of a geodynamic signature of East Gondwana during the Pan-African period.

  4. A Southern Hemisphere origin for campanulid angiosperms, with traces of the break-up of Gondwana

    PubMed Central

    2013-01-01

    Background New powerful biogeographic methods have focused attention on long-standing hypotheses regarding the influence of the break-up of Gondwana on the biogeography of Southern Hemisphere plant groups. Studies to date have often concluded that these groups are too young to have been influenced by these ancient continental movements. Here we examine a much larger and older angiosperm clade, the Campanulidae, and infer its biogeographic history by combining Bayesian divergence time information with a likelihood-based biogeographic model focused on the Gondwanan landmasses. Results Our analyses imply that campanulids likely originated in the middle Albian (~105 Ma), and that a substantial portion of the early evolutionary history of campanulids took place in the Southern Hemisphere, despite their greater species richness in the Northern Hemisphere today. We also discovered several disjunctions that show biogeographic and temporal correspondence with the break-up of Gondwana. Conclusions While it is possible to discern traces of the break-up of Gondwana in clades that are old enough, it will generally be difficult to be confident in continental movement as the prime cause of geographic disjunctions. This follows from the need for the geographic disjunction, the inferred biogeographic scenario, and the dating of the lineage splitting events to be consistent with the causal hypothesis. PMID:23565668

  5. Bathymetric and Stratigraphic Record of Gondwana Breakup from a Passive Transform Margin off the Coast of Ghana

    NASA Astrophysics Data System (ADS)

    Attoh, K.; Brown, L.; Guo, J.

    2001-05-01

    We have reprocessed and interpreted multichannel seismic reflection data off the coast of Ghana that probe the prominent Romanche fracture zone of the Equatorial Atlantic and sedimentary basins of the Ghana transform margin. The stacked seismic profiles reveal spectacular bathymetric expressions of the paleo-transform which marks the ocean- continent transition. The paleo-transform is revealed by submarine canyons up to 2 km deep with landward increasing fill of submarine fans consisting of lobes of the paleo Volta delta. Preliminary interpretation of the reflections on the seismic profiles indicate three major sequences that correlate with well log and onshore stratigraphic data. The pre-drift sequence consists of Devonian to Carboniferous strata, up to 3 km thick, deposited in Paleozoic rifts that are overlain, with increasing SW discordance, by the syn-drift sequence of Aptian to Albian continental siliclastic strata of variable thickness. Intense folding of the pre- and syn-drift sequences provide some of the clearest images of transpressional deformation associated with wrench tectonics on a passive margin. The post-drift sequences overlie the Lower Cretaceous and Paleozoic strata along a prominent unconformity and consist of a lower depositional cycle beginning with Campanian marine strata, and a younger sequence of Tertiary and Quarternary deposits represented by >3 km thick submarine fan deposits in the transform zone. This chronology is consistent with age calibrations on the opening of the Atlantic and permit evaluation of current geodynamic models of transform margin evolution with implications for the breakup of Gondwana and anomalous seismicity of the passive Ghana margin.

  6. Post-traumatic stress disorder in children and adolescents one year after a super-cyclone in Orissa, India: exploring cross-cultural validity and vulnerability factors

    Microsoft Academic Search

    Nilamadhab Kar; Prasanta K Mohapatra; Kailash C Nayak; Pratiti Pattanaik; Sarada P Swain; Harish C Kar

    2007-01-01

    BACKGROUND: It has been asserted that psychological responses to disasters in children and adolescents vary widely across cultures, but this has rarely been investigated. The objectives of the study were to clinically evaluate the construct of traumatic stress symptoms and disorder in children and adolescents after a super-cyclone in Orissa, India; to find out the prevalence at one year; compare

  7. Child Feces Disposal Practices in Rural Orissa: A Cross Sectional Study

    PubMed Central

    Majorin, Fiona; Freeman, Matthew C.; Barnard, Sharmani; Routray, Parimita; Boisson, Sophie; Clasen, Thomas

    2014-01-01

    Background An estimated 2.5 billion people worldwide lack access to improved sanitation facilities. While large-scale programs in some countries have increased latrine coverage, they sometimes fail to ensure optimal latrine use, including the safe disposal of child feces, a significant source of exposure to fecal pathogens. We undertook a cross-sectional study to explore fecal disposal practices among children in rural Orissa, India in villages where the Government of India's Total Sanitation Campaign had been implemented at least three years prior to the study. Methods and Findings We conducted surveys with heads of 136 households with 145 children under 5 years of age in 20 villages. We describe defecation and feces disposal practices and explore associations between safe disposal and risk factors. Respondents reported that children commonly defecated on the ground, either inside the household (57.5%) for pre-ambulatory children or around the compound (55.2%) for ambulatory children. Twenty percent of pre-ambulatory children used potties and nappies; the same percentage of ambulatory children defecated in a latrine. While 78.6% of study children came from 106 households with a latrine, less than a quarter (22.8%) reported using them for disposal of child feces. Most child feces were deposited with other household waste, both for pre-ambulatory (67.5%) and ambulatory (58.1%) children. After restricting the analysis to households owning a latrine, the use of a nappy or potty was associated with safe disposal of feces (OR 6.72, 95%CI 1.02–44.38) though due to small sample size the regression could not adjust for confounders. Conclusions In the area surveyed, the Total Sanitation Campaign has not led to high levels of safe disposal of child feces. Further research is needed to identify the actual scope of this potential gap in programming, the health risk presented and interventions to minimize any adverse effect. PMID:24586864

  8. Antibiotic use, resistance development and environmental factors: a qualitative study among healthcare professionals in Orissa, India

    PubMed Central

    2010-01-01

    Background Antibiotic resistance is a major public health problem affecting both current and future generations. The influence of environmental factors on antibiotic use and resistance development in bacteria is largely unknown. This study explored the perceptions of healthcare providers on antibiotic use and resistance development in relation to environmental factors i.e. physical, natural, social and behavioural factors. Methods A qualitative interview study was conducted using face-to-face, semi-structured interviews among registered allopathic doctors, veterinarians and drug dispensers in Orissa, India. The interview transcripts were analyzed using latent content analysis. Results The main findings of this study relate to two themes: 'Interrelationship between antibiotic use, resistance development and environment' and 'Antibiotic management contributing to the development and spread of resistance'. The interviewees viewed the following as possible contributors to antibiotic use/misuse and resistance development: changes in the natural and physical environment i.e. climate variability, pollution, physiography and population growth; the socioeconomic environment affecting health-seeking behaviour and noncompliance with medication; a lack of healthcare facilities and poor professional attitudes; and ineffective law enforcement regarding medicine dispensing and disposal. Conclusions Generally, the interviewees perceived that although behavioural and social environmental factors are major contributors to resistance development, changes in the physical and natural environment also influence development of antibiotic resistance. The respondents also perceived that there is a lack of information about, and poor awareness of, what constitutes prudent use of antibiotics. They suggested a need for information, education, dissemination and proper implementation and enforcement of legislation at all levels of the drug delivery and disposal system in order to improve antibiotic use and prevent pharmaceutical contamination of the environment. PMID:20964815

  9. Quantification of groundwater recharge in a hard rock terrain of Orissa: a case study.

    PubMed

    Sethi, Ranu Rani; Kumar, A; Sharma, S P

    2009-01-01

    A study was carried out to select the best method to estimate groundwater recharge in a hard rock terrain. Various standard empirical methods, soil-moisture balance method, water table fluctuation (WTF) method and commonly adopted norms set by Groundwater Estimation Committee (GEC), Govt of India were used to estimate recharge for the Munijhara watershed in the Nayagarh block of Orissa (India). The empirical formulae gave recharge rates ranging from 13 cm to 32 cm/year with average of 22.4 cm and standard deviation of 5.34, independent of other influencing factors like soil, topography and geology. The soil-moisture balance study indicated that recharge is more dependent on the continuous heavy rainfall total annual volume of rainfall. Recharge was limited at up to 10 mm per day, possibly due to presence of hard rock below the soil surface. The rise in water table depth was 3.45 m to 5.35 m with a mean rise of 4.5 m during the year 2006-2007. Annual groundwater recharge based on the WTF approach varied from 10.3 to 16.85 cm with a mean of 13.5 cm, standard deviation of 1.57 cm and coefficient of variation 11.57%. This recharge accounted for 8 to 14% of rainfall received. With a water budget approach based on GEC norms, recharge was calculated as 17 cm per year. The study showed that the magnitudes of annual groundwater recharge as estimated by the WST method and GEC norms are in conformity with other recent findings in India under the same climate conditions. Based on the results recharge structures could be planned in suitable locations to reduce fallow areas under the watershed. PMID:19717920

  10. Geochronological data from the Faxinal coal succession, southern Paraná Basin, Brazil: A preliminary approach combining radiometric U-Pb dating and palynostratigraphy

    NASA Astrophysics Data System (ADS)

    Guerra-Sommer, Margot; Cazzulo-Klepzig, Miriam; Menegat, Rualdo; Formoso, Milton Luiz Laquintinie; Basei, Miguel Ângelo Stipp; Barboza, Eduardo Guimarães; Simas, Margarete Wagner

    2008-03-01

    A radiometric zircon age of 285.4 ± 8.6 Ma (IDTIMS U-Pb) is reported from a tonstein layer interbedded with coal seams in the Faxinal coalfield, Rio Grande do Sul, Brazil. Calibration of palynostratigraphic data with the absolute age shows that the coal depositional interval in the southern Paraná Basin is constrained to the Sakmarian. Consequently, the basal Gondwana sequence in the southern part of the basin should lie at the Carboniferous-Permian boundary, not within the Sakmarian as previously considered. The new results are significant for correlations between the Paraná Basin and the Argentinian Paganzo Basin (302 ± 6 Ma and 288 ± 7 Ma) and with the Karoo Basin, specifically with the top of the Dwyka Tillite (302 ± 3 Ma and 299.2 ± 3.2 Ma) and the lowermost Ecca Group (288 ± 3 Ma and 289.6 ± 3.8 Ma). The evidence signifies widespread latest Carboniferous volcanic activity in western Gondwana.

  11. Acceptability, willing to purchase and use long lasting insecticide treated mosquito nets in Orissa State, India.

    PubMed

    Gunasekaran, K; Sahu, S S; Vijayakumar, K N; Jambulingam, P

    2009-11-01

    Long lasting insecticide treated nets (LLINs) that require no re-treatment have been advocated as an effective tool against malaria transmission. However, success of this community based intervention measure largely depends on its acceptability and proper usage by the target population, besides assuring access to bed nets. To determine the acceptability of LLIN, its usage and people's willingness to buy the net, a study was conducted in two tribal districts viz., Malkangiri (with ongoing ITN programme) and Koraput (no ITN programme) of Orissa State, India. Both qualitative and quantitative data collection methods were used to collect information regarding the objective of the study. A total of 2457 LLINs (Olyset Nets) were distributed in the selected villages of these districts at free of cost. In the study villages of Malkangiri, 58% of the households had either ITNs (73%) or other types of mosquito nets aside from the LLINs and in the villages of Koraput, only 8% had other nets, as majority (96%) informed that buying nets from market was not affordable to them. Physical verification of the nets during the house visits revealed that 75.4% and 83% (in ITNs and non-ITNs villages, respectively) of the LLINs and 76% of the other nets (including ITNs) were used by the respondents, the night before the survey as nets were in a hanging position at the time of the visit. Majority of the respondents (76-98%) felt that reduction of mosquito bites as the main perceived benefit of using the LLINs. About 55% and 67% of the respondents from non-ITNs and ITNs areas, respectively, expressed their willingness to buy the LLINs. Among them, 76.8% and 94.7% offered to pay INR<100 for a net and also ready to buy it by cash payment. Social marketing of LLINs at a subsidized price or free supply to the deserving sections of people (socially/economically poor and/or under-privileged) and ensuring the availability of nets during harvesting season could encourage people to buy and use LLINs. PMID:19631186

  12. Integration of Leprosy Elimination into Primary Health Care in Orissa, India

    PubMed Central

    Siddiqui, M. Ruby; Velidi, Nageswara Rao; Pati, Surendra; Rath, Nilambar; Kanungo, Akshay K.; Bhanjadeo, Amiya K.; Rao, Bandaru Bhaskar; Ojha, Bijaya M.; Krishna Moorthy, Kodyur; Soutar, Douglas; Porter, John D. H.; Ranganadha Rao, Pemmaraju V.

    2009-01-01

    Background Leprosy was eliminated as a public health problem (<1 case per 10,000) in India by December 2005. With this target in sight the need for a separate vertical programme was diminished. The second phase of the National Leprosy Eradication Programme was therefore initiated: decentralisation of the vertical programme, integration of leprosy services into the primary health care (PHC) system and development of a surveillance system to monitor programme performance. Methodology/Principal Findings To study the process of integration a qualitative analysis of issues and perceptions of patients and providers, and a review of leprosy records and registers to evaluate programme performance was carried out in the state of Orissa, India. Program performance indicators such as a low mean defaulter rate of 3.83% and a low-misdiagnosis rate of 4.45% demonstrated no detrimental effect of integration on program success. PHC staff were generally found to be highly knowledgeable of diagnosis and management of leprosy cases due to frequent training and a support network of leprosy experts. However in urban hospitals district-level leprosy experts had assumed leprosy activities. The aim was to aid busy PHC staff but it also compromised their leprosy knowledge and management capacity. Inadequate monitoring of a policy of ‘new case validation,’ in which MDT was not initiated until primary diagnosis had been verified by a leprosy expert, may have led to approximately 26% of suspect cases awaiting confirmation of diagnosis 1–8 months after their initial PHC visit. Conclusions/Significance This study highlights the need for effective monitoring and evaluation of the integration process. Inadequate monitoring could lead to a reduction in early diagnosis, a delay in initiation of MDT and an increase in disability rates. This in turn could reverse some of the programme's achievements. These findings may help Andhra Pradesh and other states in India to improve their integration process and may also have implications for other disease elimination programmes such as polio and guinea worm (dracunculiasis) as they move closer to their elimination goals. PMID:20020051

  13. High prevalence of bacterial spore-formers active against mosquito larvae in temporary monsoon flooded sites in Orissa, India.

    PubMed

    Rout, Regalin; Raina, Vishakha; Suar, Mrutyunjay; Luethy, Peter

    2011-06-01

    Different ecosystems were probed in the vicinity of the city of Bhubaneswar in the Indian state of Orissa for the presence of bacterial spore-formers with activity against mosquito larvae. The most productive sites were places that were flooded during the monsoon season, including roadside ditches and shorelines of ponds. Among 630 isolates screened, 44 (7%) showed larvicidal activity against larvae of Aedes aegypti. The specific activity of the bacterial spore-formers varied greatly. Isolates were found with specific activities superior to the Bacillus thuringiensis israelensis reference strain of the Pasteur Institute. All mosquitocidal strains produced crystal proteins, and based on the biochemical analyses could be classified into the species B. thuringiensis. Such strains possess the potential for the development of new microbial products for mosquito control in India. PMID:21805851

  14. Exploring the Tectonic Behavior of Patagonia During the Breakup of Gondwana: A Paleomagnetic Approach

    NASA Astrophysics Data System (ADS)

    Somoza, R.; Taylor, G. K.; Vizan, H.

    2005-05-01

    Recent paleogeographical models for southwest Gondwana place the Malvinas/Falkland islands in connection with the Cape Fold Belt in South Africa. This reconstruction is further supported by a large clockwise rotation (ca. 100°) paleomagnetically detected in Early Jurassic dolerites from the islands. The regional extent of this rotation is, however, still unknown. This led us to investigate the pre-Jurassic paleomagnetic record of the Deseado Massif, the closest continental region to the Malvinas/Falkland Islands, to determine whether it too records a Jurassic-Cretaceous rotation history. We sampled Upper Triassic and Jurassic units, both sedimentary and intrusive. The results suggest the occurrence of clockwise vertical-axis rotations comparable in both magnitude and sense to those previously detected farther north in Upper Jurassic-Lower Cretaceous rocks from the North Patagonian Massif but having considerably smaller magnitude than those in the Falklands/Malvinas. This latter contrast suggests that the intervening region between the Deseado Massif and the islands, in the present Argentine shelf, would has been a zone of major structural discontinuity, although offshore exploration did not identify any such zone yet. Alternatively it may have been a zone of distributed deformation with rotation decreasing westward. In any case, the continuity of rotations within Patagonia requires further investigation to determine its pre-breakup configuration and later kinematics. This may contribute in clarifying the microplates' puzzle of southwest Gondwana.

  15. Proterozoic to Mesozoic East Gondwana: The juxtaposition of India, Sri Lanka, and Antarctica

    NASA Astrophysics Data System (ADS)

    Yoshida, Masaru; Funaki, Minoru; Vitanage, Piyadasa W.

    1992-04-01

    Jurassic and Cambro-Ordovician paleomagnetic pole positions deduced from rocks of Sri Lanka and Antarctica generally conform when Sri Lanka is juxtaposed with the coast of Lützow-Holm Bay, East Antarctica, in a manner similar to a current Gondwana reassembly. The Highland and Southwest groups (mostly Proterozoic) of Sri Lanka are correlated with the Ongul and Skallen groups of East Antarctica on the basis of similar lithology, structural characteristics, structural trend, tectonothermal history (ranging from early Proterozoic to Mesozoic), and the pressure-temperature-time path of the main metamorphism. Some neighboring lithotectonic units are also comparable between the two areas. Fracture-lineament systems of Sri Lanka and Antarctica formed after the latest Silurian and during or before the Jurassic conform in this reconstruction. An improved fit of the 2000 m isobaths of India-Sri Lanka-Antarctica and continuation of the latest Archaean mobile belt from Enderby Land to peninsular India is obtained by fitting Sri Lanka into Lützow-Holm Bay, and Enderby Land into the embayment in the east coast of peninsular India. This juxtaposition of peninsular India to East Antarctica involves about 80 km northward movement and about 30° clock-wise rotation of Sri Lanka relative to India. The reassembly thus obtained accords well with data, supporting the idea that East Gondwana existed from the earliest Proterozoic to middle Mesozoic, although some disruption-collision events of limited scale are considered possible.

  16. Magnetic Anomalies in the Enderby Basin, the Southern Indian Ocean

    NASA Astrophysics Data System (ADS)

    Nogi, Y.; Sato, T.; Hanyu, T.

    2013-12-01

    Magnetic anomalies in the Southern indian Ocean are vital to understanding initial breakup process of Gondwana. However, seafloor age estimated from magnetic anomalies still remain less well-defined because of the sparse observations in this area. To understand the seafloor spreading history related to the initial breakup process of Gondwana, vector magnetic anomaly data as well as total intensity magnetic anomaly data obtained by the R/V Hakuho-maru and the icebreaker Shirase in the Enderby Basin, Southern Indian Ocean, are used. The strikes of magnetic structures are deduced from the vector magnetic anomalies. Magnetic anomaly signals, most likely indicating Mesozoic magnetic anomaly sequence, are obtained almost parallel to the west of WNW-ESE trending lineaments just to the south of Conrad Rise inferred from satellite gravity anomalies. Most of the strikes of magnetic structures indicate NNE-SSW trends, and are almost perpendicular to the WNW-ESE trending lineaments. Mesozoic sequence magnetic anomalies with mostly WNW-ESE strikes are also observed along the NNE-SSW trending lineaments between the south of the Conrad Rise and Gunnerus Ridge. Magnetic anomalies originated from Cretaceous normal polarity superchron are found in these profiles, although magnetic anomaly C34 has been identified just to the north of the Conrad Rise. However Mesozoic sequence magnetic anomalies are only observed in the west side of the WNW-ESE trending lineaments just to the south of Conrad Rise and not detected to the east of Cretaceous normal superchron signals. These results show that counter part of Mesozoic sequence magnetic anomalies in the south of Conrad Rise would be found in the East Enderby Basin, off East Antarctica. NNE-SSW trending magnetic structures, which are similar to those obtained just to the south of Conrad Rise, are found off East Antarctica in the East Enderby Basin. However, some of the strikes show almost E-W orientations. These suggest complicated ridge reorganization occurred during initial breakup of Gondwana in the Enderby Basin.

  17. Post-Gondwana geomorphic evolution of southwestern Africa: Implications for hte controls on landscape development from observations and numerical experiments

    NASA Astrophysics Data System (ADS)

    Gilchrist, Alan R.; Kooi, Henk; Beaumont, Christopher

    1994-06-01

    The relationship between morphology and surficial geology is used to quantify the denudation that has occurred across southwestern Africa sicne the fragmentation of Gondwana during the Early Mesozoic. Two main points emerge. Signficant denudation, of the order of kilometers, is widespread except in the Kalahari region of the continental interior. The denudation is systematically distributed so that the continental exterior catchment, draining directly to the Cape basin, is denuded to a greater depth than the interior catchment inland of the Great Escarpment. The analysis also implies tha the majority of the denudation occurred before the beginning of the Cenozoic for both teh exerior and interior catchments. Existing models of landscape development are reviewed, and implications of the denudation chronology are incorporated into a revised conceptual model. This revision implies tha thte primary effect of rifting on the subsequent landscape evolution is that it generates two distinct drainage regimes. A marginal upwarp, or rift flank uplift, separates rejuvenated rivers that drain into the subsiding rift from rivers in the continetal interior that are deflected but not rejuvenated. The two catchments evolve independently unless they are integrated by breaching of hte marginal upwarp. If this occurs, the exterior baselevel is communicated to the interior catchment that is denuded accordingly. Denudation rates generally decrease as the margin evolves, and this decrease is reinforced by the exposure of substrate that is resistant to denudation and/or a change to a more arid climate. The observations do not reveal a particular style of smaller-scale landscape evolution, sucha s escarpment retreat, that is responsible for the differential denudation across the region. It is proposed that numerical model experiments, which reflect the observational insights at the large scale, may identify the smaller-scale controls on escarpment development if the model and natural systems are analogous. Four numerical experiments are presented in which the roles of antecedent topography, resistant substrate, climte change, and lowering the baselevel of the interior catchment are investigated for an initially high elevation margin bordered by an escarpment. The model results suggest several styles of landscape evolution that are compatible with the observations. Escarpments may retreat in a regular manner, but they also degrade and are destroyed, only to reform at the drainage divide between exterior and interior catchments.

  18. Post-Gondwana geomorphic evolution of southwestern Africa: Implications for hte controls on landscape development from observations and numerical experiments

    NASA Technical Reports Server (NTRS)

    Gilchrist, Alan R.; Kooi, Henk; Beaumont, Christopher

    1994-01-01

    The relationship between morphology and surficial geology is used to quantify the denudation that has occurred across southwestern Africa sicne the fragmentation of Gondwana during the Early Mesozoic. Two main points emerge. Signficant denudation, of the order of kilometers, is widespread except in the Kalahari region of the continental interior. The denudation is systematically distributed so that the continental exterior catchment, draining directly to the Cape basin, is denuded to a greater depth than the interior catchment inland of the Great Escarpment. The analysis also implies tha the majority of the denudation occurred before the beginning of the Cenozoic for both teh exerior and interior catchments. Existing models of landscape development are reviewed, and implications of the denudation chronology are incorporated into a revised conceptual model. This revision implies tha thte primary effect of rifting on the subsequent landscape evolution is that it generates two distinct drainage regimes. A marginal upwarp, or rift flank uplift, separates rejuvenated rivers that drain into the subsiding rift from rivers in the continetal interior that are deflected but not rejuvenated. The two catchments evolve independently unless they are integrated by breaching of hte marginal upwarp. If this occurs, the exterior baselevel is communicated to the interior catchment that is denuded accordingly. Denudation rates generally decrease as the margin evolves, and this decrease is reinforced by the exposure of substrate that is resistant to denudation and/or a change to a more arid climate. The observations do not reveal a particular style of smaller-scale landscape evolution, sucha s escarpment retreat, that is responsible for the differential denudation across the region. It is proposed that numerical model experiments, which reflect the observational insights at the large scale, may identify the smaller-scale controls on escarpment development if the model and natural systems are analogous. Four numerical experiments are presented in which the roles of antecedent topography, resistant substrate, climte change, and lowering the baselevel of the interior catchment are investigated for an initially high elevation margin bordered by an escarpment. The model results suggest several styles of landscape evolution that are compatible with the observations. Escarpments may retreat in a regular manner, but they also degrade and are destroyed, only to reform at the drainage divide between exterior and interior catchments.

  19. Post-Gondwana geomorphic evolution of southwestern Africa: Implications for hte controls on landscape development from observations and numerical experiments

    Microsoft Academic Search

    Alan R. Gilchrist; Henk Kooi; Christopher Beaumont

    1994-01-01

    The relationship between morphology and surficial geology is used to quantify the denudation that has occurred across southwestern Africa sicne the fragmentation of Gondwana during the Early Mesozoic. Two main points emerge. Signficant denudation, of the order of kilometers, is widespread except in the Kalahari region of the continental interior. The denudation is systematically distributed so that the continental exterior

  20. Early Paleozoic orogenic belt of the Andes in southwestern South America: Result of Laurentia-Gondwana collision?

    Microsoft Academic Search

    Luis Dalla Salda; Carlos Cingolani; Ricardo Varela

    1992-01-01

    The late Precambrian to early Paleozoic age rock units of the Pampean ranges, the Puna, and the North Patagonian massif of southwestern South America constitute the Famatinian orogenic belt. They are interpreted as an Ordovician collisional belt between the Occidentalia terrane and the Gondwana craton. They include mafic and ultramafic belts of Neoproterozoic to early Paleozoic age. An intense tectonothermal

  1. Neoproterozoic to Palaeozoic assembly, dismemberment and assembly of Peri-Gondwana -recorded in (East Avalonian) Anglesey (Ynys Môn), NW Wales, UK

    NASA Astrophysics Data System (ADS)

    Leslie, Graham; Schofield, David; Wilby, Phil

    2014-05-01

    Late Neoproterozoic accretion at the outboard margin of East Avalonian Gondwana is recorded on Anglesey in ca. 650 Ma metamorphism in the Coedana Complex and the ca. 615 Ma supra-subduction zone Coedana Granite. Iapetan extension fragmented that assembly, crustal thinning is recorded in Anglesey by ca. 560 Ma exhumation of the Penmynydd Zone blueschists. Anglesey's present architecture is however largely a product of accretionary collisions that commenced in the Early Ordovician when coaxial to intensely non-coaxial deformation assembled those Late Neoproterozoic rocks with the Middle Cambrian (to earliest? Ordovician) Monian Supergroup greenschist facies metasediments. In western Anglesey, the Monian Supergroup rocks record NW-facing coaxial D1 deformation sheared by SE-vergent, strongly non-coaxial, D2/D3 strain after an intervening episode of mafic magmatism. In northern Anglesey, Monian Supergroup rocks record only SE-facing deformation from the onset of collision. Deformed ocean floor and slices of garnetiferous basement gneiss are located between these structurally distinct regions and imply separation of these Monian tracts prior to earliest-Arenig? onset of Caledonian collision and accretion. This deformation is contemporaneous with Penobscottian accretion in the northern Appalachians and Newfoundland. The Monian rocks were at surface (and deeply weathered?) before sub-aerial eruption of the (mid-Arenig?) Church Bay Tuff Formation. These acid to intermediate tuffs are overlain unconformably by an Upper Arenig to Llandovery marine transtensional foreland basin succession. Renewed convergence resulted in a SSE-vergent (late-Salinic?) fold and thrust imbricate stack; locally, thrusts override molasse deposits derived from an advancing thrust sheet. Active over-riding of tectonic molasse is continued in Anglesey until the Early Devonian at least. The axially sourced fluvial Old Red Sandstone of central eastern Anglesey is arranged in south-vergent folds and thrusts during Acadian deformation. The geology of Ynys Môn showcases the geometrical complexity of the continental fragments that make up late-Neoproterozoic to Palaeozoic peri-Gondwana, and of the punctuated extensional and compressional deformations that affected the exterior of that continental assembly. This fragment of the UK Caledonides provides an important trans-Atlantic link to the Appalachian geology of North America.

  2. A Gigantic Sarcopterygian (Tetrapodomorph Lobe-Finned Fish) from the Upper Devonian of Gondwana (Eden, New South Wales, Australia)

    PubMed Central

    Young, Ben; Dunstone, Robert L.; Senden, Timothy J.; Young, Gavin C.

    2013-01-01

    Edenopteron keithcrooki gen. et sp. nov. is described from the Famennian Worange Point Formation; the holotype is amongst the largest tristichopterids and sarcopterygians documented by semi-articulated remains from the Devonian Period. The new taxon has dentary fangs and premaxillary tusks, features assumed to be derived for large Northern Hemisphere tristichopterids (Eusthenodon, Hyneria, Langlieria). It resembles Eusthenodon in ornament, but is distinguished by longer proportions of the parietal compared to the post-parietal shield, and numerous differences in shape and proportions of other bones. Several characters (accessory vomers in the palate, submandibulars overlapping ventral jaw margin, scales ornamented with widely-spaced deep grooves) are recorded only in tristichopterids from East Gondwana (Australia-Antarctica). On this evidence Edenopteron gen. nov. is placed in an endemic Gondwanan subfamily Mandageriinae within the Tristichopteridae; it differs from the nominal genotype Mandageria in its larger size, less pointed skull, shape of the orbits and other skull characters. The hypothesis that tristichopterids evolved in Laurussia and later dispersed into Gondwana, and a derived subgroup of large Late Devonian genera dispersed from Gondwana, is inconsistent with the evidence of the new taxon. Using oldest fossil and most primitive clade criteria the most recent phylogeny resolves South China and Gondwana as areas of origin for all tetrapodomorphs. The immediate outgroup to tristichopterids remains unresolved – either Spodichthys from Greenland as recently proposed, or Marsdenichthys from Gondwana, earlier suggested to be the sister group to all tristichopterids. Both taxa combine two characters that do not co-occur in other tetrapodomorphs (extratemporal bone in the skull; non-cosmoid round scales with an internal boss). Recently both ‘primitive’ and ‘derived’ tristichopterids have been discovered in the late Middle Devonian of both hemispheres, implying extensive ghost lineages within the group. Resolving their phylogeny and biogeography will depend on a comprehensive new phylogenetic analysis. PMID:23483884

  3. Aeromagnetic legacy of early Paleozoic subduction along the Pacific margin of Gondwana

    USGS Publications Warehouse

    Finn, C.; Moore, D.; Damaske, D.; Mackey, T.

    1999-01-01

    Comparison of the aeromagnetic signatures and geology of southeastern Australia and northern Victoria Land, Antarctica, with similar data from ancient subduction zones in California and Japan, provides a framework for reinterpretation of the plate tectonic setting of the Pacific margin of early Paleozoic Gondwana. In our model, the plutons in the Glenelg (south-eastern Australia) and Wilson (northern Victoria Land) zones formed the roots of continental-margin magmatic arcs. Eastward shifting of arc magmatism resulted in the Stavely (south-eastern Australia) and Bowers (northern Victoria Land) volcanic eruptions onto oceanic forearc crust. The turbidites in the Stawell (southeastern Australia) and Robertson Bay (northern Victoria Land zones) shed from the Glenelg and Wilson zones, respectively, were deposited along the trench and onto the subducting oceanic plate. The margin was subsequently truncated by thrust faults and uplifted during the Delamerian and Ross orogenies, leading to the present-day aeromagnetic signatures.

  4. Avian evolution, Gondwana biogeography and the Cretaceous-Tertiary mass extinction event.

    PubMed Central

    Cracraft, J.

    2001-01-01

    The fossil record has been used to support the origin and radiation of modern birds (Neornithes) in Laurasia after the Cretaceous-Tertiary mass extinction event, whereas molecular clocks have suggested a Cretaceous origin for most avian orders. These alternative views of neornithine evolution are examined using an independent set of evidence, namely phylogenetic relationships and historical biogeography. Pylogenetic relationships of basal lineages of neornithines, including ratite birds and their allies (Palaleocognathae), galliforms and anseriforms (Galloanserae), as well as lineages of the more advanced Neoves (Gruiformes, (Capimulgiformes, Passeriformes and others) demonstrate pervasive trans-Antarctic distribution patterns. The temporal history of the neornithines can be inferred from fossil taxa and the ages of vicariance events, and along with their biogeographical patterns, leads to the conclusion that neornithines arose in Gondwana prior to the Cretaceous Tertiary extinction event. PMID:11296857

  5. Tectonically controlled sedimentation in the Mesozoic basins of the Antarctic Peninsula

    SciTech Connect

    MacDonald, D.I.M.; Butterworth, P.J. (British Antarctic Survey, Cambridge (England))

    1990-05-01

    The Antarctica Peninsula (AP) lies on a medium-size block of continental crust and is one of a mosaic of west Antarctica coastal block that underwent a complex tectonic evolution during Gondwana breakup. The peninsula represents the eroded roots of a microcontinental volcanic arc; this arc lay above the easterly subducting proto-Pacific plate, and was active throughout the Mesozoic. The exposed Mesozoic basins display a complex stratigraphy, reflecting local tectonic and volcanic events. There are a few general trends. Almost all basins are post-late Oxfordian, their fill is entirely clastic, and is largely derived from the Antarctica peninsula volcanic arc. Most basins were affected by a period of arc expansion in the latest Jurassic or earliest Cretaceous, which manifests itself as inputs of lava or coarse volcaniclastic sediment overlying mudstones with an open marine fauna. Barriasian and older mudstones are generally finer grained and darker than mudstones from post-Berriasian strata. However, it must be emphasized that these are only general trends. Deformation is variable, commonly progressive. No lithostratigraphic units can be correlated between any two basins, nor are there any interregional unconformities. No matching is possible with basins of equivalent age in formerly contiguous areas of Gondwana. There is evidence that some global eustatic events are recorded in the sedimentary records of at least two of the AP Mesozoic basins, but these have effect only in periods of local tectonic quiescence. The dominant control on sedimentation in this large segment of the Pacific rim was arc tectonics.

  6. Late Paleozoic paleolatitude and paleogeography of the Midland basin, Texas

    SciTech Connect

    Walker, D.A. (Mobil Exploration and Producing U.S., Midland, TX (United States)); Golonka, J. (Mobil Exploration and Producing Services Inc., Dallas, TX (United States)); Reid, A.M.; Reid, S.T. (Consulting Geologist, Midland, TX (United States))

    1992-04-01

    During the Late Pennsylvanian through Early Permian, the Midland basin was located in the low latitudes. In the Desmoinesian (Strawn), the basin was astride the equator; during the Missourian (Canyon), the center of the basin had migrated northward so it was located at 1-2N latitude. In the Virgilian (Cisco), the basin center was located around 2-4N latitude, and by the Wolfcampian, it was positioned at around 4-6N latitude. From the Desmoinesian (312 Ma) through the Missourian (306 Ma), the relative motion of the basin was 63NE. Later during the Virgilian (298 Ma) to Wolfcampian (280 Ma), the direction of motion was 24NE. This change in motion reflects a major tectonic event, occurring between the Missourian and Virgilian, that greatly modifed the movement of the Laurentian (North American) plate. At that time, Laurentia had collided with Gondwana and become part of the supercontinent Pangea. Throughout the late Paleozoic, Laurentia was rotated so the Midland basin was oriented 43{degree} northeast from its current setting. Late Paleozoic paleogeography and paleolatitude controlled the direction of prevailing winds and ocean currents, thereby influencing the distribution of carbonate facies in the Midland basin. Present prevailing winds and ocean currents have been shown to have a major impact on modern carbonate sedimentation and facies distribution in Belize, the Bahamas and Turks, and Caicos. A clearer understanding of how late Paleozoic latitude and geography affected sedimentation helps explain and predict the distribution of carbonates throughout the Midland basin.

  7. Natural radioactivity and radiation exposure in the high background area at Chhatrapur beach placer deposit of Orissa, India.

    PubMed

    Mohanty, A K; Sengupta, D; Das, S K; Saha, S K; Van, K V

    2004-01-01

    A high natural background radiation area is reported for the Chhatrapur beach placer deposit of Orissa state, on the southeastern coast of India, due to the presence of radiogenic heavy minerals. The average activity concentrations of radioactive elements 232Th, 238U and 40K were measured by gamma-ray spectrometry using a HPGe detector, and found to be 2500 +/-1850, 230 +/- 140 and 120 +/- 35 Bq kg-1, respectively, for the bulk sand samples. The absorbed gamma dose rates in air due to the naturally occurring radionuclides varied from 375 to 5000 nGy h-1, with an average value of 1625 +/- 1200 nGy h-1. The external annual effective dose rate of the region ranged from 0.46 to 6.12 mSv y-1, with an average value of 1625 +/- 1200 mSv y-1. The absorbed gamma dose rate levels of Chhatrapur beach area were similar to the monazite sand-bearing high background radiation areas of southern and southwestern coastal tracts of India and other similar areas of the world. The major contributors to the enhanced level of radiation are monazite and zircon sands. PMID:15149759

  8. Metamorphic Evolution of the Main Collisional Suture Zone Between East and West Gondwana

    NASA Astrophysics Data System (ADS)

    Abu-Alam, Tamer; Grosch, Eugene

    2013-04-01

    Petrological and metamorphic constraints from five metamorphic complexes which were exhumed during the collision between East- and West-Gondwana across the main collisional suture zone are presented. These include: (a) Meatiq complex in Eastern Desert of Egypt, (b) Feiran-Solaf complex in Sinai, Egypt (c) Sa'al-Zaghra complex in Sinai, Egypt, (d) Great Ruaha River area in the Mozambique Belt, and (e) Western Dronning Maud Land, East Antarctica. The metamorphic results from these complexes are compared and provide insight into the nature of Pan-African crust formation processes during Gondwana assembly. In this study we present differences and similarities between various field areas in the central collisional suture zone of Gondwana that sheds light on the crustal accretion and supercontinent assembly process from a metamorphic perspective. The Meatiq complex in the Eastern Desert of Egypt consists of a low-grade volcanic arc sequence that covers a higher-grade, biotite-garnet gneiss metamorphic core complex. A sinistral shear zone - the Najd Fault System - separates the high-grade rocks from the low-grade volcanic sequence. The combination between published data and new thermodynamic modeling shows that both the high-grade and the low-grade rocks record single clockwise P -T paths. The peak metamorphic conditions of the high-grade rocks are T = 650-700 oC and P = 7-7.5 kbar, whereas the low-grade rocks record conditions of T = 400-450 oC and P = 3-4 kbar. In Sinai, the Najd Fault System is not exposed due to the voluminous intrusion of ca. 540 Ma post-tectonic granites. However, both the garnet-biotite gneisses of the Feiran-Solaf complex (T = 700-750 oC and P = 7-8 kbar) and the low-grade rocks (T = 400-450 oC and P = 2-3 kbar) of Wadi El Kid record very similar metamorphic conditions and clockwise P -T paths to those in Eastern Desert, Egypt. Conversely, the Sa'al-Zaghra complex shows anticlockwise P-T path with peak conditions of 2.5 kbar and 42 oC. It worth mention that the peak metamorphic age of the Sa'al-Zaghra complex is much older than the Pan-African event (ca. 1100 Ma). In western Dronning Maud Land (Antarctica), a petrological and metamorphic comparison of Mesoproterozoic metabasic rocks on the eastern margin of the Archean Grunehogna Craton and the adjacent Maud Belt, revealed a difference in peak metamorphic conditions from T = 280 ± 30 oC to 710-750 oC and P = 2 ± 1.5 to 8.5-11 kbar over a distance of only 30 km across a major glacial valley. The high-grade PT-constraints derived for the western extreme of the Maud Belt, is very similar to that reported for the eastern Maud Belt dated at ca. 550 Ma. These PT-constraints do not support the presence of a westward decreasing metamorphic field gradient within the Maud Belt as previously proposed. The data presented here suggests that the inferred sub-glacial boundary between the Grunehogna Craton and the Maud Belt, might reflect a major Pan-African thrust, with the Maud Belt representing the continuation of the East African Mozambique Belt into East Antarctica.

  9. The Changning-Menglian suture zone; a segment of the major Cathaysian-Gondwana divide in Southeast Asia

    Microsoft Academic Search

    Haoruo Wu; C. A. Boulter; Baojia Ke; D. A. V. Stow; Zhongcheng Wang

    1995-01-01

    In southwest China, the major Cathaysian-Gondwana divide (the Palaeo-Tethyan suture) is very well delineated by a narrow north-south zone of oceanic siliceous sedimentary rocks and dismembered ophiolite complexes including probable remains of reef-capped oceanic islands. The location of this zone, the Changning-Menglian suture, is not well appreciated in the English language literature, probably because of the failure to recognise the

  10. EVOLUTION. A four-legged snake from the Early Cretaceous of Gondwana.

    PubMed

    Martill, David M; Tischlinger, Helmut; Longrich, Nicholas R

    2015-07-24

    Snakes are a remarkably diverse and successful group today, but their evolutionary origins are obscure. The discovery of snakes with two legs has shed light on the transition from lizards to snakes, but no snake has been described with four limbs, and the ecology of early snakes is poorly known. We describe a four-limbed snake from the Early Cretaceous (Aptian) Crato Formation of Brazil. The snake has a serpentiform body plan with an elongate trunk, short tail, and large ventral scales suggesting characteristic serpentine locomotion, yet retains small prehensile limbs. Skull and body proportions as well as reduced neural spines indicate fossorial adaptation, suggesting that snakes evolved from burrowing rather than marine ancestors. Hooked teeth, an intramandibular joint, a flexible spine capable of constricting prey, and the presence of vertebrate remains in the guts indicate that this species preyed on vertebrates and that snakes made the transition to carnivory early in their history. The structure of the limbs suggests that they were adapted for grasping, either to seize prey or as claspers during mating. Together with a diverse fauna of basal snakes from the Cretaceous of South America, Africa, and India, this snake suggests that crown Serpentes originated in Gondwana. PMID:26206932

  11. A late Devonian impact event and its association with a possible extinction event on Eastern Gondwana

    NASA Technical Reports Server (NTRS)

    Wang, K.; Geldsetzer, H. H. J.

    1992-01-01

    Evidence from South China and Western Australia for a 365-Ma impact event in the Lower crepida conodont zone of the Famennian stage of the Late Devonian (about 1.5 Ma after the Frasnian/Famennian extinction event) includes microtektitelike glassy microspherules, geochemical anomalies (including a weak Ir), a probable impact crater (greater than 70 k) at Taihu in South China, and an Ir anomaly in Western Australia. A brachiopod faunal turnover in South China, and the 'strangelove ocean'-like c-delta 13 excursions in both Chinese and Australian sections indicate that at least a regional-scale extinction might have occurred at the time of the impact. A paleoreconstruction shows that South China was very close to and facing Western Australia in the Late Devonian. The carbon isotopic excursions, which occur at the same stratigraphic level in both South China and Western Australia cannot be explained as being coincidental. The c-delta 13 excursions and the brachiopod faunal turnover in South China indicate that there might have been at least a regional (possibly global) extinction in the Lower crepida zone. The impact-derived microspherules and geochemical anomalies (especially the Ir) indicate a Lower crepida zone impact event on eastern Gondwana. The location, type of target rocks, and possibly age of the Taihu Lake crater qualify as the probable site of this Late Devonian impact.

  12. Bio-concentration of chromium--an in situ phytoremediation study at South Kaliapani chromite mining area of Orissa, India.

    PubMed

    Mohanty, Monalisa; Pattnaik, Mausumi M; Mishra, Aruna K; Patra, Hemanta K

    2012-01-01

    Mine waste water at South Kaliapani usually contains toxic levels of hexavalent Cr(VI). The present in situ study was conducted at South Kaliapani chromite mine area in Orissa state, India, to assess the phytoremediation ability of three plants, namely, rice (Oryza sativa L.), paragrass (Brachiaria mutica), and an aquatic weed (Eichhornia crassipes), in attenuating Cr(VI) from mine waste water and to correlate the bio-concentration factors (BCF) of Cr. Water hyacinth (E. crassipes) showed 24% to 54% reduction whereas paragrass (B. mutica) was able to reduce 18% to 33% of Cr(VI) from mine water. This reduction was studied over a period of 100 days of plant growth. The reduction was observed through a passage of a sum total of 2,000 sq. ft. cultivated plots and ponds separately. Reduction in Cr(VI) content in mine water varies with plant age as well as with the distance of passage. Cr accumulation and BCF values increased with high soil Cr levels as well as the age of plants. High BCF and transportation index (Ti) values, i.e., 10,924 and 32.09, respectively, were noted for water hyacinth. The Ti values indicated that the root-to-shoot translocation of Cr was very high after 100 days of growth. The total accumulation rate was maximum (8.29 mg Cr kg dry biomass(-1) day (-1)) in paragrass. The BCF values for roots were noted to be higher than those of leaves, stems, and grains of the 125-day-old plants. Hence, paragrass and water hyacinth may be used as tools of phytoremediation to combat the problem of in situ Cr contamination. PMID:21487717

  13. A new glucose-6-phosphate dehydrogenase variant, G6PD Orissa (44 Ala{yields}Gly), is the major polymorphic variant in tribal populations in India

    SciTech Connect

    Kaeda, J.S.; Bautista, J.M.; Stevens, D. [Univ. College London Medical School (United Kingdom)] [and others

    1995-12-01

    Deficiency of glucose-6-phosphate dehydrogenase (G6PD) is usually found at high frequencies in areas of the world where malaria has been epidemic. The frequency and genetic basis of G6PD deficiency have been studied in Africa, around the Mediterranean, and in the Far East, but little such information is available about the situation in India. To determine the extent of heterogeneity of G6PD, we have studied several different Indian populations by screening for G6PD deficiency, followed by molecular analysis of deficient alleles. The frequency of G6PD deficiency varies between 3% and 15% in different tribal and urban groups. Remarkably, a previously unreported deficient variant, G6PD Orissa (44 Ala{yields}Gly), is responsible for most of the G6PD deficiency in tribal Indian populations but is not found in urban populations, where most of the G6PD deficiency is due to the G6PD Mediterranean (188 Ser{yields}Phe) variant. The K{sup NADP}{sub m} of G6PD Orissa is fivefold higher than that of the normal enzyme. This may be due to the fact that the alanine residue that is replaced by glycine is part of a putative coenzyme-binding site. 37 refs., 2 figs., 3 tabs.

  14. Mass drug administration under the programme to eliminate lymphatic filariasis in Orissa, India: a mixed-methods study to identify factors associated with compliance and non-compliance.

    PubMed

    Babu, Bontha V; Mishra, Suchismita

    2008-12-01

    The present study aimed to identify the factors responsible for compliance and non-compliance of mass drug administration (MDA) under the programme to eliminate lymphatic filariasis (LF) from Orissa, India. It was based on both quantitative (through household MDA coverage survey) and qualitative data (through semi-structured interviews with heads of compliant and non-compliant households) collected during an MDA held in November 2005 in two districts of Orissa. In these districts, 83% of the eligible population received the drug (coverage) and only 49.5% people actually consumed the drug (compliance). Seventeen percent of the population did not even receive the drug. The predominant reason for not receiving the drug at household level was that the drug distributor did not visit the household, while the fear of adverse reactions is the predominant reason for not consuming it. The qualitative data revealed that the major contributor to taking the drug was the awareness that drug protects them from LF. Motivation by health workers was another reason for compliance. In many endemic areas, the issues related to non-compliance were taken casually during implementation. Hence, it is imperative to make the programme more efficient by addressing the issues linked to low compliance. PMID:18632125

  15. Geothermal structure of Australia's east coast basins

    NASA Astrophysics Data System (ADS)

    Danis, C. R.; O'Neill, C.

    2010-12-01

    The east coast sedimentary basins of Australia formed on an active margin of eastern Gondwana, and constitute an important hydrocarbon resource. The 1600km long Sydney-Gunnedah-Bowen Basin (SGBB) is largest east coast basin system, with thick Permian to Jurassic sedimentary successions overlying Palaeozoic basement rocks. The SGBB has been the focus of renewed geothermal exploration interest, however, the thermal state and geothermal potential of the system is largely unconstrained. Geothermal exploration programs require an accurate estimate of subsurface temperature information, in addition to favourable geology, to make informed decisions on potential targe developments. Primarily temperature information comes from downhole measurements, generally non-equilibrated, which are traditionally extrapolated to depth, however such extrapolation does not take into account variations in geological structure or thermal conductivity. Here we import deep 3D geological models into finite element conduction simulations, using the code Underworld, to calculate the deep thermal structure of the basin system. Underworld allows us to incorporate complex, detailed geological architecture models, incorporating different material properties for different layers, with variable temperature and depth-dependent properties. We adopt a fixed top boundary temperature on a variable topographic surface, and vary the bottom surface boundary condition, to converge of models which satisfy equilibrated downhole temperature measurement constraints. We find coal plays an important role in insulating sedimentary basins. Heat refracts around the coal interval and produces elevated temperatures beneath thick sediments, especially where thick coal intervals are present. This workflow has been formalized into an Underworld geothermal model library, enabling model centric computational workflows. Using the imported model architecture from the geology, data can be continuously updated and added to the system and models quickly re-run to take advantage of the most up to date information. The thermal models we’ve produced for the SGBB are an efficient regional assessment of the geothermal resource potential in this basin system.

  16. Evolutionary sequences and hydrocarbon potential of Kenya sedimentary basins

    SciTech Connect

    Cregg, A.K. (Western Atlas International, Inc., Carrollton, TX (United States))

    1991-03-01

    Kenya basins have evolved primarily through extension related to episodic continental rifting. In eastern Kenya, thick accumulations of sediments formed within grabens during the prerift phase (Precambrian to Carboniferous) of the Gondwana breakup. Synrift sedimentation (Late Carboniferous to Middle Jurassic) occurred within a north-south rift system, which included the Mandera basin, South Anza basin, and Lamu embayment. During the Early Jurassic, a marine transgression invaded the margins of the eastern Kenya rift basins, resulting in the deposition of platform carbonates and shales. A Callovian-aged salt basin formed in the offshore regions of the Lamu embayment. Intermittent tectonic activity and eustatic sea-level changes controlled sedimentation, which produced marine shales, carbonates or evaporites, and fluvio-deltaic to lacustrine sandstones. From the Early Cretaceous to recent, continental sediments were deposited within the North Anza and Turkana basins. These fluvial-lacustrine sediments are similar to the Lower Cretaceous sequences that have produced oil in the Mesozoic Sudanese Abu Gabra rift. Although exploration activities began in the early 1950s, significant occurrences of potential reservoir, source, and seal lithologies as well as trapping configurations remain in many areas. Favorable structures and sequences of reservoir sandstones and carbonates overlain by potentially sealing lacustrine or marine shales, evaporites, or volcanics have been noted. Potential source beds are believed to be present within shales of the lacustrine or marine depositional environments.

  17. Micropaleontology and biostratigraphy of the coastal basins of West Africa

    NASA Astrophysics Data System (ADS)

    Kogbe, C. A.; Me'hes, K.

    The West African Coastal sedimentary basins are mostly "open"-type basins, which originated as a result of the break-up of the Gondwana and the separation of Africa and South America. Several of the basins are merely separated by thin coastal strips and they show far-reaching uniformity in their sedimentary sequences and fossil faunas. Almost all the basins, from Angola to Senegal, have a non-marine beginning followed by the development of marine sedimentation in Aptian-Albian time and continuing into the Tertiary. Most of the basins have yielded many important diagnostic index microfossils (foraminifera and ostracoda) which are different from those from the Boreal, Mediterranean and Pacific regions. These fossils, which have previously only been described in private unpublished company reports or scattered in various journals and bulletins published in different languages are assembled, described, illustrated and correlated in this single volume. The stratigraphic subdivisions in the different coastal basins from Angola to Senegal are simplified, described and their microfossil content listed. Three general charts listing the important foraminifera (benthonic and planctonic) and ostracod species with their straigraphic range emphasize the usefulness of these fossils as a most important tool in the study of the stratigraphy of the economically interesting sedimentary sequences of coastal West Africa.

  18. Changes in carbon dioxide during an oceanic anoxic event linked to intrusion into Gondwana coals.

    PubMed

    McElwain, Jennifer C; Wade-Murphy, Jessica; Hesselbo, Stephen P

    2005-05-26

    The marine sedimentary record exhibits evidence for episodes of enhanced organic carbon burial known as 'oceanic anoxic events' (OAEs). They are characterized by carbon-isotope excursions in marine and terrestrial reservoirs and mass extinction of marine faunas. Causal mechanisms for the enhancement of organic carbon burial during OAEs are still debated, but it is thought that such events should draw down significant quantities of atmospheric carbon dioxide. In the case of the Toarcian OAE (approximately 183 million years ago), a short-lived negative carbon-isotope excursion in oceanic and terrestrial reservoirs has been interpreted to indicate raised atmospheric carbon dioxide caused by oxidation of methane catastrophically released from either marine gas hydrates or magma-intruded organic-rich rocks. Here we test these two leading hypotheses for a negative carbon isotopic excursion marking the initiation of the Toarcian OAE using a high-resolution atmospheric carbon dioxide record obtained from fossil leaf stomatal frequency. We find that coincident with the negative carbon-isotope excursion carbon dioxide is first drawn down by 350 +/- 100 p.p.m.v. and then abruptly elevated by 1,200 +/- 400 p.p.m.v, and infer a global cooling and greenhouse warming of 2.5 +/- 0.1 degrees C and 6.5 +/- 1 degrees C, respectively. The pattern and magnitude of carbon dioxide change are difficult to reconcile with catastrophic input of isotopically light methane from hydrates as the cause of the negative isotopic signal. Our carbon dioxide record better supports a magma-intrusion hypothesis, and suggests that injection of isotopically light carbon from the release of thermogenic methane occurred owing to the intrusion of Gondwana coals by Toarcian-aged Karoo-Ferrar dolerites. PMID:15917805

  19. Origin of northern Gondwana Cambrian sandstone revealed by detrital zircon SHRIMP dating

    USGS Publications Warehouse

    Avigad, D.; Kolodner, K.; McWilliams, M.; Persing, H.; Weissbrod, T.

    2003-01-01

    Voluminous Paleozoic sandstone sequences were deposited in northern Africa and Arabia following an extended Neoproterozoic orogenic cycle that culminated in the assembly of Gondwana. We measured sensitive high-resolution ion microprobe (SHRIMP) U-Pb ages of detrital zircons separated from several Cambrian units in the Elat area of southern Israel in order to unravel their provenance. This sandstone forms the base of the wide-spread siliciclastic section now exposed on the periphery of the Arabian-Nubian shield in northeastern Africa and Arabia. Most of the detrital zircons we analyzed yielded Neoproterozoic concordant ages with a marked concentration at 0.55-0.65 Ga. The most likely provenance of the Neoproterozoic detritus is the Arabian-Nubian shield; 0.55-0.65 Ga was a time of posttectonic igneous activity, rift-related volcanism, and strike-slip faulting there. Of the zircons, 30% yielded pre-Neoproterozoic ages grouped at 0.9-1.1 Ga (Kibaran), 1.65-1.85 Ga, and 2.45-2.7 Ga. The majority of the pre-Neoproterozoic zircons underwent Pb loss, possibly as a consequence of the Pan-African orogeny resetting their provenance. Rocks of the Saharan metacraton and the southern Afif terrane in Saudi Arabia (???000 km south of Elat) are plausible sources of these zircons. Kibaran basement rocks are currently exposed more than 3000 km south of Elat (flanking the Mozambique belt), but the shape of the detrital zircons of that age and the presence of feldspar in the host sandstone are not fully consistent with such a long-distance transport. Reworking of Neoproterozoic glacial detritus may explain the presence of Kibaran detrital zircons in the Cambrian of Elat, but the possibility that the Arabian-Nubian shield contains Kibaran rocks (hitherto not recognized) should also be explored.

  20. Geology and metallogeny of the Ar Rayn terrane, eastern Arabian shield: Evolution of a Neoproterozoic continental-margin arc during assembly of Gondwana within the East African orogen

    USGS Publications Warehouse

    Doebrich, J.L.; Al-Jehani, A. M.; Siddiqui, A.A.; Hayes, T.S.; Wooden, J.L.; Johnson, P.R.

    2007-01-01

    The Neoproterozoic Ar Rayn terrane is exposed along the eastern margin of the Arabian shield. The terrane is bounded on the west by the Ad Dawadimi terrane across the Al Amar fault zone (AAF), and is nonconformably overlain on the east by Phanerozoic sedimentary rocks. The terrane is composed of a magmatic arc complex and syn- to post-orogenic intrusions. The layered rocks of the arc, the Al Amar group (>689 Ma to ???625 Ma), consist of tholeiitic to calc-alkaline basaltic to rhyolitic volcanic and volcaniclastic rocks with subordinate tuffaceous sedimentary rocks and carbonates, and are divided into an eastern and western sequence. Plutonic rocks of the terrane form three distinct lithogeochemical groups: (1) low-Al trondhjemite-tonalite-granodiorite (TTG) of arc affinity (632-616 Ma) in the western part of the terrane, (2) high-Al TTG/adakite of arc affinity (689-617 Ma) in the central and eastern part of the terrane, and (3) syn- to post-orogenic alkali granite (607-583 Ma). West-dipping subduction along a trench east of the terrane is inferred from high-Al TTG/adakite emplaced east of low-Al TTG. The Ar Rayn terrane contains significant resources in epithermal Au-Ag-Zn-Cu-barite, enigmatic stratiform volcanic-hosted Khnaiguiyah-type Zn-Cu-Fe-Mn, and orogenic Au vein deposits, and the potential for significant resources in Fe-oxide Cu-Au (IOCG), and porphyry Cu deposits. Khnaiguiyah-type deposits formed before or during early deformation of the Al Amar group eastern sequence. Epithermal and porphyry deposits formed proximal to volcanic centers in Al Amar group western sequence. IOCG deposits are largely structurally controlled and hosted by group-1 intrusions and Al Amar group volcanic rocks in the western part of the terrane. Orogenic gold veins are largely associated with north-striking faults, particularly in and near the AAF, and are presumably related to amalgamation of the Ar Rayn and Ad Dawadimi terranes. Geologic, structural, and metallogenic characteristics of the Ar Rayn terrane are analogous to the Andean continental margin of Chile, with opposite subduction polarity. The Ar Rayn terrane represents a continental margin arc that lay above a west-dipping subduction zone along a continental block represented by the Afif composite terrane. The concentration of epithermal, porphyry Cu and IOCG mineral systems, of central arc affiliation, along the AAF suggests that the AAF is not an ophiolitic suture zone, but originated as a major intra-arc fault that localized magmatism and mineralization. West-directed oblique subduction and ultimate collision with a land mass from the east (East Gondwana?) resulted in major transcurrent displacement along the AAF, bringing the eastern part of the arc terrane to its present exposed position, juxtaposed across the AAF against a back-arc basin assemblage represented by the Abt schist of the Ad Dawadimi terrane. Our findings indicate that arc formation and accretionary processes in the Arabian shield were still ongoing into the latest Neoproterozoic (Ediacaran), to about 620-600 Ma, and lead us to conclude that evolution of the Ar Rayn terrane (arc formation, accretion, syn- to postorogenic plutonism) defines a final stage of assembly of the Gondwana supercontinent along the northeastern margin of the East African orogen. ?? 2007 Elsevier B.V. All rights reserved.

  1. Structural framework, stratigraphy, and evolution of Brazilian marginal basins

    SciTech Connect

    Ojeda, H.A.O.

    1982-06-01

    The structural framework of the Brazilian continental margin is basically composed of eight structural types: antithetic tilted step-fault blocks, synthetic untilted step-fault blocks, structural inversion axes, hinges with compensation grabens, homoclinal structures, growth faults with rollovers, diapirs, and igneous structures. The antithetic tilted and synthetic untilted step-fault blocks are considered as synchronous, complementary structural systems, separated by an inversion axis. Two evaporitic cycles (Paripueira and Ibura) were differentiated in the Sergipe-Alagoas type basin and tentatively correlated to the evaporitic section of other Brazilian marginal basis. Four phases are considered in the evolution of the Brazilian marginal basins: pre-rift, rift, transitional, and drift. During the pre-rift phase (Late Jurassic-Early Cretaceous), continental sediments were deposited in peripheral intracratonic basins. In the rift phase (Early Cretaceous), the breakup of the continental crust of the Gondwana continent gave rise to a central graben and rift valleys where lacustrine sediments were deposited. The transitional phase (Aptian) developed under relative tectonic stability, when evaporitic and clastic lacustrine sequences were being deposited. In the drift phase (Albian to Holocene), a regionl homoclinal structure developed, consisting of two distinct sedimentary sequences, a lower clastic-carbonate and an upper clastic. From the Albian to the Holocene Epoch, structures associated to plastic displacement of salt or shale developed in many Brazilian marginal basins. Two phases of major igneous activity occurred: one in the Early Cretaceous associated with the rift phase of the Gondwana continent, and the other in the Tertiary during the migration phase of the South American and African plates.

  2. Apparent polar wander paths carboniferous through cenozoic and the assembly of Gondwana

    NASA Astrophysics Data System (ADS)

    Irving, E.; Irving, G. A.

