Geological characteristics from the Cretaceous to Eocene metamorphic and igneous basement rocks from the Guajira and the NW corner of the Sierra Nevada de Santa Marta massifs in the northern Colombian Caribbean region, and the stratigraphy of adjacent basins, reveal different stages of growth of a segmented Late Cretaceous to Eocene accretionary orogen ...

extended northward beneath the Okinawa back-arc basin. If we examine the Ryukyu accretionary wedge1 Oblique subduction of the Gagua Ridge beneath the Ryukyu accretionary