    1982-07-01

    Directions of magnetization observed from rock-units from a given continental block are conveniently summarized by a path of apparent polar wander (apw) relative to that block. This article documents apw paths for the major continental blocks spanning the interval from Late Carboniferous (approximately -300 Ma) to the present. It is shown that by passing moving windows of 30 or 40 Ma duration over the data an apw path can be obtained with little or no loss of features through smoothing. It also is shown that mean pole positions obtained using Fisher's statistics or by calculating modes do not differ significantly. In the analysis ‘poor’ results are screened out by applying certain minimum reliability criteria. Unit weight is then given to each of the remaining results. No attempt has been made to weight the results differentially because of the risk of added subjectivity. The paths contain many interesting features. One is an interval of rapid apparent polar motion relative to all major land-masses that occurred sometime in the Late Permian and Triassic. The general form of these motions is roughly established, but their timing and detailed form is poorly known because of inadequacies in the paleomagnetic record. Although it is clear that the motions occurred sometime around the Paleozoic-Mesozoic boundary it is not known whether the motions are or are not contemporaneous from continent to continent. Apw paths are of great importance for many problems in geology and geophysics. As an example, the new paths are applied to the question of how should Gondwana be correctly assembled. The results show that the best available reconstruction is the 1937 assembly of Alex du Toit as quantified by Smith and Hallam, with a minor modification by Barton and Molnar for the fit of Australia and Antarctica. Assemblies, that place Antaretica to the south and wrap the Antarctic Peninsula around the southern Andes, are not supported by the paleomagnetic data. There are, however, several obscurities, which derive, it is argued, from the uncertainties in timing the Late Permian to Triassic transitions alluded to above.

  3. Sub-horizontal channel flow: an exhumation mechanism during the Gondwana collision

    NASA Astrophysics Data System (ADS)

    Abu-Alam, Tamer; Stüwe, kurt

    2013-04-01

    The Arabian-Nubian Shield is made up of juvenile crust which was formed due to arc-arc accretion during the East- and West-Gondwana collision (Pan-African event) and the closing of the Mozambique Ocean. Thus the shield is composed of ophiolitic and volcanic material with oceanic affinity. However rocks with continental affinity can be found as high grade metamorphic complexes that were exposed from underneath the arc-related rocks during the late stages of the Pan-African event. Two tectonic models explain the exhumation mechanism of these metamorphic complexes. The first model is exhumation as core complexes in extension setting. This model appears to pertain to the metamorphic complexes of the Eastern Desert of Egypt. The second model is exhumation in oblique transpressional regime as it was found - for example - for the Feiran-Solaf complex of Sinai Peninsula. These models are correct with regard to the structural elements in the outer zones of the metamorphic complexes, which formed during the final exhumation mechanism during the later stages of the deformation history (e.g. D3 of the Feiran complex). However the models cannot explain the sub-horizontal lineations that formed during the early deformation phases and are still recorded in the core of the metamorphic complexes (e.g. D1 of the Feiran-Solaf complex). Here we propose sub-horizontal channel flow as a mechanism to exhume the metamorphic complexes and a mechanism that can account for both types of structural elements as part of one exhumation history. We suggest that the rocks flowed horizontally at mid-crustal levels to the NW of the Arabian-Nubian Shield. The front of the channel flows was then exhumed to the Earth surface in a transpression regime. This middle crustal flow will produce extensional tectonic regime in the upper crust (i.e. ?3 is horizontal and oriented in the NW-SE direction). This extensional setting produces low-angle detachments which assisted the middle crustal rocks to be exhumed as tectonic windows of the Eastern Desert of Egypt. The complexes then can be exhumed completely to the Earth surface in either extensional or oblique transpressional regime depend on the orientation of the principle stresses. Examples from Saudi Arabia will be presented during the EGU2013 to demonstrate this new tectonic model.

  4. Paleozoic Orogens of Mexico and the Laurentia-Gondwana Connections: an Update

    NASA Astrophysics Data System (ADS)

    Ortega-Gutierrez, F.

    2009-05-01

    The present position of Mexico in North America and the fixist tectonic models that prevailed prior to the seventies of the past century, have considered the main Paleozoic tectonic systems of Mexico as natural extensions of the orogens that fringed the eastern and southern sides of the Laurentian craton. Well known examples of pre-Mesozoic orogens in Mexico are the Oaxacan, Acatlan, and Chiapas polymetamorphic terranes, which have been correlated respectively with the Grenville and Appalachian-Ouachitan orogens of eastern North America. Nonetheless, several studies conducted during the last decade in these Mexican orogenic belts, have questioned their Laurentian connections, regarding northwestern Gondwana instead as the most plausible place for their birth and further tectonic evolution. This work pretends to approach the problem by briefly integrating the massive amount of new geological information, commonly generated through powerful dating methods such as LA-ICPM-MS on detrital zircon of sedimentary and metasedimentary units in the Paleozoic crustal blocks, which are widely exposed in southern and southeastern Mexico. The Acatlan Complex bears the closest relationships to the Appalachian orogenic system because it shows thermotectonic evidence for opening and closure of the two main oceans involved in building the Appalachian mountains in eastern Laurentia, whereas two other Paleozoic terranes in NW and SE Mexico, until recently rather geologically unknown, may constitute fundamental links between the Americas for the last-stage suturing and consolidation of western Pangea. The buried basement of the Yucatan platform (400,000 squared km) on the other hand, remains as one of the most relevant problems of tectonostratigraphic correlations across the Americas, because basement clasts from the Chicxulub impact ejecta reveal absolute and Nd-model ages that suggest close Gondwanan affinities. Major changes in the comprehension of the Paleozoic orogens in Mexico include the swift of the Acatlan Complex from Iapetus to Rheic scenarios, and the apparent continuation of the Ouachita belt across northern Mexico into south central Sonora, rather than displaced eastwards along the legendary Mojave-Sonora megashear. And yet, poorly known suture-related lithotectonic associations of Paleozoic metamorphic rocks and arc granitoids that underlie the eastern margin of Mexico, have not been explained by existing models dealing with the Appalachian-Mexico-Gondwanan connections.

  5. Petrography of Permian "Gondwana" coals from boreholes in northwestern Bangladesh, based on semiautomated reflectance scanning

    USGS Publications Warehouse

    Bostick, N.H.; Betterton, W.J.; Gluskoter, H.J.; Nazrul, Islam M.

    1991-01-01

    Drilling through Quaternary alluvium and Tertiary cover at low-gravity anomalies in northwestern Bangladesh showed the presence of Permian sedimentary rocks in depressions that may be as much as a thousand meters deep in the crystalline basement. These Permian strata include low-sulfur, high-volatile bituminous coals in beds as thick as 15 m. The maceral group composition of these coals was determined by semiautomated reflectance scanning with a motorized microscope stage, rather than by point counting. This method was chosen to give objectively recorded raw analytical data and to provide a graphical picture of each sample. The coals are mostly "Gondwana" type (poorly layered "plum pudding" with abundant minerals and inertinite in a vitrinite groundmass) that would be classed as semi-dull (inerto-gelitite) coals. However, six samples have more than 70% vitrinite. None of the samples would be classed as sapropelic (liptinitic). The upper, middle, and lower main seams in borehole GDH-45 were sampled in 10 benches (0.1-3 m thick) each. Inertinite ranges from 7 to 100 vol% (mineral free basis) in individual benches, but composite seam averages are 41, 54 and 67%. Inertinite increases toward the top of two main seams so the bottom would yield the most valuable first mine slices. Some benches with extremely high inertinite content, such as the top 7 m of the lower thick seam, might be mined specially for blending with foreign low-inert coals to increase coke strength. The free swelling index reaches 7.5 in several vitrinite-rich benches, which can indicate good coking coal. Much of the vitrinite is fluorescent, which indicates secondary bituminization characteristic of vitrinite in good coking coals. Ash yields range from 8 to 52%, with composite seam averages of 15, 14 and 24%. Rare visible pyrite is in veinlets or small nodules; framboids and dispersed pyrite are absent. In borehole GDH-40 near Barapukuria (200-500 m depth), the mean random reflectance of vitrinite "A" ranges from 0.60 to 0.80% Ro and vitrinite "B" ranges from 0.55 to 0.65%. In borehole GDH-45 near Khalaspir (287-442 m), the reflectance of vitrinite ranges from 0.79 to 0.94%. In individual cases, the vitrinite is difficult to define because of semivitrinite at higher reflectance (forming a separate peak on several reflectograms) and because of surface bitumen films or resinous (?) inclusions at lower reflectance. On the basis of vitrinite reflectance, the coals can be considered to have entered the "main phase of bitumen generation" of organic thermal maturation as understood in petroleum geochemistry. ?? 1991.

  6. The evolution of mammal-like crocodyliforms in the Cretaceous Period of Gondwana

    Microsoft Academic Search

    Patrick M. O'Connor; Joseph J. W. Sertich; Nancy J. Stevens; Eric M. Roberts; Michael D. Gottfried; Tobin L. Hieronymus; Zubair A. Jinnah; Ryan Ridgely; Sifa E. Ngasala; Jesuit Temba

    2010-01-01

    Fossil crocodyliforms discovered in recent years have revealed a level of morphological and ecological diversity not exhibited by extant members of the group. This diversity is particularly notable among taxa of the Cretaceous Period (144-65million years ago) recovered from former Gondwanan landmasses. Here we report the discovery of a new species of Cretaceous notosuchian crocodyliform from the Rukwa Rift Basin

  7. "Gondwana Dispersion and Asian Accretion (Metcalfe, I., Ren Jishun, Chalvet, J. & Hada, S. eds.)", A.A. Balkema Publishers, Rotterdam & Brookfield, pp.361, 1999.

    E-print Network

    Banbara, Mutsunori

    "Gondwana Dispersion and Asian Accretion (Metcalfe, I., Ren Jishun, Chalvet, J. & Hada, S. eds and Asian Accretion: 67-87. Rotterdam, A.A. Balkema Publ., 1999. "Catastrophic Loess, mass mortality". Journal of the Geological Society of Thailand, No.1, 1-17, 1999. "Asian accretion of Gondwanaland

  8. Cyclicity and stacking patterns in Carboniferous strata of the Black Warrior Foreland Basin

    SciTech Connect

    Pashin, J.C. [Geological Survey of Alabama, Tuscaloosa, AL (United States)

    1994-09-01

    Cyclicity in Carboniferous stratigraphic successions has long been attributed to tectonism and climate, but the ways these variables interact to determine the architecture of sedimentary basin fills remain a subject of intense debate. Geophysical well logs and cores from the Black Warrior basin were used to test the effects of tectonism and climate on cyclicity and stacking patterns in a foreland-basin setting. The Black Warrior basin formed in Carboniferous time by diachronous tectonic loading of the Alabama continental promontory along the Appalachian-Ouachita juncture. Climatic changes affecting the basin during this time include drift of southeastern North America from the arid southern tradewind belt toward the humid equatorial belt, as well as the onset of a major Gondwana glaciation just prior to the end of the Chesterian. The fill of the Black Warrior basin comprises carbonate and coal-bearing depositional cycles, and the composition, frequency, and stacking patterns of those cycles reflect dynamically interwoven tectonic and climatic factors. Tectonic loading evidently gave rise to flexural movements that determined cycle stacking patterns by controlling spatial and temporal variation of subsidence rate. Evolving tectonic highlands, moreover, fostered a shift from cratonic to orogenic sources of terrigenous elastic sediment, thereby affecting stratal geometry. Climate, by contrast, regulated the composition and frequency of the cycles. The transition from carbonate-bearing cycles with oxidized, calcic paleosols to coal-bearing cycles with reduced, histic paleosols reflects drift of southeastern North America into the humid equatorial belt. Change of average cycle duration from 1.3 m.y. to less than 0.4 m.y. corresponds with the onset of Gondwana glaciation, suggesting significant climatic forcing of sea level variation.

  9. Deep seismic reflection profiling of sedimentary basins offshore Brazil: Geological objectives and preliminary results in the Sergipe Basin

    NASA Astrophysics Data System (ADS)

    Mohriak, Webster Ueipass; Lira Rabelo, JoséHenrique; De Matos, Renato Darros; De Barros, Mozart C.

    1995-12-01

    The first deep seismic reflection profiles offshore Brazil were acquired in Campos Basin and processed to 10 s TWT in 1984. Starting in 1989, Petrobrás acquired an extensive data set of deep seismic profiles using special acquisition equipment capable of effectively penetrating through the sedimentary layers and imaging the whole crustal architecture. These deep (18 s TWT) seismic reflection profiles extend across the Atlantic-type marginal basins, from the platform to the deepwater province, presently considered frontier regions for petroleum exploration. This work addresses the geological objectives of a deep seismic profile in the Sergipe Basin and discusses the results obtained by integrating regional seismic, gravity and magnetic data. When combined, these data provide evidence that deep seismic reflectors observed in the Sergipe Basin are related to intracrustal-upper mantle structures rather than sedimentary features. The deep seismic reflection profile in the Sergipe Basin also suggests that, rather than a non-volcanic passive margin, the deepwater extension of this basin is marked by several magmatic structures, including thick wedges of seaward-dipping reflectors and volcanic plugs. These magmatic features are associated with basinforming processes resulting from lithospheric extension during the breakup of Gondwana in the Early Cretaceous and subsequent emplacement of oceanic crust. These results are compared to the crustal scale structures observed in the Campos Basin, in the southeastern margin of Brazil. The interpretation of the deep structure of these basins indicates that final separation between the South American and African plates formed passive margins characterized by different patterns of crustal attenuation underlying the rift blocks.

  10. 3D crustal-scale heat-flow regimes at a developing active margin (Taranaki Basin, New Zealand)

    NASA Astrophysics Data System (ADS)

    Kroeger, K. F.; Funnell, R. H.; Nicol, A.; Fohrmann, M.; Bland, K. J.; King, P. R.

    2013-04-01

    The Taranaki Basin in the west of New Zealand's North Island has evolved from a rifted Mesozoic Gondwana margin to a basin straddling the Neogene convergent Australian-Pacific plate margin. However, given its proximity to the modern subduction front, Taranaki Basin is surprisingly cold when compared to other convergent margins. To investigate the effects of active margin evolution on the thermal regime of the Taranaki Basin we developed a 3D crustal-scale forward model using the petroleum industry-standard basin-modelling software Petromod™. The crustal structure inherited from Mesozoic Gondwana margin breakup and processes related to modern Hikurangi convergent margin initiation are identified to be the main controls on the thermal regime of the Taranaki Basin. Present-day surface heat flow across Taranaki on average is 59 mW/m2, but varies by as much as 30 mW/m2 due to the difference in crustal heat generation between mafic and felsic basement terranes alone. In addition, changes in mantle heat advection, tectonic subsidence, crustal thickening and basin inversion, together with related sedimentary processes result in variability of up to 10 mW/m2. Modelling suggests that increased heating of the upper crust due to additional mantle heat advection following the onset of subduction is an ongoing process and heating has only recently begun to reach the surface, explaining the relatively low surface heat flow. We propose that the depth of the subducted slab and related mantle convection processes control the thermal and structural regimes in the Taranaki Basin. The thermal effects of the subduction initiation process are modified and overprinted by the thickness, structure and composition of the lithosphere.

  11. The Toarcian Bathonian succession of the Antsiranana Basin (NW Madagascar): Facies analysis and tectono-sedimentary history in the development of the East Africa-Madagascar conjugate margins

    NASA Astrophysics Data System (ADS)

    Papini, Mauro; Benvenuti, Marco

    2008-04-01

    The latest Early to Middle Jurassic succession of the Antsiranana Basin (NW Madagascar) records the complex transition from the continental rifting of Gondwana to the drifting of Madagascar-India from East Africa. The Madagascan Late Paleozoic-Mesozoic successions have been included in several paleogeographic and geodynamic models explaining the evolution of the Gondwana margins. Nevertheless, in some cases, as for the Toarcian-Bathonian deposits of the Antsiranana Basin, no significant stratigraphic revision has been carried out since the early 1970s. New field surveys allow reconsidering the stratigraphic and structural context and the palaeoenvironmental meaning of Toarcian-Bathonian successions occurring in different parts of the basin. These successions rest on the Triassic-Early Jurassic Isalo Sandstone which records pre-breakup rift events with a dominantly fluvial deposition. This situation is similar to other continental rift basins of Gondwana. After a regional Toarcian transgression the different portions of the Antsiranana Basin were characterized by significantly diversified and coeval depositional environments. The basin can be subdivided in a SW and NE part separated by a NW-SE trending structural high. In the SW part of the basin (Ampasindava sub-basin) the so-called "Jurassique paralique" [Rerat, J.C., 1964. Note sur les variations de faciès des sèries jurassiques du nord de Madagascar. Comptes Rendus Semaine gèologique, Tananarive, pp. 15-22] or " Facies Mixtes de la Presqu'ile de Ampasindava" [Besairie, H., Collignon, M., 1972. Géologie de Madagascar; I. Les terrains sédimentaires. Annales Géologiques de Madagascar, 35, 1-463], a 1500 m thick prevalently terrigenous deposit, has been subdivided into four units. They document the long-lasting development of coastal-deltaic systems in a highly subsiding area. In the NE portion of the basin (Ankarana-Analamera sub-basin), a coeval mixed carbonate-terrigenous succession subdivided in five units for a total thickness of 500 m, was deposited during relative sea-level fluctuations in a ramp setting characterized by relatively lower subsidence. The stratigraphic-depositional evolution was dependant on the presence of NW-trending, actively growing highs which fed the south-western sub-basin. The clastic supply balanced the tectonically created accommodation space in this portion of the basin. The revised and extended paleogeographical reconstruction has been included into a breakup model of the East Africa-Madagascar rift during the opening of the Mozambique Channel.

  12. Regional S-type granites in the Ecuadorian Andes: Possible remnants of the breakup of western Gondwana

    NASA Astrophysics Data System (ADS)

    Aspden, J. A.; Fortey, N.; Litherland, M.; Viteri, F.; Harrison, S. M.

    1992-10-01

    Reconnaissance geological mapping of the Ecuadorian Cordillera Real has established the presence of a previously unrecognized regional suite of variably deformed granitoids for which poorly constrained Rb?Sr whole-rock data indicate a minimum Early Jurassic age of 200 ± 12 Ma (initial ratio = 0.7120). This suite, which is associated with low- to medium-grade, semipelitic metamorphic rocks, is dominated by peraluminous monzogranites containing biotite ± garnet ± muscovite. Geochemically, these granites are S-types and can be readily distinguished from juxtaposed I-type granitoids of the Middle-Upper Jurassic Zamora, Abitagua, and Azafrán batholiths located immediately to the east. Intrusion of these S-type granites may be related to the breakup of western Gondwana.

  13. Stratigraphy of Midland basin in regional and global context

    SciTech Connect

    Robinson, R.M. (Robinson Drilling of Texas, Big Spring, TX (United States)); Hayner, D. (Greenstar Exploration, Dallas TX (United States))

    1994-03-01

    A new correlation of 85 well logs provides the data for a continuous set of structure and isopach maps covering one square degree of longitude and latitude from 101 to 102 west and 32 to 33 north. A corresponding set of maps showing paleogeography and tectonics relates each of the above maps to its surroundings in the southwest quarter of North America. A further set of maps of the globe then relates the paleogeographic settings to global plate tectonics. The logs were chosen for an even distribution throughout the study areas and they illustrate the stratigraphic development of the Midland basin from the Early Ordovician up to the middle of the Leonardian stage, i.e., up to the union of Gondwana.

  14. Prepared to react? Assessing the functional capacity of the primary health care system in rural Orissa, India to respond to the devastating flood of September 2008

    PubMed Central

    Phalkey, Revati; Dash, Shisir R.; Mukhopadhyay, Alok; Runge-Ranzinger, Silvia; Marx, Michael

    2012-01-01

    Background Early detection of an impending flood and the availability of countermeasures to deal with it can significantly reduce its health impacts. In developing countries like India, public primary health care facilities are frontline organizations that deal with disasters particularly in rural settings. For developing robust counter reacting systems evaluating preparedness capacities within existing systems becomes necessary. Objective The objective of the study is to assess the functional capacity of the primary health care system in Jagatsinghpur district of rural Orissa in India to respond to the devastating flood of September 2008. Methods An onsite survey was conducted in all 29 primary and secondary facilities in five rural blocks (administrative units) of Jagatsinghpur district in Orissa state. A pre-tested structured questionnaire was administered face to face in the facilities. The data was entered, processed and analyzed using STATA® 10. Results Data from our primary survey clearly shows that the healthcare facilities are ill prepared to handle the flood despite being faced by them annually. Basic utilities like electricity backup and essential medical supplies are lacking during floods. Lack of human resources along with missing standard operating procedures; pre-identified communication and incident command systems; effective leadership; and weak financial structures are the main hindering factors in mounting an adequate response to the floods. Conclusion The 2008 flood challenged the primary curative and preventive health care services in Jagatsinghpur. Simple steps like developing facility specific preparedness plans which detail out standard operating procedures during floods and identify clear lines of command will go a long way in strengthening the response to future floods. Performance critiques provided by the grass roots workers, like this one, should be used for institutional learning and effective preparedness planning. Additionally each facility should maintain contingency funds for emergency response along with local vendor agreements to ensure stock supplies during floods. The facilities should ensure that baseline public health standards for health care delivery identified by the Government are met in non-flood periods in order to improve the response during floods. Building strong public primary health care systems is a development challenge. The recovery phases of disasters should be seen as an opportunity to expand and improve services and facilities. PMID:22435044

  15. Parana basin

    SciTech Connect

    Zalan, P.V.; Wolff, S.; Conceicao, J.C.J.; Vieira, I.S.; Astolfi, M.A.; Appi, V.T.; Zanotto, O.; Neto, E.V.S.; Cerqueira, J.R.

    1987-05-01

    The Parana basin is a large intracratonic basin in South America, developed entirely on continental crust and filled with sedimentary and volcanic rocks ranging in age from Silurian to Cretaceous. It occupies the southern portion of Brazil (1,100,000 km/sup 2/ or 425,000 mi/sup 2/) and the eastern half of Paraguay (100,000 km/sup 2/ or 39,000 mi/sup 2/); its extension into Argentina and Uruguay is known as the Chaco-Parana basin. Five major depositional sequences (Silurian, Devonian, Permo-Carboniferous, Triassic, Juro-Cretaceous) constitute the stratigraphic framework of the basin. The first four are predominantly siliciclastic in nature, and the fifth contains the most voluminous basaltic lava flows of the planet. Maximum thicknesses are in the order of 6000 m (19,646 ft). The sequences are separated by basin wide unconformities related in the Paleozoic to Andean orogenic events and in the Mesozoic to the continental breakup and sea floor spreading between South America and Africa. The structural framework of the Parana basin consists of a remarkable pattern of criss-crossing linear features (faults, fault zones, arches) clustered into three major groups (N45/sup 0/-65/sup 0/W, N50/sup 0/-70/sup 0/E, E-W). The northwest- and northeast-trending faults are long-lived tectonic elements inherited from the Precambrian basement whose recurrent activity throughout the Phanerozoic strongly influenced sedimentation, facies distribution, and development of structures in the basin. Thermomechanical analyses indicate three main phases of subsidence (Silurian-Devonian, late Carboniferous-Permian, Late Jurassic-Early Cretaceous) and low geothermal gradients until the beginning of the Late Jurassic Permian oil-prone source rocks attained maturation due to extra heat originated from Juro-Cretaceous igneous intrusions. The third phase of subsidence also coincided with strong tectonic reactivation and creation of a third structural trend (east-west).

  16. A review of the stratigraphy and sedimentary environments of the Karoo-aged basins of Southern Africa

    NASA Astrophysics Data System (ADS)

    Smith, R. M. H.; Eriksson, P. G.; Botha, W. J.

    1993-02-01

    The Karoo Basin of South Africa was one of several contemporaneous intracratonic basins in southwestern Gondwana that became active in the Permo-Carboniferous (280 Ma) and continued to accumulate sediments until the earliest Jurassic, 100 million years later. At their maximum areal extent, during the early Permian, these basins covered some 4.5 million km 2. The present outcrop area of Karoo rocks in southern Africa is about 300 000 km 2 with a maximum thickness of some 8000 m. The economic importance of these sediments lies in the vast reserves of coal within the Ecca Group rocks of northern and eastern Transvaal and Natal, South Africa. Large reserves of sandstone-hosted uranium and molybdenum have been proven within the Beaufort Group rocks of the southern Karoo trough, although they are not mineable in the present market conditions. Palaeoenvironmental analysis of the major stratigraphic units of the Karoo succession in South Africa demonstrates the changes in depositional style caused by regional and localized tectonism within the basin. These depocentres were influenced by a progressive aridification of climate which was primarily caused by the northward drift of southwestern Gondwana out of a polar climate and accentuated by the meteoric drying effect of the surrounding land masses. Changing palaeoenvironments clearly influenced the rate and direction of vertebrate evolution in southern Gondwana as evidenced by the numerous reptile fossils, including dinosaurs, which are found in the Karoo strata of South Africa, Lesotho, Namibia and Zimbabwe. During the Late Carboniferous the southern part of Gondwana migrated over the South Pole resulting in a major ice sheet over the early Karoo basin and surrounding highlands. Glacial sedimentation in upland valleys and on the lowland shelf resulted in the Dwyka Formation at the base of the Karoo Sequence. After glaciation, an extensive shallow sea covered the gently subsiding shelf, fed by large volumes of meltwater. Marine clays and muds accumulated under cool climatic conditions (Lower Ecca Group) including the distinctive Mesosaurus-bearing carbonaceous shales of the Whitehill Formation. Subduction of the palaeo-Pacific plate reslted in an extensive chain of mountains which deformed and later truncated the southern rim of the main Karoo Basin. Material derived from these "Gondwanide" mountains as well as from the granitic uplands to the north-east, accumulated in large deltas that prograded into the Ecca sea (Upper Ecca Group). The relatively cool and humid climate promoted thick accumulations of peat on the fluvial and delta plains which now constitute the major coal reserves of southern Africa. As the prograding deltas coalesced, fluvio-lacustrine sediments of the Beaufort Group were laid down on broad gently subsiding alluvial plains. The climate by this time (Late Permian) had warmed to become semi-arid with highly seasonal rainfall. Vegetation alongside the meander belts and semi-permanent lakes supported a diverse reptilian fauna dominated by therapsids or "mammal-like reptiles". Pulses of uplift in the southern source areas combined with possible orographic effects resulted in the progadation of two coarse-grained alluvial fans into the central parts of the basin (Katberg Sandstone Member and Molteno Formation). In the upper Karoo Sequence, progressive aridification and tectonic deformation of the basin through the late Triassic and early Jurassic led to the accumulation, in four separate depositories, of "redbeds" which are interpreted as fluvial and flood-fan, playa and dune complexes (Elliot Formation). This eventually gave way to westerly wind-dominated sedimentation that choked the remaining depositories with fine-grained dune sand. The interdune areas were damp and occasionally flooded and provided a habitat for small dinosaurs and the earliest mammals. During this time (Early Jurassic), basinwide volcanic activity began as a precursor to the break-up of Gondwana in the late Jurassic and continued until the early Cretaceous. This

  17. A Megaraptor-like theropod (Dinosauria: Tetanurae) in Australia: support for faunal exchange across eastern and western Gondwana in the Mid-Cretaceous.

    PubMed

    Smith, Nathan D; Makovicky, Peter J; Agnolin, Federico L; Ezcurra, Martín D; Pais, Diego F; Salisbury, Steven W

    2008-09-22

    The fossil record of Australian dinosaurs in general, and theropods in particular, is extremely sparse. Here we describe an ulna from the Early Cretaceous Eumeralla Formation of Australia that shares unique autapomorphies with the South American theropod Megaraptor. We also present evidence for the spinosauroid affinities of Megaraptor. This ulna represents the first Australian non-avian theropod with unquestionable affinities to taxa from other Gondwanan landmasses, suggesting faunal interchange between eastern and western Gondwana during the Mid-Cretaceous. This evidence counters claims of Laurasian affinities for Early Cretaceous Australian dinosaur faunas, and for the existence of a geographical or climatic barrier isolating Australia from the other Gondwanan continents during this time. The temporal and geographical distribution of Megaraptor and the Eumeralla ulna is also inconsistent with traditional palaeogeographic models for the fragmentation of Gondwana, but compatible with several alternative models positing connections between South America and Antarctica in the Mid-Cretaceous. PMID:18544511

  18. Hydrocarbon potential of the Lamu basin of south-east Kenya

    SciTech Connect

    Nyagah, K.; Cloeter, J.J.; Maende, A. [National Oil Corp. of Kenya, Nairobi (Kenya)

    1996-12-31

    The Lamu basin occupies the coastal onshore and offshore areas of south-east Kenya. This fault bounded basin formed as a result of the Paleozoic-early Mesozoic phase of rifting that developed at the onset of Gondwana dismemberment. The resultant graben was filled by Karroo (Permian-Early Jurassic) continental siliciclastic sediments. Carbonate deposits associated with the Tethyan sea invasion, dominate the Middle to Late Jurassic basin fill. Cessation of the relative motion between Madagascar and Africa in the Early Cretaceous, heralded passive margin development and deltaic sediment progradation until the Paleogene. Shallow seas transgressed the basin in the Miocene when another carbonate regime prevailed. The basin depositional history is characterized by pulses of transgressive and regressive cycles, bounded by tectonically enhanced unconformities dividing the total sedimentary succession into discrete megasequences. Source rock strata occur within Megasequence III (Paleogene) depositional cycle and were lowered into the oil window in Miocene time, when the coastal parts of the basin experienced the greatest amount of subsidence. The tectono-eustatic pulses of the Tertiary brought about source and reservoir strata into a spatial relationship in which hydrocarbons could be entrapped. A basement high on the continental shelf has potential for Karroo sandstone and Jurassic limestone reservoirs. Halokinesis of Middle Jurassic salt in Miocene time provides additional prospects in the offshore area. Paleogene deltaic sands occur in rotated listric fault blacks. A Miocene reef Play coincides with an Eocene source rock kitchen.

  19. Hydrocarbon potential of the Lamu basin of south-east Kenya

    SciTech Connect

    Nyagah, K.; Cloeter, J.J.; Maende, A. (National Oil Corp. of Kenya, Nairobi (Kenya))

    1996-01-01

    The Lamu basin occupies the coastal onshore and offshore areas of south-east Kenya. This fault bounded basin formed as a result of the Paleozoic-early Mesozoic phase of rifting that developed at the onset of Gondwana dismemberment. The resultant graben was filled by Karroo (Permian-Early Jurassic) continental siliciclastic sediments. Carbonate deposits associated with the Tethyan sea invasion, dominate the Middle to Late Jurassic basin fill. Cessation of the relative motion between Madagascar and Africa in the Early Cretaceous, heralded passive margin development and deltaic sediment progradation until the Paleogene. Shallow seas transgressed the basin in the Miocene when another carbonate regime prevailed. The basin depositional history is characterized by pulses of transgressive and regressive cycles, bounded by tectonically enhanced unconformities dividing the total sedimentary succession into discrete megasequences. Source rock strata occur within Megasequence III (Paleogene) depositional cycle and were lowered into the oil window in Miocene time, when the coastal parts of the basin experienced the greatest amount of subsidence. The tectono-eustatic pulses of the Tertiary brought about source and reservoir strata into a spatial relationship in which hydrocarbons could be entrapped. A basement high on the continental shelf has potential for Karroo sandstone and Jurassic limestone reservoirs. Halokinesis of Middle Jurassic salt in Miocene time provides additional prospects in the offshore area. Paleogene deltaic sands occur in rotated listric fault blacks. A Miocene reef Play coincides with an Eocene source rock kitchen.

  20. Permian Basin

    SciTech Connect

    Donaldson, D.A.

    1981-12-01

    A description of the geology of the Permian Basin of the West Texas And Southeastern New Mexico was presented. Also, a brief history of the petroleum and natural gas drilling in the region was given. It was concluded that the New Mexico portion of the Permian Basin has the greatest potential for future fuel production. During 1980, there were 646 oil well completions, and 168 dry holes were recorded in southeast New Mexico. The average total depths of new wells completed was 4,901 feet for oil wells, 8,987 feet for gas wells, and 6,250 feet for dry holes.

  1. Triassic arc-derived detritus in the Triassic Karakaya accretionary complex was not derived from either the S Eurasian margin (Istanbul terrane) or the N Gondwana margin (Taurides)

    NASA Astrophysics Data System (ADS)

    Ustaömer, Timur; Ayda Ustaömer, Petek; Robertson, Alastair H. F.; Gerdes, Axel; Zulauf, Gernold

    2014-05-01

    We present new U-Pb zircon source age data for Upper Triassic sandstones of the Istanbul Terrane (S Eurasian margin) and also for Triassic sandstones of the Taurides (N Gondwana margin). The main aim is to detect and quantify the contribution of Triassic magmatism as detritus to either of these crustal blocks. This follows the recent discovery of a Triassic magmatic arc source for the Triassic sandstones of the Palaeotethyan Karakaya subduction-accretion complex (Ustaömer et al. 2013; this meeting). Carboniferous (Variscan) zircon grains also form a significant detrital population, plus several more minor populations. Six sandstone samples were studied, two from the ?stanbul Terrane (Bak?rl?k?ran Formation of the Kocaeli Triassic Basin) and four from the Tauride Autochthon (latest Triassic Üzümdere Formation and Mid-Triassic Kas?mlar Formations; Bey?ehir region). Detrital zircon grains were dated by the laser ablation-inductively coupled plasma-mass spectrometer (LA-ICP-MS) U-Pb method at Goethe University, Frankfurt. Our results do not reveal Triassic detritus in the Üzümdere Formation. The U-Pb age of the analysed zircon grains ranges from 267 Ma to 3.2 Ga. A small fraction of Palaeozoic zircons are Permian (267 to 296 Ma), whereas the remainder are Early Palaeozoic. Ordovician grains (4%) form two age clusters, one at ca. 450 Ma and the other at ca. 474 Ma. Cambrian-aged grains dominate the zircon population, while the second largest population is Ediacaran (576 to 642 Ma). Smaller populations occur at 909-997 Ma, 827-839 Ma, 1.8-2.0 Ga and 2.4-2.6 Ga. The sandstones of the Kas?mlar Formation have similar zircon age cluster to those of the somewhat younger Üzümdere Formation, ranging from 239 Ma to 2.9 Ga. A few grains gave Anisian ages. Cambrian zircon grains are less pronounced than in the Kas?mlar Formation compared to the Üzümdere Formation. The detrital zircon record of Tauride sandstones, therefore, not indicates significant contribution of Triassic or Carboniferous (Variscan) arc sources, in marked contrast to those of the Triassic Karakaya subduction complex. In comparison, the ages of the analysed zircons in the Upper Triassic sandstones of the Istanbul Terrane range from 294 Ma to 3.1 Ga. Triassic zircons are again absent, while Variscan-aged zircons (294 to 339 Ma) dominate the zircon population. Additional zircon populations are dated at 554 to 655 Ma, 0.9 to 1.2 Ga, 1.5 Ga, 1.65 Ga, 2.0 to 2.15 and 2.5 to 2.8 Ga. The Precambrian zircon age spectra are compatible with derivation from an Avalonian/Amazonian/Baltic crustal provenance. In summary, there is no evidence in either the Triassic sandstones of the ?stanbul Terrane or of the Taurides of the Triassic magmatic arc source that dominates the Triassic Karakaya subduction-accretion complex. Where then was the source of the Karakaya arc detritus? A likely option is that the Karakaya subduction-accretion complex is an exotic terrane that was detached from a source magmatic arc and displaced to its present location, probably prior the initial deposition of the Early Jurassic cover sediments. This study was supported by TUBITAK, Project No: 111R015

  2. Sundaland basins

    NASA Astrophysics Data System (ADS)

    Hall, Robert; Morley, Christopher K.

    The continental core of Sundaland, comprising Sumatra, Java, Borneo, the Thai-Malay Peninsula and Indochina, was assembled during the Triassic Indosinian orogeny, and formed an exposed landmass during Pleistocene lowstands. Because the region includes extensive shallow seas, and is not significantly elevated, it is often assumed to have been stable for a long period. This stability is a myth. The region is today surrounded by subduction and collision zones, and merges with the India-Asia collision zone. Cenozoic deformation of Sundaland is recorded in the numerous deep sedimentary basins alongside elevated highlands. Some sediment may have been supplied from Asia following Indian collision but most was locally derived. Modern and Late Cenozoic sediment yields are exceptionally high despite a relatively small land area. India-Asia collision, Australia-SE Asia collision, backarc extension, subduction rollback, strike-slip faulting, mantle plume activity, and differential crust-lithosphere stretching have been proposed as possible basin-forming mechanisms. In scale, crustal character, heat flow and mantle character the region resembles the Basin and Range province or the East African Rift, but is quite unlike them in tectonic setting. Conventional basin modeling fails to predict heat flow, elevation, basin depths and subsidence history of Sundaland and overestimates stretching factors. These can be explained by interaction of a hot upper mantle, a weak lower crust, and lower crustal flow in response to changing forces at the plate edges. Deformation produced by this dynamic model explains the maintenance of relief and hence sediment supply over long time periods.

  3. Correlation between plate motions and tectonic subsidence of sedimentary basins in Africa

    SciTech Connect

    Janssen, M.E. (Vrije Universiteit, Amsterdam (Netherlands))

    1993-09-01

    From the early Mesozoic until the Holocene, the African continent was generally in a state of extension, based on plate tectonic reconstructions and sedimentary basin subsidence studies. Beginning with the breakup of Gondwana in the Permian-Triassic, this resulted in the formation of the present-day African continental margins and a series of intracontinental rift basins, located mainly on older (late Proterozoic) shear zones. Numerous wells from marginal, as well as intracontinental rift basins, have been backstripped to elucidate their Mesozoic and Tertiary tectonic histories. They show a generally consistent patterns of subsidence and uplift phases in all basins. During the evolution of these basins, the direction of African plate motion changed several times. This was related to the differential opening of the central and south Atlantic oceans, changes in spreading rates in both the Atlantic and Indian oceans, and the collision between Africa and Europe. Episodes of compressional deformation related to these plate tectonic changes are revealed in backstripped tectonic subsidence curves.

  4. Records of Late Permian surface temperatures in continental Gondwana in isotope geochemistry of upper Permian early diagenetic calcite concretions

    SciTech Connect

    Yeman, E. (Univ. Pennsylvania, Philadelphia, PA (United States)); Kelts, K. (Univ. of Minnesota, Minneapolis, MN (United States))

    1996-01-01

    We present geochemical and isotopic evidence of paleotemperatures from freshwater continental deposits from 55[degrees]S in interior southern Gondwana. Lacustrine shales host spheroidal concretions with abundant septarian cracks. Cement carbonate varies from 65% at the centre to 15% at the edges. Cistraccide remains are preserved. Septarian calcite occurs in dull and bright bands, with three distinct generations of vein-fills. Early-formed cement both in concretions and septarian veins is magnesium-rich whereas, later-formed carbonates are pure calcite. Carbon- and oxygen-isotope ratios (PDB) are: host shales, [delta][sup 13]C= -4.36 to o.77[per thousand], [delta][sup 18]O= -12.73 to -17.12[per thousand]; concretion cements, [delta][sup 13]C=+0.26 to [delta][sup 18]O= -9.34[per thousand]; and vein-fills, [delta][sup 13]C= -7.05 to +1.09[per thousand], [delta][sup 18]O= -8.28 to -18.24[per thousand]. 13C and 18O ratios are depleted from the center of concretions to the periphery, as well as from the centre of veins to the tip. Near-surface cementation is suggested by textural evidence. [delta]18O in the range of -12.636[per thousand] to -8.989 SMOW is calculated for the meteoric palaeowaters, from which average annual surface temperatures of 5-8[degrees]C are inferred. [delta]18O of early-formed cements also yields a mean annual surface temperature of 2-6[degrees]C. Based on continentality and palaeolatitudes of northern Malawi during the Late Permian, we propose that mean annual surface palaeotemperatures may have been as high as 10[degrees]C, similar to those found in modern continental temperate climates.

  5. Records of Late Permian surface temperatures in continental Gondwana in isotope geochemistry of upper Permian early diagenetic calcite concretions

    SciTech Connect

    Yeman, E. [Univ. Pennsylvania, Philadelphia, PA (United States); Kelts, K. [Univ. of Minnesota, Minneapolis, MN (United States)

    1996-12-31

    We present geochemical and isotopic evidence of paleotemperatures from freshwater continental deposits from 55{degrees}S in interior southern Gondwana. Lacustrine shales host spheroidal concretions with abundant septarian cracks. Cement carbonate varies from 65% at the centre to 15% at the edges. Cistraccide remains are preserved. Septarian calcite occurs in dull and bright bands, with three distinct generations of vein-fills. Early-formed cement both in concretions and septarian veins is magnesium-rich whereas, later-formed carbonates are pure calcite. Carbon- and oxygen-isotope ratios (PDB) are: host shales, {delta}{sup 13}C= -4.36 to o.77{per_thousand}, {delta}{sup 18}O= -12.73 to -17.12{per_thousand}; concretion cements, {delta}{sup 13}C=+0.26 to {delta}{sup 18}O= -9.34{per_thousand}; and vein-fills, {delta}{sup 13}C= -7.05 to +1.09{per_thousand}, {delta}{sup 18}O= -8.28 to -18.24{per_thousand}. 13C and 18O ratios are depleted from the center of concretions to the periphery, as well as from the centre of veins to the tip. Near-surface cementation is suggested by textural evidence. {delta}18O in the range of -12.636{per_thousand} to -8.989 SMOW is calculated for the meteoric palaeowaters, from which average annual surface temperatures of 5-8{degrees}C are inferred. {delta}18O of early-formed cements also yields a mean annual surface temperature of 2-6{degrees}C. Based on continentality and palaeolatitudes of northern Malawi during the Late Permian, we propose that mean annual surface palaeotemperatures may have been as high as 10{degrees}C, similar to those found in modern continental temperate climates.

  6. The Mississippian Pedroches Basin: A failed attempt to propagate a Palaeotethys Arm across Southern Iberia?

    NASA Astrophysics Data System (ADS)

    Armendáriz, Maider; Quesada, Cecilio; Rosales, Idoia

    2013-04-01

    The Pedroches basin, straddling the boundary between the Ossa Morena (OMZ) and the Central Iberian (CIZ) zones of the Iberian Massif, forms one of the largest exposures of Mississippian rocks in the Iberian Peninsula. With the only exception of transitional facies near the northern and southern margins, the basin fill mostly consists of volcanic and sedimentary rocks deposited in relatively shallow continental shelf environments, in which storm activity was the main process of sediment supply and dispersal. Significantly, the Pedroches basin is split into several compartments (structural units), among which three syn-sedimentary, sigmoidal shape igneous belts, produced the most severe facies, structural and palaeogeographic changes. Owing to its timing of formation during the period of Variscan convergence, its location within an area undergoing active Variscan deformation, and the fact that the basin fill was itself affected by the Variscan orogeny, the Pedroches basin was considered a typical example of a syn-orogenic, peripheral foreland basin. Recent stratigraphical, sedimentological and isotope geology work has allowed a reinterpretation of the basin fill, in which two different sequences may be distinguished, with distinct tectono-stratigraphic significance. Above a basal conglomerate, the several hectometres thick lower part of the basin fill succession shows the highest variability among the various structural units in terms of lithology, facies and thickness. Most volcanic rocks are located within this lower part, within and in between the igneous belts, suggesting the important role of lithosphere-through, extension-related faulting in the origin of the basin. Significant across-strike thickness changes attest for syn-sedimentary horst and graben formation at this stage. On the contrary, the upper part of the basin fill is very similar in all units and corresponds to flyschoid greywacke-mudstone alternations (Culm facies). The change between the lower and the upper parts of the basin fill is interpreted as evidence for a transition from an overall extensional (transtensional?) regime during basin generation to an overall transpressional one, during which the basin was transformed into a sort of peripheral foreland basin and inverted soon after. A possibility opened to further research, here outlined as a provocative hypothesis, is that during the Variscan collision between Laurussia and Gondwana the latter might have been pushed southeastwards and eventually collided with a Palaeotethys spreading ridge or, perhaps, a branch departing from it. In this context, the first part of the evolution of the Pedroches basin could in fact be the consequence of a combination of both transtension and the overriding of a slab window developed as a result of ridge-trench collision, itself inducing rifting in the upper (Iberian) plate. Final collision of the southern margin of the OMZ (south Iberian part of Gondwana) with Laurussia by the late Viséan, which culminated the closure of this part of the Rheic Ocean, imposed a change to more orthogonal strain conditions that may have caused the abortion of the propagating rift and also triggered subsequent basin inversion.

  7. Rugose corals at the Tournaisian-Viséan transition in the Central Taurides (S Turkey) - Palaeobiogeography and palaeoceanography of the Asian Gondwana margin

    NASA Astrophysics Data System (ADS)

    Denayer, Julien

    2015-02-01

    This paper gives the first taxonomic description of the Upper Tournaisian-Lower Viséan rugose coral fauna of the Yaricak Formation (Aladag Unit, Central Taurides, South Turkey). Fifteen species belonging to twelve genera were identified, one species is newly described: Eokoninckocarinia gemmina. The corals are stratigraphically distributed in four assemblages. The two typical assemblages of the Upper Tournaisian are composed of widely distributed taxa (Uralinia, Caninia, Proheterelasma, Zaphrentites). The assemblage crossing the Tournaisian-Viséan boundary is characterized by Eurasian and cosmopolitan and widely distributed taxa (Calmiussiphyllum, Siphonophyllia, Bifossularia Amygdalophyllum, Caninophyllum, Keyserlingophyllum) and Asian taxa (Kueichouphyllum). The youngest assemblage, dominated by Eokoninckocarinia gemmina sp. nov., has yielded foraminifers Moliniacian (Lower Viséan) in age. These assemblages form a low diversity level-bottom community which is typical of the South Palaeotethys 'Kueichouphyllum Zone' extending along the Asian margin of Gondwana (Cimmerian Terrane) during Lower Carboniferous times. As in the other Cimmerian blocks, all the corals are solitary and colonial taxa are virtually absent. This absence is tentatively explained by the high palaeolatitude (c. 50°S) position of the Cimmerian Terrane in the southern part of the Palaeotethys Ocean for this time slice. A cold-water palaeo-current running eastward along the Gondwana margin might also be considered as it possibly could explain the wide distribution of the Kueichouphyllum fauna, restricted east of Africa in the southern coast of the Palaeotethys. Palaeoceanography, palaeoclimate and facies issues are discussed as possible causes of the diversity gradient observed between the eastern (Australia, Malaya) and the western (North Africa) margin of the Gondwana.

  8. Upper Devonian microvertebrates from the Canning Basin, Western Australia

    NASA Astrophysics Data System (ADS)

    Roelofs, Brett; Playton, Ted; Barham, Milo; Trinajstic, Kate

    2015-03-01

    A diverse microvertebrate fauna is described from the Virgin Hills and Napier formations, Bugle Gap Limestone Canning Basin, Western Australia. Measured sections at Horse Spring and Casey Falls (Virgin Hills Formation) and South Oscar Range (Napier Formation) comprise proximal to distal slope carbonates ranging in age from the Late Devonian Frasnian to middle Famennian. A total of 18 chondrichthyan taxa are identified based on teeth, including the first record of Thrinacodus tranquillus, Cladoides wildungensis, Protacrodus serra and Lissodus lusavorichi from the Canning Basin. A new species, Diademodus dominicus sp. nov. is also described and provides the first record of this genus outside of Laurussia. In addition, the upper range of Australolepis seddoni has been extended to Late Devonian conodont Zone 11, making it the youngest known occurrence for this species. The Virgin Hills and Napier formations microvertebrate faunas show close affinities to faunas recovered from other areas of Gondwana, including eastern Australia, Iran, Morocco and South China, which is consistent with known conodont and trilobite faunas of the same age.

  9. The first stages of evolution of the Western Somali Basin

    NASA Astrophysics Data System (ADS)

    Labails, Cinthia; Gaina, Carmen; Skogseid, Jakob; Pilskog, Bjørn; Graue, Knut

    2010-05-01

    The rifted and transform margins created by the separation of Madagascar and Africa offer an opportunity to jointly investigate the structural and geodynamic evolution of conjugate continental passive margins. It is generally accepted that the continental breakup of Gondwana in the East African region began with the onset of the southward drift of Madagascar (then connected with Antarctica and India) along the Davie Fracture Zone probably during the Middle Jurassic, and subsequently led to the opening of the western Somali Basin. Although published kinematic models are able to explain and date some of the broad scale features of the Somali and Mozambique oceanic basins, the exact timing of rifting, the early stages of seafloor spreading and the timing of seafloor cessation in the western Somali Basin remain debatable. Our new study aims to investigate the relationship between the long history of rifting along the East African margins and the breakup structures by constructing a consistent database that contains structural elements and information about their evolution from updated published literature. Next, a thorough investigation of the potential field data (magnetic and gravity anomalies) is undertaken in order to establish the structure (and possibly timing) of the early seafloor spreading. An analysis of multichannel seismic reflection, gravity, magnetic and bathymetric datasets is aimed to identify deep crustal structure and continent-ocean transition zone in the study area. We present preliminary results showing the evolution of the East African margin (along Somali and Mozambique basins), the location of the transition zone between the continental and oceanic crust, and a regional kinematic analysis of the Jurassic-mid Cretaceous tectonic events.

  10. Control of deep lithospheric roots on crustal scale GOCE gravity and gradient fields evident in Gondwana reconstructions

    NASA Astrophysics Data System (ADS)

    Braitenberg, Carla; Mariani, Patrizia

    2015-04-01

    The GOCE gravity field is globally homogeneous at the resolution of about 80km or better allowing for the first time to analyze tectonic structures at continental scale. Geologic correlation studies based on age determination and mineral composition of rock samples propose to continue the tectonic lineaments across continents to the pre-breakup position. Tectonic events which induce density changes, as metamorphic events and magmatic events, should then show up in the gravity field. Therefore gravity can be used as a globally available supportive tool for interpolation of isolated samples. Applying geodynamic plate reconstructions to the GOCE gravity field places today's observed field at the pre-breakup position. In order to test the possible deep control of the crustal features, the same reconstruction is applied to the seismic velocity models, and a joint gravity-velocity analysis is performed. The geophysical fields allow to control the likeliness of the hypothesized continuation of lineations based on sparse surface outcrops. Total absence of a signal, makes the cross-continental continuation of the lineament improbable, as continental-wide lineaments are controlled by rheologic and compositional differences of lithospheric mantle. It is found that the deep lithospheric roots as those found below cratons control the position of the positive gravity values. The explanation is that the deep lithospheric roots focus asthenospheric upwelling outboard of the root protecting the overlying craton from magmatic intrusions. The study is carried out over the African and South American continents. The background for the study can be found in the following publications where the techniques which have been used are described: Braitenberg, C., Mariani, P. and De Min, A. (2013). The European Alps and nearby orogenic belts sensed by GOCE, Boll. Bollettino di Geofisica Teorica ed Applicata, 54(4), 321-334. doi:10.4430/bgta0105 Braitenberg, C. and Mariani, P. (2015). Geological implications from complete Gondwana GOCE-products reconstructions and link to lithospheric roots. Proceedings of 5th International GOCE User Workshop, 25 - 28 November 2014. Braitenberg, C. (2015). Exploration of tectonic structures with GOCE in Africa and across-continents. Int. J.Appl. Earth Observ. Geoinf. 35, 88-95. http://dx.doi.org/10.1016/j.jag.2014.01.013 Braitenberg, C. (2015). A grip on geological units with GOCE, IAG Symp. 141, in press.

  11. Structure and metamorphism of the granitic basement around Antananarivo: A key to the Pan-African history of central Madagascar and its Gondwana connections

    NASA Astrophysics Data System (ADS)

    NéDéLec, Anne; Ralison, Bruno; Bouchez, Jean-Luc; GréGoire, Vincent

    2000-10-01

    The Precambrian basement of Madagascar acquired a polyphase imprint during the Pan-African orogeny. In northern central Madagascar, emplacement of stratoid alkaline granites at midcrustal depth (4-5 kbars) led to formation of a layered crust in a postcollisional extensional regime at 630 Ma (D1). Subsequently, the structures of the stratoid granites were rotated by the sinistral and transpressive E-W Antananarivo flexure (or virgation) zone (D2). East of Antananarivo the structures of the D1 layered crust and the D2 virgation are crosscut by the steeply dipping N-S foliations of the Angavo belt. Lineations gently plunging to the north attest that the Angavo belt is a major strike-slip shear zone that formed under low-pressure granulitic conditions (3 kbars, 790°C). The nearby porphyritic Carion granite was emplaced at the end of this period of N-S shearing (D3), which can thus be no younger than 530 Ma. Late-Pan-African (580-550 Ma) strike-slip motion along broadly N-S shear zones has been recognized elsewhere in Madagascar and in its Gondwana connections. Continuation of the Angavo belt as one of the high strain belts of the Arabian-Nubian Shield is discussed in the general framework of Gondwana assembly.

  12. Reassembling Gondwana: A new high quality constraint from vibroseis exploration of the sub-ice shelf geology of the East Antarctic continental margin

    NASA Astrophysics Data System (ADS)

    Kristoffersen, Yngve; Hofstede, Coen; Diez, Anja; Blenkner, Richard; Lambrecht, Astrid; Mayer, Christoph; Eisen, Olaf

    2014-12-01

    The breakup of Gondwana is manifested by coeval early Jurassic Karoo magmatism in South Africa and East Antarctica. In South Africa, the large volumes of volcanic rocks of the adjoining Lebombo and Mwenetzi-Save monoclines represent a volcanic rift margin, and in East Antarctica, a corresponding feature, the Explora Wedge is buried below sediments and floating ice shelves on the continental margin of Dronning Maud Land. We use the seismic vibrator source to explore the sub-ice geology in Antarctica, and the new seismic reflection and available regional aeromagnetic data enable us to outline a dogleg landward extent of the Explora Wedge in Dronning Maud Land. The congruent inboard wedge geometries on the two continents define a high quality constraint, which facilitate for the first time, a geologically consistent and tight reconstruction of Africa relative to East Antarctica within Gondwana. The uncertainties in correlations of major geological features (mobile belts) from one continent to the other may now be of the order of ten's of kilometers rather than hundreds of kilometers.

  13. Bathymetric and Stratigraphic Record of Gondwana Breakup from a Passive Transform Margin off the Coast of Ghana

    Microsoft Academic Search

    K. Attoh; L. Brown; J. Guo

    2001-01-01

    We have reprocessed and interpreted multichannel seismic reflection data off the coast of Ghana that probe the prominent Romanche fracture zone of the Equatorial Atlantic and sedimentary basins of the Ghana transform margin. The stacked seismic profiles reveal spectacular bathymetric expressions of the paleo-transform which marks the ocean- continent transition. The paleo-transform is revealed by submarine canyons up to 2

  14. Model a Catchment Basin

    NSDL National Science Digital Library

    The GLOBE Program, UCAR (University Corporation for Atmospheric Research)

    2003-08-01

    The purpose of this resource is to introduce what a catchment basin is and how it works. Students will make a 3-dimensional model of a catchment basin to understand how water moves through the basin and explore how water is affected when there are changes in the basin.

  15. Seismo and sequence stratigraphy of Cenozoic units of the Morondava Basin, offshore western Madagascar

    NASA Astrophysics Data System (ADS)

    Kaufmann, Dirk; Stollhofen, Harald; Klimke, Jennifer; Franke, Dieter

    2015-04-01

    The N-S trending Morondava Basin extends in width from western onshore Madagascar over about 350 km westwards to the offshore Davie Ridge in the Mozambique Channel. Although basin formation was initiated during Karoo times, the main basin evolution took place during Jurassic rifting and subsequent drifting until middle Cretaceous as a result of Gondwana breakup (Geiger et al., 2004). Contemporaneous to the separation of India and Madagascar widespread flood basalts were emplaced during the late Cretaceous (Storey et al., 1995). Present knowledge of the Morondava Basin is mainly based on outcrop studies, seismic surveys and borehole information (e.g. Geiger et al., 2004), gathered in western onshore Madagascar, although the fast majority of the basin, including its depocenter is located offshore in the Mozambique Channel, now at up to 3,500 m water depth. Almost all of the recent offshore studies of the Morondava Basin rely on industrial data but up to date publications of exploration results are generally rare and mostly anonymized. Our study aims to extend knowledge, particularly on the offshore seismic and sequence stratigraphy of the Morondava Basin. A key question is also to test the proposed tectonic stability of the Davie Ridge over the last 40 Ma. For this purpose 12 seismic profiles and bathymetric data, acquired in early 2014 by RV SONNE, are interpreted. Most of the profiles cover the distal deep marine areas of the northern Morondava Basin between the Davie Ridge and the shelf break of Madagascar. Top Cretaceous, Top Eocene, Top Oligocene, the Middle Miocene Unconformity and the Base Pliocene, are mapped as major seismic marker horizons. Especially shelf and slope sedimentary units are important resources to reconstruct the tectonostratigraphic basin evolution. At the continental slope diffuse to chaotic seismic pattern of Miocene and younger age are identified which are subdivided by laterally continuous, high frequency reflectors with a higher impedance contrast. Bounded by the Base Tertiary and the Base Pliocene these units can be used to develop and verify a sequence stratigraphic approach for the Cenozoic in the Morondava Basin. Prelimary results indicate that the major sedimentation at the continental slope moved after Early Pliocene significantly landwards. In general the thickness of post-Pliocene units increases to the east. Work in progress encompasses the application of seismo and sequence stratigraphic concept for Mesozoic sedimentary units and a correlation with other, potentially time-equivalent, basins in the area, such as the Mandawa Basin in northern Mozambique. References Geiger, M., Clark, D.N., und Mette, W., 2004, Reappraisal of the timing of the break-up of Gondwana based on sedimentological und seismic evidence from the Morondava Basin, SW Madagascar: Journal of African Earth Sciences, v. 38, p. 363-381. Storey, M., Mahoney, J. J., Saunders, A. D., Duncan, R. A., Kelley, S. P., und Coffin, M. F., 1995, Timing of Hot Spot--Related Volcanism und the Breakup of Madagascar und India: Science, v. 267, no. 5199, p. 852-855.

  16. Break-up of Gondwana and opening of the South Atlantic: Review of existing plate tectonic models

    USGS Publications Warehouse

    Ghidella, M.E.; Lawver, L.A.; Gahagan, L.M.

    2007-01-01

    each model. We also plot reconstructions at four selected epochs for all models using the same projection and scale to facilitate comparison. The diverse simplifying assumptions that need to be made in every case regarding plate fragmentation to account for the numerous syn-rift basins and periods of stretching are strong indicators that rigid plate tectonics is too simple a model for the present problem.

  17. Controls on volatile content and distribution in the continental upper mantle of Southern Gondwana (Patagonia & W. Antarctica)

    NASA Astrophysics Data System (ADS)

    Rooks, Eve; Gibson, Sally; Petrone, Chiara; Leat, Phillip

    2015-04-01

    Water content is known to affect many physical and chemical properties of the upper mantle, including melting temperature and viscosity. Water is hosted by hydrous phases, such as amphibole and phlogopite, and also by more dominant, nominally-anhydrous mantle minerals (e.g. olivine and pyroxene). The latter have the potential to incorporate hundreds of ppm of water in point defects, and may explain geophysical observations such as seismic and conductivity anomalies in the upper mantle [1]. However, the significance of the reported concentrations of H2O in nominally anhydrous minerals in mantle xenoliths is still a subject of debate primarily due to the effects of post-entrainment loss [1,2]. Unlike H2O and Li, F is less susceptible to post entrainment loss and can potentially be used to constrain the source of volatiles. We present high-precision SIMS analyses of H2O, Li and F in mantle xenoliths hosted by recently-erupted (5-10 Ka) alkali basalts from south Patagonia and the Antarctic Peninsula. These two regions formed part of the southern margin of the Gondwana supercontinent, prior to break-up, and were located above long-lived subduction zones for at least 200 M.yr., making them highly-appropriate to investigating long term evolution of the sub-continental lithospheric mantle in this setting. The xenoliths are well characterised peridotites, sourced from the off-craton spinel- and spinel-garnet facies lithospheric mantle (40-80 km). Samples are relatively dry: H2O contents of olivine span 0-49 ppm, orthopyroxene 150-235 ppm and clinopyroxene 100-395 ppm. West Antarctic samples are more hydrated than Patagonian samples, on average. These H2O concentrations fall within the global measured range for off-craton mantle minerals [4]. We attribute low H2O concentrations in olivine to diffusive loss, either by exchange with the host magma, shallow level degassing or during cooling [2]. F shows less variability than H2O and is most highly concentrated in clinopyroxenes - with one Antarctic sample (a websterite)k having abundances of up to 200 ppm. In other samples, values rarely exceed 65 ppm. F/Nd ratios of MORB are around 20.5, with arc magmas displaying higher ratios [4] and while some clinopyroxenes have similar or lower values than MORB, others show F/Nd >> 20.5, implying potential interaction with subduction-related melts. Li concentrations follow similar patterns as F in all minerals. Slightly higher average H2O and generally higher F contents in the West Antarctic lithospheric mantle correlate with other indicators of subduction-related metasomatism, and most likely reflect the closer proximity of this region to the continental margin and also a younger, shallower slab than beneath south Patagonia. Here we explore in detail correlations between H, Li, F and other tracers of mantle processes in both localities, in order to determine the primary control on volatile content in the sub-continental lithospheric mantle. [1] Peslier et al. 2006. EPSL, 242, 392-319 [2] Plank, T. et al. 2014. AGU Fall V51E-04 [3] Koga, K.T. et al. 2014. AGU Fall V51E-05 [4] Bonadiman et al. 2009., Eur. J. Mineral. 21, 637-64

  18. A Study on Ground Water Resource Management in Gondwana Formations in Western Part of West Godavari District Andhra Pradesh India

    NASA Astrophysics Data System (ADS)

    Singara, S.

    2006-05-01

    Groundwater source forms nearly fifty percent of the total irrigation in the country. With green revolution, there has been an increasing demand for water for agricultural and this led to overexploitation of groundwater resources in many parts of the state and the study area is not an exception. With the success of groundwater exploration and development through deep tube wells in the study area, the farmers plunged into hectic activity of tapping groundwater. The present study was taken up to assess to groundwater recharge and draft in the area and to suggest remedial measures to redress overexploitation condition. The study area is underlain by a vide range of geological formations from Archean to Tertiary age. Crystallines consist of two-tier setting of aquifers with weathered and fracture zones. The Gondwana formations with Sandstone, shale and clay zones form unconfined to confined aquifer system. Deccan trap basalt occurs subsurface in some parts. Crystalline aquifers are exploited through borewells with a depth range of 29 to 101.5 m. Static water levels range in depth from 2.5 and 19.27 m bgl. Their yields range from 2.53 to 19.27 m3/hr. Sedimentary aquifers are exploited through tube wells with a depth range of 18 to 293 m and static water levels range from 2.1m agl to 48.0 m bgl. Yields of the wells vary form 1.3 to 67 m3 /hr. Groundwater is lifted by monoblock pumpsets of 5 HP in some places but mostly by submersible pumpsets with 5 to 12.5 HP. The tube wells are subjected to pumping from 5 to 18 hours per day depending on availability of electricity (power supply). They are operated form 90 days to throughout the year in different places. Groundwater development in the study area shows a steady increase since 1960 with number of tube wells uniformly increasing in each decade, from an initial figure of 592 wells in 1960 to 17,173 tube wells in 2002. Crop pattern was shifted from dry crops to paddy and sugar cane as major crops and irrigated dry crops like maize, tobacco, palm oil, garden crops in minor extent and coconut was planted in large extents. Piezometric surface shows uniform gradient over the entire area indicating hydraulic continuity between different geological formations. The water budgeting was computed by using norms recommended by GEC (Ground Water Estimation Committee) of CGWB 1997, Govt. of India. For the present study, June 2000 to May 2001 period is taken as groundwater year. Groundwater recharge is calculated (formation wise) by rainfall infiltration and water table fluctuation methods, and recharge from other sources reservoirs, tanks, canals, irrigation water returns etc. the total recharge comes to be 626 MCM. Groundwater draft for irrigation and domestic purposes is found to be 994.96 MCM. Groundwater balance shows overdraft by 364.15 MCM. Well density is increased from <1/Sq. km in 60s to >30/Sq.km in 2000. Piezometric surface profiles in N-S direction also show a drop from 1960 to 2000 year by 44m. Taking into consideration, the mined water during 1990-2000, the overdraft comes to 704 MCM i.e. 70.4 MCM/year. Groundwater draft in the study area is found to be 2.85 times more than the actual requirement (342 MCM) of the crops in the area due to highly permeable sandy soils. In view of the alarming imbalance in the groundwater recharge and draft, some management practices are suggested to restore the original groundwater condition which includes proper well spacing, artificial recharge, change of cropping pattern and irrigation methods to suit to the local conditions. Quality of groundwater is suitable for drinking and agricultural purposes.

  19. Forearc basin correlations from around the Texas Orocline, New England Orogen, east Australia

    NASA Astrophysics Data System (ADS)

    Hoy, Derek; Rosenbaum, Gideon; Shaanan, Uri; Wormald, Richard

    2014-05-01

    The late Paleozoic to early Mesozoic New England Orogen occupies much of the eastern seaboard of Australia. The orogen formed by west-dipping subduction (present-day coordinates) of the paleo-Pacific plate beneath eastern Gondwana. The southern part of the orogen exhibits a series of tight bends (oroclines) that are evident in the curvature of a Devonian-Carboniferous subduction complex, in particular the forearc basin and accretionary complex. The Emu Creek Block is thought to be part of the forearc basin that is exposed in the eastern limb of the Texas Orocline, but until now the tectonostratigraphic origin of the Emu Creek Block has only been inferred from limited geological data. Here we present detrital zircon geochronology (U/Pb ICP-MS ages), a new geological map of the block, and a revised stratigraphic section. Lithological investigation of strata within the block and the age distribution of detrital zircons indicate that the sediments in the Emu Creek Block were derived from a Carboniferous magmatic arc and were most likely deposited in a forearc basin. Our new geochronological constraints indicate deposition during the late Carboniferous. We therefore propose that rocks in the Emu Creek Block are arc-distal correlatives of the forearc basin in the opposing (western) limb of the Texas Orocline, specifically the Willuri and Currabubula formations. Extensive orocline-parallel structures in the forearc basin indicate that the eastern limb of the Texas Orocline was rotated in the course of oroclinal bending by approximately 135 degrees relative to the western limb. The correlation of the forearc basin blocks on opposite limbs of the Texas Orocline provides an independent constraint on its geometry and further improves our understanding of New England Orogen tectonostratigraphy and the crustal structure of eastern Australia.

  20. Evolution of faulting and plate boundary deformation in the Southern Taranaki Basin, New Zealand

    NASA Astrophysics Data System (ADS)

    Reilly, Cathal; Nicol, Andrew; Walsh, John J.; Seebeck, Hannu

    2015-05-01

    Faulting and folding in the Southern Taranaki Basin constrain the evolution of the New Zealand plate boundary since ~ 80 Ma. Sedimentary rocks up to 8 km thick record multiple phases of deformation which have been examined using 2D and 3D seismic reflection data, resulting in fault displacement-time curves and basin-wide isopach maps with temporal resolutions of 5-10 Myr and 1-4 Myr pre- and post-~ 23 Ma respectively. Three main phases of tectonic activity have been recognised; Late Cretaceous and Palaeocene extension (~ 80-55 Ma), mainly Oligocene and younger contraction and Plio-Pleistocene (~ 3.7-0 Ma) extension. Most of the largest faults (e.g., Cape Egmont Fault) accrued displacement during the Late Cretaceous and were reactivated one or more times during subsequent episodes of deformation. The oldest phase of extension occurred during Gondwana break-up and was ubiquitous throughout the basin. Contraction along the eastern boundary of the basin, associated with the onset of Hikurangi Margin subduction, commenced as early as Late Eocene. The zone of contraction widened and migrated westward during the Miocene with reverse faults and folds in westernmost parts of the basin formed in the Late Miocene (~ 7-5 Ma). Initiation and episodic widening of this zone of contraction may have been partly triggered by changes in the rate of plate convergence. Contraction is now mainly confined to the northern South Island and has been succeeded to the north by Plio-Pleistocene extension. The present day transition zone between extension in the north and contraction in the south is defined by a WNW-trending line across the basin. The extension-contraction transition migrated southward during the Late Miocene and Pliocene consistent with steepening of the subducting plate and associated southward movement of the southern termination of the Hikurangi subduction system.

  1. 40Ar-39Ar thermochronology of the southern Gawler Craton, Australia: Implications for Mesoproterozoic and Neoproterozoic tectonics of East Gondwana and Rodinia

    NASA Astrophysics Data System (ADS)

    Foster, David A.; Ehlers, Karin

    1998-05-01

    40Ar-39Ar thermochronology of the southern Gawler Craton, Australia, reveals a protracted history of slow cooling, with local crustal heating, rapid cooling, and fault reactivation, between ˜1700 and ˜700 Ma. Hornblendes from most of the southern part of the Craton, including the Kalinjala Mylonite Zone, yield ages ˜1580-1610 Ma, with younger more discordant samples showing evidence of retrogression. These results indicate that the region cooled below ˜500°C ˜100 m.y. after the Kimban Orogeny and coincident with the Gawler Range-Hiltaba Suite magmatism, to the north, perhaps associated with postorogenic extension. Biotite and K-feldspar data indicate that regional cooling after this time was more gradual, with a few exceptions. Locally, in the southeastern Eyre Peninsula, rapid cooling at ˜1425 Ma is indicated by nearly concordant hornblende and biotite ages and may record a phase of regional extension. Other exceptions include areas of lower grade Archean rocks that cooled to <350°C by ˜1700-1640 Ma. Greenschist facies reactivation of shear zones occurred at ˜1100 Ma, during the Musgravian Orogeny, on the basis of biotite single-grain data and retrogressed amphiboles. K-feldspar age spectra record cooling at 700-800 Ma following regional intrusion of the Gairdner Dike Swarm and/or denudation during rifting along the Pacific margin of East Gondwana and breakup of Rodinia. Tectonothermal events revealed by these results, previous geochronological, and geological studies and available paleomagnetic data are comparable to other cratons and mobile belts in Australia, East Gondwana, and Laurentia, providing evidence that southeastern Australia and North America were adjacent during much of Proterozoic time.

  2. Neo-Tethyan rifting at the Indian Gondwana margin (NW Himalayas): evidence from conjugate deformation bands in the early Devonian Muth Formation

    NASA Astrophysics Data System (ADS)

    Draganits, E.; Grasemann, B.; Hager, C.

    2003-04-01

    The late Palaeozoic rifting event between northern Gondwana and the Peri-Gondwana blocks (i.e. Cimmerian micro-continents), beginning in the early Carboniferous, was the most drastic tectonic event at the former northern Indian passive margin, before the Himalayan orogeny in Tertiary time. Nevertheless, reports on deformation structures formed by the Neo-Tethys rifting event hardly exist and the event has mainly been deduced from widespread stratigraphic gaps and a prominent angular unconformity formed by the thermal uplift of the rift shoulders. Due to the dominance of deformation structures that formed during the Tertiary Himalayan orogeny, possibly existing older structures of pre-Himalayan deformation events are obscured or only fragmentary preserved. We present conjugate, cataclastic deformation bands and zones of deformation bands, which have been found in the lower Devonian Muth Formation in the Pin Valley, Tethyan Zone, NW Himalayas. As deformation bands generally form in porous sandstone and the spatial orientation of the deformation bands in the Muth Formation is different form the orientation of brittle deformation structures of the Tertiary Himalayan orogeny, a pre-Himalayan origin of these structures is concluded. The older age limit of the deformation bands is obviously constrained by the depositional age of the sediment and the younger age limit by the timing of complete cementation. Palaeostrain analysis of the conjugate deformation bands broadly indicate ESE-WNW shortening, associated with a contemporaneous N-S stretching component. The deformation bands are associated with mafic dykes related to the Neo-Tethys rifting event and they probably formed during the same deformation. Although the palaeostrain of the deformation bands is consistent with structural observations in Upper Lahaul, more data from other locations in the Tethyan NW-Himalaya are needed for a regional interpretation. Due to the peculiarities of deformation band deformation and their microstructural characteristics, they have the potential to be separated from other brittle deformation structures in complex, poly-phase orogens.

  3. Cambrian rift-related magmatism in the Ossa-Morena Zone (Iberian Massif): Geochemical and geophysical evidence of Gondwana break-up

    NASA Astrophysics Data System (ADS)

    Sarrionandia, F.; Carracedo Sánchez, M.; Eguiluz, L.; Ábalos, B.; Rodríguez, J.; Pin, C.; Gil Ibarguchi, J. I.

    2012-10-01

    Volcanic rocks of Cambrian age from Zafra (Ossa-Morena Zone, Iberian Massif) are the result of rift processes that affected Cadomian arc units accreted to the NW edge of Gondwana during the Neoproterozoic-Early Cambrian transition. Tephrite to rhyolite volcanics define an alkaline transitional association (Coombs type). Basic-ultrabasic rocks exhibit typical alkaline REE-patterns, strongly enriched in LREE with respect to HREE. Two parental magmas are identified, one with a mantle signature, lack of Nb negative anomaly and ?Nd500Ma + 3.8 to + 4.2; another with crustal contribution, minor Nb negative anomaly and ?Nd500Ma + 0.8 to + 1.8. Intermediate-acid rocks show variable REE fractionation and share geochemical characteristics of both basic-ultrabasic groups with restricted ?Nd500Ma + 2.2 to 3.1 and general absence of Nb negative anomaly. Basic-ultrabasic melts resulted from different amounts of partial melting of a homogeneous source and segregation at the garnet-spinel transition zone. We argue that the "Hales transition" recently recognized in reflection seismic experiments of SW Iberia might image such a source region. Mantle-derived magmas ponded at the base of the crust and weakly interacted with crustal rocks/melts, whilst intermediate-acid rocks were generated by plagioclase ± clinopyroxene ± amphibole fractionation. Melt ascent took place through fractures, with limited crustal interaction. Based upon the new geochemical results and complementary cartographic and geophysical data, a model is presented for the Cambrian break-up of North Gondwana due to magma ascent from the mantle.

  4. Effect of Household-Based Drinking Water Chlorination on Diarrhoea among Children under Five in Orissa, India: A Double-Blind Randomised Placebo-Controlled Trial

    PubMed Central

    Boisson, Sophie; Stevenson, Matthew; Shapiro, Lily; Kumar, Vinod; Singh, Lakhwinder P.; Ward, Dana; Clasen, Thomas

    2013-01-01

    Background Boiling, disinfecting, and filtering water within the home can improve the microbiological quality of drinking water among the hundreds of millions of people who rely on unsafe water supplies. However, the impact of these interventions on diarrhoea is unclear. Most studies using open trial designs have reported a protective effect on diarrhoea while blinded studies of household water treatment in low-income settings have found no such effect. However, none of those studies were powered to detect an impact among children under five and participants were followed-up over short periods of time. The aim of this study was to measure the effect of in-home water disinfection on diarrhoea among children under five. Methods and Findings We conducted a double-blind randomised controlled trial between November 2010 and December 2011. The study included 2,163 households and 2,986 children under five in rural and urban communities of Orissa, India. The intervention consisted of an intensive promotion campaign and free distribution of sodium dichloroisocyanurate (NaDCC) tablets during bi-monthly households visits. An independent evaluation team visited households monthly for one year to collect health data and water samples. The primary outcome was the longitudinal prevalence of diarrhoea (3-day point prevalence) among children aged under five. Weight-for-age was also measured at each visit to assess its potential as a proxy marker for diarrhoea. Adherence was monitored each month through caregiver's reports and the presence of residual free chlorine in the child's drinking water at the time of visit. On 20% of the total household visits, children's drinking water was assayed for thermotolerant coliforms (TTC), an indicator of faecal contamination. The primary analysis was on an intention-to-treat basis. Binomial regression with a log link function and robust standard errors was used to compare prevalence of diarrhoea between arms. We used generalised estimating equations to account for clustering at the household level. The impact of the intervention on weight-for-age z scores (WAZ) was analysed using random effect linear regression. Over the follow-up period, 84,391 child-days of observations were recorded, representing 88% of total possible child-days of observation. The longitudinal prevalence of diarrhoea among intervention children was 1.69% compared to 1.74% among controls. After adjusting for clustering within household, the prevalence ratio of the intervention to control was 0.95 (95% CI 0.79–1.13). The mean WAZ was similar among children of the intervention and control groups (?1.586 versus ?1.589, respectively). Among intervention households, 51% reported their child's drinking water to be treated with the tablets at the time of visit, though only 32% of water samples tested positive for residual chlorine. Faecal contamination of drinking water was lower among intervention households than controls (geometric mean TTC count of 50 [95% CI 44–57] per 100 ml compared to 122 [95% CI 107–139] per 100 ml among controls [p<0.001] [n?=?4,546]). Conclusions Our study was designed to overcome the shortcomings of previous double-blinded trials of household water treatment in low-income settings. The sample size was larger, the follow-up period longer, both urban and rural populations were included, and adherence and water quality were monitored extensively over time. These results provide no evidence that the intervention was protective against diarrhoea. Low compliance and modest reduction in water contamination may have contributed to the lack of effect. However, our findings are consistent with other blinded studies of similar interventions and raise additional questions about the actual health impact of household water treatment under these conditions. Trial Registration ClinicalTrials.gov NCT01202383 Please see later in the article for the Editors' Summary PMID:23976883

  5. The oldest sediments of Greece revealed by detrital zircon LA-ICP-MS U-Pb dating: Cambro-Ordovician sandstones from northern Gondwana in the External Hellenides - implications on the evolution of the eastern Mediterranean

    NASA Astrophysics Data System (ADS)

    Kydonakis, Konstantinos; Kostopoulos, Dimitrios; Poujol, Marc; Brun, Jean-Pierre; Papanikolaou, Dimitrios; Paquette, Jean-Louis

    2013-04-01

    Detrital zircon U-Pb ages of a quartzite from the Feneos locality of Peloponnesus, S. Greece, were determined by LA-ICPMS. The rock classifies as a mature quartz arenite and belongs to an original shale-sandstone succession now metamorphosed into a phyllite-quartzite unit. The latter chiefly represents the External Blueschist Belt of the Hellenides widely known as the Arna or Phyllite - Quartzite (PQ) Unit. Zircon age clusters at 0.5-0.75, 0.85, 0.95-1.1, 1.75-2 and 2.4-3 Ga point at the Saharan Metacraton and the Transgondwanan Supermountain as contributing sources; the youngest concordant grain is 522 Ma old. Based on great similarities in lithology, zircon age-distribution patterns and depositional setting between the Feneos quartzite and intact Cambro-Ordovician sandstone-shale sequences of Libya (Murzuq and Kufrah basins) we propose that the protolith of the former was deposited in an epeiric sea north of Libya during the Cambro-Ordovician. Feneos, as part of the Cimmerian block, had become detached from the NE Gondwanan margin during Late Carboniferous - Early Permian times and drifted northward. In central Crete, similar-looking sequences (Galinos beds) were originally deposited in an accretionary/fore-arc complex outboard of the south Laurussian active margin (Pelagonia) between ~297-230 Ma. The southern Pelagonian margin eventually collided (mild docking) with the northward drifting Cimmerian block signaling the closure of Palaeotethys by early Late Triassic. The Gondwanan affinity of the Feneos quartzite strongly contrasts the European one of the Galinos beds; the suture of Palaeotethys can thus be traced in S. Greece within the pre-Triassic sedimentary sequences of Peloponnesus and Crete. In the eastern Mediterranean realm, rocks with similar age clusters crop out in Greece (Peloponnesus, this study; eastern Crete, Sfaka locality; north-central Macedonia, Vertiskos terrane), NW Turkey (central Sakarya terrane), Libya (Murzuq and Kufrah basins), Israel (Elat locality) and Jordan (El-Quweira locality). Their zircon age spectra plotted with respect to sediment depositional age indicate a collisional margin setting for all. Evaluating the depositional setting of the arguably similar sedimentary sequences above we demonstrate their common provenance from the Gondwana Super-fan System which draped the northern Gondwanan periphery from ~525 to 460 Ma (Lower Cambrian - Middle Ordovician). Using as anchoring points the non-metamorphosed Early Palaeozoic outcrops of Libya and the Middle East that remained intact at their original deposition sites we have traced, in space and time, the path of the remainder time- and facies-equivalent rocks presently cropping out in the Hellenic and Turkish mountain belts. The fate of the northern Gondwanan margin was multiple rifting and travelling of the fragments thereof throughout the Palaeozoic before their final incorporation into younger orogenic belts.

  6. Water Basins Civil Engineering

    E-print Network

    Provancher, William

    Water Basins Civil Engineering Objective · Connect the study of water, water cycle, and ecosystems with engineering · Discuss how human impacts can effect our water basins, and how engineers lessen these impacts: · The basic concepts of water basins are why they are important · To use a topographic map · To delineate

  7. Climate Change Impacts on Water Resources in Mahanadi River basin (India)

    NASA Astrophysics Data System (ADS)

    Lilhare, R.; Mishra, V.

    2014-12-01

    Streamflow estimation using hydrological modeling and assessing the impact of climate change on it can increasingly help in dealing with the challenges that water resource managers and planners. In the present study, continuous distributed hydrological model named Soil and Water Assessment Tool (SWAT) is used for streamflow estimation at five gauging stations within Mahanadi river basin, Orissa, India. Further streamflow response to climate change has been examined. For this, the SWAT model has been first calibrated and validated for the period of 1951-2007. Then, with the aim of evaluating the impact of climate change on the basin hydrology for the period of 2010-2099, downscaled and bias corrected data from the CMIP5 (Coupled Model Intercomparison Project) models (i.e. bcc-csm1-1, inmcm4, mpi-esm-Ir, mri-cgcm3 and noresm1-m) under the RCP 4.5 and RCP 8.5 scenarios were used to derive the SWAT model. We find that streamflow variations are more sensitive to changing climate in the monsoon (JJAS) and pre-monsoon (FMAM) seasons than that of the post-monsoon season. Moreover, simulated runoff for the projected period (2010-2099) was found to be changing in a range of -17 to 59% in the monsoon, -18 to 65% in the post-monsoon, -76 to 451% in pre-monsoon under the RCP 4.5 scenario and for the RCP 8.5 streamflow changes have been assessed between -5 to 107% in monsoon, -0.45 to 105% in post-monsoon, -61 to 202% in pre-monsoon period. Keywords: SWAT; Climate Change; CMIP; RCP; Mahanadi

  8. Divergent/passive margin basins

    SciTech Connect

    Edwards, J.D. (Shell Oil Company (US)); Santogrossi, P.A. (Shell Offshore Inc. (US))

    1989-01-01

    This book discusses the detailed geology of the four divergent margin basins and establishes a set of analog scenarios which can be used for future petroleum exploration. The divergent margin basins are the Campos basin of Brazil, the Gabon basin, the Niger delta, and the basins of the northwest shelf of Australia. These four petroleum basins present a wide range of stratigraphic sequences and structural styles that represent the diverse evolution of this large and important class of world petroleum basins.

  9. Upper Cisuralian palynology and palaeoclimate of Manuguru area Godavari basin, India and their global correlation

    NASA Astrophysics Data System (ADS)

    K, Pauline Sabina; Jha, Neerja

    2014-10-01

    The Permian system of the Palaeozoic Erathem is divided into three series, the Early Permian Cisuralian Series, the Middle Permian Guadalupian Series, and the Late Permian Lopingian Series. The Cisuralian Series encompasses the Asselian to Kungurian stages which constitute the basal part of the Gondwana supersequence I. In India, they are represented lithostratigraphically by the Talchir, Karharbari, and Barakar formations. This paper presents the palynological results from the Barakar Formation of the Upper Cisuralian Series from Manuguru which lies in the southeastern part of the Godavari basin. The succession studied comprises 35 subsurface samples from bore hole 1007 represented by clay, shale, sandstone, and coal. The palynofloras in this sequence have a homogenous composition demonstrating that not many significant floral changes took place through the considered stratigraphic range. The entire sequence is characterized by the dominance of nonstriate bisaccate genus Scheuringipollenites and sub-dominance of striate bisaccate genus Faunipollenites(= Protohaploxypinus). The other pollen genera among the nonstriate bisaccates are Rhizomaspora, Primuspollenites, Ibisporites, and Platysaccus. The striate bisaccates include Striatites, Striatopodocarpites, and Stroterosporites. The taeniate taxa are represented by Lueckisporites and Lunatisporites. The common monosaccate genera include Caheniasaccites, Potoniesporites, and Barakarites. Spores are less common and include Latosporites, Brevitriletes, Horriditriletes, Microbaculispora, and Callumispora. They characterize the palynofloral composition of the Lower Barakar Formation. The correlation of this assemblage with some of the biostratigraphic palynozones proposed previously for the Cisuralian sequences of the Paraná Basin of South America, Kalahari Karoo Basin of South Africa, Ruhuhu Basin of Tanzania, East Africa as well as palynoassemblages from South Victoria Land and Dronning Maud Land, Antarctica and Collie Basin of west Australia point out to their Early Permian (Late Sakmarian-Early Artinskian) age. Palynomorphs such as Botryococcus sp., Tetraporinia sp., Balmeela sp. and Leiosphaeridia sp. are also recorded which suggest that these sediments were deposited during post-glacial near shore, cool and humid environment.

  10. Santa Barbara Basin Los Angeles Basin

    E-print Network

    Einat, Aharonov

    of Groundwater Salinity Seawater Intrusion Mixing with Basinal Brines Dissolution of Evaporites Evaporation ca. 2:1 slope Ca-Enrichment Mineral Buffering Hanor (2006) #12;McIntosh and Walter (2005) Subglacial

  11. Palaeoenvironmental and geochemical approach of Archaeocyath-rich facies from Lower Cambrian of Western Gondwana margin at Central Iberian Zone (Urda, Toledo Mountains, Spain)

    NASA Astrophysics Data System (ADS)

    Menéndez, Silvia; Rodríguez-Martínez, Marta; Moreno-Eris, Elena; Perejón, Antonio; Reitner, Joachim

    2010-05-01

    Archaeocyath-rich facies are located in a quarry close to Urda village, at Toledo Mountains, Spain. The outcrops belong to the Caliza de los Navalucillos Formation and they record a considerably high diverse archaeocyath assemblage in the Lower Cambrian successions from the Central Iberian Zone (Julivert et al. 1972 [1974]). In fact, it is first time recorded the presence of Agyrekocyathus, Dokidocyathus, and Plicocyathus in the Central Iberian Zone. Therefore Plicocyathus is no longer exclusive to biozone VI in Spain. The presence of Anthomorpha is characteristic for the early Botomian, presently early Stage 4 (ICS, 2009), and the assemblage corresponds to the biozone VII (late Ovetian, following the biozonation of Perejón & Moreno-Eiris, 2006). The fossiliferous part of the succession is formed by seven lithofacies, all of them tectonically folded and with a low grade metamorphic overprint. They are comprised by two main groups of facies: (a) mound-shaped to massive lithofacies (A1, A2, A3, A4) and (b) massive to bedded and nodular lithofacies (B1, B2, B3). Archaeocyaths occur in several facies: (A1) mound-shaped white marble with irregular to stromatactoid cavities; (A2) massive mottled white to grey limestone; (A3) massive grey limestone with slumps levels; (A4) massive archaeocyath-rich orange limestone; as well as in carbonate nodules embedded in siltstones and cherts (B1, B2 and B3). The best preserved assemblage comes from the nodule record, where fossils are partially pyritized. This type of preservation is exceptional and has never been described before. XRD and wavelength-dispersive electron microprobe analyses reveal the presence of pyrite and pyrrotine partially altered to iron oxides and hydroxides (hematite and goethite) surrounding the archaeocyath cups. In Central Iberian Zone, the development of mounds and nodular facies like those described here is unusual, although the Botomian marks the peak for Early Cambrian archaeocyathan-microbial mounds in Western Gondwana margin. Powdered microsamples have been analysed for their elemental and isotopic composition (?13C values range from + 0.41 to + 3.05). Sulphur minerals and silicates where analyzed with XRD and wavelength-dispersive electron microprobe. Major elements were measured with ICP-OES and minor and trace elements were analyzed with ICP-MS. These are the first palaeontological, sedimetological, geochemical and isotopical data provided to reconstruct the depositional environment of these Archaeocyath-rich facies at the Western Gondwana margin. References Julivert, M., Fontboté, J.M., Ribeiro, A., Nabais Conde L.E. 1972. Mapa tectónico de la Península Ibérica y Baleares, Escala 1: 1.000.000, Memoria Explicativa [1974], 113 pp. Instituto Geológico y Minero de España. Perejón, A., Moreno-Eiris, E. 2006. Biostratigraphy and palaeobiography of the archaeocyaths on the south-western margin of Gondwana. Zeitschrift der Deutschen Gesellschaft für Geowissenschaften 157 (4): 611-627.

  12. BASINS 2.0

    NSDL National Science Digital Library

    1998-01-01

    The Environmental Protection Agency (EPA) first created BASINS (Better Assessment Science Integrating Point and Nonpoint Sources) in 1996 as an aid to water resource planners concerned with water quality and watershed analyses. The strength of BASINS is its integration of "a geographic information system (GIS), national watershed data, and state-of-the-art environmental assessment and modeling tools." The updated version of the program, BASINS 2, can be downloaded from this site.

  13. The Heidelberg Basin Drilling Project — basin analysis

    NASA Astrophysics Data System (ADS)

    Tanner, David C.; Martini, Nicole; Buness, Hermann; Gabriel, Gerald; Krawczyk, Charlotte M.

    2010-05-01

    Within the context of the Heidelberg Basin Project (Gabriel et al. 2008), we present the first results of three-dimensional structural modelling of the basin, based on interpretation of reflection seismics and decompaction using porosity data measured from core material. Firstly, we interpreted six horizons (Base Quaternary, Internal and Base Pliocene, Base Upper Miocene, Internal and Base Mid Miocene Hydrobien beds) from all available industrial (ca. 100 km) and our own reflection seismic sections (ca. 15 km), which lie within a 8 km radius around the Heidelberg UniNord 1/2 boreholes. This data was used to construct a three-dimensional geometrical model of the Heidelberg Basin. Using 300 core samples, we determined the porosity of the Quaternary sediments and constructed an exponential porosity/depth relationship for these rocks, which were then attributed to the model. Lower strata were given values from the literature. The model shows that the Heidelberg basin has a N-S and E-W areal extent of only 10 × 6 km, directly abutting the eastern fault boundary of the Upper Rhine Graben. The strongest synsedimentary tectonic subsidence occurred during the Upper Miocene, Upper Pliocene, and Quarternary. Faults are not seen within the basin at this level, but a NW-SE striking strike-slip structure is recorded to the west of the basin. Furthermore, the sedimentary depocentre shifted 2 km northwards over time to the present location, directly below the city of Heidelberg. We determined that Quaternary sediments have porosities of over 60% at the surface, but at the Base Quaternary porosity is less than 35%. This strong decrease means that 740 m of sediments were compacted to produce the present ca. 500 m thickness of Quaternary strata. Gabriel, G., Ellwanger, D., Hoselmann, C. & Weidenfeller, M. (2008): The Heidelberg Basin Drilling Project. -- Quaternary Science Journal, 57, 3-4, 253-260.

  14. Magnetic Fabric of the Itararé Group, Paraná Basin Brazil: Preliminary Results

    NASA Astrophysics Data System (ADS)

    Raposo, M. B.; Bilardello, D.; Santos, P. R.

    2012-12-01

    The late Paleozoic Itararé Group and equivalent beds in the Paraná Basin of Brazil extend into Paraguay, Argentina, and Uruguay. The Itararé Group contains the most extensive lithological record of Gondwana glaciation in the world. The succession has a maximum subsurface thickness of around 1400 m and extends over a total area greater than 1 million km2. The lower boundary of the Itararé Group is nonconformable with Precambrian to early Paleozoic crystalline basement and with Devonian strata of the Furnas and Ponta Grossa Formations, which together constitute the base of the Gondwana supersequence of the Paraná Basin. This boundary encompasses a hiatus that is loosely estimated in 45 Ma. The upper contact with the overlying Rio Bonito Formation is described as conformable to partially erosional. We performed our study on 13 sites from sedimentary rocks (sandstones and siltites) from the Itararé beds in the Brazilian portion of the Paraná Basin (mainly in São Paulo State). Magnetic fabrics were determined on oriented cylindrical specimens (2.54 cm x 2.2 cm) using the anisotropy of low-field magnetic susceptibility (AMS). Rock-magnetic analyses reveal that magnetite is the main magnetic mineral. In one of the sampled site, however, the ferromagnetic minerals are both magnetite and hematite. Regarding the eingenvector orientations, the sites usually gave good results. The analysis at the individual-site scale defines three AMS fabric types. The first type (7 sites) shows Kmin perpendicular to the bedding plane while Kmax and Kint are scattered within the bedding plane itself. This fabric is usually interpreted as primary (sedimentary-compactional), typical of undeformed sediments. The second type (5 sites) shows good clustering of the AMS principal axes with Kmin still sub-perpendicular to the bedding plane. The third type, pertaining to an intensely folded site previously interpreted as slumped, is characterized in geographic coordinates by well-clustered Kmax in the bedding plane, while Kmin and Kint are distributed along a NE-SW girdle with a sub-vertical, yet elongate Kmin distribution. In stratigraphic coordinates Kmax maintains the same NNW-SSE clustering, yet Kmin and Kint become scattered within the girdle. The second fabric type would be interpreted as combination of sedimentary-compactional and tectonic contributions if some strain markers or evidence for tectonic deformation had been found in the studied area. On the other hand, the tight Kmax grouping in this fabric type could be explained by the action of currents since they cause Kmax to be aligned sub-parallel to the paleocurrent direction.

  15. Geysers: Lower Geyser Basin

    NSDL National Science Digital Library

    Yellowstone National Park

    This Yellowstone National Park web site is dedicated to Lower Geyser Basin. It includes images and descriptions of Queen's Laundry and Sentinel Meadows, Sentinel Cone, Ojo Caliente, Pocket Basin Mud Pots, Imperial Geyser, Spray Geyser, Octopus Spring, Great Fountain Geyser, White Dome Geyser, Pink Cone Geyser, Bead Geyser, Narcissus Geyser, Steady Geyser, Silex Spring, Fountain Paint Pot, Fountain Geyser, Clepsydra Geyser, and Jelly Geyser.

  16. ROANOKE RIVER BASIN DATA

    EPA Science Inventory

    Data files for the Roanoke River Basin provided for use with the Roanoke River Basin Reservoir Model. Includes data on daily pan evaporation, monthly water usage and daily inflow. (see http://www.dwr.ehnr.state.nc.us/roanoke/index.htm)...

  17. Anomalous electrical structure in the northwestern Paraná Basin, Brazil, observed with broadband magnetotellurics

    NASA Astrophysics Data System (ADS)

    Bologna, Mauricio S.; Nunes, Higo O.; Padilha, Antonio L.; Vitorello, Ícaro; Pádua, Marcelo B.

    2013-03-01

    The deep structure of the northern part of the Paraná Basin has been investigated through the analysis of a SW-NE magnetotelluric (MT) profile composed of 24 broadband stations with periods from 0.001 to ˜1000 s that are regularly spaced ˜10 km apart. The SW portion of the profile crosses a negative Bouguer anomaly with amplitudes of ˜20 mGal. Our analyses show that there are two lithospheric domains with different gravity and electric conductivity properties. In the regularized two-dimensional MT inversion model the mid-to-lower crust in the SW part of the profile is almost two orders in magnitude more conductive compared to the NE portion. This difference in conductivity extends to the uppermost mantle depths, suggesting the existence of a major lithospheric discontinuity in the north-central Paraná Basin, locally coincident with the position of the Aporé River. We interpret this discontinuity as a juxtaposition of terranes with distinct natures and ages, possibly as result of tectonic accretion during the formation of Western Gondwana.

  18. Leaiid conchostracans from the uppermost Permian strata of the Paraná Basin, Brazil: Chronostratigraphic and paleobiogeographic implications

    NASA Astrophysics Data System (ADS)

    Ferreira-Oliveira, Luis Gustavo; Rohn, Rosemarie

    2010-03-01

    Conchostracan fossils are abundant and relatively diversified in the Rio do Rasto Formation (Passa Dois Group, Paraná Basin, southern Brazil), but leaiids (' Leaia pruvosti' [Reed, F.R.C., 1929. Novos Phyllopodos Fósseis do Brasil. Boletim do Serviço Geológico e Mineralógico do Brasil 34, 2-16]) were previously found at only one locality of the formation in the northern Santa Catarina State. New specimens of the Family Leaiidae, collected from two outcrops in central Paraná State near the top of the formation, stimulated a revision of related taxa. Both the new and the previously known leaiids are herein assigned to Hemicycloleaia mitchelli [Etheridge Jr., R., 1892. On Leaia mitchelli Etheridge. Proceedings of the Linnean Society of New South Wales 7, 307-310] based on the presence of three carinae and subovate shape. This species was originally recorded in the upper Tatarian (Wuchiapingian, Late Permian) of Sydney Basin, eastern Australia and therefore corroborates the interpretation that the leaiid bearing strata of the Rio do Rasto Formation cannot be younger than Permian. H. mitchelli possibly was one of the most widespread, eurytopic and conservative Late Paleozoic conchostracans of Gondwana (although records from Africa, India and Antarctica must still be confirmed) and it was also found in the Tatarian of Russia. The sudden disappearance of leaiids after their apparent success is consistent with the hypothesis about the biotic crisis around the Permo-Triassic boundary.

  19. Refined stratigraphy of the Middle Permian Abrahamskraal Formation (Beaufort Group) in the southern Karoo Basin

    NASA Astrophysics Data System (ADS)

    Jirah, Sifelani; Rubidge, Bruce S.

    2014-12-01

    Fluvially deposited rocks of the Abrahamskraal Formation of the lower Beaufort Group in the South African Karoo record sediment deposition during the Middle Permian, the earliest terrestrial environment of Gondwana. A rich diversity of fossil tetrapods from this Formation provides a unique opportunity for understanding Middle Permian biodiversity changes in Gondwanan terrestrial ecosystems, but this is dependent on the existence of a robust stratigraphic framework that has been hampered by lack of lateral continuity of lithological markers combined with structural complexities relating to formation of the Cape Fold Belt. Because the Abrahamskraal Formation covers a large geographic area of the main Karoo Basin previous stratigraphic studies have been undertaken over large areas. This study combines geology and palaeontology to refine the stratigraphy of the Abrahamskraal Formation in a part of the southwestern Karoo Basin and revealed mappable lithological units with lateral continuity throughout the study area. The measured stratigraphic section manifests a total thickness of 2565 m for the Formation (the thickest occurrence of the Abrahamskraal Formation in the Beaufort Group). For the first time stratigraphic ranges of biostratigraphically important Middle Permian index taxa which have restricted stratigraphic ranges have been determined and, apart from dicynodonts, include the parareptile Eunotosaurus and the biarmosuchid therapsid Hipposaurus. The Abrahamskraal Formation comprises a 1104 m thick basal Eodicynodon Assemblage Zone, overlain by a 1441 m thick Tapinocephalus Assemblage Zone whose upper limit is 20 m below the Poortjie Member of the Teekloof Formation.

  20. Stratigraphy and reservoir potential of glacial deposits of the Itarare Group (Carboniferous-Permian), Parana basin, Brazil

    SciTech Connect

    Franca, A.B. (Petrobras/Depex/Nexpar, Curitiba (Brazil)); Potter, P.E. (Univ. of Cincinnati, OH (United States))

    1991-01-01

    Drilling in the Parana basin of Brazil in the mid-1980s discovered gas and condensate in the Itarare Group, and showed that glacial deposits in Brazil can contain hydrocarbons. The reservoir potential of the Carboniferous-Permian Itarare Group of the basin is analyzed using new subsurface data from 20 deep wells drilled in the early to middle 1980s. Central to the analysis was the construction of over 3000 km of cross sections based on more than 100 wells, the description of more than 400 m of core, and study of 95 thin sections. Subsurface exploration and mapping of the Itarare are greatly aided by the recognition of three recently defined and described formations and four members, which are traceable for hundreds of kilometers. These units belong to three major glacial cycles in which the pebbly mudstones and shales are seals and glacially related sandstones are reservoirs. The best sandstone reservoirs in the deep subsurface belong to the Rio Segredo Member, the upper-most sandy unit of the Itarare. The Rio Segredo Member is the best petroleum target because it is overlain by thick seals and massive pebbly mudstones and shales, and because it is shallower and less compacted than underlying, more deeply buried sandstones. This member has little detrital matrix and much of its porosity is secondary, developed by carboxylic acid and CO{sub 2} generated when Jurassic-Cretaceous basalts, sills, and dikes were intruded into the Parana basin as Gondwana broke up.

  1. UPPER SNAKE RIVER BASIN, PRELIMINARY BASIN EVALUATION

    EPA Science Inventory

    The purpose of this paper was to provide a process and a plan by which the Environmental Protection Agency can insure that water quality goals established in the Water Pollution Control Act Amendments of 1972 are met in the waters of the Upper Snake Basin (17040201, 17040206, 170...

  2. Tectonic Evolution of Tethyan Ophiolites and Backarc Basins in Subduction Rollback Systems in the Eastern Mediterranean Region

    NASA Astrophysics Data System (ADS)

    Dilek, Y.; Furnes, H.

    2009-04-01

    The late Mesozoic-Cenozoic evolution of the Eastern Mediterranean region was controlled by a series of collisions between Gondwana-derived continental blocks and Eurasia as the intervening ocean basins closed. Rifting of these ‘ribbon continents' from the northern edge of Gondwana occurred within a broadly convergent Tethyan realm and was mostly driven by slab-pull generated far-field stresses. Continued subduction of the Paleo-Tethyan ocean floor northward beneath Eurasia was responsible for both these continental rifting events in its trailing edge and rapid backarc extension in the leading edge of Eurasia in the upper plate. Collapse of the backarc basins and Neo-Tethys through intra-oceanic subduction and ensuing slab rollback processes produced extended incipient arc-forearc crust nested within the older Tethyan lithosphere. Fragments of these ancient protoarc-forearc lithospheric material constitute most of the Jurassic-Cretaceous suprasubduction zone (SSZ) ophiolites along the Tethyan suture zones. Igneous accretion of the SSZ Tethyan ophiolites involved upper plate extension and advanced melting of previously depleted asthenosphere in host basins, showing a progressive evolution from MORB-like to IAT (island arc tholeiite) to boninitic (extremely refractory) proto-arc assemblages. Although all ophiolites exhibit geochemical features indicating increased subduction influence during the melt evolution of their younger extrusive sequences and dike intrusions, as evidenced by their negative ?Nd values, their overall characteristic trace-element patterns seem to have been strongly affected by the maturity of the subduction systems in which they developed. Emplacement of SSZ ophiolites was facilitated by passive margin-trench collisions, which led into and was followed by partial subduction of continental edges, their high-P metamorphism, continental collisions, slab breakoff, and crustal exhumation and core complex formation. The suture zones between the amalgamated microcontinents are marked by ophiolites, accretionary melanges (including seamounts), and rift assemblages that are commonly telescoped structurally in this descending order. The Tethyan suture zones include, therefore, a variety of tectonostratigraphic units with different geochemical and tectonic affinities, ages, and structural architecture, representing the remnants of collapsed backarc basin and protoarc-forearc oceanic lithosphere, and passive margin units of the bounding microcontinents.

  3. 3D Geophysical Modelling of the Beattie Magnetic Anomaly and Karoo Basin, South Africa

    NASA Astrophysics Data System (ADS)

    Scheiber-Enslin, Stephanie; Ebbing, Jörg; Eberle, Detlef; Webb, Susan

    2013-04-01

    The Karoo Basin, the broad arid plateau that covers much of the interior of South Africa, is supported by the stable Archean Kaapvaal Craton in the north and several surrounding Proterozoic basement blocks in the south, and formed within the continental interior of Gondwana during the Late Carboniferous (300 Ma) to Middle Jurassic (125 Ma). No clear tectonic model exists for the Karoo Basin, with several hypotheses regarding the nature of the subsidence resulting in basin formation. To the southern edge of the Karoo basin the enigmatic Beattie magnetic anomaly (BMA) is seen, which stretches east to west for ~1000 km across a large portion of South Africa, and for which a variety of explanations have been proposed. Here we present detailed 2D gravity and magnetic models across the southwestern Karoo along with a combined first-order regional 3D model. The models presented here are based on seismic and potential field data, along with geological and structural information that cover the entire basin. Information about the Moho structure was derived from teleseismic data. The models have been further constrained using deep boreholes, as well as on- and off-shore seismic lines, Magnetotelluric data, and magnetic depth-to-basement estimates. Density and susceptibility values are based on borehole and hand sample data, as well as on the conversion of p-wave seismic velocity to densities. In order to produce an accurate potential field model of the Karoo basin and to understand the evolution of the basin, a clear understanding is needed of the source of the Beattie. Seismic data over the western section of the Beattie magnetic anomaly place the source in the mid-crust (10-15 km). Earlier studies have attributed the anomaly to partially serpentinized oceanic lithosphere possibly linked to a suture zone, or to massive disseminate magnetite-sulphide bodies within the basement. However, our analysis lets us support the idea that the BMA is part of the tectono-metamorphic Namaqua-Natal Mobile Belt and associated shear zones.

  4. Tectono-stratigraphic evolution and exhumation of the Haymana basin: Unravelling the subduction and collision history of Neotethys in Turkey

    NASA Astrophysics Data System (ADS)

    Gülyüz, Erhan; Özkaptan, Murat; Lefebvre, Côme; Kaymakci, Nuretdin; Persano, Cristina; Stuart, Finlay M.

    2014-05-01

    The Haymana basin straddles the Izmir-Ankara-Erzincan Suture Zone (IAESZ) in the north and Intra-Tauride Suture Zone (ITSZ) in the south. The two suture zones developed in response to the subduction and demise of Neotethys Ocean in Turkey during the late Cretaceous to early Tertiary; the tectonic significance of the basin and its relationship with the ITSZ are still poorly constrained. In order to unravel subduction and subsequent collision history of the Neotethys in the region, we have carried out a detailed analysis of the stratigraphy and sedimentology of the Haymana basin infill and, using a combination of palaeomagnetic and thermochronometric data we have unravelled its structural evolution since its formation. The basin developed on the IAESZ and comprises fore-arc late Cretaceous to foreland Middle Eocene sedimentary sequences. The analysis of the sedimentogical facies and depositional environments indicate four Late Cretaceous to Paleogene key sequences in the basin. These sequences grade laterally and vertically into each other and are continuous from the late Cretaceous to Eocene whereas local progressive syn-sedimentary unconformities and frequent depocenter migrations are common. Late Cretaceous sequences fine upward whereas coarsening upwards sequences are common in the later units. These characteristics possibly reflect the response to local uplift and subsidence in front of south-verging thrust faults associated with the transition from fore-arc to foreland basin settings, following the terminal subduction of the Neotethys at the end of Cretaceous. About 4000 paleomagnetic and magnetostratigraphic data from the basin infill units and the Neogene cover indicate large clockwise vertical axes rotations in the NW and counter-clockwise rotations in the SE part of the basin. We suggest that these rotations are related to the northward movement and indentation of the Gondwana-derived continental blocks into Eurasia. A model of southward thrust propagation is also supported by apatite fission track (AFT) and (U+Th)/He thermochronometric data from 12 samples of basin infill, which show a consistent northward age increase. The major change in the rotation senses and structural trends within the basin are related to a large strike-slip fault which might be the westward extension into the Haymana Basin of the Savc?l? Thrust Zone, an important structural feature that separated the K?rsehir Block into two sectors.Fault kinematic analysis, based on 2000 fault slip data from 50 stations, indicates that the basin was subjected to NE-SW directed compression and coeval E-W extension during the late Cretaceous to Neogene. Constructed and balanced cross-sections for different time intervals indicate northward thickening, wedge-like geometry of the basin and large vertical axes rotations. We propose that the Haymana basin was a fore-arc basin developed at the southern margin of Eurasia along the northwards subducted Neotethys Ocean. From the Palaeogene, the basin evolved into a foreland basin in front of a south-vergent fold and thrust belt developed during continental collision. The northward move- ment of KB caused the basin to rotate along vertical axes, whereas the thrust propagation promoted its exhumation.

  5. Late Permian Palynology and depositional environment of Chintalapudi sub basin, Pranhita-Godavari basin, Andhra Pradesh, India

    NASA Astrophysics Data System (ADS)

    Jha, Neerja; Pauline Sabina, K.; Aggarwal, Neha; Mahesh, S.

    2014-01-01

    The present study deals with the palynological dating, correlation and depositional setting of the sediments from bore cores MGP-11 and MGP-4 from Gauridevipet area of Chintalapudi sub-basin of Godavari master basin, south India. On the basis of palynological studies, three palynoassemblages have been identified, one in bore core MGP-11 a Faunipollenites (=Protohaploxypinus) and Striasulcites assemblage and two in bore core MGP-4; one is characterized by the dominance of striate bisaccates and Densipollenites and the other by Striatopodocarpites and Cresentipollenites palynoassemblages. The other stratigraphically significant taxa include Guttulapollenites hannonicus, Lunatisporites noviaulensis, Lunatisporites pellucidus, Densoisporites contactus, Chordasporites australiensis, Goubinispora spp., Lundbladispora microconata, Lundbladispora raniganjensis and Klausipollenites schaubergeri. The recovered taxa suggest a Late Permian, Lopingian age for these rocks. This interpretation is based on the correlation of the assemblages with similar assemblages from previous Gondwana studies chiefly Densipollenites magnicorpus Zone of Damodar Basin, India and Late Permian palynoassemblages from Africa, Antarctica, Australia and South America. On the basis of palaeobotanical affinity of the identified microflora it has been inferred that the peat forming plant community was composed mainly of gymnosperm pollen attributable to glossopterids, that includes striate and non-striate bisaccates and paucity of cordaites which includes monosaccates. Spores are subordinate and are derived from lycopsids (Lundbladispora, Densoisporites), sphenopsids (Latosporites) and filicopsids (Horriditriletes, Lophotriletes, Verrucosisporites, Osmundacidites, Leiotriletes, Callumispora, Brevitriletes and Microbaculispora) occurring in variable proportions. The dominance of subarborescent/arborescent vegetation suggests a development in a forest swamp probably in a small distant marginal part of the mire or periods of standing water. This flooding environment favoured the growth of herbaceous lycopsids, filicopsids and sphenopsids in the palaeomire. More or less similar environments of deposition have been deduced for both the sedimentary sequences on the basis of palynofacies analysis. Anaerobic, reducing, water logged peat-forming conditions have been inferred based on the abundance of phytoclasts. The relative abundance of structured organic matter implies the existence of a fairly dense vegetation cover in the hinterland. The charcoal fragments recovered from the present study area reflects a possible wildfire in the accumulated swamps or a wildfire in the hinterland after which the sediments were flushed by fluvial systems into the swamps.

  6. Aquifer - Basin and range

    NSDL National Science Digital Library

    Aquifer basics outlining the makeup of the basin and range aquifers. Description and maps of unconsolidated sand and gravel aquifers. This site consists of information for the Southwestern portion of the United States, consisted of Arizona, California, Nevada, and Utah.

  7. K Basin Hazard Analysis

    SciTech Connect

    PECH, S.H.

    2000-08-23

    This report describes the methodology used in conducting the K Basins Hazard Analysis, which provides the foundation for the K Basins Final Safety Analysis Report. This hazard analysis was performed in accordance with guidance provided by DOE-STD-3009-94, Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports and implements the requirements of DOE Order 5480.23, Nuclear Safety Analysis Report.

  8. The tectonic evolution of Cenozoic extensional basins, northeast Brazil: Geochronological constraints from continental basalt 40Ar/39Ar ages

    NASA Astrophysics Data System (ADS)

    de Souza, Zorano Sérgio; Vasconcelos, Paulo Marcos; Knesel, Kurt Michael; da Silveira Dias, Luiz Gustavo; Roesner, Eduardo Henrique; Cordeiro de Farias, Paulo Roberto; de Morais Neto, João Marinho

    2013-12-01

    The Boa Vista and Cubati Basins, Paraíba, Brazil, are NW-SE extension-related intracratonic basins that resulted from tectonic stresses after the opening of the South Atlantic. These basins contain lacustrine fossiliferous sediments, bentonite beds, and basalt flows that preserve Cenozoic continental records. 40Ar/39Ar ages for six whole-rocks from two distinct basaltic flows underlying the sediments in the Boa Vista basin are 27.3 ± 0.8 and 25.4 ± 1.3 Ma, while three grains from a basaltic flow overlying the sediments yield 22.0 ± 0.2 Ma. The sediments at the nearby Cubati Basin are overlain by a basalt flow with ages of ˜25.4 Ma. Three whole-rocks from an NE-SW-trending trachytic dyke cross cutting the sediments at the Boa Vista Basin yield 40Ar/39Ar ages of ˜12.45 ± 0.06, 12.59 ± 0.07, and 12.58 ± 0.07 Ma. Three whole-rocks from a nearby volcanic plug (Chupador) yield an age of 23.4 ± 0.1 Ma. The geochronological results combined with stratigraphic correlations between the two basins allow bracketing the age of the main sedimentary and bentonic units within the Boa Vista and Cubati Basins between 25.5 ± 1.3 and 24.9 ± 0.1 Ma. The ages, combined with field observations reveal that the formation of the Boa Vista and Cubati basins is associated with mantle-derived magmas channelled through reactivated Precambrian shear zones. Our geochronological results suggest that a temporal link with the Fernando de Noronha and Saint Helena hot spots can be excluded as possible sources of the Boa Vista and Cubati magmas. Rather, the extensional tectonics in the 30-20 Ma interval, long after Gondwana break-up, may be associated with the re-activation of continental-scale shear zones that channelled small batches of mantle-derived magmas.

  9. Efficacy of permethrin treated long-lasting insecticidal nets on malaria transmission and observations on the perceived side effects, collateral benefits and human safety in a hyperendemic tribal area of Orissa, India.

    PubMed

    Sharma, Surya K; Tyagi, Prajesh K; Upadhyay, Ashok K; Haque, Mohammed A; Mohanty, Suman S; Raghavendra, Kamaraju; Dash, Aditya P

    2009-11-01

    Studies were conducted on the efficacy of Olyset nets-a long-lasting insecticidal net (LLIN) factory treated with 2% (w/w) permethrin on malaria transmission in an area under the influence of pyrethroid susceptible vector species Anopheles culicifacies and A. fluviatilis in Sundargarh District, Orissa, India. The study area comprised 22 villages that were randomized into three clusters and designated as Olyset net, untreated net, and no net area. Malaria incidence in the study population was measured through longitudinal active surveillance at fortnightly intervals. There was a reduction of 65-70% in malaria incidence in Olyset net area as compared to the control areas. The attack rate of Plasmodium falciparum or number of episodes per person per year in different age groups also showed significant reduction in Olyset net area as compared to untreated net and no net areas. Cross-sectional point prevalence surveys showed 45.7% reduction of malaria prevalence in Olyset net users, whereas there was an increase of 33.3% and 51% in untreated net and no net villages respectively. The compliance rate of Olyset net usage in the study population was 80-98% during different months, whereas it was between 70% and 90% for untreated nets. There were minimal complains of skin irritation (4%), itching (8%) and eye irritation (1.2%). However, these effects were only transitory in nature lasting for few hours of the first usage. Olyset nets also provided collateral benefits in terms of relief not only from mosquitoes and malaria but also from other household pests such as head lice, bed bugs, cockroaches, ants and houseflies. The Olyset nets were found to be safe to humans as no adverse event was recorded in the net users that can be attributed to the use of net. The study showed that Olyset nets are effective personal protection tool that can be used in a community based intervention programme. PMID:19647715

  10. Geology, exploration status of Uruguay's sedimentary basins

    SciTech Connect

    Goso, C.; Santa Ana, H. de (Administracion Nacional de Combustibles, Alcohol y Portland (Uruguay))

    1994-02-07

    This article attempts to present the geological characteristics and tectonic and sedimentary evolution of Uruguayan basins and the extent to which they have been explored. Uruguay is on the Atlantic coast of South America. The country covers about 318,000 sq km, including offshore and onshore territories corresponding to more than 65% of the various sedimentary basins. Four basins underlie the country: the Norte basin, the Santa Lucia basin, the offshore Punta del Este basin, and the offshore-onshore Pelotas-Merin basin. The Norte basin is a Paleozoic basin while the others are Mesozoic basins. Each basin has been explored to a different extent, as this paper explains.

  11. Nam Con Son Basin

    SciTech Connect

    Tin, N.T.; Ty, N.D.; Hung, L.T.

    1994-07-01

    The Nam Con Son basin is the largest oil and gas bearing basin in Vietnam, and has a number of producing fields. The history of studies in the basin can be divided into four periods: Pre-1975, 1976-1980, 1981-1989, and 1990-present. A number of oil companies have carried out geological and geophysical studies and conducted drilling activities in the basin. These include ONGC, Enterprise Oil, BP, Shell, Petro-Canada, IPL, Lasmo, etc. Pre-Tertiary formations comprise quartz diorites, granodiorites, and metamorphic rocks of Mesozoic age. Cenozoic rocks include those of the Cau Formation (Oligocene and older), Dua Formation (lower Miocene), Thong-Mang Cau Formation (middle Miocene), Nam Con Son Formation (upper Miocene) and Bien Dong Formation (Pliocene-Quaternary). The basement is composed of pre-Cenozoic formations. Three fault systems are evident in the basin: north-south fault system, northeast-southwest fault system, and east-west fault system. Four tectonic zones can also be distinguished: western differentiated zone, northern differentiated zone, Dua-Natuna high zone, and eastern trough zone.

  12. What role does crustal heterogeneity play on continental break-up; the interplay of a foldbelt, rift system and ocean basin in the South Atlantic

    NASA Astrophysics Data System (ADS)

    Paton, Douglas; Mortimer, Estelle; Hodgson, Neil

    2015-04-01

    Although extensively studied, two key questions remain unanswered regarding the evolution of the southern South Atlantic. Firstly, where is the Cape Foldbelt (CFB) in offshore South Africa? The CFB is part of the broader Gonwanian Orogeny that prior to South Atlantic rifting continued into the Ventana Foldbelt of Argentina but to date its location in the offshore part of South Africa remains enigmatic. Secondly, the conjugate rift basin to South Africa is the Colorado Basin in Argentina but why does it trend east-west despite its perpendicular orientation to the Atlantic spreading ridge? Current plate models and structural understands cannot explain these fundamental questions. We use newly acquired deep reflection seismic data in the Orange Basin, South Africa, to develop a new structural model for the southern South Atlantic. We characterise the geometry of the Cape Foldbelt onshore and for the first time correlate it into the offshore. We show that it has a north-south trend immediately to the north of the Cape Peninsula but then has a syntaxis (Garies syntaxis) that results in a change to an east-west orientation. This forms the missing jigsaw piece of the Atlantic reconstruction as this is directly beside the restored Colorado Basin. When considered within the pre-break up structural configuration our observations imply that prior to the main phase of Atlantic rifting in the Mezosoic there was significant variation in crustal geometry incorporating the Orange Basin of South Africa, the Colorado Basin and the Gariep Belt of Namibia. These faults were active during Gondwana rifting, but the Colorado rift failed resulting in the present day location of the South Atlantic. Not only do our results improve our understanding of the evolution of the South Atlantic ocean, they highlight the importance of differentiating between early rift evolution and strain localisation during the subsequent rift phase prior to seafloor spreading.

  13. Age and tectonic evolution of Neoproterozoic ductile shear zones in the Southern Granulite Terrain of India, with implications for Gondwana studies

    NASA Astrophysics Data System (ADS)

    Ghosh, Joy Gopal; de Wit, Maarten J.; Zartman, R. E.

    2004-06-01

    The high-grade rocks of the Southern Granulite Terrain (SGT) of Peninsular India are bounded to the north by the Archean Dharwar Craton. Another high-grade terrane, the Mesoproterozoic Eastern Ghats, occurs to the northeast of the SGT. The tectonic relationship between these crustal domains is complex. We present new geochronological and structural data that indicate a continuation of the Dharwar Craton into the Southern Granulite Terrain as far south as a newly identified Neoproterozoic shear zone, here named the Karur-Kamban-Painavu-Trichur Shear Zone (KKPTSZ). South of the KKPTSZ, Mesoproterozoic dates of the SGT are similar to those recorded in the Eastern Ghats, and the two domains may have been conterminous. Thirty-three new U/Pb/Th single zircon and monazite dates of samples from six structural transects across the regional shear zones indicate that the SGT has experienced at least seven thermo-tectonic events at 2.5 Ga, ˜2.0 Ga, ˜1.6 Ga, ˜1.0 Ga, ˜800 Ma, ˜600 Ma, and ˜550 Ma, and two distinct episodes of metasomatism/charnockitization between 2.50-2.53 and between 0.55-0.53 Ga. Deformation along a number of major shear zones in the SGT is Neoproterozoic to earliest Paleozoic in age, with an early phase (D2) concentrated between 700-800 Ma, and a later phase (D3) between 550 and 600 Ma. Major charnockitization (530-550 Ma) post dates D3, and is, in turn, overprinted by granitization, retrogression, and uplift between 525 and 480 Ma. The KKPTSZ, active between 560 and 570 Ma, is either a terrane boundary, or a tectonized décollement between cover and Archean basement rocks represented by predominantly paragneisses to the south and orthogneisses to the north, respectively. Other regional Neoproterozoic shear zones do not appear to separate allochthonous terranes as previously suggested on the basis of Nd model ages and Rb/Sr biotite/whole rock dates. The Neoproterozoic-Cambrian tectonothermal history of the SGT and Eastern Ghats is similar to that recorded in parts of Madagascar, East Africa, and Antarctica, and is used to reconstruct parts of central Gondwana, here named the Deccan Continent, with more robust confidence.

  14. Petrology and mineral equilibrium modeling of incipient charnockite from the Lützow-Holm Complex, East Antarctica: implications for granulite formation in a Gondwana fragment

    NASA Astrophysics Data System (ADS)

    Tsunogae, Toshiaki

    2015-04-01

    Charnockite (orthopyroxene-bearing granitoid) is regarded as one of the fundamental lithologies in many high-grade metamorphic terranes including Neoproterozoic collisional orogen formed during the amalgamation of Gondwana supercontinent. Although both magmatic (massive) and metamorphic charnockites have been reported, several classic examples for the spectacular development of 'incipient charnockites' within orthopyroxene-free felsic gneisses are exposed in several quarry sections in Neoproterozoic granulite terrenes in southern India (e.g., Trivandrum Block) and Sri Lanka. (e.g., Wanni Complex). The charnockite-forming process in these localities is considered to have been triggered by the infiltration of CO2-rich anhydrous fluids along structural pathways within upper amphibolite facies gneisses, resulting in the lowering of water activity and stabilization of orthopyroxene through the breakdown of biotite. However, no detailed study of incipient charnockites in the Lützow-Holm Complex of East Antarctica, which is regarded as an extension of Neoproterozoic to Cambrian orogeny in India and Sri Lanka, has been reported so far. This study thus reports new petrological data of incipient charnockite patches in orthopyroxene-free felsic gneiss from Skallevikshalsen in the granulite-facies region of the Lützow-Holm Complex, East Antarctica, and discuss the timing and process of charnockite formation. Incipient charnockite (Opx + Qtz + Pl + Kfs + Grt) occurs as dark brownish patches of several cm in length within coarse-grained leucocratic gneiss (Qtz + Pl + Kfs + Grt) interlayered with various supracrustal lithologies such as mafic granulite, pelitic granulite, and marble. Orthopyroxene, which occurs only in garnet-bearing portion of the rock, probably formed by a FMAS continuous reaction: Grt + Qtz => Opx + Pl. Phase equilibrium modeling in the system NCKFMASH suggests a wide range of P-T stability (>780 C, >6 kbar), although the condition is broadly consistent with retrograde P-T conditions of the region. The texture and estimated P-T range suggest that the incipient charnockite formation in Skallevikshalsen is a post-peak event probably related to decompression after the peak event possibly without the effect of infiltration of low H2O activity fluids.

  15. Crinoids columnals (Echinodermata) of the Ererê Formation (late Eifelian-early Givetian, Amazon Basin), State of Pará, Brazil

    NASA Astrophysics Data System (ADS)

    Scheffler, S. M.; Fernandes, A. C. S. F.; da Fonseca, V. M. M.

    2014-01-01

    The faunal composition of stalked echinoderms in the Brazilian Devonian is still largely unknown despite the great abundance of crinoids in the shallow epicontinental seas of the Paleozoic. The first Devonian crinoids of Brazil, recorded in the literature in 1875 and 1903, were from the sedimentary rocks of the Ererê Formation in the Amazon Basin. Since then, the echinoderms of this formation have not been studied. This study, based on isolated pluricolumnals and columnals, described and identified Botryocrinus meloi n. sp., the first record for this genus in Brazil. In addition to this species, two other morphological patterns were identified: Tjeecrinus sp. and Morphotype AM/Er-01. The form of occurrence of the crinoid material and the paleoautoecology of B. meloi allow preliminary characterization of the habitat as a moderately deep water with weak to moderate currents and soft substrate. The similarity between B. meloi and Botryocrinus montguyonensis and of Tjeecrinus? sp. and T. crassijugatus, from the Devonian of the Armorican and Rhenan Massif, represents new evidence for the existence of contact between the faunas of the Amazon Basin with those of northern Gondwana and Armorica during the Middle Devonian.

  16. Great Basin National Park

    NSDL National Science Digital Library

    This National Park Service site describes the biology of Great Basin's plants and animals; geology and ecology of the Lehman Caves; air quality of the park; and past human activities in the Great Basin such as farming, ranching, and gold mining. There is a list of historical, geological, and archeological dates important to the park and an instructor guide containing activities such as creating a nature notebook and adopting a tree. There is also information on: planning a visit to the park and the Lehman Caves, park projects such as weeding out non-native plants and the reintroduction of Bonneville Cutthroat Trout, and a self-guided geology field trip.

  17. Hierarchy of tectonic control on stratigraphic signatures: Base-level changes during the Early Permian in the Paraná Basin, southernmost Brazil

    NASA Astrophysics Data System (ADS)

    Holz, Michael; Küchle, Juliano; Philipp, Ruy Paulo; Bischoff, Alan Patrick; Arima, Naoki

    2006-12-01

    The Lower Permian sedimentary succession of the Paraná Basin in southernmost Brazil has an overall transgressive sedimentation regime, recorded by a clear retrogradation of the facies belt. However, important depositional strike-orientated variations and regional inversions occur in the sedimentation regime along the paleo-shoreline (i.e., along-strike) of the basin. At the regional scale, a huge source area was uplifted by the end of the Artinskian in the north and caused regression; the southern part of the study area increasingly was transgressed by the epicontinental sea (= regional inversion). This important tectonic overprint on the stratigraphic signature of the basin's infill has a tectonic origin. The variable sedimentation regime along the paleo-shoreline is controlled by the structural framework of the basement, which is formed by several crustal blocks with different responses to tectonic strain induced by terrain accretion on the occidental margin of Gondwana during the Permian. Stratigraphic data indicate that during the Early Permian, there were at least two differential subsidence and uplift events, one by the end of the Sakmarian-Artinskian and another during the Late Artinskian-Kungurian.

  18. The lunar Procellarum basin

    NASA Astrophysics Data System (ADS)

    Whitaker, E. A.

    It is still widely assumed that the Imbrium basin is the largest such structure on the lunar nearside, even though it has been pointed out that geochemical and other data from the Apollo missions strongly indicate that the Imbrium impact occurred eccentrically within the confines of a pre-existing, much larger (the 'Gargantuan') basin. There does, in fact, also exist supporting topographical evidence for the reality of this basin, although the centroid of high radioactivity lies a little west of the topographical center. This topographical evidence consists of incomplete arcs of three closely concentric circles marked by mare shorelines, major systems of mare ridges, and some minor scarps. The rings have surface diameters of 1700, 2400 and 3200 km, and are centered at about 23 deg N, 15 deg W, near the crater Timocharis. Any discussions of the distribution of surface minerals, the compositions, ages, histories and petrology of lunar rocks, etc. should recognize and include any possible effects resulting from the formation of this basin.

  19. Cenozoic basin development in Hispaniola

    SciTech Connect

    Mann, P.; Burke, K.

    1984-04-01

    Four distinct generations of Cenozoic basins have developed in Hispaniola (Haiti and Dominican Republic) as a result of collisional or strike-slip interactions between the North America and Caribbean plates. First generation basins formed when the north-facing Hispaniola arc collided with the Bahama platform in the middle Eocene; because of large post-Eocene vertical movements, these basins are preserved locally in widely separated areas but contain several kilometers of arc and ophiolite-derived clastic marine sediments, probably deposited in thrust-loaded, flexure-type basins. Second generation basins, of which only one is exposed at the surface, formed during west-northwesterly strike-slip displacement of southern Cuba and northern Hispaniola relative to central Hispaniola during the middle to late Oligocene; deposition occurred along a 5-km (3-mi) wide fault-angle depression and consisted of about 2 km (1 mi) of submarine fan deposits. Third generation basins developed during post-Oligocene convergent strike-slip displacement across a restraining bend formed in central Hispaniola; the southern 2 basins are fairly symmetrical, thrust-bounded ramp valleys, and the third is an asymmetrical fault-angle basin. Fourth generation basins are pull-aparts formed during post-Miocene divergent strike-slip motion along a fault zone across southern Hispaniola. As in other Caribbean areas, good source rocks are present in all generations of basins, but suitable reservoir rocks are scarce. Proven reservoirs are late Neogene shallow marine and fluvial sandstones in third generation basins.

  20. Newly discovered Martian impact basins

    NASA Astrophysics Data System (ADS)

    Stam, M.

    1985-04-01

    Three previously unrecognized Martian impact basins were discovered through detailed mapping of landforms, structures and terrains near Cassini and Al Qahira basins. Al Qahira A lies on the Martian dichotomy boundary and intersects the older basin, Al Qahira. It has four rings that are expressed by a variety of landforms. Southwestward Al Qahira A is out by a younger Basin, Al Qahira B. Al Qahira B is a highly degraded basin with one identifiable ring. Its ring is expressed by a few massifs, knobs and inward-facing scarps, but is recognized by the distributions of wrinkle ridges and plains units. Cassini A lies southward of the younger Cassini Basin and is intersected by it. It probably has four rings. The importance of detailed mapping of various types of landforms and terrains to the discovery of basins on Mars are demonstrated.

  1. Global analysis of intraplate basins

    NASA Astrophysics Data System (ADS)

    Heine, C.; Mueller, D. R.; Dyksterhuis, S.

    2005-12-01

    Broad intraplate sedimentary basins often show a mismatch of lithospheric extension factors compared to those inferred from sediment thickness and subsidence modelling, not conforming to the current understanding of rift basin evolution. Mostly, these basins are underlain by a very heterogeneous and structurally complex basement which has been formed as a product of Phanerozoic continent-continent or terrane/arc-continent collision and is usually referred to as being accretionary. Most likely, the basin-underlying substrate is one of the key factors controlling the style of extension. In order to investigate and model the geodynamic framework and mechanics controlling formation and evolution of these long-term depositional regions, we have been analysing a global set of more than 200 basins using various remotely sensed geophysical data sets and relational geospatial databases. We have compared elevation, crustal and sediment thickness, heatflow, crustal structure, basin ages and -geometries with computed differential beta, anomalous tectonic subsidence, and differential extension factor grids for these basins. The crust/mantle interactions in the basin regions are investigated using plate tectonic reconstructions in a mantle convection framework for the last 160 Ma. Characteristic parameters and patterns derived from this global analysis are then used to generate a classification scheme, to estimate the misfit between models derived from either crustal thinning or sediment thickness, and as input for extension models using particle-in-cell finite element codes. Basins with high differential extension values include the ``classical'' intraplate-basins, like the Michigan Basin in North America, the Zaire Basin in Africa, basins of the Arabian Penisula, and the West Siberian Basin. According to our global analysis so far, these basins show, that with increasing basin age, the amount of crustal extension vs. the extension values estimated from sediment thickness decreases decreased. This could be used as a indicator for ``basin maturity''. Furthermore, basins with higher differential beta values show generally slightly lower heatflux values. We have attempted to integrate the results from the observations with numerical modelling of different crustal extension scenarios involving a varying heterogeneous basement architecture and attempting to connect the ``pure'' numerical models with real world data as tightly as possible. In the scope of the project we have tried to build a numerical model library linked to the large scale observations, which offers a new powerful way to investigate the complex lithosphere dynamics and geological processes that account for the evolution of intraplate basins, and the influence of the basement architecture on successful or failed rifts.

  2. Buried-euxenic-basin model sets Tarim basin potential

    SciTech Connect

    Hsu, K.J. (Tarim Associates for Oil and Mineral Exploration AG, Zurich (Switzerland))

    1994-11-28

    The Tarim basin is the largest of the three large sedimentary basins of Northwest China. The North and Southwest depressions of Tarim are underlain by thick sediments and very thin crust. The maximum sediment thickness is more than 15 km. Of the several oil fields of Tarim, the three major fields were discovered during the last decade, on the north flank of the North depression and on the Central Tarim Uplift. The major targets of Tarim, according to the buried-euxenic-basin model, should be upper Paleozoic and lower Mesozoic reservoirs trapping oil and gas condensates from lower Paleozoic source beds. The paper describes the basin and gives a historical perspective of exploration activities and discoveries. It then explains how this basin can be interpreted by the buried-euxenic-basin model. The buried-euxenic-basin model postulates four stages of geologic evolution: (1) Sinian and early Paleozoic platform sedimentation on relic arcs and deep-marine sedimentation in back-arc basins in Xinjiang; (2) Late Paleozoic foreland-basin sedimentation in north Tarim; (3) Mesozoic and Paleogene continental deposition, subsidence under sedimentary load; and (4) Neogene pull-apart basin, wrench faulting and extension.

  3. Crustal geoelectric structure of the Sikkim Himalaya and adjoining Gangetic foreland basin

    NASA Astrophysics Data System (ADS)

    Pavan Kumar, G.; Manglik, A.; Thiagarajan, S.

    2014-12-01

    We present the results of a broadband magnetotelluric survey along a 200-km-long profile across the Sikkim Himalaya. The data were acquired at average station spacing of 5-6 km and transfer functions of 31 sites in 0.01-1000 s period range have been used for 2-D joint inversion of TE and TM modes. The composite model incorporating the effect of transverse strike reveals several features that correlate with the available seismic and kinematic models of the region. A major result of the present study is that the Main Himalayan Thrust forms the base of several resistive blocks within the wedge and that a ramp structure is present south of the Main Central Thrust Zone (MCTZ). Another significant result is that the crust and mantle lithosphere beneath the MCTZ and the Higher Himalayan Crystallines (HHC) seem to be compositionally/geologically different from the lithosphere south of the MCTZ. A steep crustal-scale fault with the Moho offset of 14 km is inferred to be separating these two blocks. The deep crustal seismicity could be related to this fault whereas shallow seismicity can be linked to the deformation within the wedge. The results also reveal the presence of some more conductors. We relate the conductor within the HHC to the sedimentary rocks of the Tethyan sequence exposed in a window about 40 km west of the profile and north of the South Tibetan Detachment System (STDS). The conductor at 90 km profile location is linked to the Gondwana rocks exposed in the Rangit Window. A 4-6 km thick sedimentary layer overlies the basement in the Gangetic foreland basin. We also delineate a sub-crustal conductor at 50-60 km depth beneath the foreland basin at the southern end of the profile, the cause of which is not apparent and needs to be explored.

  4. Caribbean basin framework, 3: Southern Central America and Colombian basin

    SciTech Connect

    Kolarsky, R.A.; Mann, P. (Univ. of Texas, Austin (United States))

    1991-03-01

    The authors recognize three basin-forming periods in southern Central America (Panama, Costa Rica, southern Nicaragua) that they attempt to correlate with events in the Colombian basin (Bowland, 1984): (1) Early-Late Cretaceous island arc formation and growth of the Central American island arc and Late Cretaceous formation of the Colombian basin oceanic plateau. During latest Cretaceous time, pelagic carbonate sediments blanketed the Central American island arc in Panama and Costa Rica and elevated blocks on the Colombian basin oceanic plateau; (2) middle Eocene-middle Miocene island arc uplift and erosion. During this interval, influx of distal terrigenous turbidites in most areas of Panama, Costa Rica, and the Colombian basin marks the uplift and erosion of the Central American island arc. In the Colombian basin, turbidites fill in basement relief and accumulate to thicknesses up to 2 km in the deepest part of the basin. In Costa Rica, sedimentation was concentrated in fore-arc (Terraba) and back-arc (El Limon) basins; (3) late Miocene-Recent accelerated uplift and erosion of segments of the Central American arc. Influx of proximal terrigenous turbidites and alluvial fans in most areas of Panama, Costa Rica, and the Colombian basin marks collision of the Panama arc with the South American continent (late Miocene early Pliocene) and collision of the Cocos Ridge with the Costa Rican arc (late Pleistocene). The Cocos Ridge collision inverted the Terraba and El Limon basins. The Panama arc collision produced northeast-striking left-lateral strike-slip faults and fault-related basins throughout Panama as Panama moved northwest over the Colombian basin.

  5. ADVANCED CHEMISTRY BASINS MODEL

    SciTech Connect

    William Goddard III; Lawrence Cathles III; Mario Blanco; Paul Manhardt; Peter Meulbroek; Yongchun Tang

    2004-05-01

    The advanced Chemistry Basin Model project has been operative for 48 months. During this period, about half the project tasks are on projected schedule. On average the project is somewhat behind schedule (90%). Unanticipated issues are causing model integration to take longer then scheduled, delaying final debugging and manual development. It is anticipated that a short extension will be required to fulfill all contract obligations.

  6. Advanced Chemistry Basins Model

    SciTech Connect

    William Goddard; Mario Blanco; Lawrence Cathles; Paul Manhardt; Peter Meulbroek; Yongchun Tang

    2002-11-10

    The DOE-funded Advanced Chemistry Basin model project is intended to develop a public domain, user-friendly basin modeling software under PC or low end workstation environment that predicts hydrocarbon generation, expulsion, migration and chemistry. The main features of the software are that it will: (1) afford users the most flexible way to choose or enter kinetic parameters for different maturity indicators; (2) afford users the most flexible way to choose or enter compositional kinetic parameters to predict hydrocarbon composition (e.g., gas/oil ratio (GOR), wax content, API gravity, etc.) at different kerogen maturities; (3) calculate the chemistry, fluxes and physical properties of all hydrocarbon phases (gas, liquid and solid) along the primary and secondary migration pathways of the basin and predict the location and intensity of phase fractionation, mixing, gas washing, etc.; and (4) predict the location and intensity of de-asphaltene processes. The project has be operative for 36 months, and is on schedule for a successful completion at the end of FY 2003.

  7. Drainage Basin Morphometry

    NSDL National Science Digital Library

    Rick Ford

    The goal of this activity is for to students to observe and quantify the inherent organization within the channel network of a single drainage basin (a la Horton, 1945). The students will use the contour-crenulation method to flesh out the channel network within a selected drainage basin. They will then use the Strahler system to deterime the stream order of each channel segment. They then measure and average various attributes (slope, length, etc.) of the channel segments, by stream order. These data will then be plotted on semi-log graph paper to illustrate the matematical relationships between channel attributes and stream order. This activity gives students practice in delineating drainage divides and channel networks on topographic maps, using map scales to measure distances on topographic maps, and graphing data using a semi-log format. In addition, they are asked to compare their "real-world" results against the classic "laws" of basin morphometry presented in their textbook. This permits a discussion of sample size and measurement error versus theoretical relationships presented in a textbook. Designed for a geomorphology course

  8. Rift architecture and evolution: The Sirt Basin, Libya: The influence of basement fabrics and oblique tectonics

    NASA Astrophysics Data System (ADS)

    Abdunaser, K. M.; McCaffrey, K. J. W.

    2014-12-01

    The Cretaceous-Tertiary northwest-trending Sirt Basin system, Libya, is a rift/sag basin formed on Pan-African to Paleozoic-aged basement of North Africa. In this study, we investigate the rift-basin architecture and tectonic framework of the western Sirt Basin. Using remote sensed data, supported by borehole data from about 300 deep wells and surface geologic maps, we constructed geological cross sections and surface geology maps. Indication of the relative timing of structures and movement along faults has been determined where possible. Direction statistics for all the interpreted linear features acquired in the study area were calculated and given as a total distribution and then the totals are broken down by the major basin elements of the area. Hundreds of lineaments were recognized. Their lengths, range between a hundred meters up to hundreds of kilometers and the longest of the dominant trends are between N35W-N55W and between N55E-N65E which coincides with Sirt Basin structures. The produced rose diagrams reveal that the majority of the surface linear features in the region have four preferred orientations: N40-50W in the Zallah Trough, N45-55W in the Dur al Abd Trough, N35-55W in the Az Zahrah-Al Hufrah Platform, and in contrast in the Waddan Uplift a N55-65E trend. We recognize six lithostratigraphic sequences (phases) in the area's stratigraphic framework. A Pre-graben (Pre-rift) initiation stage involved the Pre-Cretaceous sediments formed before the main Sirt Basin subsidence. Then followed a Cretaceous to Eocene graben-fill stage that can divided into four structurally-active and structurally-inactive periods, and finally a terminal continental siliciclastics-rich package representing the post-rift stage of the development in post-Eocene time. In general five major fault systems dissect and divide the study area into geomorphological elevated blocks and depressions. Most of the oil fields present in the study area are associated with structural hinge zones and adjoining highs. Late Eocene rocks exposed in the western part of the basin exhibit a complex network of branching segmented normal and strike-slip faults, generally with a NNW-SSE structural orientations. Many surface structural features have been interpreted from satellite images which confirm sinistral strike-slip kinematics. Relay ramp structures, numerous elongate asymmetric synclines associated with shallow west limbs and steeper dipping east limbs are developed in the hangingwalls adjacent to west downthrowing normal faults. These structural patterns reflect Cretaceous/Tertiary extensional tectonics with additional control by underlying pre-existing Pan-African basement fabrics and ENE-WSW trending Hercynian structures. We relate the Sirt Basin rift development as exemplified in our study area to the break-up of Gondwana represented by the structural evolution of the West-Central African rift system, and the South and Central Atlantic, the Tethys and the Indian Oceans.

  9. Flexural analysis of two broken foreland basins; Late Cenozoic Bermejo basin and Early Cenozoic Green River basin

    Microsoft Academic Search

    P. B. Flemings; T. E. Jordan; S. Reynolds

    1986-01-01

    Lithospheric flexure that generates basin in a broke foreland setting (e.g., the Laramide foreland of Wyoming) is a three-dimensional system related to shortening along basin-bounding faults. The authors modeled the elastic flexure in three dimensions for two broken foreland basins: the early Cenozoic Green River basin and the analogous late Cenozoic Bermejo basin of Argentina. Each basin is located between

  10. Foreland basins and fold belts

    SciTech Connect

    Macqueen, R.W.; Leckie, D.A. (Geological Survey of Canada, Inst. of Sedimentary and Petroleum Geology, Calgary, Alberta (Canada))

    1992-01-01

    The papers in this book describe six foreland basins and fold belts in terms of their regional setting, stratigraphy, tectonics, and structure, and their oil and gas systems. All of the basins show general similarities, but each differs significantly in detail from the others, posing something of a problem in terms of arriving at a 'typical' foreland basin and fold belt. Some are major hydrocarbon producers; others are not. The major characteristics of the six foreland basins and fold belts are summarized in Tables 1 through 5, which provide a convenient means of comparing and contrasting these basins and their hydrocarbon resources. The Western Canada foreland basin and fold belt serves as the type example for several reasons. These include: its setting and clear relationship to a major orogene of Mesozoic-Cenozoic age; the fact that it is uncomplicated by later overprinting, segmentation, or cover rocks unlike the Ouachita, Eastern Venezuela, and U.S. Rocky Mountain foreland basins and fold belts); the fact that there is a large volume of publicly available data on the basin and an active exploration and research community; and the fact that it has reasonable oil and gas reserves in a well-defined stratigraphic framework.

  11. 5, 1105511090, 2005 Basin convergence

    E-print Network

    Paris-Sud XI, Université de

    ACPD 5, 11055­11090, 2005 Basin convergence patterns due to low level jets B. de Foy et al. Title and Physics Discussions Distinct wind convergence patterns due to thermal and momentum forcing of the low 5, 11055­11090, 2005 Basin convergence patterns due to low level jets B. de Foy et al. Title Page

  12. Atlantic marginal basins of Africa

    SciTech Connect

    Moore, G.T.

    1988-02-01

    The over 10,000-km long Atlantic margin of Africa is divisible into thirty basins or segments of the margin that collectively contain over 18.6 x 10/sup 6/ km/sup 3/ of syn-breakup and post-breakup sediments. Twenty of these basins contain a sufficiently thick volume of sediments to be considered prospects. These basins lie, at least partially, within the 200 m isobath. The distribution of source rocks is broad enough to give potential to each of these basins. The sedimentation patterns, tectonics, and timing of events differ from basin to basin and are related directly to the margin's complex history. Two spreading modes exist: rift and transform. Rifting dates from Late Triassic-Early Jurassic in the northwest to Early Cretaceous south of the Niger Delta. A complex transform fault system separated these two margins. Deep-water communication between the two basins became established in the middle Cretaceous. This Mesozoic-Cenozoic cycle of rifting and seafloor spreading has segmented the margin and where observable, basins tend to be bounded by these segments.

  13. MASSACHUSETTS DRAINAGE SUB-BASINS

    EPA Science Inventory

    MassGIS has produced a statewide digital datalayer of the approximately 2300 sub-basins as defined and used by the USGS Water Resources Division and the Mass Water Resources Commission and as modified by Executive Office of Environmental Affairs (EOEA) agencies. These sub-basins...

  14. Estancia Basin dynamic water budget.

    SciTech Connect

    Thomas, Richard P.

    2004-09-01

    The Estancia Basin lies about 30 miles to the east of Albuquerque, NM. It is a closed basin in terms of surface water and is somewhat isolated in terms of groundwater. Historically, the primary natural outlet for both surface water and groundwater has been evaporation from the salt lakes in the southeastern portion of the basin. There are no significant watercourses that flow into this basin and groundwater recharge is minimal. During the 20th Century, agriculture grew to become the major user of groundwater in the basin. Significant declines in groundwater levels have accompanied this agricultural use. Domestic and municipal use of the basin groundwater is increasing as Albuquerque population continues to spill eastward into the basin, but this use is projected to be less than 1% of agricultural use well into the 21st Century. This Water Budget model keeps track of the water balance within the basin. The model considers the amount of water entering the basin and leaving the basin. Since there is no significant surface water component within this basin, the balance of water in the groundwater aquifer constitutes the primary component of this balance. Inflow is based on assumptions for recharge made by earlier researchers. Outflow from the basin is the summation of the depletion from all basin water uses. The model user can control future water use within the basin via slider bars that set values for population growth, water system per-capita use, agricultural acreage, and the types of agricultural diversion. The user can also adjust recharge and natural discharge within the limits of uncertainty for those parameters. The model runs for 100 years beginning in 1940 and ending in 2040. During the first 55 years model results can be compared to historical data and estimates of groundwater use. The last 45 years are predictive. The model was calibrated to match to New Mexico Office of State Engineer (NMOSE) estimates of aquifer storage during the historical period by making adjustments to recharge and outflow that were within the parameters uncertainties. Although results of this calibrated model imply that there may be more water remaining in the aquifer than the Estancia Water Plan estimates, this answer is only another possible result in a range of answers that are based on large parameter uncertainties.

  15. Advanced Chemistry Basins Model

    SciTech Connect

    Blanco, Mario; Cathles, Lawrence; Manhardt, Paul; Meulbroek, Peter; Tang, Yongchun

    2003-02-13

    The objective of this project is to: (1) Develop a database of additional and better maturity indicators for paleo-heat flow calibration; (2) Develop maturation models capable of predicting the chemical composition of hydrocarbons produced by a specific kerogen as a function of maturity, heating rate, etc.; assemble a compositional kinetic database of representative kerogens; (3) Develop a 4 phase equation of state-flash model that can define the physical properties (viscosity, density, etc.) of the products of kerogen maturation, and phase transitions that occur along secondary migration pathways; (4) Build a conventional basin model and incorporate new maturity indicators and data bases in a user-friendly way; (5) Develop an algorithm which combines the volume change and viscosities of the compositional maturation model to predict the chemistry of the hydrocarbons that will be expelled from the kerogen to the secondary migration pathways; (6) Develop an algorithm that predicts the flow of hydrocarbons along secondary migration pathways, accounts for mixing of miscible hydrocarbon components along the pathway, and calculates the phase fractionation that will occur as the hydrocarbons move upward down the geothermal and fluid pressure gradients in the basin; and (7) Integrate the above components into a functional model implemented on a PC or low cost workstation.

  16. Basin infill architecture and evolution from magnetostratigraphic cross-basin correlations in the southeastern Pyrenean foreland basin

    Microsoft Academic Search

    C. Taberner; J. Dinarès-Turell; J. Giménez; C. Docherty

    1999-01-01

    Magnetostratigraphy, numerical dating, and facies mapping have been combined to provide the first cross-basin correlation of the Eocene southeastern Pyrenean foreland basin in northeastern Spain. This has enabled (1) depositional systems on the northern and south- ern margins of the basin to be dated and correlated across the basin and (2) changes in the rates of sediment accumulation in time

  17. Lower Palaeozoic unconformities in an intracratonic platform setting: glacial erosion versus tectonics in the eastern Murzuq Basin (southern Libya)

    NASA Astrophysics Data System (ADS)

    Ghienne, Jean-François; Moreau, Julien; Degermann, Lionel; Rubino, Jean-Loup

    2013-03-01

    The stratigraphic record of the eastern Murzuq Basin has been importantly influenced by deformation resulting in angular and/or deeply erosional unconformities, though the overall context is intracratonic. Major transgressive events and the Ordovician glaciation are nevertheless documented, allowing the delineation of tectonic-, eustasy- or climate-driven unconformities. Lower Palaeozoic key events and related unconformities that characterize the North Gondwana platform have therefore a signature in the eastern Murzuq Basin. The basement/cover unconformity, also known as the infra-Tassilian surface, truncates all the deformed and metamorphosed Lower Cambrian and older rocks. Above is a ?Middle Cambrian to Lower Ordovician megasequence (Murizidié and Hasawnah Fms.), which is in turn truncated by an intra-Ordovician, angular unconformity. This megasequence is unconformably overlain by a Middle Ordovician (Hawaz Fm.) to Silurian (Tanzzuft and Akakus Fms) megasequence, which includes the Upper Ordovician glaciogenic unit (Mamuniyat Fm.), bounded at the base by a polygenic glacial erosion surface showing corrugated glacial lineations, tillites, and glaciotectonic structures. The Middle Ordovician to Silurian megasequence is finally truncated by a base-Devonian, angular unconformity overlain by fluvial sandstones. Regarding the possibility that those fluvial deposits may be as younger as Late Devonian in the eastern Murzuq Basin based on palaeoflora, the so-called Caledonian unconformity might be here a much younger (mid-Eifelian?) surface, and the occurrence of the Lower Devonian "Tadrart Fm." is questioned. The Upper Ordovician glacial erosion surface, which is sometimes referred to as the Taconic unconformity, usually truncates Middle Ordovician strata in the Murzuq Basin but reaches significantly deeper stratigraphic levels in places that have been previously involved in the intra-Ordovician deformation event. In the Murizidié (southeastern Murzuq Basin), the infra-Tassilian surface, the intra-Ordovician unconformity, and the Upper Ordovician glacial erosion surface amalgamate together. Here, an estimate of the glacial erosion depth cannot be derived from the stratigraphic hiatus beneath the glacial incision, the main part of which relate to the intra-Ordovician tectonic event. The Upper Ordovician climate-related glacial erosion surface is not a valid unconformity for a sequence hierarchy framework of the Lower Palaeozoic, although it presents most of the physical attributes of tectonic-driven unconformities.

  18. New deeper exploration frontiers in Bass basin

    Microsoft Academic Search

    P. E. Williamson; C. J. Pigram; A. S. Scherl; K. L. Lockwood; M. A. Etheridge; J. C. Branson

    1985-01-01

    The Bass basin is the sister basin to the Gippsland. Both are extensional basins in southeast Australia between Tasmania and the mainland, and both occupy areas in excess of 60,000 km². The Bass and Gippsland basins were resurveyed seismically by the Bureau of Mineral Resources to provide regional correlation and to penetrate seismic energy barriers caused by Eocene coals. Analyses

  19. SOME ETHNOMEDICINAL PLANTS OF KORAPUT DISTRICT ORISSA

    PubMed Central

    Das, P.K.; Misra, M.K.

    1988-01-01

    The paper presents the ethnomedicinal use of 35 plants by the tribals of Koraput district to cure 25 diseases they suffer from. Apart from this, a note on the vegetation pattern, tribal population and geography of the district is given here. PMID:22557632

  20. Arc Boudinage, Basin Inversion and Obduction in an Evolving Subduction System of East Antarctica

    NASA Astrophysics Data System (ADS)

    Ferraccioli, F.; Balbi, P.; Armadillo, E.; Crispini, L.; Capponi, G.

    2014-12-01

    The paleo-Pacific margin of Gondwana experienced protracted subduction and accretionary tectonics starting in late Neoproterozic-early Cambrian times. Northern Victoria Land (NVL), in East Antarctica, preserves a cryptic record of these active margin processes. Most models indicate that NVL contains three main terranes, namely the Robertson Bay, Bowers and Wilson terranes. Significant debate centres, however, on whether these are far travelled terranes with respect to the East Antarctic Craton, and on the tectonic and magmatic processes that affected its active margin and were ultimately responsible for the formation of the Ross Orogen. Here we interpret new aeromagnetic, aerogravity and land-gravity compilations that enable us to trace the extent of major subglacial faults in the basement of NVL, examine crustal architecture, and propose a new evolutionary model for the active margin of the craton. Prominent aeromagnetic anomalies at the edge of the Wilkes Subglacial Basin delineate the extent of an early-stage magmatic arc (ca 530 Ma?). This arc may have accreted as an exotic element onto the former Neoproterozoic rifted margin of East Antarctica or (perhaps more likely) developed in situ upon a pre-existing suture. Remnants of magnetic arc basement are also identified ca 150 km further to the east within the Wilson Terrane (WT). We propose that these were originally adjacent arc segments and that transtension triggered significant arc boudinage separating these segments. Transtension may have created accommodation space for the development of thick Cambrian sedimentary basins, which are marked by regional magnetic lows with an en-echelon geometry. Basin inversion likely occurred in a later traspressional stage of the Ross-Delamerian Orogen (ca. 490-460 Ma) that triggered the development of a major pop-up structure within the WT. Several buried thrusts of the pop-up can be traced in the aeromagnetic images and a prominent residual gravity high delineates its high-grade metamorphic core. High amplitude magnetic and gravity anomalies also delineate buried oceanic basement of the northern Bowers Terrane. Oceanic basement was likely uplifted and obducted onto to the margin either because of oblique subduction or because of docking of a microcontinent inferred to underlie part of the Robertson Bay Terrane.

  1. Mineralogical and geochemical characteristics of the Noamundi-Koira basin iron ore deposits (India)

    NASA Astrophysics Data System (ADS)

    Mirza, Azimuddin; Alvi, Shabbar Habib; Ilbeyli, Nurdane

    2015-04-01

    India is one of the richest sources of iron ore deposits in the world; and one of them is located in the Noamundi-Koira basin, Singhbhum-Orissa craton. The geological comparative studies of banded iron formation (BIF) and associated iron ores of Noamundi-Koira iron ore deposits, belonging to the iron ore group in eastern India, focus on the study of mineralogy and major elemental compositions along with the geological evaluation of different iron ores. The basement of the Singhbhum-Orissa craton is metasedimentary rocks which can be traced in a broadly elliptical pattern of granitoids, surrounded by metasediments and metavolcanics of Greenstone Belt association. The Singhbhum granitoid is intrusive into these old rocks and to younger, mid Archaean metasediments, including iron formations, schists and metaquartzites and siliciclastics of the Precambrian Iron Ore Group (Saha et al., 1994; Sharma, 1994). The iron ore of Noamundi-Koira can be divided into seven categories (Van Schalkwyk and Beukes 1986). They are massive, hard laminated, soft laminated, martite-goethite, powdery blue dust and lateritic ore. Although it is more or less accepted that the parent rock of iron ore is banded hematite jasper (BHJ), the presence of disseminated martite in BHJ suggests that the magnetite of protore was converted to martite. In the study area, possible genesis of high-grade hematite ore could have occurred in two steps. In the first stage, shallow, meteoric fluids affect primary, unaltered BIF by simultaneously oxidizing magnetite to martite and replacing quartz with hydrous iron oxides. In the second stage of supergene processes, deep burial upgrades the hydrous iron oxides to microplaty hematite. Removal of silica from BIF and successive precipitation of iron resulted in the formation of martite- goethite ore. Soft laminated ores were formed where precipitation of iron was partial or absent. The leached out space remains with time and the interstitial space is generally filled with kaolinite and gibbsite, which make it low grade. Massive iron ores are devoid of any lamination and usually associated with BHJ and lower shale. The thickness of the massive ore layer varies with the location. The massive iron ore grades in to well-developed bedded BHJ in depth. Blue dust occurs in association with BHJ as pockets and layers. Although blue dust and friable ore are both powdery ores, and subjected to variable degree of deformation, leading to the formation of folding, faulting and joints of complex nature produce favourable channels. Percolating water play an important role in the formation of blue dust and the subterranean solution offers the necessary acidic environment for leaching of quartz from the BHJ. The dissolution of silica and other alkalis are responsible for the formation of blue dust. The friable and powdery ore on the other hand are formed by soft laminated ore. As it is formed from the soft laminated ore, its alumina content remains high similar to soft laminated ore compaired to blue dust. Mineralogy study suggests that magnetite was the principal iron oxide mineral, now a relict phase whose depositional history is preserved in BHJ, where it remains in the form of martite. The platy hematite is mainly the product of martite. The different types of iron ores are intricately related with the BHJ. Hard laminated ores, martite-goethite ore and soft laminated ore are resultant of desilicification process through the action of hydrothermal fluids. Geochemistry of banded iron-formations of the Noamundi-Koira iron ore deposits shows that they are detritus-free chemical precipitates. The mineralogical and geochemical data suggest that the hard laminated, massive, soft laminated ores and blue dust had a genetic lineage from BIF's aided with certain input from hydrothermal activity. The comparative study of major elemental composition of the basin samples and while plotting a binary diagram, it shows a relation between major oxides against iron oxides, in which iron oxides is taken as a reference oxide (Mirza, 2011). On the other hand

  2. GRACE gravity evidence for an impact basin in Wilkes Land, Antarctica

    NASA Astrophysics Data System (ADS)

    von Frese, Ralph R. B.; Potts, Laramie V.; Wells, Stuart B.; Leftwich, Timothy E.; Kim, Hyung Rae; Kim, Jeong Woo; Golynsky, Alexander V.; Hernandez, Orlando; Gaya-Piqué, Luis R.

    2009-02-01

    New details on the east Antarctic gravity field from the Gravity Recovery and Climate Experiment (GRACE) mission reveal a prominent positive free-air gravity anomaly over a roughly 500-km diameter subglacial basin centered on (70°S, 120°E) in north central Wilkes Land. This regional inverse correlation between topography and gravity is quantitatively consistent with thinned crust from a giant meteorite impact underlain by an isostatically disturbed mantle plug. The inferred impact crater is nearly three times the size of the Chicxulub crater and presumably formed before the Cretaceous formation of the east Antarctic coast that cuts the projected ring faults. It extensively thinned and disrupted the Wilkes Land crust where the Kerguelen hot spot and Gondwana rifting developed but left the adjacent Australian block relatively undisturbed. The micrometeorite and fossil evidence suggests that the impact may have occurred at the beginning of the greatest extinction of life on Earth at ~260 Ma when the Siberian Traps were effectively antipodal to it. Antipodal volcanism is common to large impact craters of the Moon and Mars and may also account for the antipodal relationships of essentially half of the Earth's large igneous provinces and hot spots. Thus, the impact may have triggered the ``Great Dying'' at the end of the Permian and contributed to the development of the hot spot that produced the Siberian Traps and now may underlie Iceland. The glacial ice up to a few kilometers thick that has covered the crater for the past 30-40 Ma poses formidable difficulties to sampling the subglacial geology. Thus, the most expedient and viable test of the prospective crater is to survey it for relevant airborne gravity and magnetic anomalies.

  3. Alpine tectonics of the Pannonian basin

    SciTech Connect

    Tari, G. (Rice Univ., Houston, TX (United States))

    1993-09-01

    The Neogene evolution of the Pannonian basin is fairly well understood in terms of back-arc extension behind the Carpathian thrust-fold belt. This middle Miocene-Holocene basin, however, is superimposed on an earlier middle Eocene-early Miocene basin traditionally called the Paleogene basin of Hungary. Although the Paleogene stratigraphy of the basin is well known, its structural evolution is not clear; however, a transtensional origin is assumed analogous to the overlying Pannonian basin. The existing data set on the Paleogene basin can be integrated easily into a compressional basin model. Other intra-Carpathian Paleogene basins, such as the Transylvanian and Slovenian basins, are now considered to be flexural in origin. Systematic interpretation of reflection seismic data shows that these Tertiary basins are superimposed on a Cretaceous Alpine thrust-fold belt. The internal geometry of this belt in the basement of the Pannonian basin indicates a close relationship to the surrounding mountain belts (Alps, Carpathians, and Dinarides). Whereas the neogene Pannonian basin is in a mature stage of exploration, the underlying Paleogene flexural basins are much less explored. Furthermore, the Cretaceous thrust-fold belts should be regarded as frontier areas for future oil and gas exploration efforts.

  4. Hydrogeologic framework of sedimentary deposits in six structural basins, Yakima River basin, Washington

    USGS Publications Warehouse

    Jones, M.A.; Vaccaro, J.J.; Watkins, A.M.

    2006-01-01

    The hydrogeologic framework was delineated for the ground-water flow system of the sedimentary deposits in six structural basins in the Yakima River Basin, Washington. The six basins delineated, from north to south are: Roslyn, Kittitas, Selah, Yakima, Toppenish, and Benton. Extent and thicknesses of the hydrogeologic units and total basin sediment thickness were mapped for each basin. Interpretations were based on information from about 4,700 well records using geochemical, geophysical, geologist's or driller's logs, and from the surficial geology and previously constructed maps and well interpretations. The sedimentary deposits were thickest in the Kittitas Basin reaching a depth of greater than 2,000 ft, followed by successively thinner sedimentary deposits in the Selah basin with about 1,900 ft, Yakima Basin with about 1,800 ft, Toppenish Basin with about 1,200 ft, Benton basin with about 870 ft and Roslyn Basin with about 700 ft.

  5. Improved Basin Analog System to Characterize Unconventional Gas Resource

    E-print Network

    Wu, Wenyan 1983-

    2012-10-02

    and consistently identify analogous reference basins for a target basin. My research focused on continuing that work, comprehensively improving the basin analog system in four areas: the basin analog method; the database; the software functionality...

  6. Exploration potential of offshore northern California basins

    SciTech Connect

    Bachman, S.B.; Crouch, J.K.

    1988-01-01

    A series of exploratory wells was drilled in the northern California offshore basins in the 1960s following leasing of federal tracts off northern California, Oregon, and Washington. The drilling, although encountering numerous oil shows, was considered at the time to indicate low prospectivity in an area that extended as far south as the offshore Santa Maria basin. However, subsequent major discoveries in this decade in the offshore Santa Maria basin, such as the Point Arguello field, indicate that these offshore basins may be highly prospective exploration targets. Many of the key features of Monterey production in central and southern California are also present in the offshore basins of northern California. A new 5-year leasing plan has scheduled leasing in the northern California OCS starting in early 1989. The first basins on the schedule, the Point Arena and Eel River basins, differ in some respects. The Point Arena basin is more typical of a Monterey basin, with the potential for fractured chert reservoirs and organic-rich sections, deep burial of basinal sections to enhance the generation of higher gravity oils, and complex folding and faulting. The Eel River basin is more clastic-rich in its gas-producing, onshore extension. Key questions in the Eel River basin include whether the offshore, more distal stratigraphy will include Monterey-like biogenic sediments, and whether the basin has oil potential in addition to its proven gas potential. The Outer Santa Cruz basin shares a similar stratigraphy, structure, and hydrocarbon potential with the Point Arena basin. The Santa Cruz-Bodega basin, also with a similar stratigraphy, may have less exploration potential because erosion has thinned the Monterey section in parts of the basin.

  7. Water Accounting from Ungauged Basins

    NASA Astrophysics Data System (ADS)

    Bastiaanssen, W. G.; Savenije, H.

    2014-12-01

    Water scarcity is increasing globally. This requires a more accurate management of the water resources at river basin scale and understanding of withdrawals and return flows; both naturally and man-induced. Many basins and their tributaries are, however, ungauged or poorly gauged. This hampers sound planning and monitoring processes. While certain countries have developed clear guidelines and policies on data observatories and data sharing, other countries and their basin organization still have to start on developing data democracies. Water accounting quantifies flows, fluxes, stocks and consumptive use pertaining to every land use class in a river basin. The objective is to derive a knowledge base with certain minimum information that facilitates decision making. Water Accounting Plus (WA+) is a new method for water resources assessment reporting (www.wateraccounting.org). While the PUB framework has yielded several deterministic models for flow prediction, WA+ utilizes remote sensing data of rainfall, evaporation (including soil, water, vegetation and interception evaporation), soil moisture, water levels, land use and biomass production. Examples will be demonstrated that show how remote sensing and hydrological models can be smartly integrated for generating all the required input data into WA+. A standard water accounting system for all basins in the world - with a special emphasis on data scarce regions - is under development. First results of using remote sensing measurements and hydrological modeling as an alternative to expensive field data sets, will be presented and discussed.

  8. Fuel storage basin seismic analysis

    SciTech Connect

    Kanjilal, S.K.; Winkel, B.V.

    1991-08-01

    The 105-KE and 105-KW Fuel Storage Basins were constructed more than 35 years ago as repositories for irradiated fuel from the K East and K West Reactors. Currently, the basins contain irradiated fuel from the N Reactor. To continue to use the basins as desired, seismic adequacy in accordance with current US Department of Energy facility requirements must be demonstrated. The 105-KE and 105-KW Basins are reinforced concrete, belowground reservoirs with a 16-ft water depth. The entire water retention boundary, which currently includes a portion of the adjacent reactor buildings, must be qualified for the Hanford Site design basis earthquake. The reactor building interface joints are sealed against leakage with rubber water stops. Demonstration of the seismic adequacy of these interface joints was initially identified as a key issue in the seismic qualification effort. The issue of water leakage through seismicly induced cracks was also investigated. This issue, coupled with the relatively complex geometry of the basins, dictated a need for three-dimensional modeling. A three-dimensional soil/structure interaction model was developed with the SASSI computer code. The development of three-dimensional models of the interfacing structures using the ANSYS code was also found to be necessary. 8 refs., 7 figs., 1 tab.

  9. Stormwater detention basin sediment removal

    SciTech Connect

    Gross, W.E. [SCS Engineers, West Nyack, NY (United States)

    1995-12-31

    In the past, stormwater runoff from landfills has been treated mainly by focusing on reducing the peak storm discharge rates so as not to hydraulically impact downstream subsheds. However, with the advent of stricter water quality regulations based on the Federal Clean Water Act, and the related NPDES and SPDES programs, landfill owners and operators are now legally responsible for the water quality of the runoff once it leaves the landfill site. At the Fresh Kills Landfill in New York City, the world`s largest covering over 2000 acres, landfilling activities have been underway since 1945. With the main objective at all older landfill sites having focused on maximizing the available landfill footprint in order to obtain the most possible airspace volume, consideration was not given for the future siting of stormwater basin structures. Therefore, when SCS Engineers began developing the first comprehensive stormwater management plan for the site, the primary task was to locate potential sites for all the stormwater basins in order to comply with state regulations for peak stormwater runoff control. The basins were mostly constructed where space allowed, and were sized to be as large as possible given siting and subshed area constraints. Seventeen stormwater basins have now been designed and are being constructed to control the peak stormwater runoff for the 25-year, 24-hour storm as required by New York State. As an additional factor of safety, the basins were also designed for controlled discharge of the 100-year, 24 hour storm.

  10. Rainbow Basin, CA mapping project

    NSDL National Science Digital Library

    Joan Fryxell

    Rainbow Basin is just north of Barstow, CA, and is an excellent badlands-style exposure of the Barstow syncline in the Miocene Barstow Formation. In the first mapping class, their assignment is to map the basic geology of the basin, using a couple of distinctive marker beds within the Barstow Formation. Several faults postdate the fold, and three different ages of alluvial deposits occur within the basin. We camp in the nearby Owl Canyon campground, and spend three days in the field. More time could be spent with an introductory class, but three suffices to get most of the basin on the map. They are charged with writing up descriptions of the rock units they encounter. From the field map, students transfer information to an office copy, add a map explanation, and draw a cross-section through the map area. Mapping is done on a topographic map, specifically developed for the basin, with 10-foot contour intervals. This is a proprietary map, so permission is needed for its use.

  11. Origin of the earth's ocean basins

    NASA Technical Reports Server (NTRS)

    Frex, H.

    1977-01-01

    The earth's original ocean basins were mare-type basins produced 4 billion years ago by the flux of asteroid-sized objects responsible for the lunar mare basins. Scaling upwards from the observed number of lunar basins for the greater capture cross-section and impact velocity of the Earth indicates that at least 50 percent of an original global crust would have been converted to basin topography. These basins were flooded by basaltic liquids in times short compared to the isostatic adjustment time for the basin. The modern crustal dichotomy (60 percent oceanic, 40 percent continental crust) was established early in the history of the earth, making possible the later onset of plate tectonic processes. These later processes have subsequently reworked, in several cycles, principally the oceanic parts of the earth's crust, changing the configuration of the continents in the process. Ocean basins (and oceans themselves) may be rare occurrences on planets in other star systems.

  12. Effect of basin physical characteristics on solute fluxes in nine alpine\\/subalpine basins, Colorado, USA

    Microsoft Academic Search

    Julie K. Sueker; David W. Clow; Joseph N. Ryan; Robert D. Jarrett

    2001-01-01

    Alpine\\/subalpine basins may exhibit substantial variability in solute fluxes despite many apparent similarities in basin characteristics. An evaluation of controls on spatial patterns in solute fluxes may allow development of predictive tools for assessing basin sensitivity to outside perturbations such as climate change or deposition of atmospheric pollutants. Relationships between basin physical characteristics, determined from geographical information system (GIS) tools,

  13. Dynamic reorganization of river basins.

    PubMed

    Willett, Sean D; McCoy, Scott W; Perron, J Taylor; Goren, Liran; Chen, Chia-Yu

    2014-03-01

    River networks evolve as migrating drainage divides reshape river basins and change network topology by capture of river channels. We demonstrate that a characteristic metric of river network geometry gauges the horizontal motion of drainage divides. Assessing this metric throughout a landscape maps the dynamic states of entire river networks, revealing diverse conditions: Drainage divides in the Loess Plateau of China appear stationary; the young topography of Taiwan has migrating divides driving adjustment of major basins; and rivers draining the ancient landscape of the southeastern United States are reorganizing in response to escarpment retreat and coastal advance. The ability to measure the dynamic reorganization of river basins presents opportunities to examine landscape-scale interactions among tectonics, erosion, and ecology. PMID:24604204

  14. Hydrocarbon entrapment in Alberta deep basin

    Microsoft Academic Search

    Gies

    1984-01-01

    Entrapment of hydrocarbon accumulations in the deepest region of the Alberta sedimentary basin is linked to certain principles of subsurface fluid flow behavior in generally tight sandstones, and to active hydrocarbon generation in adjacent source beds. Similar geologic conditions and associated deep-basin-type hydrocarbon accumulations no doubt exist in the deeper portions of other sedimentary basins. Deep-basin concepts of hydrocarbon entrapment

  15. The Borealis Basin of Mars

    NASA Technical Reports Server (NTRS)

    Wilhelms, D. E.; Squyres, S. W.

    1984-01-01

    Why the lowlands of Mars are concentrated in the Northern Hemisphere and the highlands in the Southern Hemisphere is probably the most fundamental unsolved problem in martian geology. No explanation that accounts both for this asymmetric distribution and for the isostatic equilibrium across the scarp or sloping transition zone dividing the two provinces has been generally accepted; thinning of the lithosphere in the northern hemisphere by internal processes has been suggested. Because other lowland-highland distributions on Mars, Moon, and Mercury are controlled by impact basins, it is proposed that a giant basin formed early in Mars' history has caused the martian hemispheric dichotomy as well.

  16. Geological Modeling of Dahomey and Liberian Basins 

    E-print Network

    Gbadamosi, Hakeem B.

    2010-01-16

    The objective of this thesis is to study two Basins of the Gulf of Guinea (GoG), namely the Dahomey and the Liberian Basins. These Basins are located in the northern part of the GoG, where oil and gas exploration has significantly increased...

  17. THE CASE OF BLUE NILE RIVER BASIN

    Microsoft Academic Search

    Abebe Sine; Semu Ayalew

    Blue Nile River Basin has been regionalized into similar flood producing characteristics based on statistical values of at site data. The basin was delineated in to five homogeneous regions. Accordingly, region one comprises the widest portion of the basin, covering 37.6 % of the area. It includes the upper Guder catchment, middle and lower Didesa, lower part of the main

  18. GUNNISON RIVER (COLORADO) BASIN SELENIUM TARGETING

    EPA Science Inventory

    The Gunnison and Uncompahgre River Basins Targeting Project will gather water quality data necessary to characterize the selenium loads that are being contributed from within the basins. Evaluation of the variabiliy of selenium loading in the basins will guide the implementation...

  19. IMPROVEMENTS IN PUMP INTAKE BASIN DESIGN

    EPA Science Inventory

    Pump intake basins (or wet wells or pump sumps) designed in accordance with accepted criteria often pose many operation and maintenance problems. The report summarizes field surveys of three trench-type pump intake basins representative of 29 such basins that have been in satisfa...

  20. IMPROVEMENTS IN PUMP INTAKE BASIN DESIGN

    EPA Science Inventory

    Pump intake basins (or wet wells or pump sumps) designed in accordance with accepted criteria often pose many operation and maintenance problems. he report summarizes field surveys of three trench-type pump intake basins representative of 29 such basins that ave been in satisfact...

  1. Caribbean basin framework, 4: Maracaibo basin, northwestern Venezuela

    SciTech Connect

    Lugo, J. (Univ. of Texas, Austin (United States))

    1991-03-01

    The Maracaibo basin is presently located in a topographic depression on the Maracaibo block, a triangular, fault-bounded block within the Caribbean-South America plate boundary of northwestern Venezuela. Intense oil exploration over the last 50 years has produced a large amount of seismic and well data that can be used to constrain four Jurassic to Recent tectonic and depositional events that affected the region: (1). Late Jurassic rift phase and subsidence along normal faults striking north-northeast across the floor of the basin; (2) Cretaceous to early Eocene subsidence recorded by shallow to deep marine carbonate and clastic rocks that thicken from south to north and completely cover Permian rocks of the Merida arch; (3) Eocene folding, thrusting, and initial reactivation of Jurassic normal faults as convergent strike-slip and reverse faults. Eocene clastic sediments are thickest in a narrow northwest-trending foredeep on the northeastern margin of the basin; (4) Late Miocene to Recent northwest-southeast convergence is marked by continued reactivation of Jurassic normal faults as reverse and left-lateral strike-slip faults, uplift of mountain ranges bordering the basin, and deposition of up to 10 km of clastic sediment.

  2. New bifurcations of basin boundaries involving Wada and a smooth Wada basin boundary

    NASA Astrophysics Data System (ADS)

    Zou, Hai-Lin; Xu, Jian-Xue; Jiang, Jun

    2008-01-01

    This paper demonstrates and analyses double heteroclinic tangency in a three-well potential model, which can produce three new types of bifurcations of basin boundaries including from smooth to Wada basin boundaries, from fractal to Wada basin boundaries in which no changes of accessible periodic orbits happen, and from Wada to Wada basin boundaries. In a model of mechanical oscillator, it shows that a Wada basin boundary can be smooth.

  3. Polyphemidae of the Pontocaspian Basin

    Microsoft Academic Search

    Mordukhai-Boltovskoi

    1965-01-01

    Polyphemidae constitute one of the most characteristic groups of the peculiar auchtochthonous fauna of the Caspian Sea. While in all open seas and freshwaters of the globe they are represented by 8 species only, in Caspian Sea 24 polyphemid species are found and about 15 intraspecific forms. Except one species, all of them are endemic for the Pontocaspian basin (and

  4. The Macleod evaporite basin, Western Australia

    SciTech Connect

    Not Available

    1988-01-01

    MacLeod is one of the few Quaternary basins that resembles the evaporite basins of earlier epochs in that a large-scale evaporite system, sustained by sea water inflow, continues to operate there today. New insights from MacLeod research relate to the definitive role of seepage in sustaining a large basin system and in controlling systems status. This book analyzes MacLeod as a desiccation basin and provides an actualistic basis for the desiccation-basin concept. It reviews contemporary environments and reconstructs paleoenvironments as dynamic, open systems defined in terms of interrelated water and salt budgets.

  5. Comparative analysis of the Late Cretaceous to Recent post-breakup basin evolution of the South-American and South-African margin of the southern Atlantic

    NASA Astrophysics Data System (ADS)

    Kukla, Peter; Back, Stefan

    2010-05-01

    Recently, considerable attempts have been made to compare the sedimentary basin evolution and the associated tectonic framework on both sides of the South-Atlantic (e.g. Mohriak et al., 2008, and references therein). Yet there are still unresolved questions. Amongst the most striking observations is that multiple phases of volcanism, uplift and subsidence are recorded after the break-up of the southern South Atlantic margin segment on both sides of the Florianopolis - Walvis Ridge volcanic complex, features that are regarded as atypical when compared to published examples of other post-breakup continental margin successions. However, the tectono-sedimentary and magmatic styles markedly differ from south to north across the volcanic complex. In seismic reflection data, voluminous extrusives are manifested by the occurrence of large wedges of seaward dipping reflector sequences south of the volcanic complex, whilst large volumes of Cretaceous mafic alkaline rocks only occur north of the Florianopolis - Walvis Ridge complex. It can be expected that these differences are of a broad importance for the understanding of both break-up and post-breakup processes. This presentation focuses on a comparison of the post-breakup stratigraphic development of the South American and South African continental margins that both record thick post-rift sedimentary successions. Basins along the southern African margin are much narrower in comparison to their South American counterparts, constituting a pronounced margin asymmetry across the Atlantic. Adding to the heterogeneity of the system, the northernmost segment of the South Atlantic rift and salt basins is also characterized by a pronounced asymmetry, with the Brazilian margin now comprising narrower and deeper rift basins with less salt than the Congo-Gabon conjugate margin. In general, it seems that in the salt-prone areas both offshore South America and southern Africa, salt-related tectonics are amongst the key parameters controlling differential post-rift margin development, adding significant complexity to the conjugate margin systems. Mohriak, W., Nem?ok M. & Enciso, G. (2008): South Atlantic divergent margin evolution: rift-border uplift and salt tectonics in the basins of SE Brazil. In: Pankhurst R.J., Trouw, R.A.J., Brito Neves, B.B. & De Wit, M.J. (eds) West Gondwana: pre-cenozoic correlations across the South Atlantic region. Geological Society, London, Special Publications, 294, 365-398.

  6. Thin-skinned extension of Vienna basin

    SciTech Connect

    Royden, L.

    1984-04-01

    The Vienna basin is an area of middle Miocene (Karpatian-Badenian, 17.5-13.0 Ma) extension and contains up to 6 km (20,000 ft) of Miocene to Quaternary sedimentary rocks. This basin is partly superimposed on the north-vergent flysch belt of the outer West Carpathians and partly on more internal Carpathian nappes. The obvious rhombohedral shape of the Vienna basin, the left-stepping pattern of en echelon faults within the basin, and the southward migration of basin extension through time strongly suggest that this basin is a pull-apart feature formed during middle Miocene sinistral strike-slip faulting along a northeast-trending fault (or fault system). This interpretation is supported by geologic mapping in the Carpathians indicating several tens of kilometers of Tertiary sinistral displacement along a fault that trends northeast from the Vienna basin. This fault appears to have functioned mainly as a middle Miocene tear fault within the Carpathian nappes, separating the areas of active northvergent thrusting east of the Vienna basin from areas west of the basin where thrusting had already been completed. Reflection seismic lines show that the autochthonous European plate basement continues beneath the allochthonous Carpathian nappes and beneath the Vienna basin, and that the European plate is not significantly disrupted by the normal faults that bound the basin. Thus both the normal faults that bound the basin and the associated strike-slip faults appear to merge into a gently southeast-dipping detachment horizon at depth. Detailed analyses of subsidence and heat-flow data indicate that little or no heating of the lithosphere occurred during extension of the Vienna basin, and support the interpretation that extension was confined to shallow crustal levels.

  7. Thin-skinned extension of Vienna basin

    SciTech Connect

    Royden, L.

    1984-04-01

    The Vienna basin is an area of middle Miocene (Karpatian-Badenian, 17.5-13.0 Ma) extension and contains up to 6 km (20,000 ft) of Miocene to Quaternary sedimentary rocks. This basin is partly superimposed on the north-vergent flysch belt of the outer West Carpathians and partly on more internal Carpathian nappes. The obvious rhombohedral shape of the Vienna basin, the left-stepping pattern of en echelon faults within the basin, and the southward migration of basin extension through time strongly suggest that this basin is a pull-apart feature formed during middle Miocene sinistral strike-slip faulting along a northeast-trending fault (or fault system). This interpretation is supported by geologic mapping in the Carpathians indicating several tens of kilometers of Tertiary sinistral displacement along a fault that trends northeast from the Vienna basin. This fault appears to have functioned mainly as a middle Miocene tear fault within the Carpathian nappes, separating the areas of active northvergent thrusting east of the Vienna basin from areas west of the basin where thrusting had already been completed. Reflection seismic lines show that the autochthonous European plate basement continues beneath the allochthonous Carpathian nappes and beneath the Vienna basin, and that the European plate is not significantly disrupted by the normal faults that bound the basin. Thus both the normal faults that bound the basin and the associated strike-slip faults appear to merge into a gently southeast-dipping detachment horizon at depth. In this way extension of the Vienna basin appears to have been restricted mainly to shallow crustal levels above that detachment horizon at depth.

  8. Palaeobotanical evidence of wildfires in the Late Palaeozoic of South America - Early Permian, Rio Bonito Formation, Paraná Basin, Rio Grande do Sul, Brazil

    NASA Astrophysics Data System (ADS)

    Jasper, André; Uhl, Dieter; Guerra-Sommer, Margot; Mosbrugger, Volker

    2008-12-01

    Fossil charcoal, as direct evidence of palaeowildfires, has repeatedly been reported from several plant-bearing deposits from the Late Palaeozoic of the Northern Hemisphere. In contrast charcoal reports from the Late Palaeozoic deposits of the Southern Hemisphere are relatively rare in comparison to the Northern Hemisphere. Although the presence of pyrogenic coal macerals has repeatedly been reported from Late Palaeozoic coals from South America, no detailed anatomical investigations of such material have been published so far. Here is presented an anatomical analysis of charcoal originating from Early Permian sediments of the Quitéria Outcrop, Rio Bonito Formation, Paraná Basin, located in the central-eastern portion of Rio Grande do Sul, Brazil. This charcoal comes from two different coaly facies, and it was possible to scrutinize between three types, based on anatomical characters of the charcoal. Two of these charcoal types can be correlated to gymnosperm woods, and the other type corresponds to strongly permineralized bark with characteristic features of lycopsids. The presence of charcoal in different facies, ranging from parautochtonous to allochtonous origin, indicates that different vegetation types, i.e. plants which grew under wet conditions in the lowland as well as in the more dry hinterland, have experienced wildfires. Taking into account previous petrographic and lithological analyses from the facies in which the charcoal occurs and from the conditions of the wood and bark fragments, it was possible to speculate that the intensity of such wildfires most probably corresponds to forest-crown fires. Moreover, it is possible to state that wildfires have been a more or less common element in distinct Late Palaeozoic terrestrial ecosystems in the South American part of Gondwana. The data support previous assumptions on the occurrence of wildfires in the Early Permian of the Paraná Basin which were based solely on coal-petrographic data.

  9. Kinematic Analysis of Normal Faults from 3D Seismics within the Otway Basin, Australia: Evidence for Oblique Movement in a Passive Margin

    NASA Astrophysics Data System (ADS)

    Tanner, D. C.; Ziesch, J.; Beilecke, T.; Krawczyk, C. M.

    2014-12-01

    The onshore Otway Basin is dominated by normal faults and only minimal strike-slip faulting has been reported. The basin is part of the NW-striking, passive margin that records the break-up of Gondwana and the Antarctic-Australian separation between Late Jurassic and Miocene times. From a 3D seismic cube (ca. 8 km x 7 km x 4 km depth) around the CO2CRC Otway site in SE Australia, we interpreted eight major, Cretaceous and Tertiary stratigraphic horizons (all syn-rift) and over 24 major normal faults. Detailed analysis of the fault system in our 3D geological model shows that the area is characterised by southwest-dipping, normal faults that have a listric character in the SW and planar character in the NE. North-dipping, antithetic faults developed secondarily due to movement on the major faults. Syn-sedimentary movement caused fourfold strata thicknesses in the hanging-wall of the faults. Fault offset increases towards the south; up to 800 m in the lower stratigraphy. Most faults, however, die out before the Eocene. Using different techniques we determined that 60% the major faults didn't move in a pure dip-slip fashion, rather the movement contained a component of dextral strike-slip. In particular, juxtaposition maps of the stratigraphic horizons on the fault surfaces shows that in the obliquely-displaced faults the tip-lines of the faults are extremely asymmetric, with one flatly-dipping tip-line and one steep, overturned tip-line. Dip-slip faults demonstrate symmetrical convergence of the tip-lines. However faults with different kinematics are not grouped, but heterogeneously distributed over the model, suggesting strain-partitioning took place. This evidences that faults react differently when the stress field in the passive margin changes direction, but in a way that suggests that they are interacting.

  10. Formation of lunar basin rings

    NASA Technical Reports Server (NTRS)

    Hodges, C. A.; Wilhelms, D. E.

    1978-01-01

    The outer rings of impact basins are interpreted as the bounding rings of the excavated basin cavities analogous to Copernicus-type crater rim crests. It is suggested that the inner rings are strata from depth uplifted during excavation of the transient cavity. Spacing relations and morphology appear to indicate a transition from central peaks to rings but not from terraces to rings. Evidence related to terrestrial craters with rings or peaks produced by meteorite impacts suggests that one or more crater rims may form inside the main, outer crater rim, resulting in nested craters. There is some evidence that peaks grade into inner rings as material is ejected from their cores in progressively larger impacts. Multiply layered materials may produce multiple rings by differential excavation of the layers.

  11. Experimental Drainage Basins in Israel

    NASA Astrophysics Data System (ADS)

    Laronne, J. B.; Lekach, J.; Cohen, H.; Gray, J.

    2002-12-01

    Within the hyper-arid to semiarid areas of Israel are three experimental drainage basins. They are the Nahal (stream in Hebrew) Yael, subdivided into five sub-basins, Rahaf-Qanna'im (main and tributary, respectively) and Eshtemoa. These basins vary in drainage area and climate, and in monitoring duration and type. All are drained by gravel-bed channels. As the size of monitored drainage area is limited, 3-4 additional representative basins covering areas of 300, 1000, 2000 and 8000 square kilometers will likely be implemented in the next decade. The basins have precipitation, runoff, sediment and fluviomorphological records. Each was conceived for differing purposes, but all share the common two objectives for the continuous monitoring: 1. Many hydrological issues may be approached if, and only if, there are prototype databases on a wide spectrum of hydrological processes; and 2. There is a need for long-term records to assess large floods and subsequent hydrologic and geomorphic recovery. Lessons derived from a large number of research projects on these experimental basins focus on characteristics of runoff in arid climates. For example, the effect of the spatial distribution of rainfall on runoff generation becomes increasingly important with aridity. Rainfall angle on hillslopes and storm intensity and direction derived from rainfall recorders and radar backscatter are crucial for explanation of runoff response. Runoff hydrographs tend to have more bores, shorter-duration peaks, briefer recessions, longer dry periods, and are more variable in terms of flood volume and peaks with increased aridity. Suspended-sediment fluxes, yields and concentrations are relatively large in the semiarid realm, reaching maxima at the beginning of a flood season and after long dry spells. Bedload fluxes are exceptionally high from dryland basins in which hillslopes are minimally vegetated and where bedload transport takes place in channels lacking an armor layer. Bedload/suspended-sediment load ratios increase with aridity. Bedload yield may represent up to 70% of the total load. Hillslope to channel connectivity is high in drylands. In the hyperarid region suspended-sediment sources are hillslopes and the coarser, sandy fraction of the channel bedmaterial. The depth of channel bed activity is indicated by a fluvio-pedogenic unit beneath the channel surface. National and regional hydrological research needs will dictate future global monitoring in experimental basins. International collaboration may bring about considerable cost reduction by exclusion of monitoring aspects that can be evaluated based on the monitoring in other, similar conditions. Advanced international collaboration on validation and calibration of and consistency in monitoring means, as well as syntheses of lessons derived from international collaboration, such as from an International Watershed Research Network, are required for maximizing our understanding of water and sediment responses in varied global regions.

  12. CLEAR LAKE BASIN 2000 PROJECT

    SciTech Connect

    LAKE COUNTY SANITATION DISTRICT

    2003-03-31

    The following is a final report for the Clear Lake Basin 2000 project. All of the major project construction work was complete and this phase generally included final details and testing. Most of the work was electrical. Erosion control activities were underway to prepare for the rainy season. System testing including pump stations, electrical and computer control systems was conducted. Most of the project focus from November onward was completing punch list items.

  13. Stratigraphic Analysis of Upper Cretaceous Rocks in the Mahajanga Basin, Northwestern Madagascar: Implications for Ancient and Modern Faunas.

    PubMed

    Rogers; Hartman; Krause

    2000-05-01

    Upper Cretaceous strata of the Mahajanga Basin, northwestern Madagascar, yield some of the most significant and exquisitely preserved vertebrate fossils known from Gondwana. The sedimentology of these strata and their stratigraphic relations have been the focus of renewed geological investigations during the course of five expeditions since 1993. We here designate stratotypes and formalize the terrestrial Maevarano Formation, with three new members (Masorobe, Anembalemba, Miadana), and the overlying marine Berivotra Formation. The Maevarano Formation accumulated on a broad, semiarid alluvial plain bounded to the southeast by crystalline highlands and to the northwest by the Mozambique Channel. The Berivotra Formation was deposited in an open marine setting that evolved from a clastic- to a carbonate-dominated shelf, resulting in deposition of the overlying Betsiboka limestone of Danian age. New stratigraphic data clearly indicate that the Maevarano Formation correlates, at least in part, with the Maastrichtian Berivotra Formation, and this in turn indicates that the most fossiliferous portions of the Maevarano Formation are Maastrichtian in age, rather than Campanian as previously reported. This revised age for the Maevarano vertebrate assemblage indicates that it is approximately contemporaneous with the vertebrate fauna recovered from the Deccan basalt volcano-sedimentary sequence of India. The comparable age of these two faunas is significant because the faunas appear to be more similar to one another than either is to those from any other major Gondwanan landmass. The revised age of the Maevarano Formation, when considered in the light of our recent fossil discoveries, further indicates that the ancestral stocks of Madagascar's overwhelmingly endemic modern vertebrate fauna arrived on the island in post-Mesozoic times. The basal stocks of the modern vertebrate fauna are conspicuously absent in the Maevarano Formation. Finally, the revised age of the Maevarano Formation serves to expand our global perspective on the K/T event by clarifying the age of a diverse, and arguably the best preserved, sample of Gondwanan vertebrates from the terminal Cretaceous. PMID:10769157

  14. UPPER SNAKE RIVER PRIORITY BASIN ACCOMPLISHMENT PLAN, APRIL 1973

    EPA Science Inventory

    The Upper Snake Accomplishment Basin (17040104, 170402, 170501) is defined as the Idaho and Oregon portions of 2 STORET Basins, the Upper Snake Basin and the Central Snake Basin. The Basin drains approximately 62,100 square miles in Southern Idaho and Southeastern Oregon. Four ...

  15. Biological science in the Great Basin

    USGS Publications Warehouse

    U.S. Geological Survey

    2005-01-01

    The Great Basin is an expanse of desert and high moun-tains situated between the Rocky Mountains and the Sierra Nevada of the western United States. The most explicit description of the Great Basin is that area in the West where surface waters drain inland. In other words, the Great Basin is comprised of many separate drainage areas - each with no outlet. What at first glance may appear as only a barren landscape, the Great Basin upon closer inspection reveals island mountains, sagebrush seas, and intermittent aquatic habitats, all teeming with an incredible number and variety of plants and animals. Biologists at the USGS are studying many different species and ecosystems in the Great Basin in order to provide information about this landscape for policy and land-management decision-making. The following stories represent a few of the many projects the USGS is conducting in the Great Basin.

  16. Strange nonchaotic attractors with Wada basins

    NASA Astrophysics Data System (ADS)

    Zhang, Yongxiang

    2013-09-01

    We demonstrate strange nonchaotic attractors with Wada basins (SNAsWB), and verify the abundance of SNAsWB in a quasiperiodically forced Holmes map. We identify the routes to the creation of the SNAsWB in a two-parameter space. The SNAsWB are characterized by the maximal Lyapunov exponent, by the estimation of the phase sensitivity exponent, and by the singular-continuous spectra. We observe that the SNAs’ basins are totally Wada basins in a large range of parameters. The topological structures of the SNAs’ Wada basins are distinguished by the basin cell method. We investigate the underlying mechanism for the abundance of SNAsWB, which is responsible for different types of basin cell in the absence of forcing. This suggests that the SNAs cannot be predicted reliably for specific initial conditions. These SNAsWB can thus be expected to occur more commonly in dynamical systems.

  17. Quaternary Faults and Basin-fill Sediments of the Las Vegas Basin, Southern Nevada

    Microsoft Academic Search

    W. J. Taylor; E. Fossett; B. Luke; C. Snelson; T. Rasmussen; D. McCallen; A. Rodgers; J. Louie

    2003-01-01

    The N-S elongated extensional Las Vegas basin, southern Nevada, contains 100's of meters of Cenozoic basin-fill sediments that are cut by several Quaternary (Q) faults. These faults define or influence the basin geometry. The basin is generally an asymmetrical half graben defined by the W-dipping, Q Frenchman Mountain fault (FMF) along its E side and a series of smaller offset

  18. Deformed river basins of the Himalaya

    NASA Astrophysics Data System (ADS)

    Walcott, R.; Sinclair, H.

    2009-04-01

    Identification of the controls on basin morphology in mountain belts is needed to understand how landscapes evolve under changing conditions. Although river basins vary enormously in area, many of their morphological relationships, such as Hack's law, are scale invariant irrespective of mountain type. This suggests that, in most mountain belts, the fundamental process(es) that control basin morphology are also scale invariant and therefore largely insensitive to variations in tectonic activity. However, river basins in the Himalaya are anomalously wide when compared with basins developed on the flanks of other semi-linear ranges. We present a detailed study of Himalayan river basin morphology to determine how the evolution of this orogen may have influenced the shape of these unusual basins. We investigate, in particular, the statistical geometric properties of basins, such as the length, width and area of basins, with respect to the scale and the location of the basin within the mountain belt. Our results show that the anomalously wide basins found over much of the Himalaya have a limited scale range and distribution. These data therefore provide an indication of the significant control that the evolution of this mountain range has had on basin morphology at the local scale. The fact that these catchments have departed from what is perceived as a stable scaling relationship implies that, while their rivers can incise at a rate broadly comparable to the rate of rock uplift, their drainage divides can not migrate fast enough to reconfigure in response to tectonic shortening. As a result, long-term crustal shortening has significantly deformed the river network within the central and western Himalaya.

  19. Sandakan basin prospects rise following modern reappraisal

    SciTech Connect

    Walker, T. (WMC Petroleum, Kuala Lumpur (Malaysia))

    1993-05-10

    Borneo is fringed by six large Neogene deltaic basins, all but one producing substantial hydrocarbons. The Sandakan basin off Northeast Borneo is the exception, but the latest exploration results suggest that it will not remain so. The paper describes its complex history; its exploration history; exploration results; stratigraphy; and geologic structures and traps. The Sandakan basin is conservatively estimated to contain 1 billion bbl of oil and 3tcf of gas.

  20. Geological Modeling of Dahomey and Liberian Basins

    E-print Network

    Gbadamosi, Hakeem B.

    2010-01-16

    of Guinea. (Brownfield and Charpentier, 2007) ......................................................... 5 1.3 The location of the main structural domain of the Niger Delta from the onshore to the offshore depocenters. (Corredor et al., 2005... is mainly the Niger Delta (as shown in Figure 1.3) and the Lower part extends from Douala to Walvis ridge in Namibe Basin which is also referred to as the Aptian Salt Basin (as shown in Figure 1.4). Because we focus on the Liberian and Dahomey Basins...

  1. A commentary on the tectono-sedimentary record of the pre-2.0 Ga continental growth of India vis-à-vis a possible pre-Gondwana Afro-Indian supercontinent

    NASA Astrophysics Data System (ADS)

    Mazumder, Rajat; Bose, Pradip K.; Sarkar, Subir

    2000-02-01

    An integrated chronicle of major events leading to the growth of the pre-2.0 Ga Indian Craton, which is the aim of this paper, is an essential requirement to constrain the possibility of Neoarchaean unification between Africa and India. The primordial sialic crust that eventually developed into the early Indian Craton segregated from the mantle before 3.8 Ga. Intially there were two seperate Indian blocks, the northern (NIB) and the southern (SIB), and they possibly amalgamated before 2.5 Ga. Rapid and extensive crustal growth at ca 3.1, 2.5 and 2.0 Ga, in conjunction with a related rise in relative sea level due to ocean basin volume reduction, kept the continental freeboard at a moderate level. The 2.5 Ga event was the greatest in magnitude and is likely to have led to the formation of an Indian supercontinent. Four sedimentary basins, one in the NIB and three in the SIB, developed on the typical Archaean tonal ite-trondhjemite-granodiorite basement, through rifting induced by mantle upwelling. Continental freeboard was lowered as a consequence and transgressions generally followed. Rifting persisted in all the pre-2.0 Ga basins, except one (Bastar) in the SIB, which only underwent a Wilson cycle as the two blocks collided. All the SIB basins were closed by 2.0 Ga, while the basin in the NIB, which only developed at ca 2.5 Ga, still persisted. Neoarchaean continuity between the Central Indian Tectonic Zone and the Limpopo Belt appears likely from all major aspects, but for the deformation history, which still remains elusive.

  2. Late Paleozoic structural evolution of Permian basin

    SciTech Connect

    Ewing, T.E.

    1984-04-01

    The southern Permian basin is underlain by the NNW-trending Central Basin disturbed belt of Wolfcamp age (Lower Permian), the deep Delaware basin to its west, and the shallower Midland basin to its eat. The disturbed belt is highly segmented with zones of left-lateral offset. Major segments from south to north are: the Puckett-Grey Ranch zone; the Fort Stockton uplift; the Monahans transverse zone; the Andector ridges and the Eunice ridge; the Hobbs transverse zone; and the Tatum ridges, which abut the broad Roosevelt uplift to the north. The disturbed belt may have originated along rift zones of either Precambrian or Cambrian age. The extent of Lower and Middle Pennsylvanian deformation is unclear; much of the Val Verde basin-Ozona arch structure may have formed then. The main Wolfcamp deformation over thrust the West Texas crustal block against the Delaware block, with local denudation of the uplifted edge and eastward-directed backthrusting into the Midland basin. Latter in the Permian, the area was the center of a subcontinental bowl of subsidence - the Permian basin proper. The disturbed belt formed a pedestal for the carbonate accumulations which created the Central Basin platform. The major pre-Permian reservoirs of the Permian basin lie in large structural and unconformity-bounded traps on uplift ridges and domes. Further work on the regional structural style may help to predict fracture trends, to assess the timing of oil migration, and to evaluate intrareservoir variations in the overlying Permian giant oil fields.

  3. Regional geophysics and the basement of cratonic basins: a comparative study with the Michigan basin

    SciTech Connect

    Hinze, W.J.; Lidiak, E.G.

    1986-08-01

    The basement of the Michigan basin consists of four major provinces - the complex metasedimentary, metavolcanic, and igneous rocks of the Penokean orogenic assemblage in the north, the felsic anorogenic igneous rocks to the south, the highly metamorphosed schists, gneisses, and related igneous intrusions of the Grenville province in the east, and a middle Proterozoic rift zone, which transects the basin from the north to the southeast margin. Sparse basement drill holes and characteristic geophysical patterns support this interpretation. The direct geologic information on the basement of other cratonic basins is not as well known. However, regional geophysical surveys and sparse, poorly distributed basement drill holes provide information on the complex character and structural relationships of the basement of other basins. Like the Michigan basin, many cratonic basins (e.g., Illinois, Williston, and Paris basins) are underlain by dense and commonly more magnetic rocks than adjacent areas. As in the Michigan basin, these rocks are interpreted to have a profound effect on the origin and tectonic development of the basins. Geologic and geophysical evidence indicates that many of these dense basement rocks originated in rifts that formed hundreds of millions of years prior to basin development. A comparison of the basement in cratonic basins provides important constraints on the origin and tectonic development of the Michigan basin.

  4. Reserves in western basins: Part 1, Greater Green River basin

    SciTech Connect

    Not Available

    1993-10-01

    This study characterizes an extremely large gas resource located in low permeability, overpressured sandstone reservoirs located below 8,000 feet drill depth in the Greater Green River basin, Wyoming. Total in place resource is estimated at 1,968 Tcf. Via application of geologic, engineering and economic criteria, the portion of this resource potentially recoverable as reserves is estimated. Those volumes estimated include probable, possible and potential categories and total 33 Tcf as a mean estimate of recoverable gas for all plays considered in the basin. Five plays (formations) were included in this study and each was separately analyzed in terms of its overpressured, tight gas resource, established productive characteristics and future reserves potential based on a constant $2/Mcf wellhead gas price scenario. A scheme has been developed to break the overall resource estimate down into components that can be considered as differing technical and economic challenges that must be overcome in order to exploit such resources: in other words, to convert those resources to economically recoverable reserves. Total recoverable reserves estimates of 33 Tcf do not include the existing production from overpressured tight reservoirs in the basin. These have estimated ultimate recovery of approximately 1.6 Tcf, or a per well average recovery of 2.3 Bcf. Due to the fact that considerable pay thicknesses can be present, wells can be economic despite limited drainage areas. It is typical for significant bypassed gas to be present at inter-well locations because drainage areas are commonly less than regulatory well spacing requirements.

  5. An entropy-based morphological analysis of river basin networks 

    E-print Network

    Fiorentino, Mauro; Claps, Pierluigi; Singh, Vijay P.

    1993-01-01

    Under the assumption that the only information available on a drainage basin is its mean elevation, the connection between entropy and potential energy is explored to analyze drainage basins morphological characteristics. The mean basin elevation...

  6. Gravity modeling of Cenozoic extensional basins, offshore Vietnam

    E-print Network

    Mauri, Steven Joseph

    1993-01-01

    , the idea of substantial crustal thinning beneath these basins is supported by high geothermal gradients in both basins. Formation of the Mekong basin is believed associated with a Paleocene to Oligocene episode of left-lateral movement on the NW...

  7. 77 FR 23508 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-19

    ...Bureau of Reclamation Colorado River Basin Salinity Control Advisory Council AGENCY: Bureau...SUMMARY: The Colorado River Basin Salinity Control Advisory Council (Council) was established by the Colorado River Basin Salinity Control Act of 1974 (Pub. L....

  8. 76 FR 61382 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-04

    ...Bureau of Reclamation Colorado River Basin Salinity Control Advisory Council AGENCY: Bureau...SUMMARY: The Colorado River Basin Salinity Control Advisory Council (Council) was established by the Colorado River Basin Salinity Control Act of 1974 (Pub. L....

  9. 76 FR 24515 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-02

    ...Bureau of Reclamation Colorado River Basin Salinity Control Advisory Council AGENCY: Bureau...announces that the Colorado River Basin Salinity Control Advisory Council (Council...INFORMATION: The Colorado River Basin Salinity Control Advisory Council was...

  10. 78 FR 23784 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-22

    ...Bureau of Reclamation Colorado River Basin Salinity Control Advisory Council AGENCY: Bureau...SUMMARY: The Colorado River Basin Salinity Control Advisory Council (Council) was established by the Colorado River Basin Salinity Control Act of 1974 (Public Law...

  11. 75 FR 25877 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-10

    ...Bureau of Reclamation Colorado River Basin Salinity Control Advisory Council AGENCY: Bureau...SUMMARY: The Colorado River Basin Salinity Control Advisory Council (Council) was established by the Colorado River Basin Salinity Control [[Page 25878

  12. 75 FR 66389 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-28

    ...Bureau of Reclamation Colorado River Basin Salinity Control Advisory Council AGENCY: Bureau...SUMMARY: The Colorado River Basin Salinity Control Advisory Council (Council) was established by the Colorado River Basin Salinity Control Act of 1974 (Pub. L....

  13. 75 FR 27360 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-14

    ...Bureau of Reclamation Colorado River Basin Salinity Control Advisory Council AGENCY: Bureau...SUMMARY: The Colorado River Basin Salinity Control Advisory Council (Council) was established by the Colorado River Basin Salinity Control Act of 1974 (Pub. L....

  14. 48 CFR 25.405 - Caribbean Basin Trade Initiative.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Caribbean Basin Trade Initiative. 25.405 Section 25.405...SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Trade Agreements 25.405 Caribbean Basin Trade Initiative. Under the Caribbean Basin...

  15. 48 CFR 25.405 - Caribbean Basin Trade Initiative.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Caribbean Basin Trade Initiative. 25.405 Section 25.405...SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Trade Agreements 25.405 Caribbean Basin Trade Initiative. Under the Caribbean Basin...

  16. 48 CFR 25.405 - Caribbean Basin Trade Initiative.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Caribbean Basin Trade Initiative. 25.405 Section 25.405...SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Trade Agreements 25.405 Caribbean Basin Trade Initiative. Under the Caribbean Basin...

  17. 48 CFR 25.405 - Caribbean Basin Trade Initiative.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Caribbean Basin Trade Initiative. 25.405 Section 25.405...SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Trade Agreements 25.405 Caribbean Basin Trade Initiative. Under the Caribbean Basin...

  18. 48 CFR 25.405 - Caribbean Basin Trade Initiative.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Caribbean Basin Trade Initiative. 25.405 Section 25.405...SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Trade Agreements 25.405 Caribbean Basin Trade Initiative. Under the Caribbean Basin...

  19. Basin-scale relations via conditioning

    USGS Publications Warehouse

    Troutman, B.M.; Karlinger, M.R.; Guertin, D.P.

    1989-01-01

    A rainfall-runoff model is used in conjunction with a probabilistic description of the input to this model to obtain simple regression-like relations for basin runoff in terms of basin and storm characteristics. These relations, similar to those sought in regionalization studies, are computed by evaluating the conditional distribution of model output given basin and storm characteristics. This method of conditioning provides a general way of examining model sensitivity to various components of model input. The resulting relations may be expected to resemble corresponding relations obtained by regionalization using actual runoff to the extent that the rainfall-runoff model and the model input specification are physically realistic. The probabilistic description of model input is an extension of so-called "random-model" of channel networks and involves postulating an ensemble of basins and associated probability distributions that mimic the variability of basin characteristics seen in nature. Application is made to small basins in the State of Wyoming. Parameters of the input variable distribution are estimated using data from Wyoming, and basin-scale relations are estimated both, parametrically and nonparametrically using model-generated runoff from simulated basins. Resulting basin-scale relations involving annual flood quantiles are in reasonable agreement with those presented in a previous regionalization study, but error estimates are smaller than those in the previous study, an artifact of the simplicity of the rainfall-runoff model used in this paper. We also obtain relations for peak of the instantaneous unit hydrograph which agree fairly well with theoretical relations given in the literature. Finally, we explore the issues of sensitivity of basin-scale, relations and error estimates to parameterization of the model input probability distribution and of how this sensitivity is related to making inferences about a particular ungaged basin. ?? 1989 Springer-Verlag.

  20. Timing and geometry of early Gondwana breakup

    Microsoft Academic Search

    Wilfried Jokat; Tobias Boebel; Matthias König; Uwe Meyer

    2003-01-01

    The Mesozoic opening history of the Southern Ocean between South America, Africa, and Antarctica is one of the largest gaps in knowledge on the evolution of this region. Competing geodynamic models were published during the last two decades to explain the geophysical and geological observations. Here we report on aeromagnetic data collected along the East Antarctic coast during five seasons.

  1. Permian geology of Gondwana countries: An overview

    SciTech Connect

    Dickins, J.M. (Australian Bureau of Mineral Resources, Canberra (Australia))

    1992-10-01

    Earliest Permian sequences of Antarctica, southern and east-central Africa, the southern part of the Arabian Peninsula, Pakistan, peninsular and Himalayan India, Tibet, western and eastern Australia, New Zealand, and South America are all characterized by glacial deposits and cold-water marine faunas. In the course of the Permian, considerable faunal (and floral) and climatic divergence occurred. Although folding is not necessarily present, the effects of the strong compressive tectonic phase (Hunter-Bowen Orogenic Folding Phase of Dickins) beginning in the mid-Permian (traditional two-fold subdivision) and of acidic and intermediate volcano-magmatic activity are apparent in all these regions as in other parts of the world. The progressive continentality of the Upper Permian (worldwide regression) culminates at the Permian-Triassic (Changxingian-Griesbachian) boundary.

  2. Central Nebraska river basins Nebraska

    USGS Publications Warehouse

    Huntzinger, Thomas L.; Ellis, Michael J.

    1993-01-01

    The Central Nebraska Basins (NAWQA) study unit includes the Platte River and two major tributaries, the Loup and Elkhorn Rivers. Platte River flows are variable of diversions, but the Loup and Elkhorn Rivers originate in an area of dune sand covered by grassland that generates consistent base flows. Ground water has no regional confining units and the system is a water table aquifer throughout. Macroinvertebrate and fish taxa were related to stream flow. One of the four wetland complexes includes habitat for threatened and endangered bird species. A water quality assessments will be based on the differences in environmental setting in each of four subunits within the study unit.

  3. Delaware Basin Monitoring Annual Report

    SciTech Connect

    Washington Regulatory and Environmental Services; Washington TRU Solutions LLC

    2001-09-28

    The Delaware Basin Drilling Surveillance Program (DBDSP) is designed to monitor drilling activities in the vicinity of the Waste Isolation Pilot Plant (WIPP). This program is based on Environmental Protection Agency (EPA) requirements. EPA requires the Department of Energy (DOE) to demonstrate the expected performance of the disposal system using a probabilistic risk assessment or performance assessment (PA). This PA must show that the expected repository performance will not release radioactive material above limits set by the EPA's standard and must consider inadvertent drilling into the repository at some future time.

  4. Magnetic Fabric of the Aquidauana Formation, western border of the Paraná Basin Central Brazil: Preliminary Results

    NASA Astrophysics Data System (ADS)

    Raposo, M. B.

    2013-05-01

    The glaciogenic sedimentation (Carboniferous-Permian) on the western border of the Paraná Basin is represented by reddish-brown strata of the Aquidauana Formation. Subsurface data suggest that this Formation is equivalent to the Itararé Group, which contains the most extensive lithological record of Gondwana glaciation in the world. The Aquidauna Formation crops out as an NNE-SSW-oriented elongated belt at the western portion of the Maracaju-Campo Grande Plateau in Mato Grosso do Sul State (Central part of Brazil), and extents to the north up to Mato Grosso and Goias states. This Formation is composed of a variety of types of sandstones, siltites, and mudstones. The magnetic studies were performed on sites of undeformed reddish-brown sandstones, siltites, and mudstones, which crop out mainly in Mato Grosso do Sul State. Magnetic fabrics were determined on oriented cylindrical specimens (2.54 cm x 2.2 cm) using anisotropy of low-field magnetic susceptibility (AMS). Rock-magnetic analyses reveal that both magnetite and hematite are the main magnetic minerals in the majority of the analyzed sites. Regarding the eingenvector orientations, the sites usually gave good results. The analysis at the individual-site scale defines two AMS fabric types. The first type shows Kmin perpendicular to the bedding plane, while Kmax and Kint are scattered within the bedding plane itself. This fabric is usually interpreted as primary (sedimentary-compactional), typical of undeformed sediments and is dominant among the sites. The second type shows good clustering of the AMS principal axes with Kmin still either perpendicular or sub-perpendicular to the bedding plane. This fabric type could be interpreted as a combination of sedimentary-compactional and tectonic contributions if some strain markers or evidence for tectonic deformation had been found in the studied area. On the other hand, the tight Kmax grouping in this fabric type could be explained by the action of currents since they cause Kmax to be aligned sub-parallel to the paleocurrent direction.

  5. A brief history of Great Basin pikas

    Microsoft Academic Search

    Donald K. Grayson

    2005-01-01

    ABSTRACT Aim Within the past few decades, seven of the 25 historically described populations of American pikas (Ochotona princeps) in the Great Basin of arid western North America appear to have become extinct. In this paper, the prehistoric record for pikas in the Great Basin is used to place these losses in deeper historical context.

  6. Water Atlas of the Volta Basin

    E-print Network

    Boyer, Edmond

    W A Water Atlas of the Volta Basin Atlas de l'eau du Bassin de la Volta Jacques LemoaLLe Devaraj de Condappa 2009 Challenge Program Water and Food Institut de Recherche pour le Développement Mise. Water atlas of the Volta Basin-Atlas de l'eau dans le bas- sin de la Volta. Challenge Program on Water

  7. Geology Fieldnotes: Great Basin National Park, Nevada

    NSDL National Science Digital Library

    This Great Basin National Park site contains park geology information, park maps, visitor information, and teacher features (educational resources and links for teaching geology using National Park examples). The park geology section discusses the region's biogeography, glacial history, and the Lehman Caves. A park map and a features/relief map of the Great Basin National Park are included.

  8. 33 CFR 401.48 - Turning basins.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...7 and the Guard Gate Cut for vessels up to 180 m in overall length. (c) Turning Basin No. 3—Immediately south of Port Robinson (Mile 13). (d) Turning Basin No. 4—North of Lock No. 8 for vessels up to 170 m in overall length. (e)...

  9. 33 CFR 401.48 - Turning basins.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...7 and the Guard Gate Cut for vessels up to 180 m in overall length. (c) Turning Basin No. 3—Immediately south of Port Robinson (Mile 13). (d) Turning Basin No. 4—North of Lock No. 8 for vessels up to 170 m in overall length. (e)...

  10. 33 CFR 401.48 - Turning basins.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...7 and the Guard Gate Cut for vessels up to 180 m in overall length. (c) Turning Basin No. 3—Immediately south of Port Robinson (Mile 13). (d) Turning Basin No. 4—North of Lock No. 8 for vessels up to 170 m in overall length. (e)...

  11. 33 CFR 401.48 - Turning basins.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...7 and the Guard Gate Cut for vessels up to 180 m in overall length. (c) Turning Basin No. 3—Immediately south of Port Robinson (Mile 13). (d) Turning Basin No. 4—North of Lock No. 8 for vessels up to 170 m in overall length. (e)...

  12. 33 CFR 401.48 - Turning basins.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...7 and the Guard Gate Cut for vessels up to 180 m in overall length. (c) Turning Basin No. 3—Immediately south of Port Robinson (Mile 13). (d) Turning Basin No. 4—North of Lock No. 8 for vessels up to 170 m in overall length. (e)...

  13. Basin wildrye: the forgotten grass revisited

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Basin wildrye was once a very abundant and widely occurring species throughout the landscapes of northern Nevada. When Captain Simpson, of the topographical Engineers, explored the route for a wagon road across the central Great Basin he marveled at the grass in the valley bottoms that reached to h...

  14. Lunar Multiring Basins and the Cratering Process

    Microsoft Academic Search

    Mark A. Wieczorek; Roger J. Phillips

    1999-01-01

    Numerous studies of the lunar gravity field have concluded that the lunar Moho is substantially uplifted beneath the young multiring basins. This uplift is presumably due to the excavation of large quantities of crustal material during the cratering process and subsequent rebound of the impact basin floor. Using a new dual-layered crustal thickness model of the Moon, the excavation cavities

  15. Structure of the Western Somali Basin

    Microsoft Academic Search

    Elizabeth T. Bunce; M. G. Langseth; R. L. Chase; M. Ewing

    1967-01-01

    The western Somali Basin in the northwestern Indian Ocean is covered by thick deposits of terrigenous sediments. Seismic reflection profiles show, however, the northern and southern parts to be very different. The northern sections is a deep basin filled with thick uniformly stratified sediments. It is enclosed by the continental margin to the west and north, Chain ridge to the

  16. Cenozoic Climates of the Great basin

    Microsoft Academic Search

    Ernst Antevs

    1952-01-01

    The Great Basin in the western United States consists of almost level desert basins and alternating parallel mountain ranges. It has sparse, mostly interior, drainage and a few permanent lakes. The climate is arid and semiarid. Fairly large areas are true deserts. The main Cenozoic climatic changes have been: 1. a general cooling during the Tertiary and the early Pleistocene,

  17. Thermal and subsidence history of sedimentary basins

    Microsoft Academic Search

    D. L. Turcotte; J. L. Ahern

    1977-01-01

    The cooling of the oceanic lithosphere causes subsidence by isostasy. This subsidence results in the formation of ocean basins. In this paper we assume that the subsiding lithosphere is covered with sediments. A similarity solution is obtained for the coupled problem of heat conduction in the sediments and basement. The subsidence history of the sedimentary basin is obtained from isostasy.

  18. Mackenzie - Liard Valley Hydrocarbon Basins, NWT

    Microsoft Academic Search

    James R. Taylor

    The Mackenzie - Liard area of the mainland Northwest Territories (NWT) is underlain by a series of superimposed sedimentary basins formed over the last billion years. Many of these basins have established hydrocarbon systems in which stacked reservoir rocks, trap seals and source rocks have been identified. The area includes the southern NWT where oil and gas pipelines are presently

  19. Corrosion in ICPP fuel storage basins

    Microsoft Academic Search

    1993-01-01

    The Idaho Chemical Processing Plant currently stores irradiated nuclear fuel in fuel storage basins. Historically, fuel has been stored for over 30 years. During the 1970`s, an algae problem occurred which required higher levels of chemical treatment of the basin water to maintain visibility for fuel storage operations. This treatment led to higher levels of chlorides than seen previously which

  20. Sedimentary basins in Ross Sea, Antarctica

    SciTech Connect

    Cooper, A.K.; Davey, F.J.

    1986-07-01

    The Ross Sea lies in the Pacific sector of the Antarctic continental margin. Three major sedimentary basins (from east to west, the Eastern, Central, and Victoria Land basins) lie beneath the broad, deep continental shelf of the Ross Sea. These north-south-trending basins occur in the extensionally deformed region between East and West Antarctica. Multichannel seismic reflection (MCS) surveys have been conducted over these basins since 1980 by West German, French, Japanese, and US expeditions. The MCS and previous geophysical surveys have shown that the three basins contain 5-6 km of sedimentary rock, possibly Late Cretaceous and younger. An additional 6-8 km of sedimentary and volcanic rock lies within the deeper parts of the Victoria Land basin. The basins are separated by uplifted and eroded basement ridges covered by thin sedimentary sections. Each basin has distinct characteristics, commonly related to its extensional origin. Petroleum hydrocarbons are unknown from the Ross Sea region, with the possible exception of ethane gas recovered by the Deep Sea Drilling Project. Previous model studies, based on estimated sediment thickness, assumed temperature gradients, and postulated seismostratigraphy, indicate that hydrocarbons could be generated at depths of 3.5-6km within the sedimentary section. However, this hypothesis cannot be verified without further geologic and geophysical data from the Ross Sea region.

  1. Field size distributions for California Basins

    Microsoft Academic Search

    Bartel

    1994-01-01

    Distribution curves for oil and gas field sizes can aid in assessing the future exploration potential of a basin. Field size distribution curves are presented for the San Joaquin, Sacramento, Ventura-Santa Barbara Channel, and Santa Maria basins. The data used here are largely from the published summaries of the California Division of Oil and Gas. It is not only important

  2. Hydrocarbon entrapment in Alberta deep basin

    SciTech Connect

    Gies, R.M.

    1984-04-01

    Entrapment of hydrocarbon accumulations in the deepest region of the Alberta sedimentary basin is linked to certain principles of subsurface fluid flow behavior in generally tight sandstones, and to active hydrocarbon generation in adjacent source beds. Similar geologic conditions and associated deep-basin-type hydrocarbon accumulations no doubt exist in the deeper portions of other sedimentary basins. Deep-basin concepts of hydrocarbon entrapment are opposed to conventional ideas. Hydrocarbon-bearing sands in deep basin regions grade laterally updip into permeable water-bearing sands without reservoir barriers to segregate the fluids. Water-over-hydrocarbon contacts appear at the updip limits of the accumulations and generally are absent downdip. Original hydrocarbon accumulation pressures are usually less than projected formation-water pressures at common depth points. Deep-basin accumulations fed by active downdip source rocks may be in a dynamic state of slow, updip hydrocarbon migration. Hydrocarbons lost across the updip water/gas contact are replaced by new hydrocarbon influx from downdip source rocks. Prolonged hydrocarbon flux through deep-basin reservoirs may result in exceptionally low residual water saturations and favorable hydrocarbon relative permeabilities in tight sandstones. These unusual physical principles of the Alberta deep-basin hydrocarbon accumulations are illustrated by Elmworth field examples and by physical fluid flow models.

  3. Great Salt Lake Basin Hydrologic Observatory

    E-print Network

    Tarboton, David

    Great Salt Lake Basin Hydrologic Observatory Contact Information David Tarboton Utah State. The Great Salt Lake Basin Hydrologic Observatory development team is highly committed to this concept lead aspects of the proposed observatory. Please contact us if you would like to become part

  4. Analysis of K west basin canister gas

    Microsoft Academic Search

    Trimble; Fluor Daniel Hanford

    1997-01-01

    Gas and Liquid samples have been collected from a selection of the approximately 3,820 spent fuel storage canisters in the K West Basin. The samples were taken to characterize the contents of the gas and water in the canisters providing source term information for two subprojects of the Spent Nuclear Fuel Project (SNFP) (Fulton 1994): the K Basins Integrated Water

  5. An alternative basin characteristic for use in estimating impervious area in urban Missouri basins

    USGS Publications Warehouse

    Southard, R.E.

    1986-01-01

    A previous regression analysis of flood peaks on urban basins in St. Louis County, Missouri, indicated that the basin characteristics of percentage of impervious area and drainage area were statistically significant for estimating the 2-, 5-, 10-, 25-, 50-. and 100-yr peak discharges at ungaged urban basins. In this statewide regression analysis of the urban basins for Missouri, an alternative basin characteristic called the percentage of developed area was evaluated. A regression analysis of the percentage of developed area (independent variable), resulted in a simple equation for computing percentage of impervious area. The percentage of developed area also was evaluated using flood-frequency data for 23 streamflow gaging stations, and the use of this variable was determined to be valid. Using nationwide data, an urban basin characteristic known as the basin development factor was determined to be valid for inclusion in urban regression equations for estimating flood flows. The basin development factor and the percentage of developed area were compared for use in regression equations to estimate peak flows of streams in Missouri. The equations with the basin development factor produced peak flow estimates with slightly smaller average standard errors of estimate than the equation with the percentage of developed area; however, this study indicates that there was not enough statistical or numerical difference to warrant using the basin development factor instead of the percentage of developed area in Missouri. The selection of a basin characteristic to describe the physical conditions of a drainage basin will depend not only on its contribution to accuracy of regression equations, but also on the ease of determining the characteristics; the percentage of developed area has this advantage. A correlation analysis was made by correlating drainage area to percentage of impervious area, the percentage of developed area, and the basin development factor. The results of the analysis indicate that the three basin characteristics are independent of drainage area and appropriate to use in multiple-regression analysis. (Author 's abstract)

  6. Field-based evidence of sedimentary and tectonic processes related to continental collision: the Early Cenozoic basins of Central Eastern Turkey 

    E-print Network

    Booth, Matthew Graham

    2013-07-01

    Turkey is widely accepted to have formed from a collage of microcontinents that rifted from the northern margin of Gondwana and assembled from the Mesozoic to Mid Cenozoic in response to the closure, collision and suturing ...

  7. Rocky Mountain Tertiary coal-basin models and their applicability to some world basins

    USGS Publications Warehouse

    Flores, R.M.

    1989-01-01

    Tertiary intermontane basins in the Rocky Mountain region of the United States contain large amounts of coal resources. The first major type of Tertiary coal basin is closed and lake-dominated, either mud-rich (e.g., North Park Basin, Colorado) or mud plus carbonate (e.g., Medicine Lodge Basin, Montana), which are both infilled by deltas. The second major type of Tertiary coal basin is open and characterized by a preponderance of sediments that were deposited by flow-through fluvial systems (e.g., Raton Basin, Colorado and New Mexico, and Powder River Basin, Wyoming and Montana). The setting for the formation of these coals varies with the type of basin sedimentation, paleotectonism, and paleoclimate. The mud-rich lake-dominated closed basin (transpressional paleotectonism and warm, humid paleoclimate), where infilled by sandy "Gilbert-type" deltas, contains thick coals (low ash and low sulfur) formed in swamps of the prograding fluvial systems. The mud- and carbonate-rich lake-dominated closed basin is infilled by carbonate precipitates plus coarse-grained fan deltas and fine-grained deltas. Here, thin coals (high ash and high sulfur) formed in swamps of the fine-grained deltas. The coarse-clastic, open basins (compressional paleotectonism and warm, paratropical paleoclimate) associated with flow-through fluvial systems contain moderately to anomalously thick coals (high to low ash and low sulfur) formed in swamps developed in intermittently abandoned portions of the fluvial systems. These coal development patterns from the Tertiary Rocky Mountain basins, although occurring in completely different paleotectonic settings, are similar to that found in the Tertiary, Cretaceous, and Permian intermontane coal basins in China, New Zealand, and India. ?? 1989.

  8. Gladden Pull-Apart Basin, offshore Belize

    SciTech Connect

    Morrice, S. (BNR Ltd., Denver, CO (United States))

    1993-02-01

    The junction of the American and Caribbean plates in Belize has created a complex structural setting for oil and gas exploration. Recent seismic offshore Belize has been used to identify three structural provinces, from west to east: a shallow thrust zone, a narrow upthrown wrench faulted zone and a deeper extensional basin, named the Gladden Pull-Apart Basin. Hydrocarbon leakage from recent fault movement appears to have depleted the shallow structures to the west, but the pull-apart basin has a thick sequence of low-frequency clay-dominated sealing rocks with the potential to preserve hydrocarbon accumulations in Cretaceous carbonate banks. These buried carbonate are of the same age and depositional environment of Mexico's Golden Lane/Tabasco Reforma carbonate banks which are world class giant fields. The Belize and Mexican carbonate banks are within the same Cretaceous depositional basin, the Peten Basin. Seismic interpretations in offshore Belize have been integrated with gravity and magnetic surveys. This provides additional support for the deep extensional basin. The location of the thick Cretaceous carbonate banks is better interpreted with the integration of these three geophysical tools. Airborne geochemical surveys were used to detect the presence of oil seeps on the east and west basin margins.

  9. Instantaneous dynamics of the cratonic Congo basin

    NASA Astrophysics Data System (ADS)

    Downey, Nathan J.; Gurnis, Michael

    2009-06-01

    Understanding the formation mechanisms of cratonic basins provides an examination of the rheological, compositional and thermal properties of continental cratons. However, these mechanisms are poorly understood because there are few currently active cratonic basins. One cratonic basin thought to be active is the Congo basin located in equatorial Africa. The Congo basin is coincident with a large negative free-air gravity anomaly, an anomalous topographic depression, and a large positive upper mantle shear wave velocity anomaly. Localized admittance models show that the gravity anomaly cannot be explained by a flexural support of the topographic depression at the Congo. We analyze these data and show that they can be explained by the depression of the Congo basin by the action of a downward dynamic force on the lithosphere resulting from a high-density object within the lithosphere. We formulate instantaneous dynamic models describing the action of this force on the lithosphere. These models show that the gravity and topography of the Congo basin are explained by viscous support of an anomalously dense region located at 100 km depth within the lithosphere. The density anomaly has a magnitude within the range of 27-60 kg m-3 and is most likely compositional in origin. Our models do not provide a constraint on the lithospheric viscosity of the Congo craton because the shallow location of the anomaly ensures strong coupling of the anomaly to the surface regardless of viscosity structure.

  10. Geology and hydrocarbon potential of the Oued Mya basin, Algeria

    Microsoft Academic Search

    O. Benamrane; M. Messaoudi; H. Messelles

    1993-01-01

    The Oued Mya hydrocarbon system is located in the Sahara basin. It is one of the best producing basins in Algeria, along with the Ghadames and Illizi basins. The stratigraphic section consists of Paleozoic and Mesozoic, and is about 5000 m thick. This intracratonic basin is limited to the north by the Toughourt saddle, and to the west and east

  11. INTEGRATED BASIN ANALYSIS OF THE MARCELLUS FORMATION IN THE

    E-print Network

    Slingerland, Rudy

    INTEGRATED BASIN ANALYSIS OF THE MARCELLUS FORMATION IN THE DEVONIAN BLACK SHALE BASIN of the Marcellus Fm. and associated facies in the northern Appalachian Basin and use the model to predict analysis of the Marcellus Shale in the Pennsylvania-New York Appalachian Basin utilizing well logs, cores

  12. Preparing T Plant for Storing Sludge from the K Basins

    Microsoft Academic Search

    W. S. Ayers; E. G. Erpenbeck; D. E. McKenney; T. A. Shrader

    2003-01-01

    For a number of years, the spent nuclear fuel (SNF) from the N Reactor has been stored underwater in the basins at the 100 K Area complex of the Hanford Site (K Basins). Fluor Hanford is managing a significant effort to remove the fuel from the K Basins and place it in dry storage. Removing accumulated sludges from the basins

  13. Repository site definition in basalt: Pasco Basin, Washington

    Microsoft Academic Search

    R. V. Guzowski; F. B. Nimick; A. B. Muller

    1982-01-01

    Discussion of the regional setting, geology, hydrology, and geochemistry of the Pasco Basin are included in this report. Pasco basin is a structural and topographic basin of approximately 2000 mi² (5180 km²) located within the Yakima Fold Belt Subprovince of the Columbia Plateau. The stratigraphic sequence within the basin consists of an undetermined thickness of lower Miocene and younger flood

  14. Neuse River Basin, North Carolina Ecosystem Restoration Project

    E-print Network

    US Army Corps of Engineers

    Neuse River Basin, North Carolina Ecosystem Restoration Project 5 October 2012 ABSTRACT: The study area encompasses the Neuse River Basin, the third-largest river basin in North Carolina. The Basin the state. The Neuse River originates at the confluence of the Eno and Flat Rivers in north- central North

  15. Deep structure of hyperextended basins offshore Norway

    NASA Astrophysics Data System (ADS)

    Terje Osmundsen, Per; Peron-pinvidic, Gwenn; Ebbing, Jorg; Erratt, Duncan

    2014-05-01

    The 3D architecture of rifted margins is controlled by lateral variations in the location of domain boundaries and displacement gradients along the structures that define them. The deep structure of the Mid-Norway rifted margin is characterized by a fault-controlled necking domain, a hyperextended block-faulted area of variable width and an array of distal detachment breakaways that border areas that resemble exhumation domains. From Jurassic to Late Cretaceous times, the suite of extensional faults and basins appear to show a temporal migration towards the future location of breakup, but parts of the deep margin provide evidence for a complex evolution with more than one phase of extensional faulting in the deep basin areas, and with `out of sequence' faults that cut and deactivated earlier detachments. A number of distinct extensional basin types evolved that can be identified and classified according to their structural setting and location in the margin system. In the necking domain, supradetachment basins became perched on rider blocks on gently dipping detachment faults that were abandoned in shallow structural positions as they were incised by a second generation of detachments. The taper break or coupling basin is the innermost basin in the distal margin and occupies a position at the base of a tens of kilometres wide crustal slope, defined by the faults associated with construction of the necking domain. Arrays of very deep half-graben basins are associated with hyperextended crust outboard of the necking domain. Outboard of the distal detachment breakaway, or the exhumation limit in the case of mantle windows, supradetachment basins are associated with extensional allochthon and multiply extended ridges. The necking and distal domains present variable contact relationships to the overlying sag basin in terms of downlap, onlap and erosional unconformities. The combined stratal architecture reflects the position with respect to the various margin domains.

  16. Evaluation of Ordos Basin in China

    SciTech Connect

    Zhou, J.G. [CSI Consulting, Bellaire, TX (United States)

    1996-06-01

    Ordos basin lies in the north-central China, in a compression tectonic regime, with an area of approximately 250,000 km{sup 2}, including several pay zones ranging from Cambrian to Jurassic. It is one of the earliest-formed marine to continental-superimposed basin in China, characterized by Proterozoic basin-marginal rifling and Lower-Paleozoic carbonate platform development followed by western thrusting and foreland depression during Mesozoic. It underwent several tectonic movements and is covered by several structural layers, with many play types developed, primarily thrust and anticlinal plays in the west, and differential compaction (river-channel sand lens) or drape as well as buried hill plays in the basin center and east. Ordos basin is a prolific gas basin with an estimated resource potential of gas 656,091 billion m{sup 3} in the Paleozoic strata and oil 2.0474 billion tons in the Mesozoic strata. In 1986, in the western part of the basin, the well Tian-1 on the Tianchi structure tested gas at a rate of 16 x 10{sup 4} m{sup 3}/d (about 5.6496 MCF per day). By year-end 1991, only 26 wells had been drilled in the Jingbian to Hengshan areas (northeastern part of the basin), but 16 of them flowed commercial gas, ranging from 3.2 x 10{sup 4} m{sup 3}/d to 126 x 10{sup 4} m{sup 3}/d. However, the gas pipe just starts budding. Therefore, there will be a lot of gas yet to find, and the most critical factor for petroleum potential of each local structure or play in this basin is the reservoir development.

  17. Delaware Basin Monitoring Annual Report

    SciTech Connect

    Washington Regulatory and Environmental Services; Washington TRU Solutions LLC

    2002-09-21

    The Delaware Basin Drilling Surveillance Program (DBDSP) is designed to monitor drilling activities in the vicinity of the Waste Isolation Pilot Plant (WIPP). This program is based on Environmental Protection Agency (EPA) requirements. The EPA environmental standards for the management and disposal of transuranic (TRU) radioactive waste are codified in 40 CFR Part 191 (EPA 1993). Subparts B and C of the standard address the disposal of radioactive waste. The standard requires the Department of Energy (DOE) to demonstrate the expected performance of the disposal system using a probabilistic risk assessment or performance assessment (PA). This PA must show that the expected repository performance will not release radioactive material above limits set by the EPA's standard. This assessment must include the consideration of inadvertent drilling into the repository at some future time.

  18. Delaware Basin Monitoring Annual Report

    SciTech Connect

    Washington Regulatory and Environmental Services

    1999-09-30

    The Delaware Basin Drilling Surveillance Program (DBDSP) is designed to monitor drilling activities in the vicinity of the Waste Isolation Pilot Plant (WIPP). This program is based on Environmental Protection Agency (EPA) requirements. The EPA environmental standards for the management and disposal of transuranic (TRU) radioactive waste are codified in 40 CFR Part 191 (EPA 1993). Subparts B and C of the standard address the disposal of radioactive waste. The standard requires the Department of Energy (DOE) to demonstrate the expected performance of the disposal system using a probabilistic risk assessment or performance assessment (PA). This PA must show that the expected repository performance will not release radioactive material above limits set by the EPA's standard. This assessment must include the consideration of inadvertent drilling into the repository at some future time.

  19. Delaware Basin Monitoring Annual Report

    SciTech Connect

    Washington Regulatory and Environmental Services; Washington TRU Solutions LLC

    2000-09-28

    The Delaware Basin Drilling Surveillance Program (DBDSP) is designed to monitor drilling activities in the vicinity of the Waste Isolation Pilot Plant (WIPP). This program is based on Environmental Protection Agency (EPA) requirements. The EPA environmental standards for the management and disposal of transuranic (TRU) radioactive waste are codified in 40 CFR Part 191 (EPA 1993). Subparts B and C of the standard address the disposal of radioactive waste. The standard requires the Department of Energy (DOE) to demonstrate the expected performance of the disposal system using a probabilistic risk assessment or performance assessment (PA). This PA must show that the expected repository performance will not release radioactive material above limits set by the EPA's standard. This assessment must include the consideration of inadvertent drilling into the repository at some future time.

  20. The materials and formation of the imbrium basin

    NASA Technical Reports Server (NTRS)

    Spudis, P. D.

    1985-01-01

    The deposits around the Imbrium basin form a widespread stratigraphic datum, to which other lunar geological units may be relatively dated. More importantly, as a relatively well preserved multi-ring basin, Imbrium provides an important target of geologic investigation to study the processes involved in lunar basin formation and evolution. Two Apollo missions (Apollo 14 and 15) were send to landing sites chosen specifically to address problems of the Imbrium basin geology. Data about the deposits of the Imbrium basin are reviewed. Formational mechanics of lunar basins in general and the relations of materials collected at the highlands adjacent to the Apollo 15 landing site to Imbrium and other basins are examined.

  1. Gravity Analysis of the Jeffera Basin, Tunisia

    NASA Astrophysics Data System (ADS)

    Mickus, K.; Gabtni, H.; Jallouli, C.

    2004-12-01

    Southern Tunisia consists of two main tectonic provinces: 1) the Saharan Platform and 2) the folded Atlasic domain, separated by the North Saharan Flexure. The Saharan Platform, which contains the Ghadames Basin and the Telemzane Arch, consists of gently dipping Paleozoic strata overlain by Triassic to Cretaceous sediments. The Atlasic domain consists of a thicker sequence of mainly Mesozoic and younger rock with less complete sequences of Paleozoic strata. Within the Atlasic domain are the still actively subsiding Chotts and Jeffera basins. The Jeffera basin, which occurs to the east of the Telemzane Arch contains at least eight kilometers of Paleozoic and younger sediment that were formed during numerous subsidence episodes since Carboniferous time. The Jeffera basin is dominated by tilted fault blocks that were formed during numerous tectonic episodes. Several unpublished seismic reflection profiles and well data exist for the Jeffera basin, however a deep structural analysis of the basin has not been published. We examined the existing gravity data in conjunction with available well and geologic data to determine structural features within the basin. The Bouguer gravity anomaly map shows that the Jeffera basin is dominated by a narrow northwest-trending gravity minimum. However, a more detailed analysis consisting of wavelength filtering and edge enhancements indicate that the structure of the basin is more complicated than indicated by the Bouguer gravity anomaly map. A residual gravity anomaly map indicates that the Jeffera basin consists of at least three and maybe four subbasins. Additionally, the Jeffera Fault marks the boundary between northwest-trending gravity anomalies to its northeast and east-trending anomalies over the Saharan Platform. The above observation is amplified by the construction of the enhanced horizontal derivatives (EHG) of both the complete Bouguer gravity and the residual gravity anomaly maps. The EHG maps highlight the lateral boundaries of subsurface density contrasts and emphasizes that the Jeffera basin is dominated by northwest-trending anomalies while the Saharan Platform consists of a series of northeast- and east-trending anomalies. The final interpretation of the gravity data will consist of constructing a series of two and one-half dimensional gravity models across the Jeffera basin.

  2. K Basins isolation barriers summary report

    SciTech Connect

    Strickland, G.C., Westinghouse Hanford

    1996-07-31

    The 105-K East and 105-K West fuel storage basins (105-K Basins) were designed and constructed in the early 1950`s for interim storage of irradiated fuel following its discharge from the reactors. The 105-K- East and 105-K West reactor buildings were constructed first, and the associated storage basins were added about a year later. The construction joint between each reactor building structure and the basin structure included a flexible membrane waterstop to prevent leakage. Water in the storage basins provided both radiation shielding and cooling to remove decay heat from stored fuel until its transfer to the Plutonium Uranium Extraction (PUREX) Facility for chemical processing. The 105-K West Reactor was permanently shut down in February 1970; the 105-K East Reactor was permanently shut down in February 1971. Except for a few loose pieces, fuel stored in the basins at that time was shipped to the PUREX Facility for processing. The basins were then left idle but were kept filled with water. The PUREX Facility was shut down and placed on wet standby in 1972 while N Reactor continued to operate. When the N Reactor fuel storage basin began to approach storage capacity, the decision was made to modify the fuel storage basins at 105-K East and 105-K West to provide additional storage capacity. Both basins were subsequently modified (105-K East in 1975 and 105-K West in 1981) to provide for the interim handling and storage of irradiated N Reactor fuel. The PUREX Facility was restarted in November 1983 to provide 1698 additional weapons-grade plutonium for the United States defense mission. The facility was shut down and deactivated in December 1992 when the U.S. Department of Energy (DOE) determined that the plant was no longer needed to support weapons-grade plutonium production. When the PUREX Facility was shut down, approximately 2.1 x 1 06 kg (2,100 metric tons) of irradiated fuel aged 7 to 23 years was left in storage in the 105-K Basins pending a decision on final disposition of the material. The Hanford Federal Facility Agreement and Consent Order (Ecology et al. 1994), also known as the Tri-Party Agreement, commits to the removal of all fuel and sludge from the 105-K Basins by the year 2002.

  3. A Basin-Wide Integrated Analysis of Human Impacts on River Basins Using Horton-Strahler Stream Ordering

    Microsoft Academic Search

    H. Miyamoto; T. Hashimoto; K. Michioku

    2010-01-01

    Human impacts, such as land use change and human population distributed within a river basin, may affect the balance of water resources utilization and the ecological condition on the river basin environment. In this study, we proposed a mathematical model developed using Horton-Strahler's stream order to analyze basin-wide distributions of the human activity impacts across several river basins with different

  4. The Donets Basin (Ukraine\\/Russia): coalification and thermal history

    Microsoft Academic Search

    R. F. Sachsenhofer; V. A. Privalov; M. V. Zhykalyak; C. Bueker; E. A. Panova; T. Rainer; V. A. Shymanovskyy; R. A. Stephenson

    2002-01-01

    The Donets Basin (Donbas) is one of the major late Paleozoic coal basins in the world. The Donbas Foldbelt is an inverted part of the Donets Basin characterized by WNW–ESE-trending folds and faults. The age of basin inversion is under discussion. Large parts of the Donets Basin host anthracite and meta-anthracite. Low-rank coals are restricted to the western and northern

  5. The record of India-Asia collision preserved in Tethyan ocean basin sediments.

    NASA Astrophysics Data System (ADS)

    Najman, Yani; Jenks, Dan; Godin, Laurent; Boudagher-Fadel, Marcelle; Bown, Paul; Horstwood, Matt; Garzanti, Eduardo; Bracialli, Laura; Millar, Ian

    2015-04-01

    The timing of India-Asia collision is critical to the understanding of crustal deformation processes, since, for example, it impacts on calculations regarding the amount of convergence that needs to be accommodated by various mechanisms. In this research we use sediments originally deposited in the Tethyan ocean basin and now preserved in the Himalayan orogeny to constrain the timing of collision. In the NW Himalaya, a number of workers have proposed a ca 55-50 Ma age for collision along the Indus suture zone which separates India from the Kohistan-Ladakh Intraoceanic Island arc (KLA) to the north. This is based on a number of factors including the age of youngest marine sediments in the Indus suture (e.g. Green et al. 2008), age of eclogites indicative of onset of Indian continental subduction (e.g. de Sigoyer et al. 2000), and first evidence of detritus from north of the suture zone deposited on the Indian plate (e.g. Clift et al. 2002). Such evidence can be interpreted as documenting the age of India-Asia collision if one takes the KLA to have collided with the Asian plate prior to its collision with India (e.g. Petterson 2010 and refs therein). However, an increasing number of workers propose that the KLA collided with Asia subsequent to its earlier collision with India, dated variously at 85 Ma (Chatterjee et al. 2013), 61 Ma (Khan et al. 2009) and 50 Ma (Bouilhol et al. 2013). This, plus the questioning of earlier provenance work (Clift et al. 2002) regarding the validity of their data for constraining timing of earliest arrival of material north of the suture deposited on the Indian plate (Henderson et al. 2011) suggests that the time is right for a reappraisal of this topic. We use a provenance-based approach here, using combined U-Pb and Hf on detrital zircons from Tethyan ocean basin sediments, along with petrography and biostratigraphy, to identify first arrival of material from north of the Indian plate to arrive on the Indian continent, to constrain the time of collision. With the recent discovery that the Indus Group sediments in the suture zone cannot be used for this purpose as previously proposed (Henderson et al. 2011) we turn to the 54 Ma Kong and Chulung La Formation youngest Tethyan sediments on the Indian margin (Garzanti et al. 1987) to investigate whether we can identify such material, and whether it be Spong arc (Fuchs and Willems 1990), KLA or Trans-Himalayan derived, thus determining what collided with India and when. References Bouilhol P, Jagoutz O, Hanchar JM, Dudas FO. 2013. Dating the India-Eurasia collision through arc magmatic records. Earth and Planetary Science Letters 366, 163-175. Chatterjee S, Goswami A, Scotese CR. 2013. The longest voyage: Tectonic, magmatic, and paleoclimatic evolution of the Indian plate during its northward flight from Gondwana to Asia. Gondwana Research 23, 238-267. Clift P, Carter A, Krol M, Kirby E. 2002. Constraints on India-Eurasia collision in the Arabian sea region taken from the Indus Group, Ladakh Himalaya, India. The tectonic and climatic evolution of the Arabian Sea region Geological Society of London Special Publication 195, 97-116. de Sigoyer J, Chavagnac V, Blichert-Toft J, Villa IM, Luais B, Guillot S, Cosca M, Mascle G. 2000. Dating the Indian continental subduction and collisional thickening in the northwest Himalaya: Multichronology of the Tso Morari eclogites. Geology 28, 487-490. Fuchs G, Willems H. 1990. The final stages of sedimentation in the Tethyan zone of Zanskar and their geodynamic significance (Ladakh - Himalaya). Jahrbuche Geologische Bundenstalt 133: 259-273. Garzanti E, Baud A, Mascle G. 1987. Sedimentary Record of the Northward Flight of India and Its Collision with Eurasia (Ladakh Himalaya, India). Geodinamica Acta 1, 297-312. Green OR, Searle MP, Corfield RI, Corfield RM. 2008. Cretaceous-tertiary carbonate platform evolution and the age of the India-Asia collision along the Ladakh Himalaya (northwest India). J Geol 116: 331-353. Henderson AL, Najman Y, Parrish R, Mark D, Foster GL. 2011. Constraints to the timing of India-Eur

  6. Basin genesis associated with strike-slip faulting in the Basin and Range, southeastern Nevada

    NASA Astrophysics Data System (ADS)

    Campagna, David J.; Aydin, Atilla

    1994-04-01

    The structural nature of two prominent Basin and Range strike-slip systems, the Lake Mead fault system and the Las Vegas Valley shear zone, are examined using both geological field mapping and geophysical surveys at various scales. The intent of this study is to document deformation directly attributable to strike-slip faulting with an emphasis on basin genesis. Our field study of the Lake Mead fault system reveals a major left step in the system. The stepover results in the genesis of a 2-km-deep pull-apart, the Overton Arm Basin, consistent with the kinematics and mechanics of strike-slip faulting. Having established the origin of the Overton Arm basin as a strike-slip-related pull-apart basin, the geometry of poorly exposed strike-slip systems can be revealed by understanding the related basins along their length. One such system, the Las Vegas Valley shear zone, is shown with the aid of geophysical data to be geographically related to three distinct en echelon basins. When these basins are interpreted as pull-apart basins, the geometry of the Las Vegas Valley shear zone becomes apparent for the first time. We assert that strike-slip faulting in southeastern Nevada is a deformational mechanism that contributes locally to the regional extensional tectonics. Such an interpretation modifies extant models that treat strike-slip faults in rifted terrains as passive lateral boundaries that simply accommodate extension without contributing to the process.

  7. BASIN STRUCTURE FROM TWO-DIMENSIONAL SEISMIC REFLECTION DATA, CRAZY MOUNTAINS BASIN, MONTANA

    SciTech Connect

    David J. Taylor

    2003-08-01

    Some 140 miles of multichannel seismic reflection data, acquired commercially in the 1970's, were reprocessed by the U.S. Geological Survey in late 2000 and early 2001 to interpret the subsurface geology of the Crazy Mountains Basin, an asymmetric Laramide foreland basin located in south-central Montana. The seismic data indicate that the northwestern basin margin is controlled by a thrust fault that places basement rocks over a thick (22,000 feet) sequence of Paleozoic and Mesozoic sedimentary rocks to the south. From the deep basin trough, Paleozoic through Tertiary rocks slope gently upward to the south and southeast. The northern boundary of the basin, which is not imaged well by the seismic data, appears to be folded over a basement ridge rather than being truncated against a fault plane. Seismic data along the basin margin to the south indicate that several fault controlled basement highs may have been created by thin-skinned tectonics where a series of shallow thrust faults cut Precambrian, Paleozoic, and early Mesozoic rocks, whereas, in contrast, Cretaceous and Tertiary strata are folded. The data are further interpreted to indicate that this fault-bounded asymmetric basin contains several structures that possibly could trap hydrocarbons, provided source rocks, reservoirs, and seals are present. In addition, faults in the deep basin trough may have created enough fracturing to enhance porosity, thus developing ''sweet spots'' for hydrocarbons in basin-centered continuous gas accumulations.

  8. Overflow of Radioactive Water from K Basins

    SciTech Connect

    RITTMANN, P.D.

    1999-10-06

    This report documents the dose calculations for the postulated K Basin overflow accident using current methods to model the environmental doses for radioactive releases into the Columbia River and the air.

  9. KE Basin water dispositioning engineering study

    SciTech Connect

    Hunacek, G.S.; Gahir, S.S.

    1994-09-23

    This engineering study is a feasibility study of KE Basin water treatment to an acceptable level and dispositioning the treated water to Columbia River, ground through ETF or to air through evaporation.

  10. Tidal frequency estimation for closed basins

    NASA Technical Reports Server (NTRS)

    Eades, J. B., Jr.

    1978-01-01

    A method was developed for determining the fundamental tidal frequencies for closed basins of water, by means of an eigenvalue analysis. The mathematical model employed, was the Laplace tidal equations.

  11. Pacific Basin Communication Study, volume 2

    NASA Astrophysics Data System (ADS)

    Young, E. L.; Hurd, J. N.

    1981-10-01

    Users' meeting summary report, chronology of visits, economic data for forum countries, techniques used in the study, communication choices, existing resources in the Pacific Basin, and warc 79 region 3 rules and regulations were presented in volume 2.

  12. Materials and formation of the Imbrium basin

    NASA Technical Reports Server (NTRS)

    Spudis, Paul D.; Hawke, B. Ray; Lucey, Paul G.

    1988-01-01

    A study of Imbrium basin deposits has been conducted, including geologic mapping, analysis of orbital geochemical data, earth-based near-IR spectroscopy, and analytical modeling. The morphologic facies of the deposits display an unusual bilateral symmetry with respect to the main rim of the basin, which is thought to be 1160 km in diameter and composed of Apennine-Carpathian-Alpes mountain ranges. The Imbrium ring structure consists of six concentric rings ranging from 550-3200 km in diameter. The evolution of the target for the Imbrium basin impact is discussed. It is suggested that the Imbrium impact, which occurred 3.85 Gyrs ago, formed a basin predominantly by a proportional-growth crater-forming mechanism.

  13. RIVER BASINS RESEARCH INITIATIVE 2008 SUMMER PROGRAM

    E-print Network

    by the university. The 2008 River Basins Research Initiative Summer Program is supported by a grant from: African American Pacific Islander Hispanic Caucasian Native American Other Highest level of college

  14. BOULDER AREA SUSTAINABILITY INFORMATION NETWORK (BASIN)

    EPA Science Inventory

    The primary goal of the Boulder Area Sustainability Information Network (BASIN) is to help citizens make meaningful connections between environmental data and their day-to-day activities and facilitate involvement in public policy development. Objectives include: ...

  15. Pacific Basin Communication Study, volume 2

    NASA Technical Reports Server (NTRS)

    Young, E. L.; Hurd, J. N.

    1981-01-01

    Users' meeting summary report, chronology of visits, economic data for forum countries, techniques used in the study, communication choices, existing resources in the Pacific Basin, and warc 79 region 3 rules and regulations were presented in volume 2.

  16. K-Basins S/RIDS

    SciTech Connect

    Watson, D.J.

    1995-09-22

    The Standards/Requirements Identification Document(S/RID) is a list of the Environmental, Safety, and Health (ES&H) and Safeguards and Security (SAS) standards/requirements applicable to the K Basins facility

  17. China's Qaidam Basin Landscape Similar with Mars

    USGS Multimedia Gallery

    Geologist, sedimentation expert and Mars Science Laboratory team member David Rubin of the USGS Pacific Coastal and Marine Science Center investigates longitudinal dunes in China's Qaidam Basin. He comments:

  18. VANADIUM CONCENTRATIONS IN COLORADO RIVER BASIN WATERS

    Microsoft Academic Search

    K. Daniel Linstedt; Paul Kruger

    1969-01-01

    To measure traces of vanadium, which is sometimes associated with uranium milling, in waters of the Colorado River Basin, the authors devised a radiochemical activation analysis procedure. It confirmed that highest trace concentrations occur near milling activities.

  19. K-Basins S/RIDS

    SciTech Connect

    Watson, D.J.

    1997-08-01

    The Standards/Requirements Identification Document (S/RID) is a list of the Environmental, Safety, and Health (ES{ampersand}H) and Safeguards and Security (SAS) standards/requirements applicable to the K Basins facility.

  20. The petroleum basins of the northwest Pacific

    SciTech Connect

    Khvedtchuk, I. (Oil and Gas Research Institute, Moscow (USSR))

    1990-05-01

    The northwest Pacific area includes the major petroleum basins flanking the Pacific Ocean in Asia (Japanese, Isikury-West Sakhalin, North Sakhalin, West Kamchatka, Khatyrskiy, and Anadyrskiy). The petroleum basins consist of Tertiary cover (marine, coastal, and continental terrigeneous, siliceous volcanogenic, and volcanogenic-sedimentary rocks) and pre-Genozoic basement composed of geosyncline rock associations. Sediment thickness of the basins attains 10-12 km. Northwest and northeast faults control graben feature in the basement and develop rift systems. The general thickness of the Earth's crust is 27-31 km. All petroleum basins are connected with rifts. Rifting influenced the volcanic and magmatic activity, the abnormally high temperature and pressure in oil- and gas-bearing filling of basins. Analysis of data shows that the main factors affecting deposition of the source rocks and their spatial distribution and effectiveness in generating hydrocarbon reserves are geological age, regional tectonics, paleography, dominant kerogen type, and temperature. There are various types of petroleum source rocks: upper Eocene marine shales (Khatyrskiy basin), kerogen type III; upper Oligocene siliceous shales (North Sakhalin, Japanese, West Kamchatka and Anadyrskiy basins), kerogen type II and III; and middle Miocene marine shales (Japanese, Isikury-West Sakhalin and North Sakhalin basins), kerogen type II. The quantity of organic matter in source rocks is 0.6-3.4% and the geothermal gradient is 24-44{degree}C/km. The main reservoirs are Miocene-lower Pliocene sandstones, upper Miocene deltaic sandstones, and upper Oligocene-lower Miocene siliceous shales. Oil and gas accumulated in anticline structures and stratigraphic traps.

  1. Streamflow changes over Siberian Yenisei River Basin

    Microsoft Academic Search

    Daqing Yang; Baisheng Ye; Douglas L. Kane

    2004-01-01

    This study analyzes long-term (1935–99) monthly discharge data for the major sub-basins within the Yenisei River watershed in order to document significant streamflow changes induced by reservoir regulations and by natural variations\\/changes. The results show that both the unregulated upper basin and major lower streams of the watershed experienced streamflow decreases in the early melt period and discharge increases in

  2. Bison basin, central Wyoming - geologic overview

    SciTech Connect

    Pinnell, M.L.

    1984-07-01

    The northeastern part of the Great Divide basin is a separate, unique, and until recently, little-explored subbasin sometimes called the Bison basin. It is bounded by the Wind River Mountains, Sweetwater-Granite Mountain foreland uplift, Lost Soldier-Wertz structure, and a little-studied very positive east-west structural arch approximately coincident with the Sweetwater-Fremont county line. A comprehensive seismic, Landsat, and subsurface geologic examination or, better, dissection of the Bison basin was initiated in 1978. Numerous oil and gas prospects were delineated by this study. Since this small, 12 by 40 mi (19 by 64 km) basin is bordered by known reserves of 260 million bbl of oil and 90 million bcf of gas, these prospects proved to be a popular target of the drill bit. At least one of these prospects appears to be productive; others are currently being drilled. The presence of major east-west wrench faults, a well-documented foreland uplift, until recently undrilled surface and subsurface structures, faults with throw measured in tens of thousands of feet, and an oil seep indicate possible additional hydrocarbon potential in the Bison basin that could exceed presently known reserves. Currently drilling wells and abundant already acquired reflection seismic data are the beginning step in an ongoing exploration program of an interesting, complex, and rewarding small basin with a lot of promise.

  3. Seismic stratigraphy or Cape Sorell Basin, Tasmania

    SciTech Connect

    Bellow, T.L.

    1990-05-01

    Because large new exploration areas have become scarce, the Cape Sorell basin has become an increasingly attractive frontier area. Cape Sorell basin, located along the western passive continental margin of Tasmania formed as a result of the breakup of eastern Gondwanaland 95{plus minus}5 Ma. An extensional fault system trending west-northwest with dip-slip movement down to the south-southwest forms the northern boundary and a second fault system trending north-northwest with oblique slip down to the south-southwest creates the basin. Second order extensional faults within the basin have created wrench-type flower structures, which are potential migration pathways for hydrocarbons. Nine distinct depositional sequences identified within the Cape Sorell basin record the evolution of this passive continental margin. Late Cretaceous-early Paleocene sequences were deposited as the rifting ceased and clastic progradation over the rift terrain began. Relative lowering of sea level occurred during the Paleocene, resulting in extensive channeling of the Late Cretaceous-early Paleocene sequences. A subsequent rise in relative sea level resulted in canyon-fill deposition during the early Paleocene to early Eocene. During the Eocene, sedimentation sufficiently increased to produce a downlapping sediment progradation characterized by deltaic depositional environment. Although interrupted several times by changes in relative sea level and shifting sediment sources, deltaic deposition continued until the late Oligocene. As the rate of clastic sedimentation slowed, carbonate shelf deposition began and has typified the basin since late the Oligocene.

  4. The East Falcon Basin: Its Caribbean roots

    SciTech Connect

    Bartok, P.; Boesi, T. [Pennzoil Exploration and Production, Houston, TX (United States)

    1996-08-01

    The East Falcon Basin has been described persistently in the context of the Maracaibo Basin tectonic framework. It is the objective of the present study to demonstrate that the Falcon Basin is, in effect, a Caribbean basin juxtaposed on South America and affected by Caribbean tectonics. The oldest rocks outcropping in the region are Late Paleozoic metamorphic and igneous rocks rafted from northcentral Colombia, Middle Jurassic ophiolite complexes, sediments and metasediments and Cretaceous ophiolites transported by a melange of late Cretaceous to early Tertiary sediments. The south vergence of the Caribbean Nappe province has been documented and extends to the present limit of the Andean uplift and to the southern limit of the Coastal Range. The migrating foredeep that developed during the Paleocene-Eocene deposited dominantly basinal shales and thin sandstones. During the Oligocene the Caribbean faults of the Oca system and conjugates began with a dominantly transtensional regime becoming progressively transpressional by Miocene time. The facies development of the Oligocene-Miocene documents the tectonic history. Unique blocks remained as resistant blocks creating ramparts and modifying the basin configuration. During transpression northward-verging thrusting progressively migrated towards the present coastline. The most evident structures of the region are Caribbean in affinity and combined with the sedimentary history of the region can serve to unravel the complex Caribbean-South American plate interaction.

  5. K basins sludge removal sludge pretreatment system

    SciTech Connect

    Chang, H.L.

    1997-06-12

    The Spent Nuclear Fuels Program is in the process of planning activities to remove spent nuclear fuel and other materials from the 100-K Basins as a remediation effort for clean closure. The 105 K- East and K-West Basins store spent fuel, sludge, and debris. Sludge has accumulated in the 1 00 K Basins as a result of fuel oxidation and a slight amount of general debris being deposited, by settling, in the basin water. The ultimate intent in removing the sludge and fuel is to eliminate the environmental risk posed by storing fuel at the K Basins. The task for this project is to disposition specific constituents of sludge (metallic fuel) to produce a product stream through a pretreatment process that will meet the requirements, including a final particle size acceptable to the Tank Waste Remediation System (TWRS). The purpose of this task is to develop a preconceptual design package for the K Basin sludge pretreatment system. The process equipment/system is at a preconceptual stage, as shown in sketch ES-SNF-01 , while a more refined process system and material/energy balances are ongoing (all sketches are shown in Appendix C). Thus, the overall process and 0535 associated equipment have been conservatively selected and sized, respectively, to establish the cost basis and equipment layout as shown in sketches ES- SNF-02 through 08.

  6. Water scarcity in the Jordan River basin.

    PubMed

    Civic, M A

    1999-03-01

    This article reports the problem on water scarcity in the Jordan River basin. In the Jordan River basin, freshwater scarcity results from multiple factors and most severely affects Israel, Jordan, the West Bank, and the Gaza Strip. One of these multiple factors is the duration of rainfall in the region that only occurs in a small area of highlands in the northwest section. The varying method of water use parallels that of Israel that utilizes an estimated 2000 million cu. m. The national patterns of water usage and politically charged territorial assertions compound the competition over freshwater resources in the region. The combination of political strife, resource overuse, and contaminated sources means that freshwater scarcity in the Jordan River basin will reach a critical level in the near future. History revealed that the misallocation/mismanagement of freshwater from the Jordan River basin was the result of centuries of distinct local cultural and religious practices combined with historical influences. Each state occupying near the river basin form their respective national water development schemes. It was not until the mid-1990s that a shared-use approach was considered. Therefore, the critical nature of water resource, the ever-dwindling supply of freshwater in the Jordan River basin, and the irrevocability of inappropriate policy measures requires unified, definitive, and ecologically sound changes to the existing policies and practices to insure an adequate water supply for all people in the region. PMID:12290383

  7. Lower Permian stems as fluvial paleocurrent indicators of the Parnaíba Basin, northern Brazil

    NASA Astrophysics Data System (ADS)

    Capretz, Robson Louiz; Rohn, Rosemarie

    2013-08-01

    A comprehensive biostratinomic study was carried out with abundant stems from the Lower Permian Motuca Formation of the intracratonic Parnaíba Basin, central-north Brazil. The fossils represent a rare tropical to subtropical paleofloristic record in north Gondwana. Tree ferns dominate the assemblages (mainly Tietea, secondarily Psaronius), followed by gymnosperms, sphenophytes, other ferns and rare lycophytes. They are silica-permineralized, commonly reach 4 m length (exceptionally more than 10 m), lie loosely on the ground or are embedded in the original sandstone or siltstone matrix, and attract particular attention because of their frequent parallel attitudes. Many tree fern stems present the original straight cylindrical to slightly conical forms, other are somewhat flattened, and the gymnosperm stems are usually more irregular. Measurements of stem orientations and dimensions were made in three sites approximately aligned in a W-E direction in a distance of 27.3 km at the conservation unit "Tocantins Fossil Trees Natural Monument". In the eastern site, rose diagrams for 54 stems indicate a relatively narrow azimuthal range to SE. These stems commonly present attached basal bulbous root mantles and thin cylindrical sandstone envelopes, which sometimes hold, almost adjacent to the lateral stem surface, permineralized fern pinnae and other small plant fragments. In the more central site, 82 measured stems are preferentially oriented in the SW-NE direction, the proportion of gymnosperms is higher and cross-stratification sets of sandstones indicate paleocurrents mainly to NE and secondarily to SE. In the western site, most of the 42 measured stems lie in E-W positions. The predominantly sandy succession, where the fossil stems are best represented, evidences a braided fluvial system under semiarid conditions. The low plant diversity, some xeromorphic features and the supposedly almost syndepositional silica impregnation of the plants are coherent with marked dry seasons. Thick mudstones and some coquinites below and above the sandy interval may represent lacustrine facies formed in probably more humid conditions. The taphonomic history of the preserved plants began with exceptional storms that caused fast-flowing high water in channels and far into the floodplains. In the eastern site region, many tree ferns only fell, thus sometimes covering and protecting plant litter and leaves from further fragmentation. Assemblages of the central and western sites suggest that the trees were uprooted and transported in suspension (floating) parallel to the flow. Heavier ends of stems (according to their form or because of attached basal bulbous root mantle or large apical fronds) were oriented to upstream because of inertial forces. During falling water stage, the stems were stranded on riverbanks, usually maintaining the previous transport orientation, and were slightly buried. The perpendicular or oblique positions of some stems may have been caused by interference with other stems or shallow bars. Rare observed stems were apparently waterlogged before the final depositional process and transported as bedload. The differences of interpreted channel orientations between the three sites are expected in a braided fluvial system, considering the very low gradients of the basin and the work scale in the order of tens of kilometers. The mean direction of the drainage probably was to east and the flows apparently became weaker downstream. This study seems to provide reliable data for paleocurrent interpretations, especially considering areas with scarce preserved sedimentary structures.

  8. Geometry And Timing Of The Palaeo-Tethyan Marginal Basins At The Heart Of Pangaea

    NASA Astrophysics Data System (ADS)

    Sa?diç, Nurbike G.; Celal ?engör, A. M.; Sunal, Gürsel; Yilmaz, Yücel

    2015-04-01

    The Hercynian Orogen, one of the best-known orogenic belts in the world, still hides many secrets concerning its evolut?on. This orogen formed through the collision between Laurussia and Gondwana-Land, which resulted in the supercontinent of Pangaea. Pangaea's formation began in the late Devonian with the onset of subduction and continued from the early-medial Carboniferous to the Permo-Triassic by means of collision. However, at the eastern part of this supercontinent, collision never happened and subduction continued in the Permo-Triassic. The coast of the Palaeo-Tethys known as Alpine-type Triassic succession was the scene of high mobility events in the core of the Pangaea in terms of Hercynian and Post-Hercynian stages. It is a fact that when the subduction process was still continuing, a rifting event began in the Permo-Triassic at the eastern part of Pangaea by disrupting a magmatic arc. Here, we present the geological and geometrical structures of this rift zone from the Permo-Triassic to the Jurassic-Cretaceous in which the rift zone closed and discuss the tectonic implications for the evolution of the Hercynian Orogeny. By using the comparative anatomy of orogens, the tectonic zones including the magmatic arc of the orogen was identified and by using a basic reconstruction showing the proper positions of these tectonic units, the spatial continuity of the core of the orogen was determined. The results show a continuous arc goes from the Rhodope-Pontide Fragment in the north, through the Eastern Carpathians, Tisza Block, Western Carpathians, and Pelagonian Zone, to the Eastern Pontides in the south. Additionally, the lithostratigraphic charts of all the tectonic zones indicate the volcano-sedimentary complexes, which show a rifting event as their most likely interpretation. As a consequence of this rifting, a marginal basin started to form beginning from the eastern part and tore westward by tracing the weak zones of the former arc. It began to take shape from the Karakaya Complex, goes through the Pelagonian zone and the Inner Western Carpathians namely Meliaticum into the Tisza Block in the Late Permian-Early Triassic. From the medial to the end of the late Triassic, the entire Hellenic-Dinaric System and Italy began to disintegrate, which started from the Pindos Zone in Hellenides and Sicily in Italy, and joined together into the Southern Alps by passing through all along the coast of the present Adriatic Sea. Ultimately, at the end of the Triassic the rift zone formed three branches; one comes from the Karakaya Complex to the Southern Alps in which splitting into two branches; one continued to tear the former arc along the coast of the Palaeo-Tethys, one turn into the present Italy. The resulting framework shows a triple junction geometry for the rift zone right at the core of the late Paleozoic arc orogen just like the one at the end of the New Zealand/Tonga-Kermadec arc system in the Lao Basin.

  9. Estimating tectonic history through basin simulation-enhanced seismic inversion: Geoinformatics for sedimentary basins

    USGS Publications Warehouse

    Tandon, K.; Tuncay, K.; Hubbard, K.; Comer, J.; Ortoleva, P.

    2004-01-01

    A data assimilation approach is demonstrated whereby seismic inversion is both automated and enhanced using a comprehensive numerical sedimentary basin simulator to study the physics and chemistry of sedimentary basin processes in response to geothermal gradient in much greater detail than previously attempted. The approach not only reduces costs by integrating the basin analysis and seismic inversion activities to understand the sedimentary basin evolution with respect to geodynamic parameters-but the technique also has the potential for serving as a geoinfomatics platform for understanding various physical and chemical processes operating at different scales within a sedimentary basin. Tectonic history has a first-order effect on the physical and chemical processes that govern the evolution of sedimentary basins. We demonstrate how such tectonic parameters may be estimated by minimizing the difference between observed seismic reflection data and synthetic ones constructed from the output of a reaction, transport, mechanical (RTM) basin model. We demonstrate the method by reconstructing the geothermal gradient. As thermal history strongly affects the rate of RTM processes operating in a sedimentary basin, variations in geothermal gradient history alter the present-day fluid pressure, effective stress, porosity, fracture statistics and hydrocarbon distribution. All these properties, in turn, affect the mechanical wave velocity and sediment density profiles for a sedimentary basin. The present-day state of the sedimentary basin is imaged by reflection seismology data to a high degree of resolution, but it does not give any indication of the processes that contributed to the evolution of the basin or causes for heterogeneities within the basin that are being imaged. Using texture and fluid properties predicted by our Basin RTM simulator, we generate synthetic seismograms. Linear correlation using power spectra as an error measure and an efficient quadratic optimization technique are found to be most effective in determining the optimal value of the tectonic parameters. Preliminary 1-D studies indicate that one can determine the geothermal gradient even in the presence of observation and numerical uncertainties. The algorithm succeeds even when the synthetic data has detailed information only in a limited depth interval and has a different dominant frequency in the synthetic and observed seismograms. The methodology presented here even works when the basin input data contains only 75 per cent of the stratigraphic layering information compared with the actual basin in a limited depth interval.

  10. Active transtensional intracontinental basins: Walker Lane in the western Great Basin

    USGS Publications Warehouse

    Jayko, Angela S.; Bursik, Marcus

    2012-01-01

    The geometry and dimensions of sedimentary basins within the Walker Lane are a result of Plio-Pleistocene transtensive deformation and partial detachment of the Sierra Nevada crustal block from the North American plate. Distinct morpho-tectonic domains lie within this active transtensive zone. The northeast end of the Walker Lane is partly buried by active volcanism of the southern Cascades, and adjacent basins are filled or poorly developed. To the south, the basin sizes are moderate, 25–45km × 15–10 km, with narrow 8-12km wide mountain ranges mainly oriented N-S to NNE. These basins form subparallel arrays in discrete zones trending about 300° and have documented clockwise rotation. This is succeeded to the south by a releasing stepover domain ?85-100km wide, where the basins are elongated E-W to ENE, small (?15-30km long, 5-15km wide), and locally occupied by active volcanic centers. The southernmost part of the Walker Lane is structurally integrated, with high to extreme relief. Adjacent basins are elongate, 50-200km long and ?5 -20km wide. Variations in transtensive basin orientations in the Walker Lane are largely attributable to variations in strain partitioning. Large basins in the Walker Lane have 2-6km displacement across basin bounding faults with up to 3 km of clastic accumulation based on gravity and drill hole data. The sedimentary deposits of the basins may include interbedded volcanic deposits with bimodal basaltic and rhyolitic associations. The basins may include lacustrine deposits that record a wide range of water chemistry from cold fresh water conditions to saline-evaporative

  11. Mesozoic evolution of the Amu Darya basin

    NASA Astrophysics Data System (ADS)

    Brunet, Marie-Françoise; Ershov, Andrey; Korotaev, Maxim; Mordvintsev, Dmitriy; Barrier, Eric; Sidorova, Irina

    2014-05-01

    This study, granted by the Darius Programme, aims at proposing a model of tectono-stratigraphic evolution of the Amu Darya basin since the Late Palaeozoic and to understand the relationship with the nearby basins. The Amu Darya basin, as its close eastern neighbour, the Afghan-Tajik basin, lies on the Turan platform, after the closure of the Turkestan Ocean during the Late Paleozoic. These two basins, spread on mainly lowlands of Turkmenistan, southwest Uzbekistan, Tajikistan, and northern Afghanistan, are separated from one another by the South-Western Gissar meganticline, where series of the northern Amu Darya margin are outcropping. The evolution is closely controlled by several periods of crustal thinning (post-collision rifting and back-arc extension), with some marine incursions, coming in between accretions of continental blocks and collisions that succeeded from the Late Triassic-Early Jurassic (Eo-Cimmerian orogeny) to the Cenozoic times. These orogenies controlled the deposition of thick clastics sequences, and the collision of the Indian Plate with Eurasia strongly deformed the sedimentary cover of the Afghan-Tajik basin. The more than 7 km thick Meso-Cenozoic sedimentary succession of the Amu Darya basin, lies on a complex system of rifts and blocks. Their orientation and age (late Permian, Triassic?) are not well known because of deep burial. The north-eastern margin, with the Bukhara (upper margin) and Chardzhou steps, is NW oriented, parallel to the Paleozoic Turkestan suture. The orientation bends to W-E, in the part of the Gissar situated to the North of the Afghan-Tajik basin. This EW trending orientation prevails also in the south(-eastern) margin of the basin (series of North Afghanistan highs) and in the Murgab depression, the south-eastern deepest portion of the Amu Darya basin. It is in this area and in the eastern part of the Amu Darya basin that the Jurassic as well as the lower Cretaceous sediments are the thickest. The south-western part of the basin is occupied by the Pre-Kopet Dagh Cenozoic foreland basin NW oriented, possibly underlain by an earlier extensional trough. The main elements of the sedimentary pile, which can be partly observed in the South-Western Gissar are: Lower to Middle Jurassic continental to paralic clastic rocks; upper Middle to Upper Jurassic marine carbonate then thick Tithonian evaporite rocks, sealing the reservoirs in the Jurassic carbonates; continental Neocomian clastic rocks and red beds, Aptian to Paleogene marine carbonate and clastic rocks. To reconstruct the geodynamic evolution of the Amu Darya Basin, we analysed the subsidence by backstripping of some wells/pseudo-wells and of three cross-sections with some examples of thermal modelling on the periods of maturation of the potential source rocks. The crustal thinning events take place in the Permo-Triassic? (depending on the age of the rifts underlying the basin), in Early-Middle Jurassic and during the Early Cretaceous, resulting in increases of the tectonic subsidence rates.

  12. A chrono-tectonostratigraphic framework for the Sydney Basin

    NASA Astrophysics Data System (ADS)

    Mohammad, O. A.; Jones, B. G.; Fergusson, C. L.

    2013-12-01

    The Sydney Basin is a foreland basin forming the southern part of the Bowen-Gunnedah-Sydney Basin system in Eastern Australia. Tectonically the Sydney Basin is regarded as a retro-arc foreland basin that developed through Late Carboniferous to Middle Triassic. Constructing a tectonstratigraphic framework for the basin is difficult due to the complex stratigraphy and poor age control, along with its complex tectonic history. A chrono-tectonostratigraphic framework for the Sydney Basin is presented based on literature synthesis combined with new data analysis. The chrono-tectonostratigraphic framework will provide an up-to-date and easy to follow detailed basin history which can be utilize in the exploration for conventional and unconventional resources in the Sydney Basin.

  13. Precambrian shield and basement tectonics in sedimentary basin analysis

    SciTech Connect

    Touborg, J.F.

    1984-04-01

    This study focused on the use of (1) regional structural analysis of basement and Precambrian rocks surrounding a sedimentary basin, and (2) tracing basement structures into the sedimentary basin. The structural analysis of the Precambrian shield has a fundamental bearing on interpretation of overlying sedimentary cover rocks. This is expressed in the southern part of the Hudson's Bay basin and its southeastern arm, the Moose River basin. For instance, the rims of both basins are controlled by faults or graben structures. Approximately 13 major fault systems with strike lengths of 200-300 km (125-186 mi) or more can be traced from the exposed Precambrian shield into the basin in terms of lineament arrays and/or aeromagnetic and/or gravity signature. The data suggest reactivation of faults during basin sedimentation. This type of basement structural analysis in areas adjacent to sedimentary basins can provide a valuable interpretation base for subsequent seismic surveys and basin evaluation.

  14. Petroleum geology of principal sedimentary basins in eastern China

    SciTech Connect

    Lee, K.Y.

    1986-05-01

    The principal petroliferous basins in eastern China are the Songliao, Ordos, and Sichuan basins of Mesozoic age, and the North China, Jianghan, Nanxiang, and Subei basins of Cenozoic age. These basins contain mostly continental fluvial and lacustrine detrital sediments. Four different geologic ages are responsible for the oil and gas in this region: (1) Mesozoic in the Songliao, Ordos, and Sichuan basins; (2) Tertiary in the North China, Jianghan, Nanxiang, and Subei basins; (3) Permian-Carboniferous in the southern North China basin and the northwestern Ordos basin; and (4) Sinian in the southern Sichuan basin. The most prolific oil and gas sources are the Mesozoic of the Songliao basin and the Tertiary of the North China basin. Although the major source rocks in these basins are lacustrine mudstone and shale, their tectonic settings and the resultant temperature gradients differ. For example, in the Songliao, North China, and associated basins, trapping conditions commonly are associated with block faulting of an extensional tectonic regime; the extensional tectonics in turn contribute to a high geothermal gradient (40/sup 0/-60/sup 0/C/km), which results in early maturation and migration for relatively shallow deposits. However, the Ordos and Sichuan basins formed under compressional conditions and are cooler. Hence, maturation and migration occurred late, relative to reservoir deposition and burial, the result being a poorer quality reservoir.

  15. The Middle Jurassic basinal deposits of the Surmeh Formation in the Central Zagros Mountains, southwest Iran: Facies, sequence stratigraphy, and controls

    USGS Publications Warehouse

    Lasemi, Y.; Jalilian, A.H.

    2010-01-01

    The lower part of the Lower to Upper Jurassic Surmeh Formation consists of a succession of shallow marine carbonates (Toarcian-Aalenian) overlain by a deep marine basinal succession (Aalenian-Bajocian) that grades upward to Middle to Upper Jurassic platform carbonates. The termination of shallow marine carbonate deposition of the lower part of the Surmeh Formation and the establishment of deep marine sedimentation indicate a change in the style of sedimentation in the Neotethys passive margin of southwest Iran during the Middle Jurassic. To evaluate the reasons for this change and to assess the basin configuration during the Middle Jurassic, this study focuses on facies analysis and sequence stratigraphy of the basinal deposits (pelagic and calciturbidite facies) of the Surmeh Formation, referred here as 'lower shaley unit' in the Central Zagros region. The upper Aalenian-Bajocian 'lower shaley unit' overlies, with an abrupt contact, the Toarcian-lower Aalenian platform carbonates. It consists of pelagic (calcareous shale and limestone) and calciturbidite facies grading to upper Bajocian-Bathonian platform carbonates. Calciturbidite deposits in the 'lower shaley unit' consist of various graded grainstone to lime mudstone facies containing mixed deep marine fauna and platform-derived material. These facies include quartz-bearing lithoclast/intraclast grainstone to lime mudstone, bioclast/ooid/peloid intraclast grainstone, ooid grainstone to packstone, and lime wackestone to mudstone. The calciturbidite layers are erosive-based and commonly exhibit graded bedding, incomplete Bouma turbidite sequence, flute casts, and load casts. They consist chiefly of platform-derived materials including ooids, intraclasts/lithoclasts, peloids, echinoderms, brachiopods, bivalves, and open-ocean biota, such as planktonic bivalves, crinoids, coccoliths, foraminifers, and sponge spicules. The 'lower shaley unit' constitutes the late transgressive and the main part of the highstand systems tract of a depositional sequence and grades upward to platform margin and platform interior facies as a result of late highstand basinward progradation. The sedimentary record of the 'lower shaley unit' in the Central Zagros region reveals the existence of a northwest-southeast trending platform margin during the Middle Jurassic that faced a deep basin, the 'Pars intrashelf basin' in the northeast. The thinning of calciturbidite layers towards the northeast and the widespread Middle Jurassic platform carbonates in the southern Persian Gulf states and in the Persian Gulf area support the existence of a southwest platform margin and platform interior source area. The platform margin was formed as a result of tectonic activity along the preexisting Mountain Front fault associated with Cimmerian continental rifting in northeast Gondwana. Flooding of the southwest platform margin during early to middle Bajocian resulted in the reestablishment of the carbonate sediment factory and overproduction of shallow marine carbonates associated with sea-level highstand, which led to vertical and lateral expansion of the platform and gradual infilling of the Pars intrashelf basin by late Bajocian time. ?? 2010 Springer-Verlag.

  16. Hydrological extreme events with Mike Basin

    NASA Astrophysics Data System (ADS)

    Pereira, M. G.; Carvalho, S.; Fernandes, L.; Caramelo, L.; Alencoão, A.

    2012-04-01

    This work is part of a broader project which aims to develop an integrated system to model and simulate of the hydrological cycle processes at river basin scale. All these processes involved in the dynamics of a watershed, which play an important role in the proper management and sustainable use of water resources, are influenced by many factors (e.g. soil use, vegetation cover, weather and climate) being of particular importance, all aspects related to the occurrence, amount and the spatial-temporal distribution of precipitation. We focus our work on the use of the MIKE Basin model and apply it to the Corgo River basin, which is a tributary of the Douro river, located in the Portuguese region of Trás-os-Montes and Alto Douro. Different datasets were used to characterize and model the river basin catchment hydrological processes, namely temperature, precipitation and runoff registered in several weather/hydrometric stations from the Institute of Information System for Water Resources (http://snirh.pt/) as well as land use/soil occupation and topography maps. The MIKE BASIN model runs on a Geographic Information System (GIS) to perform hydrologic modeling at basin-scale. This software allows a set of multisectoral water demands (domestic and industrial water supply, irrigation, hydropower generation, among others) and provides simulation and visualization in both space and time. We start by using the topography, soil type, soil use and vegetation cover of the region. Then the model is calibrated and tested, comparing model runoff estimates with observed data. Finally, the model is used to simulate the river basin catchment behavior to the typical conditions of the hydrological extreme events namely, heavy precipitation and drought. We present the geologic, hydrologic and climatologic characterization of the Corgo river catchment, list the most important factors that control the water availability in the river basin, describe the MIKE BASIN model calibration process, and discuss the role of each factor through sensibility tests and the estimated impacts of extreme events on the river basin management.

  17. Implication of drainage basin parameters of a tropical river basin of South India

    NASA Astrophysics Data System (ADS)

    Babu, K. J.; Sreekumar, S.; Aslam, Arish

    2014-07-01

    Drainage morphometry provides quantitative description of the drainage system which is an important aspect of the characterisation of watersheds. Chalakudi River is one of the important rivers of the South India which has attracted attention of many environmental scientists recently because of the proposed Athirapally Hydel Project across the river. SRTM (Shuttle Radar Topographic Mission) data were used for preparing DEM (Digital Elevation Model), Aspect Map and Slope Map. Geographical Information System (GIS) was used for the evaluation of linear, areal and relief aspects of morphometric parameters. The study reveals that the terrain exhibits dentritic and trellis pattern of drainage. The Chalakudi River Basin has a total area of 1,448.73 km2 and is designated as seventh-order basin. The drainage density of the basin is estimated as 2.54 and the lower-order streams mostly dominate the basin. The high basin relief indicates high runoff and sediment transport. The elongation ratio of the Chalakudi Basin is estimated as 0.48 and indicates that the shape of the basin is elongated. The development of stream segments in the basin area is more or less effected by rainfall. Relief ratio indicates that the discharge capability of watershed is very high and the groundwater potential is meagre. The low value of drainage density in spite of mountainous relief indicates that the area is covered by dense vegetation and resistant rocks permeated by fractures and joints. These studies are helpful in watershed development planning and wise utilization of natural resources.

  18. Hydrocarbon systems in the East Texas basin: A basin modeling approach

    SciTech Connect

    Wescott, W.A.; Hood, W.C. (Amoco Production Company, Houston, TX (United States))

    1993-09-01

    The East Texas basin is a prolific mature hydrocarbon province, producing oil and gas from several reservoirs and a variety of trap types. Much of the liquid hydrocarbons discovered in the basin are trapped in structures related to movement of the underlying Louann Salt. By determining the structural evolution of the basin, a framework was constructed to model the generation of hydrocarbons in the basin. Geochemical data indicate three major source horizons: the Smackover formation (Jurassic oil), shales in the Pearsal Group (Lower Cretaceous oil), and the Eagleford shale (Upper Cretaceous oil). The Jurassic source is mature throughout the basin and began to expel oil approximately 88 Ma. The distribution of Jurassic oil in Cretaceous reservoirs shows that vertical migration routes predominated. Lower Cretaceous source rocks are mature only in the deep, central part of the basin where expulsion began around 47 Ma Distribution of this oil type suggests that Lower Cretaceous source rocks occur only in localized areas of the East Texas basin. The Eagleford shale is immature in the main part of the basin, but it is mature south of the Angelina-Caldwell flexure, where is reached peak generation approximately 20 Ma. Lateral migration explains the distribution of this oil. Migration routes to the giant East Texas field may be 60 mi or more.

  19. Direct flows from the Ulleung Basin into the Yamato Basin in the East\\/Japan Sea

    Microsoft Academic Search

    Young-Gyu Park; Ara Choi; Young Ho Kim; Hong Sik Min; Jin Hwan Hwang; Sang-Hwa Choi

    2010-01-01

    Using the trajectories of ARGO floats, we report direct flows from the Ulleung Basin into the Yamato Basin through a gap between the Oki Spur and the Yamato Rise over the southern part of the East\\/Japan Sea. The gap is subdivided into two narrow (northern and southern) passages by a seamount located in the middle. The flows, therefore, are narrow

  20. Carboniferous clastic-wedge stratigraphy, sedimentology, and foreland basin evolution: Black Warrior basin, Alabama and Mississippi

    SciTech Connect

    Hines, R.A.

    1986-05-01

    Carboniferous clastic-wedge stratigraphy and sedimentology in the Black Warrior basin of Alabama and Mississippi indicate deposition in an evolving foreland basin flanking the Appalachian-Ouachita fold-thrust belt. The strata reflect specific responses to foreland basin subsidence, orogenic activity, sediment supply, and dispersal systems. Definition of the regional stratigraphy of the clastic wedge provides for interpretation of the foreland basin subsidence history by enabling quantitative reconstruction of regional compaction and subsidence profiles. Comparison of the interpreted subsidence history with model profiles of foreland basin subsidence (predicted from loading and flexure of continental lithosphere) allows evaluation of mechanical models in terms of observed clastic-wedge sedimentology and stratigraphy. Mechanical modeling of foreland basin subsidence predicts formation of a flexural bulge that migrates cratonward ahead of the subsiding foreland basin during loading. In the Black Warrior basin, local stratigraphic thins, pinch-outs, and areas of marine-reworked sediments suggest migration of the flexural bulge. Comparison of flexural bulge migration with thermal maturation history allows evaluation of timing of stratigraphic trapping mechanisms with respect to onset of hydrocarbon generation.

  1. Propagators and ridge jumps in a back-arc basin, the West Philippine Basin

    Microsoft Academic Search

    Anne Deschamps; Ryuichi Shinjo; Takeshi Matsumoto; Chao-Shing Lee; Serge E. Lallemand; Shiguo Wu

    2008-01-01

    We explore the tectono-magmatic processes in the western West Philippine Basin, Philippine Sea Plate, using bathymetric data acquired in 2003 and 2004. The northwestern part of the basin formed through a series of northwestward propagating rifts. We identify at least five sequences of propagating rifts, probably triggered by mantle flow away from the mantle thermal anomaly that is responsible for

  2. Propagating rift during the opening of a small oceanic basin: The Protector Basin (Scotia Arc, Antarctica)

    NASA Astrophysics Data System (ADS)

    Galindo-Zaldívar, Jesús; Bohoyo, Fernando; Maldonado, Andrés; Schreider, Anatoly; Suriñach, Emma; Vázquez, Juan Tomas

    2006-01-01

    The opening of oceanic basins constitutes one of the key features of Plate Tectonics because it determines the rifting and displacement of the continental crustal blocks. Although the mechanisms of development of large oceans are well known, the opening and evolution of small and middle size oceanic basins have not been studied in detail. The Protector Basin, located in the southern Scotia Sea, is a good example of a small oceanic basin developed between two thinned continental blocks, the Pirie Bank and the Terror Rise, poorly studied up to now. A new set of multibeam bathymetry, multichannel seismic reflection, and gravity and magnetic anomaly profiles obtained on the SCAN 2001 cruise led us to determine that the Protector Basin probably opened during the period comprised between C5Dn (17.4 Ma) and C5ACn-C5ABr chrons (13.8 Ma), forming a N-S oriented spreading axis. The end of spreading is slightly younger to the north. The start of spreading is clearly diachronous, with the most complete set of chrons up to C5Dn in the southern profile, C5Cn in the middle section and only up to C5ADn in the northern part of the basin. The spreading axis propagated northwards during the basin development, producing the wedge shape of the basin. In addition, at the NE part of the basin, a reverse fault developed in the border of the Pirie Bank after basin opening accentuates the sharp northern end. Moreover, the northwestern part of the Pirie Bank margin is an extremely stretched continental crust with N-S elongated magnetic anomalies related to incipient oceanic southward propagating spreading axes. The Protector Basin shows the oldest evidence of E-W continental stretching and subsequent oceanic spreading during Middle Miocene, related with the eastward development of the Scotia Arc that continues up to Present. The relative rotation of continental blocks during the development of small sized oceanic basins by continental block drifting favoured the opening of wedge shape basins like the Protector Basin and conjugate propagating rifts.

  3. Lithology of basin-fill deposits in the Albuquerque-Belen Basin, New Mexico

    USGS Publications Warehouse

    Kaehler, C.A.

    1990-01-01

    Sediments that fill the Albuquerque-Belen Basin in central New Mexico comprise an aquifer that supplies water to approximately one-third the population of the State. Analysis of driller 's logs and geophysical logs indicate that an area of fine-grained deposits generally underlies the west-central part of the basin. Coarse-grained deposits are concentrated primarily along the axis of the north-central part of the basin. Mixed lithologic textures are present in the rest of the basin and are especially pronounced in the east-central part. Lithologic interpretation of borehole-geophysical logs were used to construct 10 lithologic sections. These sections show that the upper part of the basin fill consists mostly of sandy lenses alternating with clayey or silty lenses. (USGS)

  4. Basin-centered gas evaluated in Dnieper-Donets basin, Donbas foldbelt, Ukraine

    SciTech Connect

    Law, B.E. [Law (B.E.), Lakewood, CO (United States); Ulmishek, G.F.; Clayton, J.L. [Geological Survey, Denver, CO (United States); Kabyshev, B.P. [Ukrainian State Geological Inst., Chernigov (Ukraine); Pashova, N.T.; Krivosheya, V.A. [Ukrainian State Geological Inst., Poltava (Ukraine)

    1998-11-23

    An evaluation of thermal maturity, pore pressures, source rocks, reservoir quality, present-day temperatures, and fluid recovery data indicates the presence of a large basin-centered gas accumulation in the Dnieper-Donets basin (DDB) and Donbas foldbelt (DF) of eastern Ukraine. This unconventional accumulation covers an area of at least 35,000 sq km and extends vertically through as much as 7,000 m of Carboniferous rocks. The gas accumulation is similar, in many respects, to some North American accumulations such as Elmworth in the Alberta basin of western Canada, the Greater Green River basin of southwestern Wyoming, and the Anadarko basin of Oklahoma. Even though rigorous assessments of the recoverable gas have not been conducted in the region, a comparison of the dimensions of the accumulation to similar accumulations in the US indicates gas resources in excess of 100 tcf in place. The paper describes the geology, the reservoirs, source rocks, seals, and recommendations for further study.

  5. Chicxulub impact basin: Gravity characteristics and implications for basin morphology and deep structure

    NASA Technical Reports Server (NTRS)

    Sharpton, Virgil L.; Burke, Kevin; Hall, Stuart A.; Lee, Scott; Marin, Luis E.; Suarez, Gerardo; Quezada-Muneton, Juan Manuel; Urrutia-Fucugauchi, Jaime

    1993-01-01

    The K-T-aged Chicxulub Impact Structure is buried beneath the Tertiary carbonate rocks of the Northern Yucatan Platform. Consequently its morphology and structure are poorly understood. Reprocessed Bouguer (onshore) and Free Air (offshore) gravity data over Northern Yucatan reveal that Chicxulub may be a 200-km-diameter multi-ring impact basin with at least three concentric basin rings. The positions of these rings follow the square root of 2 spacing rule derived empirically from analysis of multi-ring basins on other planets indicating that these rings probably correspond to now-buried topographic basin rings. A forward model of the gravity data along a radial transect from the southwest margin of the structure indicates that the Chicxulub gravity signature is compatible with this interpretation. We estimate the basin rim diameter to be 204 +/- 16 km and the central peak ring diameter (D) is 104 +/- 6 km.

  6. Strike-slip sedimentation: Dead Sea basin

    SciTech Connect

    Manspeizer, W.

    1986-05-01

    The Dead Sea rift extends for 1000 km along a transform plate boundary that has had left-lateral displacement of 150 km since the Miocene. The rift consists of a series of en-echelon, left-stepping (looking north), north-striking, strike-slip faults that are joined by a series of grabens (e.g., the Dead Sea basin). This basin developed as an asymmetric rhomb-shaped graben with nearly vertical, north-striking normal border faults (east and west margins), north-northeast-dipping listric normal faults (south margin), and a south-facing inclined basement (north margin). Displacement along the transform produced three basins, whose depocenters migrated north where they received Miocene fluvial clastics, Pliocene marine evaporites, and Pleistocene-Holocene lacustrine sediments. Graben filling today is governed largely by tectonism, which modifies rift climates and morphology. As warm moist air from the Mediterranean Sea rises over the rift shoulders, it cools adiabatically, yielding up to 900 mm of rain water for high discharge, ephemeral streams that prograde vast prisms of coalescing shallow water fan deltas along the western border fault. The eastern basin margin, by contrast, is dominated by an active transform boundary, a narrow shelf, and a spectacular deep (750 m below MSL) that receives deep water clastics. Whereas the northern margin of the basin receives fine-grained clastics from the prograding delta of the Jordan River (a perennial stream, whose drainage basin lies in a humid terrane far to the north), the southern margin is dominated by evaporites that are precipitated in shallow water basins (upon adiabatic warming of descending air).

  7. Kandik basin stratigraphy, sedimentology, and structure

    SciTech Connect

    Wiley, T.J.; Howell, D.G.; Kauffman-Linam, L.; Boundy-Sanders, S.; Murray, R.W.; Jones, D.L.

    1987-05-01

    East-central Alaska's Kandik basin is a structural remnant of a larger Permian to Cretaceous basin. Permian shallow-water Tahkandit Limestone and Step Conglomerate at the base of the sequence rest unconformably on Paleozoic chert-pebble conglomerate, siliceous shale, and limestone. These Permian rocks are overlain by Triassic to Lower Cretaceous open-ocean Glenn Shale, which grades upward into Lower Cretaceous (Valanginian) hummocky cross-bedded (outer shelf to upper slope) Keenan Quartzite. The quartzite grades upward into fine-grained north-northeast-flowing turbidites of the Biederman Argillite (undated). East-northeast-flowing pebbly turbidites of the Kathul Graywacke (undated) overlie Biederman strata. Locally, Cretaceous (Albian and younger) through Paleogene nonmarine rocks unconformably overlie the Kandik basin sequence. The Mesozoic part of the sequence is similar to that of Manley basin, northwest Yukon Territory, and much of the North Slope. East-directed flow for Kandik basin strata may require paleogeographic reconstructions involving local to large-scale palinspastic rotations or a western source of chert detritus. Deformation of the Mesozoic sequence in Kandik basin west of the US-Canada border shows northwest-southeast shortening. Shaly units are tightly folded with well-developed cleavage striking northeast. Strikes of beds swing from northeast to east in the extreme southwestern part of the basin, suggesting clockwise rotation. Thrust faults, reverse faults, and fold axes trend east to northeast; normal faults trend northwest. These relations are all consistent with, and probably are closely related to, right slip on the west-northwest-trending Tintina fault.

  8. Streamflow changes over Siberian Yenisei River Basin

    NASA Astrophysics Data System (ADS)

    Yang, Daqing; Ye, Baisheng; Kane, Douglas L.

    2004-08-01

    This study analyzes long-term (1935-99) monthly discharge data for the major sub-basins within the Yenisei River watershed in order to document significant streamflow changes induced by reservoir regulations and by natural variations/changes. The results show that both the unregulated upper basin and major lower streams of the watershed experienced streamflow decreases in the early melt period and discharge increases in the late melt season. These changes in snowmelt runoff pattern suggest a delay in snowcover melt in the Yenisei basin perhaps associated with cooling trends during the snowmelt months over central Siberia. This study also demonstrates that the reservoir regulation has significantly altered the monthly discharge regimes in northeast and the upper portions of the Yenisei basin. Constructions of four large dams in the northeast Yensiei regions reduced the summer peak flows in the Angara valley by 15-30% and increased the winter low flows by 5-30%. Operations of two large reservoirs in the upper Yenisei regions enhanced the winter flows by 45-85% and reduced the summer flows by 10-50%. These alterations lead to a streamflow regime change toward less seasonal variation over the eastern and lower Yenisei basin. Because of reservoir regulations, discharge records collected at the Yenisei basin outlet do not always represent natural changes and variations, they tend to underestimate the natural streamflow trends in summer and overestimate the trends in winter and fall seasons. Cold season discharge increase over the Yenisei river is not natural-caused, but mainly the effect of reservoir regulations in the Yenisei basin.

  9. Basin analysis of tertiary strata in the Pattani Basin, Gulf of Thailand

    SciTech Connect

    Chonchawalit, A. (PTT Exploration and Production Public Co., Ltd., Bangkok (Thailand)); Bustin, R.M. (Univ. of British Columbia, Vancouver (Canada))

    1994-07-01

    The stratigraphic and structural evolution of the Pattani basin, the most prolific petroleum basin in Thailand, reflects the extensional tectonics of continental southeast Asia. East-west extension, a product of the northward collision of India with Eurasia since the early Tertiary resulted in the formation of a series of north-south-trending sedimentary basins including the Pattani basin. Subsidence and thermal histories of the basin can generally be accounted for by nonuniform lithospheric stretching. The validity of nonuniform lithospheric stretching as a mechanic for the formation of the Pattani basin is confirmed by a reasonably good agreement between modeled and observed vitrinite reflectance at various depths and locations. The amount of stretching and surface heat flow generally increases from the basin margin to the basin center. Crustal stretching factor ([beta]) ranges from 1.3 at the basin margin to 2.8 in the center. Subcrustal stretching factor ([sigma]) ranges from 1.3 at the margin to more than 3.0 in the center. The stretching of the lithosphere may have extended basement rocks as much as 45 to 90 km and may have caused the upwelling of asthenosphere, resulting in high heat flow. The sedimentary succession in the Pattani basin is divisible into synrift and postrift sequences. The synrift sequences comprise (1) late Eocene ( ) to early Oligocene alluvial fan, braided river, and flood-plain deposits; (2) late Oligocene to early Miocene floodplain and channel deposits; and (3) an early Miocene regressive package of marine to nonmarine sediments. Deposition of synrift sequences corresponded to rifting and extension, which included episodic block faulting and rapid subsidence. Postrift succession comprises (1) an early to middle Miocene regressive package of shallow marine to nonmarine sediments, (2) a late early Miocene transgressive package; and (3) a late Miocene to Pleistocene transgression succession.

  10. Modified Streamflows 1990 Level of Irrigation : Missouri, Colorado, Peace and Slave River Basin, 1928-1989.

    SciTech Connect

    A.G. Crook Company; United States. Bonneville Power Administration

    1993-07-01

    This report presents data for monthly mean streamflows adjusted for storage change, evaporation, and irrigation, for the years 1928-1990, for the Colorado River Basin, the Missouri River Basin, the Peace River Basin, and the Slave River Basin.

  11. Desert basins of the Southwest

    USGS Publications Warehouse

    Leake, Stanley A.; Konieczki, Alice D.; Rees, Julie A.H.

    2000-01-01

    Ground water is among the Nation’s most important natural resources. It provides drinking water to urban and rural communities, supports irrigation and industry, sustains the flow of streams and rivers, and maintains riparian and wetland ecosystems. In many areas of the Nation, the future sustainability of ground-water resources is at risk from overuse and contamination. Because ground-water systems typically respond slowly to human actions, a long-term perspective is needed to manage this valuable resource. This publication is one in a series of fact sheets that describe ground-water-resource issues across the United States, as well as some of the activities of the U.S. Geological Survey that provide information to help others develop, manage, and protect ground-water resources in a sustainable manner. Ground-water resources in the Southwest are among the most overused in the United States. Natural recharge to aquifers is low and pumping in many areas has resulted in lowering of water tables. The consequences of large-scale removal of water from storage are becoming increasingly evident. These consequences include land subsidence; loss of springs, streams, wetlands and associated habitat; and degradation of water quality. Water managers are now seeking better ways of managing ground-water resources while looking for supplemental sources of water. This fact sheet reviews basic information on ground water in the desert basins of the Southwest. Also described are some activities of the U.S. Geological Survey (USGS) that are providing scientific information for sustainable management of ground-water resources in the Southwest. Ground-water sustainability is defined as developing and using ground water in a way that can be maintained for an indefinite time without causing unacceptable environmental, economic, or social consequences.

  12. Tectonics and Quaternary sequence development of basins along the active Vienna Basin strike-slip fault

    NASA Astrophysics Data System (ADS)

    Salcher, B.; Lomax, J.; Meurers, B.; Smit, J.; Preusser, F.; Decker, K.

    2012-04-01

    The Vienna Basin strike-slip fault is a continent scale active fault extending over a distance of some 300 km from the Eastern Alps through the Vienna Basin into the Western Carpathians. Sinistral movement causes the formation of several tight Pleistocene strike-slip basins within the older Miocene Vienna Basin. These sub-basins not only have a high relevance for groundwater exploitation but their fault activities depict serious seismic hazards. Basins are filled with fluvial sediments from the Danube and, closer to the Alpine front, with thick alluvial fan deposits. However, knowledge on the stratigraphy and tectonics is sparse and rather limited to the Miocene part of the Vienna Basin as it hosts giant hydrocarbon fields. This study tackles two major questions: (i) What is the effect of Quaternary climatic oscillations and subsidence on the sequence development of the alluvial fans and (ii) what is the deformation style of these basins? To answer (i) we present a series of new OSL ages and biotic data from both, surface and cores, to better constrain the timing of fan activity, fan abandonment but also to constrain the onset of Pleistocene basin formation. For (ii) we utilize information from unparalleled geophysical and geological data. Specifically we utilize industrial Bouguer gravity's derivatives to highlight shallow structures and to compensate for the lag of fault trace information. The integration of geological and geophysical data highlights textbook-like models of strike-slip basins, with typical features like Riedel shears with intervening relay ramps, en-echelon sidewall faults and a cross-basin fault zone delimiting opposite depocenters. The infill reflects a distinct cyclicity with thick sequences of coarse sediments deposited during colder periods and thin sequences of paleosol and flood sediments deposited during warmer periods. Ages indicate main activity around the short peak glacial periods and basin formation starting c. 300 ka ago. The distinct sequence development and the strong contrast to the underlying marine deposits is a very suitable setting to apply geophysical methods constraining basins' deformation style.

  13. Deep Mediterranean basins and their oil potential

    SciTech Connect

    Burollet, P.F.

    1984-09-01

    Mediterranean deep basins are surrounded by oil and gas producing areas, either onshore or beneath the continental shelf. In general, the Mediterranean basins have relatively flat and uniform bottoms with water depths of the order of 2,800-3,000 m (9,200-9,850 ft). In terms of the crust, the problem can be approached with the aid of geophysical studies (gravimetry, magnetism, and seismic) and variations in heat flow. The superposition of these varied data thus enables us to schematize the nature of crust of the Mediterranean basins. The main potential oil and gas objectives are the Oligocene and Miocene Series, deposited after and during the main orogenic phases, and covered by thick Messinian evaporites and Pliocene-Pleistocene marine sediments. Underlying the Ionian Sea, the Mediterranean ridge, and the eastern basins, Mesozoic and Paleogene rocks may be possible targets. In conclusion, the deep Mediterranean basins could hide large targets. The exploration effort will require various improvements (excluding that of the price o

  14. Shallow basins on Mercury: Evidence of relaxation?

    NASA Astrophysics Data System (ADS)

    Mohit, P. Surdas; Johnson, Catherine L.; Barnouin-Jha, Olivier; Zuber, Maria T.; Solomon, Sean C.

    2009-08-01

    Stereo-derived topographic models have shown that the impact basins Beethoven and Tolstoj on Mercury are shallow for their size, with depths of 2.5 and 2 (± 0.7) km, respectively, while Caloris basin has been estimated to be 9 (± 3) km deep on the basis of photoclinometric measurements. We evaluate the depths of Beethoven and Tolstoj in the context of comparable basins on other planets and smaller craters on Mercury, using data from Mariner 10 and the first flyby of the MESSENGER spacecraft. We consider three scenarios that might explain the anomalous depths of these basins: (1) volcanic infilling, (2) complete crustal excavation, and (3) viscoelastic relaxation. None of these can be ruled out, but the fill scenario would imply a thick lithosphere early in Mercury's history and the crustal-excavation scenario a pre-impact crustal thickness of 15-55 km, depending on the density of the crust, in the area of Beethoven and Tolstoj. The potential for viscous relaxation of Beethoven, Tolstoj, and Caloris is explored with a viscoelastic model. Results show that relaxation of these basins could occur at plausible heat flux values for a range of crustal thicknesses. However, the amplitude of current topographic relief points to a crustal thickness of at least 60 km under this hypothesis. Relaxation of Caloris may have occurred if the floor is underlain by crust at least 20 km thick. We discuss future observations by MESSENGER that should distinguish among these scenarios.

  15. Petroleum geology of Solimoes Basin, Brazil

    SciTech Connect

    Campos, J.N.P.; Meister, E.M.; Pereira, C.A.G.; Murakami, C.Y. (Petrobras, Rio de Janeiro (Brazil))

    1993-02-01

    Solimoes basin is located at the northwestern portion of the South American continent, adjacent to a subandean pericratonic belt. It constitutes a Paleozoic intracratonic basin covering an area of about 600,000 km[sup 2] and displaying a maximum sedimentary thickness of 3400 m. The tectono-sedimentary evolution can be largely related with important events that occurred at the western border of the continent. The regional flexural subsidence and tectonic deformation observed are correlated to two major phases: Pre-Andean (Paleozoic) and Andean (Mesozoic and Cenozoic). In the Andean phase, compression with shear components, of Triassic age, known as the Jurua Tectonism, became very important for oil exploration of the basin. The stratigraphic conditions considered of greatest interest for petroleum exploration comprise Devonian gas and oil sourcing shales and Carboniferous sandstones reservoirs with an evaporitic seal. The main traps are anticlines related to reverse faults. In this context, Petrobras discovered Jurua gas field in 1978 and the Rio Urucu gas and oil field in 1986. These were the first fields discovered in Brazilian Paleozoic basins. Total petroleum fields discovered in Brazilian Paleozoic basins. Total petroleum reserves discovered represent 400 million bbl of equivalent oil. Present migration and accumulation call for previous accumulation in intrabasinal Paleozoic highs and related stratigraphic traps. Late tectonism seems to have resulted in redistribution and/or escape of fluids into new traps. Less disturbed areas are expected to contain original accumulations.

  16. Petroleum prospects of Southern Nigeria's Anambra Basin

    SciTech Connect

    Avbovbo, A.A.; Ayoola, O.

    1981-05-04

    Surrounded by the Benue trough, the Middle Niger River depression, the Niger River delta, and the Abakaliki anticlinorium, Nigeria's Anambra basin probably holds a thick, unexplored sequence with significant hydrocarbon potential. The basin's sediment could be 16,000 ft thick; a Bouguer gravity survey indicates two parallel northeast-southwest trending gravity lows (the Anambra low and the Awka depression) separated by the Onitsha high. Although geologists interpret the basin as Upper Cretaceous-Lower Tertiary, its southern portion is down-warped and overlapped by the delta's thick Tertiary deposits, lowering the Cretaceous to prohibitive depths in the overlap areas; wells drilled to 16,000 ft at the delta's apex thus have not encountered the Cretaceous sediments. An evaluation of the basin's pre-Santonian hydrocarbon prospects will require a deep exploratory drilling program. As Nigeria shifts its production emphasis from oil to gas and firms up plans for an LNG plant in the Niger delta, exploration in the gas-prone Anambra basin will probably surge.

  17. Hydrocarbon potential of lower Magdalena basin

    SciTech Connect

    Torres, E.; Valderrama, R. (Univ. of South Carolina, Columbia (USA))

    1989-03-01

    The Lower Magdalena basin complex of Colombia has an areal extent of more than 87,000 km{sup 2}. The geologic setting of the different subbasins of the Lower Magdalena presents attractive play concepts for the generation, entrapment, and production of hydrocarbons. The sedimentary sequence within the basin attains a thickness in excess of 12,200 m, with the preponderance of this section being of Tertiary age. This major thickness of section contains good source and reservoir rocks and seals and an abundance of structural and stratigraphic traps, which make the basin attractive for new interpretation and evaluation. The Plato, San Jorge, and Sinu subbasins lie within the Lower Magdalena complex. Each of these presents different geological conditions, thereby offering a variety of play concepts for hydrocarbon exploration. Previous exploration in the Lower Magdalena has resulted in the discovery of 10 small to moderate-size fields, which have produced nearly 200 million bbl of oil. The density of exploration drilling within the basin is one well/435 km{sup 2}, thereby allowing the opportunity for more discoveries to be realized. The existence of a thick Tertiary section with excellent source beds and a tectonic history that allows for both structural and stratigraphic traps presents an excellent opportunity for the application of modern exploration techniques to reevaluate the potential of a basin that has not been thoroughly evaluated due to complex exploration problems.

  18. Subsidence modeling of the Sabah Basin, a foreland basin, Northwest Borneo, Malaysia

    SciTech Connect

    Azim-Ibrahim, N. (Petronas Research and Scientific Services, Kuala Lumpur (Malaysia)); White, N. (Univ. of Cambridge (United Kingdom))

    1994-07-01

    The Sabah Basin is located on the northwestern side of Borneo. It is a piggy back northeast-southwest-trending basin, riding on a north-westward directed imbricate thrust system. The basin contains approximately 10 to 12 km of sediment in the deepest part deposited in two main episodes of basin development; (1) a pre-early middle Miocene phase of generally deep-marine clastic deformation, which was later subjected to compression and (2) a post-early middle Miocene episode of clastic deposition, comprising bathyal to upper coastal plain sediments. Tectonic subsidence of the post-middle Miocene sequence was determined using the 1-D Airy and 2-D flexure backstripping techniques and wells and selected dip profiles, where the effects of compaction and sediment loading were removed. Variation in paleowater depth was also taken into account. The results show an extremely rapid subsidence phase dominating the earlier part of the basin history, with the later part corresponding to passive basin infilling. The boundary between these two phases becomes younger toward the northwest. The rapid subsidence phase is attributed to tectonic loading, possibly as a result of continuing thrusting at the basin margin. The results also imply that sedimentary sequences formed during the earlier phase were tectonically controlled and marked by transgressive events, while those deposited during the later phase bear the imprints of both tectonic and eustasy.

  19. Evolutionary mass-flow megaturbidites in interplate basin: example of the North Pyrenean basin

    SciTech Connect

    Bourrouilh, R.

    1986-05-01

    The Cretaceous North Pyrenean interplate basin develops in close relationship with the opening of the Bay of Biscay. The basin margins and its gravity sedimentary filling are related to differential movements of Iberian and European plates. Optimal climatic and morphologic conditions allow large amounts of carbonates to be deposited on its margins, major factors provoked the sedimentary and tectonic instability of the basin shelf and slope, particularly by reactivating a deep, ancient fault network. These events generated a single event or a series of successive autosuspended mass flows, which differentiate into megaturbidites, spreading over large areas of the basin floor. This large distribution of instantaneous evolutionary mass-flow megaturbidites, which pertain to the normal carbonate gravity sedimentation of the basin, allows us to determine: (1) paleoenvironments such as areas of paleoslopes; (2) the sedimentary and tectonic migration of the shelf break and of the basinal depocenter, and the relation of migration to regional plate tectonics; (3) evolution of local areas of special interest (petroleum geology), or evolution of the interplate basin, especially when it becomes a single trough (birth of first regional linear sequences); (4) interference of local centered transfer system (i.e., canyon fan or point slope fan) and regional linear transfer system (i.e., shelf break and slope).

  20. Detrital Mineral Record of the Central Myanmar Basin and implications for the evolution of the eastern Himalayan margin

    NASA Astrophysics Data System (ADS)

    Brezina, C. A.; Robinson, R. A. J.; Barfod, D. N.; Carter, A.; Parrish, R. R.; Horstwood, M. S.; Thein, M.; Win Oo, N.

    2014-12-01

    Single grain detrital thermochronology (40Ar/39Ar white mica, zircon fission track and Lu-Hf analysis) of Eocene, Oligocene and Miocene sedimentary rocks from the Central Myanmar Basin permits the identification of tectonothermal events in the source areas, and an understanding of how exhumation histories and changing provenance are related to the palaeogeography of the West Burma block during India-Asia collision. Robinson et al. (2014) used detrital zircon U-Pb and Lu-Hf isotopic analysis to show that Eocene and Oligocene sedimentary rocks were primarily sourced from the Gangdese magmatic arc that lies exclusively within the southern Lhasa terrane, and that the Yarlung Tsangpo and Irrawaddy River were connected at this time. Detrital thermochronology reveal these Paleogene deposits contain broadly distributed, mainly pre-Himalayan 40Ar/39Ar white mica cooling ages, reflecting the contribution from multiple source areas with a cooling history that is similar to the Lhasa terrane. A distinct change in provenance to a single, sustained source area during deposition of the Miocene units is recorded by a white mica 40Ar/39Ar cooling age peak of 37 Ma and a lesser peak of 17 - 21 Ma that is also observed in detrital zircon fission track age data. These two age peaks, 37 Ma and 17 - 21 Ma, likely reflect an initial period of crustal thickening, metamorphism and exhumation in the southern Mogok Metamorphic Belt, and a later phase of exhumation associated with deformation in the eastern syntaxis and the onset of extension in Myanmar and other parts of SE Asia. The latter events are also associated with the disconnection of the Yarlung Tsangpo from the Irrawaddy River around 18 Ma (Robinson et al., 2014). The combined dataset provides constraints on the position and movement of the West Burma block from the Late Eocene to Early Miocene, supports an Oligocene (~37 Ma) age for the timing of India-West Burma-Sibumasu coupling, and an Early Miocene age for extension-related exhumation associated with deformation in the eastern Himalayan region. Robinson, RAJ, Brezina, CA, Parrish, RR, Horstwood, MSA, Nay Win, O, Bird, MI, Myint, T, Walters, AS, Oliver, GJH, and Khin, Z, (2014) Large rivers and orogens: The evolution of the Yarlung Tsangpo-Irrawaddy system and the eastern Himalayan syntaxis: Gondwana Research, 26, 112-121.

  1. Grande Ronde Basin Fish Habitat Enhancement Project : 1998 Annual Report.

    SciTech Connect

    McGowan, Vance R.; Powell, Russ M.

    1999-05-01

    The primary goal of ''The Grande Ronde Basin Fish Habitat Improvement Project'' is to access, create, improve, protect, and restore reparian and instream habitat for anadromous salmonids, thereby maximizing opportunities for natural fish production within the basin.

  2. 75 FR 6348 - Lake Tahoe Basin Federal Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-09

    ...Nevada 89451-9500. FOR FURTHER INFORMATION CONTACT: Arla Hams, Lake Tahoe Basin Management Unit (LTBMU), Forest Service...the meeting. Please refer any written comments attention Arla Hams, Lake Tahoe Basin Management Unit at the contact address...

  3. 77 FR 42696 - Lake Tahoe Basin Federal Advisory Committee (LTFAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-20

    ...DEPARTMENT OF AGRICULTURE Forest Service Lake Tahoe Basin Federal Advisory Committee...SUMMARY: The Lake Tahoe Federal Advisory Committee will hold a meeting on August 9, 2012 at the Lake Tahoe Basin Management Unit, 35...

  4. Environmental Programme for the Danube River Basin (EPDRB)

    NSDL National Science Digital Library

    Environmental Programme for the Danube River Basin (EPDRB)

    This site measures the environmental health of the Danube River Basin and provides information on actions taken to protect the ecosystem. Links to the geography of the basin, the Danube Convention and other publications are also included.

  5. 77 FR 61784 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-11

    ...SUMMARY: The Colorado River Basin Salinity Control...Council) was established by the Colorado River Basin Salinity Control...held at the Central Arizona Water Conservation District Office...Bureau of Reclamation, Upper Colorado Regional Office, 125...

  6. 78 FR 70574 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-26

    ...Reclamation for use of funds from the Lower Colorado River Basin Development Fund and to fund...Council members from each of the seven Colorado River Basin states are planning to attend the Colorado River Water Users Association (CRWUA) annual...

  7. Radial thickness variations of Orientale basin ejecta

    NASA Technical Reports Server (NTRS)

    Cordell, B. M.

    1978-01-01

    Moore et al. (1974) measure the thickness of Orientale basin ejecta on the basis of filling of individual prebasin craters and a depth-diameter relation for fresh lunar craters. In the reported investigation the concept of filling of preexisting craters with basin ejecta is utilized somewhat differently to ascertain Orientale basin ejecta thicknesses and volume from the Cordillera ring with a radius of 450 km out to almost 2 radii. Briefly, the approach is to assume a reasonable geometric model for the form of Orientale ejecta, calculate how many pre-Orientale craters would be destroyed by the deposition of the ejecta, and match the model to Orientale crater statistics. The results of the investigation show that a radial ejecta thickness function can be derived from crater statistics.

  8. New tools attack Permian basin stimulation problems

    SciTech Connect

    Ely, J.W.; Schubarth, S.K.; Wolters, B.C.; Kromer, C. (Ely and Associates Inc., Houston, TX (US))

    1992-06-08

    This paper reports that profitable stimulation treatments in the Permian basin of the southwestern U.S. combine new tools with technology and fluids previously available. This paper reports that a wide selection of fracturing fluids and techniques needs to be considered to solve the varied problems associated with stimulating hydrocarbon reservoirs that are at diverse depths, temperatures, pressures, and lithologies. The Permian basin of West Texas and New Mexico is the most fertile ground in the U.S. for some of the newer stimulation technologies. In this basin, these new tools and techniques have been applied in many older producing areas that previously were treated with more conventional stimulation techniques, including acidizing and conventional fracturing procedures.

  9. Basin topology in dissipative chaotic scattering

    NASA Astrophysics Data System (ADS)

    Seoane, Jesús M.; Aguirre, Jacobo; Sanjuán, Miguel A. F.; Lai, Ying-Cheng

    2006-06-01

    Chaotic scattering in open Hamiltonian systems under weak dissipation is not only of fundamental interest but also important for problems of current concern such as the advection and transport of inertial particles in fluid flows. Previous work using discrete maps demonstrated that nonhyperbolic chaotic scattering is structurally unstable in the sense that the algebraic decay of scattering particles immediately becomes exponential in the presence of weak dissipation. Here we extend the result to continuous-time Hamiltonian systems by using the Hénon-Heiles system as a prototype model. More importantly, we go beyond to investigate the basin structure of scattering dynamics. A surprising finding is that, in the common case where multiple destinations exist for scattering trajectories, Wada basin boundaries are common and they appear to be structurally stable under weak dissipation, even when other characteristics of the nonhyperbolic scattering dynamics are not. We provide numerical evidence and a geometric theory for the structural stability of the complex basin topology.

  10. The origin of lunar mascon basins.

    PubMed

    Melosh, H J; Freed, Andrew M; Johnson, Brandon C; Blair, David M; Andrews-Hanna, Jeffrey C; Neumann, Gregory A; Phillips, Roger J; Smith, David E; Solomon, Sean C; Wieczorek, Mark A; Zuber, Maria T

    2013-06-28

    High-resolution gravity data from the Gravity Recovery and Interior Laboratory spacecraft have clarified the origin of lunar mass concentrations (mascons). Free-air gravity anomalies over lunar impact basins display bull's-eye patterns consisting of a central positive (mascon) anomaly, a surrounding negative collar, and a positive outer annulus. We show that this pattern results from impact basin excavation and collapse followed by isostatic adjustment and cooling and contraction of a voluminous melt pool. We used a hydrocode to simulate the impact and a self-consistent finite-element model to simulate the subsequent viscoelastic relaxation and cooling. The primary parameters controlling the modeled gravity signatures of mascon basins are the impactor energy, the lunar thermal gradient at the time of impact, the crustal thickness, and the extent of volcanic fill. PMID:23722426

  11. Hydrological characterization of Birch Creek Basin

    SciTech Connect

    Koslow, K.N.

    1984-12-01

    A hydrological characterization of the Birch Creek Basin has been conducted to analyze the flood potential from Birch Creek on the Idaho National Engineering Laboratory (INEL). Birch Creek originated from springs below Gilmore Summit, between the Lemhi and Beaverhead Mountain Ranges, and flows in a southeasterly direction onto the Snake River Plain. The channel leads to a depression on the INEL site knows as the Birch Creek Playa. Birch Creek flows reach the playa only in years of high spring runoff. Test Area North (TAN) is located in this depressional area. This study provides a detailed description of the Birch Creek Basin including a flood-frequency analysis, PMF computation and local basin snowmelt analysis to determine the possible flood potential near TAN. 8 references, 6 figures, 6 tables.

  12. Ground Motion Prediction Atop Geometrically Complex Sedimentary Basins - The Dead Sea Basin

    NASA Astrophysics Data System (ADS)

    Shani-Kadmiel, S.; Tsesarsky, M.; Louie, J. N.; Gvirtzman, Z.

    2014-12-01

    The Dead Sea Transform (DST) is the source for some of the largest earthquakes in the eastern Mediterranean. Several deep and structurally complex sedimentary basins are associated with the DST. These basins are up to 10 km deep and typically bounded by active fault zones. The low seismicity of the DST combined with the limited instrumental coverage of the seismic network in the area result in a critical knowledge gap. Therefore, it is necessary to complement the limited instrumental data with synthetic data based on computational modeling, in order to study the effects of earthquake ground motion in these sedimentary basins. We performed a 2D ground-motion analysis in the Dead Sea Basin (DSB) using a finite-difference code. Results indicate a complex pattern of ground motion amplification affected by the geometric features in the basin. To distinguish between the individual contributions of each geometrical feature in the basin, we developed a semiquantitative decomposition approach. This approach enabled us to interpret the DSB results as follows: (1) Ground-motion amplification as a result of resonance occurs basin-wide due to a high impedance contrast at the base of the uppermost layer; (2) Steep faults generate a strong edge-effect that further ampli- fies ground motions; (3) Sub-basins cause geometrical focusing that may significantly amplify ground motions; and (4) Salt diapirs diverge seismic energy and cause a de- crease in ground-motion amplitude. We address the significance of ground motion amplification due to geometrical focusing via an analytical and numerical study. We show that effective geometrical focusing occurs for a narrow set of eccentricities and velocity ratios, where seismic energy is converged to a region of ±0.5 km from surface. This mechanism leads to significant ground motion amplification at the center of the basin, up to a factor of 3; frequencies of the modeled spectrum are amplified up to the corner frequency of the source.

  13. Simulation of Seismic Wave Propagation Through Geometrically Complex Basins - The Dead Sea Basin

    NASA Astrophysics Data System (ADS)

    Shani-Kadmiel, S.; Tsesarsky, M.; Gvirtzman, Z.; Louie, J. N.

    2011-12-01

    The Dead Sea Transform (DST) is the source for some of the largest earthquakes in the Eastern Mediterranean, including the 1927 Mw 6.2 Jericho earthquake and the 1995 Mw 7.2 Gulf of Aqaba earthquake. The seismic hazard presented by the DST threatens the Israeli, Palestinian and Jordanian populations alike. In Israel, several deep and structurally complex sedimentary basins are associated with the DST. These basins are up to 10 km deep and typically bounded by active fault zones. The low seismicity rate of the DST combined with a sparse seismic network in Israel that provides poor coverage of sedimentary basins, results in a critical knowledge gap. It is therefore necessary to complement the limited instrumental data with synthetic data based on computational modeling, in order to study the effects of earthquake ground motion in these sedimentary basins. In this research we performed a ground motion analysis in the Dead Sea Basin (DSB) using a finite-difference code capable of simulating seismic wave propagation in a 3-D heterogeneous earth. Two cross-sections transecting the DSB were compiled based on currently available geological and geophysical data and were used for wave propagation simulations. Results indicate a complex pattern of ground motion amplification affected by the geometric features in the basin. To distinguish between the individual contributions of each geometrical feature in the basin, we developed a semi-quantitative decomposition approach. This approach enabled us to interpret the DSB results as follows: (a) Ground motion amplification as a result of resonance and anelastic effects, occurs basin-wide due to a high impedance contrast at the base of the uppermost layer. (b) Steep faults generate a strong edge-effect that further amplifies ground motions. (c) Sub-basins cause geometrical focusing that under certain circumstances significantly amplifies ground motions. (d) Salt diapirs diverge seismic energy and cause a decrease in ground motion amplitude.

  14. Active tectonics and Quaternary basin formation along the Vienna Basin Transform fault

    NASA Astrophysics Data System (ADS)

    Decker, Kurt; Peresson, Herwig; Hinsch, Ralph

    2005-02-01

    The Vienna Basin Transform fault is an active fault system extending over a distance of some 300 km from the Eastern Alps through the Vienna Basin into the West Carpathians. Active sinistral movement is indicated by moderate seismic activity in a NE-striking zone paralleling the fault, focal plane solutions and recent stress measurements. By analogy to the Miocene kinematics we propose that the sinistral strike-slip fault terminates in the Carpathians where horizontal offset is transformed into thin-skinned thrust-type deformation. Hypocenter depths mostly well above 12 km are in line with the inferred thin-skinned style of deformation with active faults restricted to the overthrust Alpine-Carpathian units. Mapping of active fault segments in the Vienna Basin using subcrop data, thickness maps of Quaternary deposits, seismological data, and geomorphological features seen in the digital elevation model shows that virtually all active faults are reactivated Miocene structures. In the southern part of the basin active faulting defines a small-scale pull-apart structure with an actively subsiding Quaternary basin, which is filled with up to 140 m fluvial gravel, sand and paleosoils. For this basin Quaternary sinistral displacement was quantified by adopting a geometrical model for thin-skinned extensional strike-slip duplexes. Accordingly, 1.5-2 km sinistral slip accumulated during deposition of the basin fill in the last 400 ky corresponding to a slip rate of 1.6-2.5 mm/y. Results are in good agreement with published GPS data indicating 2 mm slip per year. A second group of Quaternary basins is related to listric normal faulting, rollover and crestal collapse of the reactivated normal faults at the NW basin margin. Rollover also resulted in tilting and dissecting Late Pleistocene river terraces of the Danube.

  15. Atlantic Mesozoic marginal basins: an Iberian view

    SciTech Connect

    Wilson, R.C.L.

    1987-05-01

    In the light of theoretical models for crustal stretching that precedes ocean opening, it is unlikely that Iberian basins have mirror image counterparts beneath North American or other European continental shelves. However, certain Iberian sedimentary sequences are comparable to those found in other basins. Of particular note are (1) the almost identical pre-rift sequences in all these areas, (2) the development of Upper Jurassic carbonate buildups in Portugal, Morocco, and beneath the Scotian Shelf, and (3) the hydrocarbon-bearing Upper Jurassic and Lower Cretaceous synrift and postrift siliciclastics of North America, Iberia, and Aquitaine. In the prerift sequences, Triassic red beds are capped by evaporites, which subsequently influenced the structural development of basins. Intertidal and supratidal carbonates occur at the base of the Jurassic and are overlain by Lower and Middle Jurassic limestone-shale sequences, which in places contain bituminous shales. In Portugal only, resedimented carbonates of Toarcian-Aalenian age are associated with an uplifted basement horst. In Portugal, Aquitaine, and eastern Canada, Middle Jurassic high-energy carbonate platforms developed. Synrift siliciclastic sequences show spectacular evidence for deposition within fault-bounded basins. In Portugal, lower Kimmeridgian clastics are up to 3 km thick, but Upper-Lower Cretaceous sequences are relatively thin (ca. 1 km), in contrast to those of the Basco-Cantabrian region where they exceed 10 km. In the latter region occurs the fluvially dominated Wealden (Upper Jurassic-Neocomian) and Urgonian carbonate platforms and associated basinal sediments. In the Asturias basin, Kimmeridgian shales and fluvially dominated deltaic sandstones succeed conglomeratic fluvial sandstones of uncertain age.

  16. Evolution of the San Jorge basin, Argentina

    SciTech Connect

    Fitzgerald, M.G. (Exxon Production Research Co., Houston, TX (USA)); Uliana, M.A. (ASTRA C.A.P.S.A., Buenos Aires (Argentina)); Biddle, K.T. (Exxon Co., International, Houston, TX (USA)); Mitchum, R.M. Jr.

    1990-06-01

    The San Jorge basin, although small, is the most important hydrocarbon-producing basin in Argentina. Remaining untested potential is high because of the presence of good source rock, favorable structural complexity, and multiple reservoirs. Reservoir quality is commonly low because of the highly tuffaceous sandstones. The sedimentary fill of the basin is closely related to its tectonic history. Northwest-southeast-trending grabens formed and filled during a Triassic and Early Jurassic early rift phase, climaxing with a pervasive Middle Jurassic volcanic episode; continued growth and filling of the basin occurred during a Late Jurassic-earliest Cretaceous late rift phase and Cretaceous early and late sag phases. Late Cretaceous-early Tertiary extension set up many of the present-day structural traps along normal faults. Middle Tertiary Andean compression produced the narrow, north-south San Bernardo structural belt, which exhibits reversed movement on older, normal, graben-bounding faults and on local, low-angle thrust faults. Marked early to middle Tertiary erosion produced a significant unconformity within Cretaceous beds around basin margins. Origin of Upper Jurassic and lowermost Cretaceous sedimentary fill is primarily lacustrine or fluvial in origin. Lacustrine, organic-rich black shales are fringed by oolitic and other limestones and fluvial-deltaic sandstones derived mostly from the north. A significant southern source of sand existed during the Valanginian. Interbedded marine shales occur mostly to the west toward a presumed marine seaway connection to the northern Magallanes basin. Middle to Upper Cretaceous sedimentary rocks, sourced mostly from the north, are mainly fluvial sandstone-shale successions with some minor lacustrine influence. Reservoir quality glauconitic sands were deposited during a Late Cretaceous-early Tertiary marine incursion from the Atlantic.

  17. Sedimentation in Canada Basin, Western Arctic

    NASA Astrophysics Data System (ADS)

    Mosher, D. C.; Shimeld, J.; Jackson, R.; Hutchinson, D. R.; Chapman, B.; Chian, D.; Childs, J. R.; Mayer, L. A.; Edwards, B. D.; Verhoef, J.

    2010-12-01

    The Canada Basin of the western Arctic Ocean is the least studied ocean basin on Earth. Marine seismic field programs were conducted during the past 5 years in order to study the geology, sedimentary history and geomorphology of the region. As part of this program, five annual icebreaker expeditions acquired bathymetric, seismic reflection and seismic refraction data on a regional scale. More than 12,000 km of multi-channel seismic reflection data and 120 sonobuoy seismic refraction records over abyssal plain and continental rise regions of Canada Basin, Northwind Ridge and Alpha Ridge were acquired. The success of these programs was achieved through novel technical modifications to equipment to permit towing in heavy ice conditions and through collaboration between multiple Canadian and US agencies and institutions, enabling utilization of two ice breakers during seismic and multibeam data acquisition in heavy ice. The seafloor of the Canada Basin is remarkably flat-lying in its central region, with little bathymetric change over most of its extent. The sedimentary succession is generally flat lying with reflections extending over hundreds of km. These reflections onlap bathymetric highs, such as Alpha and Northwind ridges. The sedimentary succession is thickest in the Beaufort Sea region, reaching more than 6.5 km, and generally thins to the north and west. Reflection characteristics suggest that sediment volume input to the Arctic Ocean has been high and dominated by turbidity current deposition, similar to Amundsen and Nansen Basins of the eastern Arctic. These turbidites originate from the eastern and southern continental margins. There is no evidence of contemporaneous or post-depositional reworking by bottom currents. Additionally, there is little evidence of tectonic deformation after primary basin-forming events except in the NE quadrant, nearer Alpha Ridge. In this area, there is significant normal faulting propagating from basement through much of the sedimentary succession. Basement graben stuctures in combination with these faults imply possible crustal extension contemporaneous with deposition.

  18. Integrated Peri-Tethyan Basins studies (Peri-Tethys Programme)

    Microsoft Academic Search

    Marie-Françoise Brunet; Sierd Cloetingh

    2003-01-01

    This issue brings together 12 papers presenting results of geodynamic\\/subsidence studies performed in the frame of the Peri-Tethys Programme (PTP). The areas in question are for the northern Peri-Tethyan Platform: the Dniepr-Donets, Precaspian, Polish Basin, southern Carpathians, North Fore-Caucasus, South Caspian and Black Sea basins. For the southern Peri-Tethyan Platform, the basins studied include basins of Morocco, North Algerian Atlas'

  19. Analysis of Ignition Testing on K-West Basin Fuel

    Microsoft Academic Search

    J. Abrefah; F. H. Huang; W. M. Gerry; W. J. Gray; S. C. Marschman; T. A. Thornton

    1999-01-01

    Approximately 2100 metric tons of spent nuclear fuel (SNF) discharged from the N-Reactor have been stored underwater at the K-Basins in the 100 Area of the Hanford Site. The spent fuel has been stored in the K-East Basin since 1975 and in the K-West Basin since 1981. Some of the SNF elements in these basins have corroded because of various

  20. Basin-average data: Cloud Albedo and the Diurnal Cycle

    E-print Network

    Hurrell, James

    land- atmosphere processes in ERA40 GrADS20\\merra/Regional Basins/Basin_Map.gs ­ accesses GDS data #12.ecmwf.int/research/era/Products/Archive_Plan/Archive_plan_6.html #12;#12;MERRA Ohio Cloud Albedo GrADS20\\merra\\Regional Basins\\ACld\\Ohio_SWclr.gs (Grads Script, grads ­l) GrADS20\\merra\\Regional Basins\\ACld\\Ohio_CloudAlbedo.gs (Grads Script, grads ­l) #12

  1. Atlas of major Appalachian basin gas plays

    SciTech Connect

    Aminian, K.; Avary, K.L.; Baranoski, M.T.; Flaherty, K.; Humphreys, M.; Smosna, R.A.

    1995-06-01

    This regional study of gas reservoirs in the Appalachian basin has four main objectives: to organize all of the -as reservoirs in the Appalachian basin into unique plays based on common age, lithology, trap type and other geologic similarities; to write, illustrate and publish an atlas of major gas plays; to prepare and submit a digital data base of geologic, engineering and reservoir parameters for each gas field; and technology transfer to the oil and gas industry during the preparation of the atlas and data base.

  2. Basin-wide cooperative water resources allocation

    Microsoft Academic Search

    Lizhong Wang; Liping Fang; Keith W. Hipel

    2008-01-01

    Abstract The Cooperative Water Allocation Model,(CWAM) is designed,within a general mathematical,programming,frame- work,for modeling,equitable and,efficient water allocation among,competing,users at the basin level and,applied to a large-scale water allocation problem in the South Saskatchewan River Basin located in southern Alberta, Canada. This comprehensive,model,consists of two main steps: initial water rights allocation and subsequent,water and net benefits real- location. Two mathematical programming approaches,

  3. Conservation in the Delaware River Basin

    SciTech Connect

    Featherstone, J. [Delaware River Basin Commission, Trenton, NJ (United States)

    1996-01-01

    The Delaware River Basin Commission (DRBC) has embarked on an ambitious water conservation program to reduce the demand for water. Conservation has become an integral component of the commission`s strategy to manage water supplies in the four-state Delaware River Basin. The program includes both regulatory and educational initiatives. DRBC has adopted five conservation regulations, which pertain to source metering, service metering, leak detection and repair, water conservation performance standards for plumbing fixtures and fittings, and requirements for water conservation plans and rate structures. DRBC also sponsors information and education events, such as symposiums on selected topics and water conservation technology transfer sessions with major industrial and commercial groups.

  4. The classification of polynomial basins of infinity

    E-print Network

    DeMarco, Laura

    2011-01-01

    We consider the problem of classifying the dynamics of complex polynomials $f: \\mathbb{C} \\to \\mathbb{C}$ restricted to their basins of infinity. We synthesize existing combinatorial tools --- tableaux, trees, and laminations --- into a new invariant of basin dynamics we call the pictograph. For polynomials with all critical points escaping to infinity, we obtain a complete description of the set of topological conjugacy classes. We give an algorithm for constructing abstract pictographs, and we provide an inductive algorithm for counting topological conjugacy classes with a given pictograph.

  5. Old Basin Filled by Smooth Plains

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Old basin, 190 km in diameter, filled by smooth plains at 43 degrees S, 55 degrees W. The basin's hummocky rim is partly degraded and cratered by later events. Mariner 10 frame 166607.

    The Mariner 10 mission, managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, explored Venus in February 1974 on the way to three encounters with Mercury-in March and September 1974 and in March 1975. The spacecraft took more than 7,000 photos of Mercury, Venus, the Earth and the Moon.

    Image Credit: NASA/JPL/Northwestern University

  6. Utopia Basin, Mars: Characterization of topography and morphology and assessment of the origin and evolution of basin internal structure

    E-print Network

    Head III, James William

    deep depression $3200 km in diameter. Utopia Basin is the largest easily recognizable impact structure can be classified into two groups: one oriented dominantly radial to the basin and the other oriented

  7. ARTICLE A brief history of Great Basin pikas

    Microsoft Academic Search

    Donald K. Grayson

    Aim Within the past few decades, seven of the 25 historically described populations of American pikas (Ochotona princeps) in the Great Basin of arid western North America appear to have become extinct. In this paper, the prehistoric record for pikas in the Great Basin is used to place these losses in deeper historical context. Location The Great Basin, or area

  8. OCTOBER-NOVEMBER FORECAST FOR 2014 CARIBBEAN BASIN HURRICANE ACTIVITY

    E-print Network

    Collett Jr., Jeffrey L.

    1 OCTOBER-NOVEMBER FORECAST FOR 2014 CARIBBEAN BASIN HURRICANE ACTIVITY We expect that October-November will have below-average hurricane activity in the Caribbean basin. This forecast is due to hurricane in the tropical Pacific (a negative factor), while Caribbean basin sea surface temperatures are relatively cool

  9. Geology and hydrocarbon potential of the Oued Mya Basin, Algeria

    Microsoft Academic Search

    O. Benamrane; M. Messaoudi; H. Messelles

    1992-01-01

    The hydrocarbon System Ourd Mya is located in the Sahara Basin. It is one of the producing basin in Algeria. The stratigraphic section consists of Paleozoic and Mesosoic, it is about 5000m thick. In the eastern part, the basin is limited by the Hassi-Messaoud high zone which is a giant oil field producing from the Cambrian sands. The western part

  10. Vegetation and man in the Basin of Mexico

    Microsoft Academic Search

    C. Earle Smith; Paul Tolstoy

    1981-01-01

    As a high basin, the Basin of Mexico enjoys equable temperatures during much of the year. In terms of agriculture, the limiting factor for the usual crops grown in the Basin is the date of the last killing frost in the spring and the date of the first killing frost in the autumn. Inasmuch as much of the level surface

  11. Tunisia's unexplored basins similar to productive regions elsewhere

    Microsoft Academic Search

    Duvernoy

    1993-01-01

    Tunisia offers infrastructure, stability, and promising geology yet contains relatively unexplored basins analogous to productive regions elsewhere in the world. An important examples is a foreland basin in the northeastern Maghreb, covering northeastern Algeria, northern Tunisia, and extending on the offshore Pelagian Plateau. It is a basin type that some authorities either overlook with regard to Africa or claim to

  12. book reviews Climate Changeon the Great Lakes Basin. 1992.

    E-print Network

    book reviews Climate Changeon the Great Lakes Basin. 1992. 45 pp. $--free. Paperbound is a compilation of five papers presented at the Symposium of Climate Change on the Great Lakes Basin held as part. The resultsgivenprovideanoverviewofvariousaspectsof climaticchangerelativetotheGreatLakesBasin.The usual caveats regarding use and interpretation

  13. Overflow Risk Analysis for Stormwater Quality Control Basins

    Microsoft Academic Search

    James C. Y. Guo

    2002-01-01

    The operational cycle of a storm water quality control basin can be divided into the waiting period between events and the filling and draining period during an event. In this study, an inherent overflow risk is defined as the probability of having a large event exceed the basin storage capacity. Such a probability is prescribed by the basin storage capacity

  14. On the origin of the Southern Permian Basin, Central Europe

    Microsoft Academic Search

    J.-D van Wees; R. A. Stephenson; P. A. Ziegler; U. Bayer; T. McCann; R. Dadlez; R. Gaupp; M. Narkiewicz; F. Bitzer; M. Scheck

    2000-01-01

    A detailed study of the structural and stratigraphic evolution of the Southern Permian Basin during latest Carboniferous to Early Jurassic times, supported by quantitative subsidence analyses and forward basin modelling for 25 wells, leads us to modify the conventional model for the Rotliegend–Zechstein development of this basin. The Late Permian–Early Jurassic tectonic subsidence curves are typical for a Permian to

  15. Morphometric Controls and Basin Response in The Cascade Mountains

    Microsoft Academic Search

    Fes De Scally; Olav Slaymaker; Ian Owens

    2001-01-01

    Morphometric variables associated with 36 debris torrent, 78 snow avalanche, 45 composite debris torrent and snow avalanche and 14 streamflow basins in the Cascade Mountains of southwestern British Columbia, Canada are examined. The re- sults show significant statistical differences in top and bottom el- evations, relief, channel length and gradient, basin area, fan gra- dient and area, and basin ruggedness

  16. SUTTER BASIN, SUTTER & BUTTE COUNTIES, CA FLOOD RISK MANAGEMENT PROJECT

    E-print Network

    US Army Corps of Engineers

    SUTTER BASIN, SUTTER & BUTTE COUNTIES, CA FLOOD RISK MANAGEMENT PROJECT 22 October 2013 ABSTRACT the risk to property damage due to flooding to the Sutter Basin area located in the Sutter and Butte Protection Board (CVFPB) and the Sutter Butte Flood Control Agency (SBFCA). The Sutter Basin is a 326-square

  17. Quantum basin hopping with gradient-based local optimisation

    E-print Network

    David Bulger

    2005-07-20

    The quantum basin hopping algorithm for continuous global optimisation combines a local search with Grover's algorithm, and can locate the global optimum using effort proportional to the square root of the number of basins. This article establishes that Jordan's quantum gradient estimation method can be incorporated into the quantum basin hopper, providing an extra acceleration proportional to the domain dimension.

  18. 75 FR 11000 - Security Zone; Freeport LNG Basin, Freeport, TX

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-10

    ...RIN 1625-AA87 Security Zone; Freeport LNG Basin, Freeport, TX AGENCY: Coast Guard...permanent security zone in the Freeport LNG Basin. This security zone is needed to...NPRM) entitled Security Zone; Freeport LNG Basin, Freeport, TX in the Federal...

  19. Georgia Basin-Puget Sound Airshed Characterization Report 2014

    EPA Science Inventory

    The Georgia Basin - Puget Sound Airshed Characterization Report, 2012 was undertaken to characterize the air quality within the Georgia Basin/Puget Sound region,a vibrant, rapidly growing, urbanized area of the Pacific Northwest. The Georgia Basin - Puget Sound Airshed Characteri...

  20. HISTORY OF EARLY CENOZOIC VERTEBRATE PALEONTOLOGY IN THE BIGHORN BASIN

    E-print Network

    Gingerich, Philip D.

    HISTORY OF EARLY CENOZOIC VERTEBRATE PALEONTOLOGY IN THE BIGHORN BASIN Philip D. Gingerich Abstract. INTRODUCTION One hundred years of paleontological research on early Cenozoic faunas in the Bighorn Basin have also been found on the margin of the Bighorn Basin. The history of paleontological field work

  1. Timing and Tectonic implications of basin inversion in the Nam Con Son Basin and adjacent areas, southern South China Sea 

    E-print Network

    Olson, Christopher Charles

    2001-01-01

    illustrating the deformed Mesozoic forearc basin sediments shown in Figures 37 B-D. 102 37B Profile "A" correlates to the northern extension of the Natuna Arch basement high between the Eastern and Western Nam Con Son sub...-basins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ?. .. . . . . . . . . . . . , . . . . , . . . . . . . . . . . . 103 37C Seismic profile "B" crosses the Natuna Arch south of profile "A" . . . 37D Deformed Mesozoic forearc basin fill south of seismic profiles "A" and "B" 105 38 Eastern margin of the Natuna Arch heading into the East Natuna Basin...

  2. An integrated study of the reservoir performance in the Area Central Norte (ACN) region of the Tordillo Field (Argentina)

    E-print Network

    Tuvio, Raul

    1997-01-01

    . The basin occupies an area of approximately 27, 000 sq. miles (or approximately 70, 000 sq. kilometers). 2. 1. 1 Regional Geological Setting Deformation and subsidence in the San Jorge Basin began while South America was still part of the Gondwana... to the northwest. This early extensional event may have coincided with rifling in the Cuyo and Neuquen basins to the northwest and the Karroo 5 basin of southern Alrica, where these events heralded the breakup of Gondwana. 6 A Middle Jurassic episode...

  3. Tectonic evolution of the Colorado Basin, offshore Argentina, inferred from seismo-stratigraphy and depositional rates analysis .

    E-print Network

    Paris-Sud XI, Université de

    of a Permian pre-rift period, a Triassic/Jurassic to Early Cretaceous rift phase and a Lower Cretaceous rifting to the thermal subsidence/drift stage. Several Cretaceous to Cenozoic slumping episodes were Atlantic, sedimentation rates are in the order of 118 m/Ma. By Late Cretaceous, the Gondwana break- up had

  4. Basin analog approach answers characterization challenges of unconventional gas potential in frontier basins 

    E-print Network

    Singh, Kalwant

    2007-04-25

    To continue increasing the energy supply to meet global demand in the coming decades, the energy industry needs creative thinking that leads to the development of new energy sources. Unconventional gas resources, especially those in frontier basins...

  5. Basin Approach to Address Bacterial Impairments in Basins 15, 16, and 17 

    E-print Network

    Gregory, L.; Brown, M.; Hein, K.; Skow, K.; Engling, A.; Wagner, K.; Berthold, A.

    2014-01-01

    plan. Traditionally, impairments have been addressed one at a time. In order to more efficiently address similar impairments within the same basin, more efficiently distribute resources, and with the hopes of preventing future listings within the same...

  6. Somali Basin, Chain Ridge, and origin of the Northern Somali Basin gravity and geoid low

    NASA Technical Reports Server (NTRS)

    Cochran, James R.

    1988-01-01

    Geophysical data are used to investigate the origin of the Northern Somali Basin and its relationship to surrounding tectonic elements. The results show the Northern Somali Basin to be the third of a series of oceanic basins separated by long transform faults created during movement between East and West Gondwanaland. The flexure resulting from differential subsidence across Chain Ridge along with the difference in lithospheric thermal structure on either side of it can account for the amplitude and shape of the observed geoid step and gravity anomalies across Chain Rige. It is suggested that the geoid and gravity low over the Northern Somali Basin may result from the superposition of a continental edge effect anomaly and the fracture zone edge effect anomaly.

  7. 77 FR 45653 - Yakima River Basin Conservation Advisory Group; Yakima River Basin Water Enhancement Project...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-01

    ...oversight of the Yakima River Basin Water Conservation Program. DATES: The meeting will...review of the implementation of the Water Conservation Program, including the applicable water conservation guidelines of the Secretary used...

  8. Composition of Orientale basin deposits and implications for the lunar basin-forming process

    NASA Astrophysics Data System (ADS)

    Spudis, P. D.; Hawke, B. R.; Lucey, P.

    1984-11-01

    The geologic, spectral and geochemical characteristics of the lunar Orientale basin are discussed, and a model is defined for the generation of Orientale basin deposits. The data indicate that the basin ejecta is composed mainly of anorthositic deposits and no crustal material. The crater was originally 500-600 km across and 50-60 km deep, the latter being too shallow to reach the projected 100 km crustal depth. A proportional growth model is judged acceptable for the Orientale basin. Finally, it is concluded that neither the Apollo 14 nor 16 missions obtained Orientale ejecta material, which could in any case be unidentifiable until more thorough samplings are made of a large portion of the lunar surface.

  9. Assessing agriculture–water links at the basin scale: hydrologic and economic models of the São Francisco River Basin, Brazil

    Microsoft Academic Search

    Marco Maneta; Marcelo Torres; Stephen A. Vosti; Wesley W. Wallender; Summer Allen; Luís H. Bassoi; Lisa Bennett; Richard Howitt; Lineu Rodrigues; Julie Young

    2009-01-01

    This article uses a basin-wide hydrologic model to assess the hydrologic and economic effects of expanding agriculture in the São Francisco River Basin, Brazil. It then uses a basin-wide economic model of agriculture to examine the effects of implementing water use regulations. Preliminary results suggest that substantially expanding agriculture would put pressure on some of the river's environmental flows. Agricultural

  10. Rift basins in western margin of India and their hydrocarbon prospects with special reference to Kutch basin

    SciTech Connect

    Biswas, S.K.

    1982-10-01

    The western continental margin of India can be classed as a divergent or passive margin. The western continental shelf is an extensive carbonate bank (Bombay offshore basin) passing into clastic sediments on the north and south. Three craton-margin embayed basins-Kutch, Cambay, and Narmada- in the northern part of the shelf, are filled predominantly with clastic sediments. These basins occupy grabens bounded by faults diverging seaward. The grabens were formed by three rift systems along major Precambrian tectonic trends. The rifting developed sequentially from north to south around the Saurashtra horst. Kutch basin was formed in the Early Jurassic, followed by Cambay basin in Early Cretaceous time, and the Narmada in the Late Cretaceous. It appears that these rifting events occurred at successive stages during the northward migration of the Indian plate after its break from Gondwanaland in Late Triassic or Early Jurassic. It is inferred that these rift basins opened up successively as a result of the counterclockwise drift of the Indian craton. Bombay offshore and Cambay are two major oil-producing basins in the western margin. These basins are characterized by high geothermal gradients attributed to the shallowness of the mantle in this region. Oil has not been found in KUtch basin, which is mainly an onshore Mesozoic basin. The basin basin depocenter shifted offshore at the northwestern part of the continental shelf where the shelf is wide.

  11. Involvement of a Tertiary Foreland Basin in the Eurekan Foldbelt Deformation, NW Coast of Kane Basin, Ellesmere Island, Canada

    Microsoft Academic Search

    Karsten Piepjohn; Franz Tessensohn; Chris Harrison; Ulrich Mayr

    Summary: Along the NW eoast of Kane Basin (Ellesmere Island), a flatlying eonglomerate sueeession of a Tertiary foreland basin is overthrust by thiek Early Paleozoie sediments during the Tertial')' Eurekan deformation. In the sourhern study area between Franklin Pierce Bay and Dobbin Bay, Cambrian to Silurian sediments are thrust over the Tertiary basin along the Parrish Glaeier anel Cape Hawks

  12. Wada bifurcations and partially Wada basin boundaries in a two-dimensional cubic map

    NASA Astrophysics Data System (ADS)

    Zhang, Yongxiang; Luo, Guanwei

    2013-08-01

    The partially Wada basin boundaries are referred to the coexistence of Wada points and non-Wada points in the same basin boundary. We demonstrate two types of Wada bifurcations and analyze the transitions from totally Wada basins to partially Wada basins and from totally Wada basins to totally Wada basins in a two-dimensional cubic map. We describe some numerical experiments giving the evidence of partially Wada basin boundaries. Our results show that the basin cell erosion and the basin cell bifurcation can induce the Wada basin boundary metamorphoses.

  13. Basin-centered gas evaluated in Dnieper-Donets basin, Donbas foldbelt, Ukraine

    Microsoft Academic Search

    B. E. Law; G. F. Ulmishek; J. L. Clayton; B. P. Kabyshev; N. T. Pashova; V. A. Krivosheya

    1998-01-01

    An evaluation of thermal maturity, pore pressures, source rocks, reservoir quality, present-day temperatures, and fluid recovery data indicates the presence of a large basin-centered gas accumulation in the Dnieper-Donets basin (DDB) and Donbas foldbelt (DF) of eastern Ukraine. This unconventional accumulation covers an area of at least 35,000 sq km and extends vertically through as much as 7,000 m of

  14. RED RIVER BASIN BIOLOGICAL MONITORING WORKGROUP

    EPA Science Inventory

    The goal of this project is to improve coordination of biological monitoring efforts in the Red River Basin. This is to be accomplished through coordination of a study to develop sampling protocols for macroinvertebrates in the main stream and lower tributaries of the Red River....

  15. INTRODUCTION Late Mesozoic extensional basins are promi-

    E-print Network

    Johnson, Cari

    features of east-central Asia. These basins have been exten- sively studied in China because of their petro evolution of Asia. It extends the east-centralAsian domain of Mesozoic localized high-strain extension bearing Silurian and Permian fossils (Fig. 2). Dergunov et al. (1971), Suetenko et al. (1973), and Zheng

  16. Petroleum geology in Tarim basin, China

    SciTech Connect

    Zhou, Guojun (West Virginia Univ., Morgantown, WV (United States))

    1994-08-01

    Tarim basin is a superimposed basin with two tectonic regimes and contains multisources, multireservoirs, and multiseals. Almost all major strata within the Paleozoic, Mesozoic, and Cenozoic exist in the basin, and they are grouped by six regional unconformities, which are related to hydrocarbon accumulation. Source rocks are Cambrian marl; Lower Ordovician black carbonaceous shales; Middle Ordovician dark gray limestone; Upper Ordovician brownish black carbonaceous shales and oil shales; grayish black carbonaceous shales, dark gray and grayish brown bituminous marl, and reef limestone in the Carboniferous and Permian; and gray to dark gray shales in the Triassic-Jurassic oil-bearing strata. Reservoir rocks in the Cambrian-Ordovician oil-bearing strata and the Carboniferous-Permian oil-bearing strata are mainly fractured limestones and sandstones. The fracture distribution is related to unconformities. Vugs and casts also exist in most limestones; intergranular porosity exists in sandstones. The reservoirs in the Triassic-Jurassic are fluvial-deltaic sandstones, and above are Cretaceous gypsum and halite seals. Ten types of traps are found in this basin: (1) fold-related anticline traps, (2) anticline-fault traps, (3) fault drag-related anticline traps, (4) traps underneath thrusting faults, (5) fault-block traps (6) traps made from cross or arc-like fault and monocline, (7) salt dome traps, (8) traps created by intrusion, (9) lenticular or pinchout traps, and (10) unconformity and overlap traps.

  17. INTERIOR COLUMBIA BASIN ECOSYSTEM MANAGEMENT PROJECT (ICBEMP)

    EPA Science Inventory

    A geographic information system (GIS) spatial data library is maintained through the Interior Columbia Basin Ecosystem Management Project. Sponsored by the Bureau of Land Management, the library contains more than 200 products which include the following types of data: aquatic, a...

  18. Subsidence history in basins of northern Algeria

    Microsoft Academic Search

    Rabah Bracene; Martin Patriat; Nadine Ellouz; Jean-Michel Gaulier

    2003-01-01

    The Tellian foreland in Algeria represents a part of the southern Tethyan margin during the Mesozoic. Its tectonic evolution includes a rifting stage during the Triassic and Liassic times characterised by tilted blocks and early diapiric events during the Liassic, a post-rift regime from Middle Jurassic up to the Late Cretaceous and basin inversion during the Tertiary related to the

  19. Geology and hydrocarbon potential of Tunisia basins

    Microsoft Academic Search

    A. Ben Ferjani; A. Chine

    1988-01-01

    In Tunisia, hydrocarbon deposits have been discovered in most sedimentary rocks dating from the Paleozoic to the Tertiary. Geologically, Tunisia is subdivided in two main areas: (1) the south, with the stable Saharan platform, where Paleozoic and Triassic sandstones constitute the main petroleum objectives, and (2) the north, which includes the Tertiary and Mesozoic mobile sedimentary basins affected by tectonic

  20. Gravity Analysis of the Jeffera Basin, Tunisia

    Microsoft Academic Search

    K. Mickus; H. Gabtni; C. Jallouli

    2004-01-01

    Southern Tunisia consists of two main tectonic provinces: 1) the Saharan Platform and 2) the folded Atlasic domain, separated by the North Saharan Flexure. The Saharan Platform, which contains the Ghadames Basin and the Telemzane Arch, consists of gently dipping Paleozoic strata overlain by Triassic to Cretaceous sediments. The Atlasic domain consists of a thicker sequence of mainly Mesozoic and

  1. University of Texas of the Permian Basin.

    ERIC Educational Resources Information Center

    Cardozier, V. Ray

    1993-01-01

    The University of Texas of the Permian Basin was created as an upper-division and graduate institution for community college transfer students. It instituted many innovations, including elimination of departments, integration of undergraduate/graduate education, year-round enrollment, contract study, modular classrooms, a faculty trained at…

  2. Telecommunications facilities development in the Pacific basin

    Microsoft Academic Search

    R. J. Barber

    1986-01-01

    This paper provides an overview of satellite, submarine and terrestrial communications facilities in the Pacific basin. Existing, planned, and proposed satellite communications systems is the primary focus, covering international, regional, and selected domestic facilities. As communication satellites are but one segment in the overall telecommunication picture, attention is also given to terrestrial systems and to submarine cable facilities. Issues related

  3. Hydrology of the Bear Lake Basin, Utah

    Microsoft Academic Search

    Patsy Palacios; Chris Luecke; Justin Robinson

    2007-01-01

    Bear Lake’s natural watershed is made up of relatively low mountains covered with sagebrush at lower elevations and southern exposures and fir-aspen forests at higher elevations and northern exposures. The basin is traversed by the Bear River that begins high in the Unita Mountains and flows through Utah, Idaho, and Wyoming before feeding the Great Salt Lake. The Bear River

  4. Historical Orthoimagery of the Lake Tahoe Basin

    USGS Publications Warehouse

    Soulard, Christopher E.; Raumann, Christian G.

    2008-01-01

    The U.S. Geological Survey (USGS) Western Geographic Science Center has developed a series of historical digital orthoimagery (HDO) datasets covering part or all of the Lake Tahoe Basin. Three datasets are available: (A) 1940 HDOs for the southern Lake Tahoe Basin, (B) 1969 HDOs for the entire Lake Tahoe Basin, and (C) 1987 HDOs for the southern Lake Tahoe Basin. The HDOs (for 1940, 1969, and 1987) were compiled photogrammically from aerial photography with varying scales, camera characteristics, image quality, and capture dates. The resulting datasets have a 1-meter horizontal resolution. Precision-corrected Ikonos multispectral satellite imagery was used as a substitute for HDOs/DOQs for the 2002 imagery date, but these data are not available for download in this series due to licensing restrictions. The projection of the HDO data is set to UTM Zone 10, NAD 1983. The data for each of the three available dates are clipped into files that spatially approximate the 3.75-minute USGS quarter quadrangles (roughly 3,000 to 4,000 hectares), and have roughly 100 pixels (or 100 meters) of overlap to facilitate combining the files into larger regions without data gaps. The files are named after 3.75-minute USGS quarter quadrangles that cover the same general spatial extent. These files are available in the ERDAS Imagine (.img) format.

  5. Concealed evaporite basin drilled in Arizona

    Microsoft Academic Search

    Rauzi

    1996-01-01

    The White Mountains of Arizona are a high forested plateau underlain by volcanic rocks of Late Pliocene and Quaternary age on the south margin of the Colorado plateau province. Elevations range from 6,000--11,590 ft, with winter snow and summer rain but ideal conditions for much of the year. There was no evidence of a Permian evaporite basin concealed beneath the

  6. Hydrological characterization of Birch Creek Basin

    Microsoft Academic Search

    Koslow

    1984-01-01

    A hydrological characterization of the Birch Creek Basin has been conducted to analyze the flood potential from Birch Creek on the Idaho National Engineering Laboratory (INEL). Birch Creek originated from springs below Gilmore Summit, between the Lemhi and Beaverhead Mountain Ranges, and flows in a southeasterly direction onto the Snake River Plain. The channel leads to a depression on the

  7. Financial Sustainability of International River Basin Organizations

    E-print Network

    Wolf, Aaron

    financing of a sample of African, Asian and European River Basin Organizations (RBOs). Its focus is on financing sources for the organi- zations' regular budget, which is defined as the permanent and recurrent for the RBOs' regular budget (chapter 3), to give an analysis of their cost-sharing mechanisms for member

  8. Landsat Mosaic of the Yukon River Basin

    USGS Multimedia Gallery

    Michelle A. Bouchard, John L. Dwyer and Brian Granneman. American Geophysical Union, Fall Meeting 2009, abstract #GC51A-0708 Landsat data from the Global Land Survey (GLS) dataset for year 2000 was mosaicked to form a Yukon River Basin image map that is referenced to a geodetic base. It was produc...

  9. Field size distributions for California Basins

    SciTech Connect

    Bartel, D. (Chevron USA Production Co., Bakersfield, CA (United States))

    1994-04-01

    Distribution curves for oil and gas field sizes can aid in assessing the future exploration potential of a basin. Field size distribution curves are presented for the San Joaquin, Sacramento, Ventura-Santa Barbara Channel, and Santa Maria basins. The data used here are largely from the published summaries of the California Division of Oil and Gas. It is not only important to look at the total distribution curve, but also the changes in the field size distribution curve through history. Since the basins used by example here are relatively well explored over the past approximately 100 yr, future fields will most likely be smaller than most fields that have already been found in the basin. This can be altered if significant changes in technology or opportunity occur. The field size distribution can also be carried out at the individual reservoir pool or play level. Pool reserve size, and other parameters of the pool (e.g., net pay thickness), also seem to have a regular distribution that approximates a log-normal distribution. In the absence of other nearby geologic data for a play or prospect, such data could be used to estimate the parameters of a prospect. Summaries of existing data from the Upper Miocene Stevens reservoirs of the San Joaquin Valley will be shown. The data can be further subdivided into eastside and westside sourced Stevens reservoirs. Distribution curves for other prospective horizons could also be drawn from the available data.

  10. Resident Fish in the Columbia River Basin

    Microsoft Academic Search

    Neil E. Ward; David L. Ward

    2004-01-01

    Development and operation of Columbia River Basin hydroelectric facilities have contributed to the reduction in diversity and abundance of some native resident fish. To mitigate for effects of hydroelectric development and operations, the Bonneville Power Administration (BPA) annually funds fisheries research and management efforts. In 2003, the BPA provided $19.2 million for the implementation of 54 resident fish projects that

  11. Hydrocarbon potential of intracratonic rift basins

    SciTech Connect

    Baker, D.G.; Derksen, S.J.

    1984-09-01

    Significant world oil reserves have been added in recent years from rift system. Examples of petroliferous rift basins may be found on nearly every major continent. As our understanding of the mechanisms of sedimentation and structure in rift basins grows, more rift systems will be found. With a few notable exceptions, rifts that have been explored in the past are those that formed along continental margins. These contain marine sediments, and the conditions of source rock, sediment type, depositional environment, and structural style are well-known exploration concepts. Intracratonic rift systems containing continental sediments, and also because of the problems perceived to accompany continental sedimentation. A good modern analog is the East African rift system. Several companies have made significant oil discoveries in different components of the Central African rift system. Average daily production for 1982 from the basins associated with the Benue trough was 107.928 BOPD. In the Abu Gabra rift component, where Marathon is currently exploring, Chevron has drilled approximately 60 wells. Nineteen of these were discoveries and tested an average rate per well of 3,500 BOPD. The Abu Gabra rift may contain up to 10 billion bbl of oil. Research indicates that this type of rift system is present in other areas of the world. Ongoing worldwide exploration has shown that intracratonic rift basins have the potential to make a significant contribution to world oil reserves.

  12. GUNNISON BASIN CLIMATE CHANGE VULNERABILITY ASSESSMENT

    E-print Network

    Neff, Jason

    December 31, 2011 Prepared by The Nature Conservancy Colorado Natural Heritage Program Western Water, as well as ecosystem services, e.g., water supply. The climate of the Gunnison Basin, Colorado State College and Western Water Assessment, University of Colorado, Boulder. The Working Group

  13. OHIO RIVER BASIN ENERGY STUDY: HEALTH ASPECTS

    EPA Science Inventory

    This report was prepared as part of the Ohio River Basin Energy Study (ORBES), a multi-disciplinary program supported by the Environmental Protection Agency. It attempts to establish health damage functions for energy resource extraction, conversion (i.e., burning of coal to prod...

  14. The Great Basin Research and Management Partnership

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Great Basin is undergoing major sociological and ecological change as a result of urbanization, changing technology and land use, climate change, limited water resources, altered fire regimes, and invasive species, insects, and disease. Sustaining ecosystems, resources, and human populations of...

  15. Plate evolution and petroliferous basins of China

    SciTech Connect

    Wu Shou Cheng; Zhang Wen Zhao

    1989-03-01

    The writers have compiled a group of paleogeographic and paleostructural maps of tectonic plates and sedimentary basins of China based on paleomagnetic, paleoclimatic, and paleoecologic data. The paleoenvironments and regional conditions that instigated the origin of petroleum in the superbasins have been reconstructed.

  16. The evolution of impact basins - Cooling, subsidence, and thermal stress

    NASA Technical Reports Server (NTRS)

    Bratt, S. R.; Solomon, S. C.; Head, J. W.

    1985-01-01

    The present study is concerned with an assessment of the contribution of thermal contraction and thermal stress to the topography and tectonics of large lunar impact basins. Exploratory models are developed, giving attention to the temperature structure following basin formation, the subsequent cooling of the basin region, and the resulting thermal displacements and stresses as functions of time. The subsidence and stress at the surface are compared with topography and tectonic features in the comparatively well-preserved Orientale basin. The results of the comparison are used as a basis to derive approximate constraints on the quantity and distribution of heat implanted during the basin-formation process.

  17. Tritium hydrology of the Mississippi River basin

    USGS Publications Warehouse

    Michel, R.L.

    2004-01-01

    In the early 1960s, the US Geological Survey began routinely analysing river water samples for tritium concentrations at locations within the Mississippi River basin. The sites included the main stem of the Mississippi River (at Luling Ferry, Louisiana), and three of its major tributaries, the Ohio River (at Markland Dam, Kentucky), the upper Missouri River (at Nebraska City, Nebraska) and the Arkansas River (near Van Buren, Arkansas). The measurements cover the period during the peak of the bomb-produced tritium transient when tritium concentrations in precipitation rose above natural levels by two to three orders of magnitude. Using measurements of tritium concentrations in precipitation, a tritium input function was established for the river basins above the Ohio River, Missouri River and Arkansas River sampling locations. Owing to the extent of the basin above the Luling Ferry site, no input function was developed for that location. The input functions for the Ohio and Missouri Rivers were then used in a two-component mixing model to estimate residence times of water within these two basins. (The Arkansas River was not modelled because of extremely large yearly variations in flow during the peak of the tritium transient.) The two components used were: (i) recent precipitation (prompt outflow) and (ii) waters derived from the long-term groundwater reservoir of the basin. The tritium concentration of the second component is a function of the atmospheric input and the residence times of the groundwaters within the basin. Using yearly time periods, the parameters of the model were varied until a best fit was obtained between modelled and measured tritium data. The results from the model indicate that about 40% of the flow in the Ohio River was from prompt outflow, as compared with 10% for the Missouri River. Mean residence times of 10 years were calculated for the groundwater component of the Ohio River versus 4 years for the Missouri River. The mass flux of tritium through the Mississippi Basin and its tributaries was calculated during the years that tritium measurements were made. The cumulative fluxes, calculated in grams of 3II were: (i) 160 g for the Ohio (1961-1986), (ii) 98 g for the upper Missouri (1963-1997), (iii) 30 g for the Arkansas (1961-1997) and (iv) 780 g for the Mississippi (1961-1997). Published in 2004 by John Wiley and Sons, Ltd.

  18. Pennsylvanian-Permian tectonism in the Great Basin: The Dry Mountain trough and related basins

    SciTech Connect

    Snyder, W.S.; Spinosa, C.; Gallegos, D.M. (Boise State Univ., ID (United States))

    1991-02-01

    Pennsylvanian-Permian tectonism affected the continental margin of western North America from the Yukon to the Mojave Desert. Specific signatures of this tectonism include local angular unconformities, regional disconformities, renewed outpouring of clastic debris from a reactivated Antler and related highlands, and development of deeper water basins with anoxic sediments deposited below wave base. The basins formed include Ishbel trough (Canada), the Wood River basin (Idaho), Cassia basin, Ferguson trough, Dry Mountain trough (all Nevada), and unnamed basins in Death Valley-Mojave Desert region. The Dry Mountain trough (DMT) was initiated during early Wolfcampian and received up to 1,200 m of sediment by the late Leonardian. The lower contact is a regional unconformity with the Ely Limestone, or locally with the Diamond Peak or Vinini formations. Thus, following a period of localized regional uplift that destroyed the Ely basin, portions of the uplifted and exposed shelf subsided creating the Dry Mountain trough. Evidence suggesting a tectonic origin for the DMT includes (1) high subsidence rates (60-140 m/m.y.); (2) renewed influx of coarse clastic debris from the Antler highlands: (3) possible pre-Early Permian folding, thrusting, and tilting within the highlands; and (4) differential subsidence within the Dry Mountain trough, suggesting the existence of independent fault blocks.

  19. JOINT FOREST MANAGEMENT TOWARDS SUSTAINABLE DEVELOPMENT IN ORISSA: A STUDY

    Microsoft Academic Search

    R K Panda; C R Das

    2009-01-01

    A large number of people living in and around forest areas depend heavily on forests for their livelihood. It is estimated that 60 million people living in the rain forests of Latin America, South-East Asia and West Africa depend heavily on forests; 350 million people living in or around the dense forests depend on them for sustenance or income; and

  20. Okanogan Basin Spring Spawner Report for 2007.

    SciTech Connect

    Colville Tribes, Department of Fish & Wildlife

    2007-09-01

    The Okanogan Basin Monitoring and Evaluation Program collected data related to spring spawning anadromous salmonid stocks across the entire Okanogan River basin. Data were collected using redd surveys, traps, underwater video, and PIT-tag technology then summarized and analyzed using simple estimate models. From these efforts we estimated that 1,266 summer steelhead spawned in the Okanogan River basin and constructed 552 redds;152 of these fish where of natural origin. Of these, 121 summer steelhead, including 29 of natural origin, created an estimated 70 redds in the Canadian portion of the Okanagan basin. We estimated summer steelhead spawner escapement into each sub-watershed along with the number from natural origin and the number and density of redds. We documented redd desiccation in Loup Loup Creek, habitat utilization in Salmon Creek as a result of a new water lease program, and 10 spring Chinook returning to Omak Creek. High water through most of the redd survey period resulted in development of new modeling techniques and allowed us to survey additional tributaries including the observation of summer steelhead spawning in Wanacut Creek. These 2007 data provide additional support that redd surveys conducted within the United States are well founded and provide essential information for tracking the recovery of listed summer steelhead. Conversely, redd surveys do not appear to be the best approach for enumerating steelhead spawners or there distribution within Canada. We also identified that spawning distributions within the Okanogan River basin vary widely and stocking location may play an over riding roll in this variability.

  1. Archean foreland basin tectonics in the Witwatersrand, South Africa

    NASA Technical Reports Server (NTRS)

    Burke, K.; Kidd, W. S. F.; Kusky, T. M.

    1986-01-01

    The Witwatersrand Basin of South Africa is the best-known of Archean sedimentary basins and contains some of the largest gold reserves in the world. Sediments in the basin include a lower flysch-type sequence and an upper molassic facies, both of which contain abundant silicic volcanic detritus. The strata are thicker and more proximal on the northwestern side of the basin which is, at least locally, bound by thrust faults. These features indicate that the Witwatersrand strata may have been deposited in a foreland basin and a regional geologic synthesis suggests that this basin developed initially on the cratonward side of an Andean-type arc. Remarkably similar Phanerozoic basins may be found in the southern Andes above zones of shallow subduction. It is suggested that the continental collision between the Kaapvaal and Zimbabwe Cratons at about 2.7 Ga caused further subsidence and deposition in the Witwatersrand Basin. Regional uplift during this later phase of development placed the basin on the cratonward edge of a collision-related plateau, now represented by the Limpopo Province. Similarities are seen between this phase of Witwatersrand Basin evolution and that of active basins north of the Tibetan Plateau. The geologic evidence does not agree with earlier suggestions that the Witwatersrand strata were deposited in a rift or half-graben.

  2. Archean foreland basin tectonics in the Witwatersrand, South Africa

    NASA Technical Reports Server (NTRS)

    Burke, K.; Kidd, W. S. F.; Kusky, T. M.

    1986-01-01

    The Witwatersrand Basin of South Africa is the best-known of Archean sedimentary basins and contains some of the largest gold reserves in the world. Sediments in the basin include a lower flysch-type sequence and an upper molassic facies, both of which contain abundant silicic volcanic detritus. The strata are thicker and more proximal on the northwestern side of the basin which is, at least locally, bound by thrust faults. These features indicate that the Witwatersrand strata may have been deposited in a foreland basin and a regional geologic synthesis suggests that this basin developed initially on the cratonward side of an Andean-type arc. Remarkably similar Phanerozoic basins may be found in the southern Andes above zones of shallow subduction. It is suggested that the continental collision between the Kaapvaal and Zimbabwe Cratons at about 2.7 Ga caused further subsidence and deposition in the Witwatersrand Basin. Regional uplift during this later phase of development placed the basin on the cratonward edge of a collision-related plateau, now represented by the Limpopo Province. Similarities are seen between this Phase of Witywatersrand Basin evolution and that of active basins north of the Tibetan Plateau. The geologic evidence does not agree with earlier suggestions that the Witwatersrand strata were deposited in a rift or half-graben.

  3. Distribution, Statistics, and Resurfacing of Large Impact Basins on Mercury

    NASA Technical Reports Server (NTRS)

    Fassett, Caleb I.; Head, James W.; Baker, David M. H.; Chapman, Clark R.; Murchie, Scott L.; Neumann, Gregory A.; Oberst, Juergen; Prockter, Louise M.; Smith, David E.; Solomon, Sean C.; Strom, Robert G.; Xiao, Zhiyong; Zuber, Maria T.

    2012-01-01

    The distribution and geological history of large impact basins (diameter D greater than or equal to 300 km) on Mercury is important to understanding the planet's stratigraphy and surface evolution. It is also informative to compare the density of impact basins on Mercury with that of the Moon to understand similarities and differences in their impact crater and basin populations [1, 2]. A variety of impact basins were proposed on the basis of geological mapping with Mariner 10 data [e.g. 3]. This basin population can now be re-assessed and extended to the full planet, using data from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft. Note that small-to- medium-sized peak-ring basins on Mercury are being examined separately [4, 5]; only the three largest peak-ring basins on Mercury overlap with the size range we consider here. In this study, we (1) re-examine the large basins suggested on the basis of Mariner 10 data, (2) suggest additional basins from MESSENGER's global coverage of Mercury, (3) assess the size-frequency distribution of mercurian basins on the basis of these global observations and compare it to the Moon, and (4) analyze the implications of these observations for the modification history of basins on Mercury.

  4. Hydrocarbon potential of early mesozoic basins of eastern United States

    SciTech Connect

    Schlamel, S.

    1988-01-01

    The exposed Triassic-Liassic rift basins in the eastern United States are half-grabens filled with up to 7 km of continental sediments. The location and sense of asymmetry of the half-grabens are closely tied to the structural grain of the Appalachian crystalline terranes on which they have formed. In many instances, the faulted margins of the basins are older thrusts or terrane boundaries reactivated as listric normal faults. The sediment fill of the basins reflects their structural asymmetry. Coarse alluvial fan deposits along the main border faults pass basinward into a complex assemblage of fluvial, paludal, and lacustrine facies. The oldest sediment fill in the rift basins is dated palynologically as late Ladinian to late Carnian. Perhaps reflecting the northward opening of the central Atlantic, the youngest rift-fill sediments are older in the southern basins than in the northern-Carnian in the Righmond basin vs. Toarcian in the Hartford-Deerfield basin. Floral evidence points to a tropical to near-tropical environment, with severe oscillations between xerophytic (dry) and hydrophytic (wet) conditions. The degree of thermal maturation, as estimated from vitrinite reflectance and clay mineralogy, varies widely from basin to basin; however, most of the basins are within the oil to dry gas generative window. The basins with highest thermal maturities are those having large volumes of diabase intrusives and presumed higher paleogeothermal gradients. The peak of thermal maturation/migration may have occurred as early as the Jurassic.

  5. Hydrocarbon discoveries in Paleozoic Solimoes basin, Upper Amazon region, Brazil

    SciTech Connect

    Apoluceno, N.; Ferreira, A.; Tsubone, K.

    1989-03-01

    The Solimoes basin, previously known as Upper Amazon basin, is located in northern Brazil and has a prospectable area of more than 300,000 km/sup 2/. The Purus arch, a regional positive feature, separates this basin from the Amazonas basin. As far as the basin geology is concerned, the Solimoes basin is strikingly different from its neighboring basin due to certain structural and stratigraphic peculiarities. Between the Late Jurassic and Early Cretaceous the basin was affected by regional compressional tectonics that generated a series of northeast-southwest-oriented trends. The exploration play in the basin is classic wrench tectonics - elongated dome structures on upthrown blocks of en echelon reverse faults. Despite the problems of working in a tropical forest, Petrobras has made a systematic exploration campaign in the basin since the early 1970s. This effort was compensated by the discovery of two important hydrocarbon-bearing areas: Jurua gas province in 1978 and the Urucu River oil, gas, and condensate province in 1986. The latter, whose commercial oil production was initiated in July 1988, is considered an important marker in the petroleum exploration history of Brazil, particularly with respect to the Paleozoic basins, which total more than 3 million km/sup 2/ of the country's territory.

  6. Anomalous wave propagation across the South Caspian Basin

    SciTech Connect

    Priestly, K. [Cambridge Univ. (United Kingdom); Patton, H.J. [Los Alamos National Lab., NM (United States); Schultz, C. [Lawrence Livermore National Lab., CA (United States)

    1997-10-01

    The Caspian basin blocks the propagation of the regional seismic phase Lg and this has importance consequences for seismic discrimination in the Middle East. Intermediate period surface waves propagating across the basin are also severely affected. In a separate study we have developed a crustal model of the south Caspian basin and the surrounding region. The crust of the basin consists of 15-25 km of low velocity, highly attenuating sediments lying on high velocity crystalline crust. The Moho beneath the basin is at a depth of about 30 km as compared to about 50 km in the surrounding region. In this study we used an idealized rendition of this crustal model to compute hybrid normal mode finite difference synthetic seismograms to identify the features of the Caspian basin which lead to the seismic blockage. Of the various features of the basin, the thickness and attenuation of the sediments appear to be the dominant blocking mechanism.

  7. Structural styles in the Icarai Basin, Brazilian equatorial margin

    SciTech Connect

    Castro, A.C.M. Jr. (Petrobras, Rio de Janeiro (Brazil))

    1993-02-01

    The Icarai Basin, one of the compartments of the larger Ceara Basin located on the Brazilian equatorial margin, presents two distinct structural styles, clearly identifiable in seismic data. On the western side of the basin structures are characterized by intense folding associated with low to high angle thrust faults, whereas on the eastern side of the basin structures are represented by normal faults and tilted half graben. The change from one style to another is gradual, as both decrease in intensity towards the center of the basin, where they coexist. The distribution and relationship of structures along the basin suggests that the Icarai Basin was a transition zone between two distinct stress regimes, one predominantly transtensive and the other predominantly transpressive, which were simultaneously active in adjacent areas during the Lower Cretaceous. The existence of such distinct stress regimes is probably related to the initial geometry of development of the South American equatorial margin.

  8. Oil shale and nahcolite resources of the Piceance Basin, Colorado

    USGS Publications Warehouse

    U.S. Geological Survey Oil Shale Assessment Team

    2010-01-01

    This report presents an in-place assessment of the oil shale and nahcolite resources of the Green River Formation in the Piceance Basin of western Colorado. The Piceance Basin is one of three large structural and sedimentary basins that contain vast amounts of oil shale resources in the Green River Formation of Eocene age. The other two basins, the Uinta Basin of eastern Utah and westernmost Colorado, and the Greater Green River Basin of southwest Wyoming, northwestern Colorado, and northeastern Utah also contain large resources of oil shale in the Green River Formation, and these two basins will be assessed separately. Estimated in-place oil is about 1.5 trillion barrels, based on Fischer a ssay results from boreholes drilled to evaluate oil shale, making it the largest oil shale deposit in the world. The estimated in-place nahcolite resource is about 43.3 billion short tons.

  9. Thickness of proximal ejecta from the Orientale Basin from Lunar Orbiter Laser Altimeter (LOLA) data: Implications for multi-ring basin formation

    E-print Network

    Fassett, Caleb I.

    Quantifying the ejecta distribution around large lunar basins is important to understanding the origin of basin rings, the volume of the transient cavity, the depth of sampling, and the nature of the basin formation ...

  10. Evolution history of the Heuksan Basin, a continental rift basin in the Yellow Sea

    NASA Astrophysics Data System (ADS)

    Yoon, S.; Kim, G.; Park, M.

    2011-12-01

    This study focuses on the establishment of evolutionary framework of the Heuksan Basin regions located on the southwestern part of the concession block III of the Korean offshore in the Yellow Sea. Three fault-bounded sub-basins (SB-1, SB-2, and SB-3) are recognized on the basis of topographic map of acoustic basement, which are generally in asymmetric half-graben geometry trending WNW-ESE. The axial lengths of the sub-basins are generally less than 80 km in axial length and 20 km in width. The acoustic basement occurs at around 0.6 to 0.8 s twt bsl in generally, locally much deeper at about 2.4 s twt bsl in the deepest part of the sub-basins, and it is correlated with the Upper Paleozoic to Lower Mesozoic sequence of thick micritic limestones overlying major clastic cycles with thin coals. In the sedimentary succession, two erosional surfaces (ES-1 and ES-2) are identified based on the interpretation of truncated geometries and lap-out patterns, which provide three stratigraphic units (SU-1, SU-2, and SU-3). During the Late Cretaceous to Oligocene the basin had opened by NE-SW extension or transtension. By this tectonic movement, WNW-ESE trending sub-basins with an array of listric normal faults were formed. Until the cessation of the opening, the wedge-shaped syn-rift unit (SU-1) infilled the depressions of the rift basins. In the Late Oligocene to Early Miocene time the extensional or transtensional tectonic movement of the Heuksan Basin region was aborted or partly inverted into compressional or transpressional regime. By this tectonic movement, acoustic basement and syn-rift unit (SU-1) might have uplifted, and have experienced a regional planation process. Topographic irregularities were removed by erosion and infilling process. SU-1 might have formed during this period in the localized topographic lows of the basins. Subaerial to shallow-marine planation process on the slightly folded and uplifted SU-1during subsequent tectonic inversion in the Early Miocene might have formed regional-scale unconformity on the top of acoustic basement, SU-1. Localized topographic depressions on the SU-1 might have been infilled with the SU-2 simultaneously with the erosional process. The uppermost sedimentary unit (SU-3) has deposited on highly extensive unconformable surface under shallow marine environment. During the formation of the SU-3, the Heuksan Basin region was tectonically stable, which can be confirmed in seismic reflection profiles with highly parallel stratal pattern without significan lapout and regionally consistent thickness of the unit.

  11. Tectonic setting of Cretaceous basins on the NE Tibetan Plateau: Insights from the Jungong basin

    USGS Publications Warehouse

    Craddock, W.H.; Kirby, E.; Dewen, Z.; Jianhui, L.

    2012-01-01

    Quantifying the Cenozoic growth of high topography in the Indo-Asian collision zone remains challenging, due in part to significant shortening that occurred within Eurasia before collision. A growing body of evidence suggests that regions far removed from the suture zone experienced deformation before and during the early phases of Himalayan orogenesis. In the present-day north-eastern Tibetan Plateau, widespread deposits of Cretaceous sediment attest to significant basin formation; however, the tectonic setting of these basins remains enigmatic. We present a study of a regionally extensive network of sedimentary basins that are spatially associated with a system of SE-vergent thrust faults and are now exposed in the high ranges of the north-eastern corner of the Tibetan Plateau. We focus on a particularly well-exposed basin, located ~20km north of the Kunlun fault in the Anyemaqen Shan. The basin is filled by ~900m of alluvial sediments that become finer-grained away from the basin-bounding fault. Additionally, beds in the proximal footwall of the basin-bounding fault exhibit progressive, up-section shallowing and several intraformational unconformities which can be traced into correlative conformities in the distal part of the basin. The observations show sediment accumulated in the basin during fault motion. Regional constraints on the timing of sediment deposition are provided by both fossil assemblages from the Early Cretaceous, and by K-Ar dating of volcanic rocks that floor and cross-cut sedimentary fill. We argue that during the Cretaceous, the interior NE Tibetan Plateau experienced NW-SE contractional deformation similar to that documented throughout the Qinling-Dabie orogen to the east. The Songpan-Ganzi terrane apparently marked the southern limit of this deformation, such that it may have been a relatively rigid block in the Tibetan lithosphere, separating regions experiencing deformation north of the convergent Tethyan margin from regions deforming inboard of the east Asian margin. ?? 2011 The Authors. Basin Research ?? 2011 Blackwell Publishing Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists.

  12. Paleogeographic and paleotectonic setting of sedimentary basins in the Sevier thrust belt and hinterland, eastern Great Basin

    SciTech Connect

    Schmitt, J.G. (Montana State Univ., Bozeman, MT (United States). Dept. of Earth Sciences); Vandervoort, D.S. (Cornell Univ., Ithaca, NY (United States). Dept. of Geological Sciences); Suydam, J.D. (Washington State Univ., Pullman, WA (United States). Dept. of Geology)

    1993-04-01

    The eastern Great Basin contains a sparse record of broadly distributed Cretaceous sedimentary rocks which record: evolution of intermontane basins during development of the Sevier (Sv)contractional orogen and incipient extensional collapse of the elevated Sv hinterland (east-central NV), and complex tectono-sedimentary interactions between frontal thrust belt structures and the western margin of the adjacent foreland basin. Palinspastic restoration of these strata and associated structures to pre-Tertiary extension positions reveals a clearer pictures of Cretaceous basin paleogeography and allows comparison with the Puna/Altiplano plateau and precordillera thrust belt of the Neogene Andean orogen. Two syntectonic stratal assemblages are present in east-central NV. Lower Cretaceous alluvial strata (Newark Canyon Fm) record basin development coeval with emergence of contractional structures in the Sv hinterland. Localized early Cretaceous basins were possibly piggyback immature; periods of open drainage to the to the east and south suggest connection with the nascent Sv foreland basin to the east (Cedar Mountain/Sanpete Fms) prior to major thrust loading in central Utah. Development of hinterland structures is almost recorded by Aptian-Albian foreland basin alluvial deposits in SW Utah (Dakota Fm) and southern Nevada (Willow Tank Fm). Upper Cretaceous to Eocene strata (Sheep Pass Fm) record inception of regionally abundant alluvial-lacustrine basins which developed in response to onset of latest Cretaceous extension and associated collapse of the Sv hinterland. Evolution of the structurally complex western margin of the Sv foreland basin is recorded in Cretaceous through Eocene strata deposited in: piggyback basins which were at times hydrologically connected to the adjacent foreland basins, and thrust-proximal portions of the foreland basin. These proximal areas are characterized by folding and faulting of basin fill and development of intrabasinal unconformities.

  13. The Messinian Evaporites in the Levantine Basin

    NASA Astrophysics Data System (ADS)

    Netzeband, G. L.; Huebscher, C. P.; Gajewski, D.

    2005-12-01

    The Levantine Basin in the Southeastern Mediterranean Sea is a world class site for studying the initial stages of salt tectonics. The deposition of the evaporites took place during the Messinian salinity crisis 5.9 - 5.3 Ma ago. About 2 km of halite, gypsum and anhydrite were deposited in the basin. The evaporite body is not uniformly transparent, but marked by several internal reflections. Between these reflections, the evaporites appear transparent. This leads to the conclusion that they represent different cycles of evaporite deposition, each with a succession of upper and lower evaporites. All of these internal reflections are differently folded and distorted, proving that the deformation was syn-depositional. Thrust angles of up to 14 degrees are observed. The sediment cover on top mainly originates from Nile sediments. Hence, the sediment thickness varies between about 400 m in the northern part of the basin over 1000 m near the shelf off Israel and Lebanon to almost 3000 m near the Nile Delta. A simple 1-D backstripping analysis reveals that this immense difference in sediment load is the driving force for salt migration. Hence, the main direction of salt movement is SSW-NNE, there has been no movement in E-W direction. The superposition of 'thin-skinned' tectonics and 'thick-skinned' tectonics is clearly visible in the Levantine Basin: At the Cyprus Arc, the convergence zone of Africa and Eurasia, deep-rooted compression heavily deformed the base of the salt, whereas at the Eratosthenes Seamount mainly superficial compression affecting the Post-Messinian sediments and the top of the evaporites is observed. Shear zones and fault lines, which have been postulated in the Levantine Basin, follow two trends: SSW-NNE and NW-SE. They add a component of 'thick-skinned' transpression to the generally 'thin-skinned' compressional regime in the basin. These deep-rooted fault lines represent zones of weakness, above which salt-related pop-up structures and thrust faults develop.

  14. Hotspots within the Transboundary Selenga River Basin

    NASA Astrophysics Data System (ADS)

    Kasimov, Nikolay; Lychagin, Mikhail; Chalov, Sergey

    2013-04-01

    Gathering the efficient information on water pollution of transboundary river systems remains the crucial task in international water management, environmental pollution control and prevention health problems. Countries, located in the low parts of the river basins, depend on the water strategy and water use in the adjacent countries, located upstream. Surface water pollution is considered to be the most serious problem, facing the above-mentioned countries. Large efforts in terms of field measurement campaigns and (numerical) transport modeling are then typically needed for relevant pollution prediction and prevention. Russian rivers take inflow from 8 neighboring countries. Among them there are 2 developing economies - People Republic of China and Mongolia, which are located in water-scarce areas and thus solve their water-related problems through the consumption of international water. Negative change of water runoff and water quality in the foreign part of transboundary river is appeared inside Russian territory with more or less delay. The transboundary river system of Selenga is particularly challenging, being the biggest tributary of Lake Baikal which is the largest freshwater reservoir in the world. Selenga River contributes about 50 % of the total inflow into Baikal. It originates in the mountainous part of Mongolia and then drains into Russia. There are numerous industries and agricultural activities within the Selenga drainage basin that affect the water quality of the river system. Absence of the single monitoring system and predictive tools for pollutants transport in river system requires large efforts in understanding sources of water pollution and implemented data on the relevant numerical systems for the pollution prediction and prevention. Special investigations in the Selenga river basin (Mongolia and Russia) were done to assess hot spots and understand state-of-the art in sediment load, water chemistry and hydrobiology of transboundary systems. Hot spot assessment included 100 gauge stations in the river basin with discharge measurement by ADCP, turbidity (T) and suspended sediment concentration (SSC), bed load by bed load traps, composition of salt, biochemical oxidation, nitrogen and phosphorous content in water, pH, redox and conductivity values, and also content of heavy metals in water, suspended matter and sediments. The study revealed rather high levels of dissolved Fe, Al, Mn, Zn, Cu, and Mo in the Selenga River water which often are higher than MPC for water fishery. Most contrast distribution is characteristic for W and Mo, which is caused by mineral deposits in the Selenga basin. The most severe pollution of aquatic systems in the basin caused by mining activities is characteristic for a small river Modonkul, which flows into Dzhida River (left tributary of Selenga).

  15. Intensity attenuation in the Pannonian Basin

    NASA Astrophysics Data System (ADS)

    Gy?ri, Erzsébet; Gráczer, Zoltán; Szanyi, Gyöngyvér

    2015-04-01

    Ground motion prediction equations play a key role in seismic hazard assessment. Earthquake hazard has to be expressed in macroseismic intensities in case of seismic risk estimations where a direct relation to the damage associated with ground shaking is needed. It can be also necessary for shake map generation where the map is used for prompt notification to the public, disaster management officers and insurance companies. Although only few instrumental strong motion data are recorded in the Pannonian Basin, there are numerous historical reports of past earthquakes since the 1763 Komárom earthquake. Knowing the intensity attenuation and comparing them with relations of other areas - where instrumental strong motion data also exist - can help us to choose from the existing instrumental ground motion prediction equations. The aim of this work is to determine an intensity attenuation formula for the inner part of the Pannonian Basin, which can be further used to find an adaptable ground motion prediction equation for the area. The crust below the Pannonian Basin is thin and warm and it is overlain by thick sediments. Thus the attenuation of seismic waves here is different from the attenuation in the Alp-Carpathian mountain belt. Therefore we have collected intensity data only from the inner part of the Pannonian Basin and defined the boundaries of the studied area by the crust thickness of 30 km (Windhoffer et al., 2005). 90 earthquakes from 1763 until 2014 have sufficient number of macroseismic data. Magnitude of the events varies from 3.0 to 6.6. We have used individual intensity points to eliminate the subjectivity of drawing isoseismals, the number of available intensity data is more than 3000. Careful quality control has been made on the dataset. The different types of magnitudes of the used earthquake catalogue have been converted to local and momentum magnitudes using relations determined for the Pannonian Basin. We applied the attenuation formula by Sorensen et al. (2009) using a least-squares regression method. This expression is comparable with the common type of strong-motion attenuation equations (e.g., Joyner and Boore, 1993). Joyner, W. B. and Boore, D. M. (1993). Methods for regression analysis of strong-motion data. BSSA, 83(2), 469-487. Sørensen, M. B., Stromeyer, D., Grünthal, G. (2009). Attenuation of macroseismic intensity: a new relation for the Marmara Sea region, northwest Turkey. BSSA, 99(2A), 538-553. Windhoffer, G., Dombrádi, E., Horváth, F., Székely, B., Bada, G., Szafián, P., Dövényi, P., Tóth, L., Grenerczy, Gy. and G. Timár (2005) Geodynamic Atlas of the Pannonian Basin and the Surrounding Orogens. 7th Workshop on Alpine Geological Studies, Abstract Book, p. 109.

  16. Radionuclides in the Great Lakes basin.

    PubMed Central

    Ahier, B A; Tracy, B L

    1995-01-01

    The Great Lakes basin is of radiologic interest due to the large population within its boundaries that may be exposed to various sources of ionizing radiation. Specific radionuclides of interest in the basin arising from natural and artificial sources include 3H, 14C, 90Sr, 129I, 131I, 137Cs, 222Rn, 226Ra, 235U, 238U, 239Pu, and 241Am. The greatest contribution to total radiation exposure is the natural background radiation that provides an average dose of about 2.6 mSv/year to all basin residents. Global fallout from atmospheric nuclear weapons tests conducted before 1963 has resulted in the largest input of anthropogenic radioactivity into the lakes. Of increasing importance is the radionuclide input from the various components of the nuclear fuel cycle. Although the dose from these activities is currently very low, it is expected to increase if there is continued growth of the nuclear industry. In spite of strict regulations on design and operation of nuclear power facilities, the potential exists for a serious accident as a result of the large inventories of radionuclides contained in the reactor cores; however, these risks are several orders of magnitude less than the risks from other natural and man-made hazards. An area of major priority over the next few decades will be the management of the substantial amounts of radioactive waste generated by nuclear fuel cycle activities. Based on derived risk coefficients, the theoretical incidence of fatal and weighted nonfatal cancers and hereditary defects in the basin's population, attributable to 50 years of exposure to natural background radiation, is conservatively estimated to be of the order of 3.4 x 10(5) cases. The total number of attributable health effects to the year 2050 from fallout radionuclides in the Great Lakes basin is of the order of 5.0 x 10(3). In contrast, estimates of attributable health effects from 50 years of exposure to current nuclear fuel cycle effluent in the basin are of the order of 2 x 10(2). Although these are hypothetical risks, they show that the radiologic impact of man-made sources is very small compared to the effects of normal background radiation. PMID:8635444

  17. Geofluid Dynamics of Faulted Sedimentary Basins

    NASA Astrophysics Data System (ADS)

    Garven, G.; Jung, B.; Boles, J. R.

    2014-12-01

    Faults are known to affect basin-scale groundwater flow, and exert a profound control on petroleum migration/accumulation, the PVT-history of hydrothermal fluids, and the natural (submarine) seepage from offshore reservoirs. For example, in the Santa Barbara basin, measured gas flow data from a natural submarine seep area in the Santa Barbara Channel helps constrain fault permeability k ~ 30 millidarcys for the large-scale upward migration of methane-bearing formation fluids along one of the major fault zones. At another offshore site near Platform Holly, pressure-transducer time-series data from a 1.5 km deep exploration well in the South Ellwood Field demonstrate a strong ocean tidal component, due to vertical fault connectivity to the seafloor. Analytical solutions to the poroelastic flow equation can be used to extract both fault permeability and compressibility parameters, based on tidal-signal amplitude attenuation and phase shift at depth. These data have proven useful in constraining coupled hydrogeologic 2-D models for reactive flow and geomechanical deformation. In a similar vein, our studies of faults in the Los Angeles basin, suggest an important role for the natural retention of fluids along the Newport-Inglewood fault zone. Based on the estimates of fault permeability derived above, we have also constructed new two-dimensional numerical simulations to characterize large-scale multiphase flow in complex heterogeneous and anisotropic geologic profiles, such as the Los Angeles basin. The numerical model was developed in our lab at Tufts from scratch, and based on an IMPES-type algorithm for a finite element/volume mesh. This numerical approach allowed us model large differentials in fluid saturation and relative permeability, caused by complex geological heterogeneities associated with sedimentation and faulting. Our two-phase flow models also replicated the formation-scale patterns of petroleum accumulation associated with the basin margin, where deep faults resulted in stacked petroleum reservoirs along the Newport-Inglewood Fault, as deep geofluids migrated out of the basin to the Palo Verde Peninsula. Recent isotope data collected by our group also verify fault connectivity at the deep crustal scale.

  18. Tectonic History and Modelling of South Caspian Basin

    NASA Astrophysics Data System (ADS)

    Korotaev, M.; Nikishin, A.; Ershov, A.; Brunet, M.-F.

    South Caspian Basin is situated to the east from Caucasus mountains, to the north from Alborz mountain and to the west from Turkmenia. Basin is underlyed by oceanic crust and has extremely high thickness of sediments - up to 22 km. Generally, sedi- ments of South Caspian are divided in 9 complexes (by seismic data): from Jurassic to Quaternary, mostly terrigenous sediments. Modern stress fields obtained from struc- tural data, earthquakes data and GPS data shows compressional environments in South Caspian Region. We propose that the South Caspian Basin was opened in Callovian- Late Jurassic. Callovian-Late Jurassic rapid subsidence event is well documented for the Pre-Caucasus area. We can conclude that a large back-arc deep water basin with very thinned to local oceanic crust originated during Callovian-Late Jurassic which in- cluded Great Caucasus Trough, South Caspian Basin and Kopet-Dagh Basin. It could be recognised the following main stages of the basin history: Callovian-Late Jurassic - that main rifting and crustal extension epoch; Cretaceous-Eocene - gentle thermal sub- sidence affected by stress events; Oligocene-Miocene - rapid subsidence with domi- nant clay deposition within the basin; Pliocene-Quaternary - unusual rapid subsidence of the South Caspian Basin coincided with mountain uplift of the Great Caucasus, Kopet-Dagh and Alborz. We made a backstripping reconstruction along the seismic profile in the central part of the south Caspian Basin. We obtained main peak of the tectonic subsidence for the South Caspian Basin in the Pliocene time - 2 km of the tectonic subsidence and tectonic subsidence rate up to 1200 m/Ma. Rapid subsidence of the basin was contemporaneous with increase of compression and orogenesis on the borders of the basin. We examine the hypothesis, explaining this rapid syncompres- sional subsidence by flexural response of the basin lithosphere to increase of imposed compressional force Lithosphere of the investigated South Caspian basin has great heterogeneity: both structural and thermal. Lithosphere in the centre of the basin is proposed to be oceanic, relatively cold and strong. On the other hand, recent orogens are developing on the borders of the basin (Caucasus, Alborz), those lithosphere is mechanically weak. Compressional force of 5x1013 N/m induces tectonic subsidence with maximum of about 2 km in the centre of the basin. This is in agreement with the 'observed' tectonic subsidence from the burial history restoration.

  19. Comparative hydrocarbon geology of two Mesozoic Circum-Pacific foreland basins as function of sediment provenance: Surat basin, eastern Australia and western Canada basin

    SciTech Connect

    Hawlader, H.M. (Macquarie Univ. (Australia))

    1990-06-01

    The Surat basin in Queensland and New South Wales, Australia, is a foreland basin formed in response to a magmatic arc during Early Jurassic to mid-Cretaceous time. It has a maximum basin-fill of about 2.5 km of Jurassic and Lower Cretaceous sediments. The first commercial production of oil in Australia came from this basin in the early 1960s. The Western Canada basin is a retro-arc foreland basin with up to 3.5 km of sediments deposited during the Middle Jurassic to Late Cretaceous. The basin was developed on the cratonward side of an arc/cordillera by plate convergence. It is a composite basin with sediments ranging in age from Devonian to Tertiary and is one of the prolific petroliferous basins of the world. The famous Athabasca-Peace River-Lloydminister tar sands alone contain a reserve of about 3 {times} 10{sup 12} barrels of oil, which exceeds three times the recoverable reserves of the world's known oil. The main sediment source was, in both basins, a rising arc/cordillera that shed a cratonward tapering clastic wedge into the flanking foreland basins. Sedimentation, in both cases, was episodic and the patterns of sedimentation in each present striking similarities. During the waxing phase of magmatism/orogeny in the arc/cordillera, the foreland subsided in response to flexural loading of the foreland fold-thrust belt and downward drag by the subducting plate. Continental synorogenic sediments were rapidly emplaced in mainly terrestrial environments into the subsiding foreland. These sediments are lithic-labile in nature and because of their physical and chemical reactivity are prone to be tight and thus of little hydrocarbon reservoir potential. During the waning phase of the arc/orogen the foreland gently rose in response partly to the cessation of drag (decoupling) by the subducting plate and to isostatic rebound (tectonic relaxation).

  20. Hydrogeologic Framework of the Salt Basin, New Mexico and Texas

    NASA Astrophysics Data System (ADS)

    Ritchie, A. B.; Phillips, F. M.

    2010-12-01

    The Salt Basin is a closed drainage basin located in southeastern New Mexico (Otero, Chaves, and Eddy Counties), and northwestern Texas (Hudspeth, Culberson, Jeff Davis, and Presidio Counties), which can be divided into a northern and a southern system. Since the 1950s, extensive groundwater withdrawals have been associated with agricultural irrigation in the Dell City, Texas region, just south of the New Mexico-Texas border. Currently, there are three major applications over the appropriations of groundwater in the Salt Basin. Despite these factors, relatively little is known about the recharge rates and storage capacity of the basin, and the estimates that do exist are highly variable. The Salt Basin groundwater system was declared by the New Mexico State Engineer during 2002 in an attempt to regulate and control growing interest in the groundwater resources of the basin. In order to help guide long-term management strategies, a conceptual model of groundwater flow in the Salt Basin was developed by reconstructing the tectonic forcings that have affected the basin during its formation, and identifying the depositional environments that formed and the resultant distribution of facies. The tectonic history of the Salt Basin can be divided into four main periods: a) Pennsylvanian-to-Early Permian, b) Mid-to-Late Permian, c) Late Cretaceous, and d) Tertiary-to-Quaternary. Pennsylvanian-to-Permian structural features affected deposition throughout the Permian, resulting in three distinct hydrogeologic facies: basin, shelf-margin, and shelf. Permian shelf facies rocks form the primary aquifer within the northern Salt Basin, although minor aquifers occur in Cretaceous rocks and Tertiary-to-Quaternary alluvium. Subsequent tectonic activity during the Late Cretaceous resulted in the re-activation of many of the earlier structures. Tertiary-to-Quaternary Basin-and-Range extension produced the current physiographic form of the basin.

  1. Early, middle, and late Miocene basin development, California

    SciTech Connect

    Bachman, S.B.

    1988-03-01

    Contrary to earlier models of progressive basin development related to northward migration of the Mendocino triple junction, it can now be documented that the major basins of coastal California developed at about the same time in the late Oligocene to early Miocene. This basin development is marked by rapid deepening of basin floors, subsequent changes in depositional facies from nonmarine and shallow marine to deep marine, and widespread volcanism dated at 23-20 Ma. The coastal basins likely formed by rifting and subsidence linked to the proximity of the Farallon-pacific spreading ridge and the subduction of hot young oceanic crust, but cannot be correlated to any existing models of triple junction migration. Indeed, strike-slip restored positions of the coastal basins at their inception indicate that the basins were spread out over about 800 km of the southern coast of California. The Miocene basins were likely larger than the present coastal basins, although their configurations are obscured by late Neogene faulting and erosion. It is likely, however, that paleohighs separated at least some of the margin into proximal and distal basins. With local exceptions, structuring in the Miocene basins was primarily extensional, with widespread strike-slip and thrust tectonics restricted mainly to latest Miocene and younger events. Plate reconstructions suggest several hundred kilometers of transform motion occurred along the California margin during the Miocene, but there is only limited evidence of this movement in the known history of either the basins or the major faults of California. Sedimentation during the Miocene was controlled by both oceanic conditions (biogenic component) and the relative abundance of clastic input. The clastic input was controlled by a combination of proximal vs distal basinal positions, eustatic sea level changes, and local tectonics.

  2. Transtensional Basin Forming Processes in the Quaternary of Northern Greece: The Mygdonia Pull-Apart Basin

    NASA Astrophysics Data System (ADS)

    Venetikidis, A.; Schoenbohm, L. M.

    2014-12-01

    The geodynamic setting of the northern Aegean is governed by the superimposition of NE-SW strike-slip deformation, associated with the propagation of the North Anatolian fault zone towards the west, and N-S extension, caused by the suction of the Aegean realm towards the south due to deep seated processes of trench retreat and slab rollback. The Mygdonia basin sits at the westernmost termination of the Kavala-Xanthi-Komotini fault zone, a structure that is considered the northernmost splay of the North Anatolian fault system in the northern Aegean. It is one of the most seismically active regions in continental northern Greece, and it is herein interpreted, for the first time, as a transtensional pull-apart structure that has been progressively established since the Early Pleistocene by westward directed rupture of NW-SE and NE-SW trending oblique slip normal faults and E-W trending normal faults. The interaction of the two, separate, stress regimes in the basin demands decreasing accumulated displacement from west to east to accommodate clockwise rotation. The close correspondence between analogue models of transtensional basins and the observed spatial distribution of faulting in the Mygdonia basin attests to the importance of oblique deformation in the basin-forming processes. Detailed topographic profiles across the fault-bounded ranges confirm the decreasing trend of accrued displacement from east to west. Furthermore, topographic swaths reveal the scaling of faulting into discrete segments along the basin-bounding ranges, while calcrete maturity on abandoned hanging wall fans reveals a towards-the-west diachronous faulting with associated fan sedimentation. The Early Pleistocene age of the initial fill of the basin complex and fault displacements on the order of many hundreds of meters point to dramatic and rapid landscape forming processes in this tectonically active region. The increasing appreciation of the interaction of both strike-slip deformation and extension better refines our understanding of basin forming events in this region, in contrast to a simplistic, end-member, pure extensional basin model.

  3. Integrated Basin Scale Hydropower and Environmental Opportunity Assessment in the Deschutes River Basin, Oregon

    NASA Astrophysics Data System (ADS)

    Voisin, N.; Geerlofs, S. H.; Vail, L. W.; Ham, K. D.; Tagestad, J. D.; Hanrahan, T. P.; Seiple, T. E.; Coleman, A. M.; Stewart, K.

    2012-04-01

    The Deschutes River Basin in Oregon, USA, is home to a number of diverse groups of stakeholders that rely upon the complex snowmelt and groundwater-dominated river system to support their needs, livelihoods, and interests. Basin system operations that vary across various temporal and spatial scales often must balance an array of competing demands including maintaining adequate municipal water supply, recreation, hydropower generation, regulations related to environmental flows, mitigation programs for salmon returns, and in-stream and storage rights for irrigation water supplied by surface water diversions and groundwater pumping. The U.S. Department of Energy's Integrated Basin-scale Opportunity Assessment initiative is taking a system-wide approach to identifying opportunities and actions to increase hydropower and enhance environmental conditions while sustaining reliable supply for other uses. Opportunity scenarios are analyzed in collaboration with stakeholders, through nested integrated modeling and visualization software to assess tradeoffs and system-scale effects. Opportunity assessments are not intended to produce decisional documents or substitute for basin planning processes; assessments are instead intended to provide tools, information, and a forum for catalyzing conversation about scenarios where both environmental and hydropower gains can be realized within a given basin. We present the results of the nested integrated modeling approach and the modeling scenarios in order to identify and explore opportunities for the system.

  4. The deep structure of lunar basins - Implications for basin formation and modification

    NASA Technical Reports Server (NTRS)

    Bratt, S. R.; Solomon, S. C.; Head, J. W.; Thurber, C. H.

    1985-01-01

    Models for the crustal structure in the vicinity of nine impact basins, from an inversion of gravity and topographic data from the lunar nearside are presented. The models display a low-density nonmare crustal layer and a mare basalt layer, both of variable thicknesses. Assuming that topography in mare areas is isostatically compensated before the emplacement of mare basalts and that compensation of mare basalt units may be neglected, a decomposition of the gravity anomaly into contributions from Moho relief and mare fill is permitted. Minimum values for mare basalt thicknesses are obtained but because mare basalts and mantle material are similar in density, the thicknesses of the nonmare crust are estimated. An important constraint is the crustal thickness inferred from the Apollo 12 and 14 landing sites from seismic observations. The crustal thickness model indicates that the crust is thinner beneath each of the major nearside basins than in surrounding areas. New bounds on the volume of material ejected from each basin are derived. The geological implications of structural differences among basins for the processes of basin formation and modification are evaluated as functions of time on the moon.

  5. Serenitatis multi-ringed basin - Regional geology and basin ring interpretation

    NASA Technical Reports Server (NTRS)

    Head, J. W., III

    1979-01-01

    New topographic data allow a reassessment of the ring structure and distribution of facies of the Serenitatis basin (SB) and correlation with the younger and essentially same-size Orientale basin. Three major rings of the main (southern) SB are mapped: the Linne ring, outlined by mare ridges, average diameter 420 km; the Haemus ring, outlined by basin-facing scarps and massifs with crenulated borders, 610 km; and the Vitruvius ring, outlined by basin-facing linear scarps and massifs, 880 km. The second ring is interpreted as the rim of the transient cavity, while Serenitatis ejecta should be present in significant amounts at the junction of the Serenitatis and Imbrium third rings. The new reconstruction indicates that portions of the SB are better preserved than previously thought, consistent with recent stratigraphic and sample studies that suggest an age (as young as 3.87 plus or minus 0.04 b.y.) for SB which is older than, but close to, the time of formation of the Imbrium basin.

  6. Insights into Mejerda basin hydrogeology, Tunisia

    NASA Astrophysics Data System (ADS)

    Guellala, Rihab; Tagorti, Mohamed Ali; Inoubli, Mohamed Hédi; Amri, Faouzi

    2012-09-01

    The present study concentrates on the interpretation of Vertical Electrical Soundings (VES) and well logs to understand the geometry and the functioning of the Ghardimaou multilayered aquifer, a potential target for water supply in the Mejerda basin (Tunisia). The analysis of isobath and isopach maps established in this study, shows a tectonic influence on the reservoirs structure; the Villafranchian folding and the NE-SW, and E-W normal faulting in the recent Quaternary created an aquifer system compartmentalized by raised and tilted blocks. Geoelectrical cross sections reveal that this structure influences the thickness of permeable formations and the groundwater circulation. These results will be useful for rationalizing the future hydrogeological research that will be undertaken in the Mejerda basin.

  7. Susquehanna River Basin Hydrologic Observing System (SRBHOS)

    NASA Astrophysics Data System (ADS)

    Reed, P. M.; Duffy, C. J.; Dressler, K. A.

    2004-12-01

    In response to the NSF-CUAHSI initiative for a national network of Hydrologic Observatories, we propose to initiate the Susquehanna River Basin Hydrologic Observing System (SRBHOS), as the northeast node. The Susquehanna has a drainage area of 71, 410 km2. From the headwaters near Cooperstown, NY, the river is formed within the glaciated Appalachian Plateau physiographic province, crossing the Valley and Ridge, then the Piedmont, before finishing its' 444 mile journey in the Coastal Plain of the Chesapeake Bay. The Susquehanna is the major source of water and nutrients to the Chesapeake. It has a rich history in resource development (logging, mining, coal, agriculture, urban and heavy industry), with an unusual resilience to environmental degradation, which continues today. The shallow Susquehanna is one of the most flood-ravaged rivers in the US with a decadal regularity of major damage from hurricane floods and rain-on-snow events. As a result of this history, it has an enormous infrastructure for climate, surface water and groundwater monitoring already in place, including the nations only regional groundwater monitoring system for drought detection. Thirty-six research institutions have formed the SRBHOS partnership to collaborate on a basin-wide network design for a new scientific observing system. Researchers at the partner universities have conducted major NSF research projects within the basin, setting the stage and showing the need for a new terrestrial hydrologic observing system. The ultimate goal of SRBHOS is to close water, energy and solute budgets from the boundary layer to the water table, extending across plot, hillslope, watershed, and river basin scales. SRBHOS is organized around an existing network of testbeds (legacy watershed sites) run by the partner universities, and research institutions. The design of the observing system, when complete, will address fundamental science questions within major physiographic regions of the basin. A nested system of observations, will intersect the important landforms, climate zones, ecology, and human activities of the basin. Characterizing how humans and climate impact the sustainability of water resources in the Susquehanna River Basin will require an evolutionary approach, involving coordination of historical information and a phased-design for the new observing system. Detecting change (past and present) requires that the atmosphere, vegetation, geochemistry, and hydrology of the Susquehanna, are all observed coherently from the headwaters to the Chesapeake, from the boundary layer to the water table. The River Basin Adaptive Monitoring and Modeling Plan (RAMP) represents the design strategy to coherently select and assess core monitoring sites as well as new sites targeted for both short-term and long term scientific campaigns. Rich in historical research and infrastructure, SRBHOS will serve as a fundamental resource for the hydrologic science community into the future, while providing a "characteristic" hydrologic node in the national network.

  8. KE BASIN SLUDGE CONSOLIDATION PROCESS DESCRIPTION

    SciTech Connect

    SCHLIEBE, M.J.

    2004-02-11

    Spent nuclear fuel in canisters has been stored under water in the K-reactor fuel storage basins (K Basins) for more than 40 years. Over time, corrosion products from the degrading fuel rods, storage rack rust, concrete from pool walls, and environmental particulates have accumulated as sludge in fuel canisters, on the floors, and in the pits of the K Basins. The spent nuclear fuel and sludge release soluble fission products into the basin water. The potential exists for basin water and/or sludge to leak into the environment because of the age and condition of the basins. This potential hazard provides the impetus for removing spent nuclear fuel and sludge from the basins as soon as possible. The Fuel Transfer System (FTS) is moving the K East (KE) fuel canisters to K West (KW) for packing in multi-canister overpacks (MCOs). The KE sludge has two disposition paths; the sludge in the North Loadout pit (NLOP) will be transferred in large diameter sludge containers (LDCs) to the 325 Building for treatment as contact-handled transuranic (CH-TRU) waste and the remainder of the sludge will he consolidated in a liner(s) in KE for future treatment. Sludge containerization was directed by the U. S. Department of Energy, Richland Operations Office (RL) (Klein 2003) and allows decontamination and decommissioning (D&D) activities to progress. This document identifies process requirements, assumptions, functions, and recommends architecture to complete KE sludge consolidation. Included are a process description and potential risks and interfaces to be managed at KE to consolidate the sludge. The following design concept was selected based on the process requirements, functions, and assumptions developed. Three pit locations (both Tech View pit channels and the Weasel pit) were selected to receive a rigid liner to consolidate the sludge. A fourth location (the Weasel pit channel) was identified as contingency volume pending detail design of the liners. Rigid and free-standing pit liners were selected so the liners do not interface with the pits walls and potentially compromise the safety function of the pit walls. The sludge will be retrieved using a combination of portable Tri-Nuclear pump(s) and (once NLOP work is completed) the Sludge and Water System (SWS) equipment. A screen/strainer will be used to remove particles greater than 114 in. from the sludge and this larger material will be moved to the dummy elevator pit for the FTS to transfer to KW for disposition. Sludge consolidation is expected to require the addition of flocculants to aid in its settling and support hash water quality requirements. The flocculants will be added and mixed with the sludge just prior to its discharge into the liners. Discharging to multiple liner locations will be used to reduce velocities and therefore improve settling. Programmatic risks were identified for the sludge consolidation and the following near-term actions are recommended: Confirm that the design concept is consistent with the current Authorization Basis; Confirm flocculant addition conditions and rates; Define end points (or how clean is clean); and Develop an integrated schedule for KE Basin, including resources and floor space needs.

  9. Pleistocene Suvero slide, Paola basin, southern Italy

    USGS Publications Warehouse

    Trincardi, F.; Normark, W.R.

    1989-01-01

    The Suvero slide covers an area of about 225 km2 in the Paola slope basin on the Eastern Tyrrhenian margin. The shape and lateral extent of the deposit reflect topographic confinement of the slide between the continental slope and a morphologic barrier formed by a margin-parallel slope ridge. No headwall or slide plane comparable in scale with the slide deposit were found, suggesting that quasi in situ deformation of semi-consolidated sediments took place when the failed materials reached the floor of the slope basin. The failure occurred downslope from a basement high originating from local uplift. Continued uplift, after the Suvero slide occurred, is documented by the presence of steep upper-slope gradients within the study area and by the presence of small-scale creep and failure events that postdate the Suvero slide. ?? 1989.

  10. Concealed evaporite basin drilled in Arizona

    SciTech Connect

    Rauzi, S.L. [Arizona Geological Survey, Tucson, AZ (United States)

    1996-10-21

    The White Mountains of Arizona are a high forested plateau underlain by volcanic rocks of Late Pliocene and Quaternary age on the south margin of the Colorado plateau province. Elevations range from 6,000--11,590 ft, with winter snow and summer rain but ideal conditions for much of the year. There was no evidence of a Permian evaporite basin concealed beneath the White Mountain volcanic field until 1993, when the Tonto 1 Alpine-Federal, a geothermal test well, was drilled. This test did not encounter thermal waters, but it did encounter a surprisingly thick and unexpected sequence of anhydrite, dolomite, and petroliferous limestone assigned to the Supai (Yeso) formation of Permian age. The Tonto test was continuously cored through the Permian section, providing invaluable information that is now stored at the Arizona Geological Survey in Tucson. The paper describes the area geology and the concealed basin.

  11. Hydrocarbon prospects of southern Indus basin, Pakistan

    SciTech Connect

    Quadri, V.U.N.; Shuaib, S.M.

    1986-06-01

    The Southern Indus basin extends approximately between lat. 23/sup 0/ and 28/sup 0/31'N, and from long. 66/sup 0/E to the eastern boundary of Pakistan. Of the 55 exploratory wells drilled (1955-1984), 27 were based on results of multifold seismic surveys. Five commercial oil discoveries and one gas discovery in Cretaceous sands, three gas discoveries in Paleocene limestone or sandstone, and one gas-condensate discovery from lower Eocene limestone prove that hydrocarbons are present. The main hydrocarbon fairways are Mesozoic tilted fault blocks. Tertiary reefal banks, and drape and compressional anticlines. Older reservoirs are accessible toward the east and northeast, and younger mature source rocks are to the west, including offshore, of the Badin block oil field area. The Indus offshore basin reflects sedimentation associated with Mesozoic rifting of the Pakistan-Indian margin, superimposed by a terrigenous clastic depositional system comprised of deltas, shelves, and deep-sea fans of the Indus River.

  12. Hydrologic data for Soldier Creek Basin, Kansas

    USGS Publications Warehouse

    Carswell, William J., Jr.

    1978-01-01

    Selected hydrologic data collected in the Soldier Creek basin in northeastern Kansas are available on magnetic tape in card-image format. Data on the tape include water discharge in fifteen-minute and daily time intervals; rainfall in fifteen-minute and daily time intervals; concentrations and particle sizes of suspended sediment; particle sizes of bed material; ground-water levels; and chemical quality of water in concentrations of selected constituents. The data-collection system includes: (1) 7 recording streamflow stations; (2) 5 recording rainfall stations; (3) 51 nonrecording rainfall stations located within and adjacent to the basin; (4) 31 ground-water observation wells (two recording); and (5) intermittent chemical quality of water and sediment sampling sites. Examples of the information on magnetic tape for each type of data collected are presented in computer-printout format. (Woodard-USGS)

  13. K Basin spent nuclear fuel characterization

    SciTech Connect

    LAWRENCE, L.A.

    1999-02-10

    The results of the characterization efforts completed for the N Reactor fuel stored in the Hanford K Basins were Collected and summarized in this single referencable document. This summary provides a ''road map'' for what was done and the results obtained for the fuel characterization program initiated in 1994 and scheduled for completion in 1999 with the fuel oxidation rate measurement under moist inert atmospheres.

  14. Cenozoic Evolution of the Nile Basin

    Microsoft Academic Search

    Michael R. Talbot; Martin A. J. Williams

    The Cenozoic evolution of the Nile basin reflects a complex interaction between tectonic, volcanic and climatic events. The\\u000a Ethiopian and Ugandan headwaters of the Nile attain elevations in excess of 2 km, while the watersheds rise to over 5 km.\\u000a The Ethiopian tributaries of the Nile (notably the Blue Nile\\/Abbai and the Atbara\\/Tekezze) provide the bulk of the flood discharge

  15. Decision Support System for Catawba River Basin

    Microsoft Academic Search

    Laura H. Z. Weintraub; Larry Olmsted; Carl W. Chen; Robert Goldstein; Gene Vaughan; Steve Johnson; Ty Ziegler; Bill Foris; Andy Brown; Doug Besler; Dave Braatz

    2001-01-01

    WARMF (Watershed Analysis Risk Management Framework) was developed as a decision support system for the entire 12,330 km2 (~5,000 mile2) Catawba River Basin of North and South Carolina. The watershed is divided into a network of land catchments, stream segments, and stratified lakes. WARMF applies daily meteorology data to land catchments to simulate runoff and nonpoint loads. The nonpoint loads

  16. Multizone completion opportunities in the Appalachian basin

    SciTech Connect

    Koziar, G.

    1989-03-01

    This report identifies areas of favorable Devonian shale gas potential beyond historically productive shale regions of the Appalachian basin in West Virginia. Geologic, reservoir and production data were employed to establish parametric correlations and trends. In particular, formation stress ratio, permeability-thickness product, gas production and modified productivity index terms were used to determine relationships and define Devonian shale gas potential. 9 refs., 47 figs., 4 tabs.

  17. Caribbean basin framework, 2: Northern Central America

    SciTech Connect

    Tyburski, S.A.; Gordon, M.B.; Mann, P. (Univ. of Texas, Austin (United States))

    1991-03-01

    There are four Jurassic to Recent basin-forming periods in northern Central America (honduras, Honduran Borderlands, Belize, Guatemala, northern Nicaragua): (1) Middle Jurassic-Early Cretaceous rifting and subsidence along normal faults in Honduras and Guatemala; rifts are suggested but are not well defined in Honduras by the distribution of clastic sediments and associated volcanic rocks. Rifting is attributed to the separation of Central America from the southern margin of the North American plate; (2) Cretaceous subsidence recorded by the development of a Cretaceous carbonate platform in Honduras, Guatemala, and Belize; subsidence is attributed to thermal subsidence of the rifted margins of the various blocks; (3) Late Cretaceous-Recent development of a volcanic arc along the western margin of Middle America and the northern margin of Honduras; (4) Late Cretaceous large-scale folding in Honduras, ophiolite obduction, and formation of a foredeep basin in Guatemala (Sepur trough); deformation is attributed to the collision between a north-facing arc in northern Honduras and the Nicaraguan Rise and the passive margin of Guatemala and Belize; and (5) Eocene to Recent strike-slip faulting along the present-day North American-Caribbean plate boundary in Guatemala, northern Honduras, and Belize. Strike-slip faults and basins form a California-type borderlands characterized by elongate basins that appear as half-grabens in profile. Counterclockwise rotation of the central honduras plateau, a thicker and topographically higher-than-average block within the plate boundary zone, is accommodated by rifting or strike-slip faults at its edges.

  18. Dynamic river basin water quality model

    SciTech Connect

    Yearsley, J.

    1991-09-01

    RBM10 is a river basin model for simulating the dynamics of an aquatic ecosystem which has freely-flowing river reaches, river-run reservoirs, and vertically stratified reservoirs. An Eulerian viewpoint is adopted for solving the conservation equations for temperature, dissolved oxygen, nutrients, phytoplankton, bacteria and conservative constituents. The report describes the model development and the computer program which implements the mathematical model.

  19. Abyssal basins and the polar seas

    Microsoft Academic Search

    Philippe Blondel

    \\u000a Abyssal plains and basins are traditionally defined as areas of the deep-ocean floor in which the seabed is flat, with a slope\\u000a of less than 1°, and deeper than 4,500 meters. They were not recognized as distinct physiographic features until the late\\u000a 1940s, and there have been very few systematic investigations of limited areas. As a result, they are among

  20. LERF Basin 44 Process Test Plan

    SciTech Connect

    LUECK, K.J.

    1999-08-31

    This document presents a plan to process a portion of the Liquid Effluent Retention Facility (LERF) Basin 44 wastewater through the 200 Area Effluent Treatment Facility (ETF). The objective of this process test is to determine the most effective/efficient method to treat the wastewater currently stored in LERF Basin 44. The process test will determine the operational parameters necessary to comply with facility effluent discharge permit limits (Ecology 1995) and the Environmental Restoration Disposal Facility (ERDF) acceptance criteria (BHI-00139), while achieving ALARA goals and maintaining the integrity of facility equipment. A major focus of the test plan centers on control of contamination due to leaks and/or facility maintenance. As a pre-startup item, all known leaks will be fixed before the start of the test. During the course of the test, a variety of contamination control measures will be evaluated for implementation during the treatment of the remaining Basin 44 inventory. Of special interest will be techniques and tools used to prevent contamination spread during sampling and when opening contaminated facility equipment/piping. At the conclusion of the test, a post ALARA review will be performed to identify lessons learned from the test run which can be applied to the treatment of the remaining Basin 44 inventory. The volume of wastewater to be treated during this test run is 500,000 gallons. This volume limit is necessary to maintain the ETF radiological inventory limits per the approved authorization basis. The duration of the process test is approximately 30 days.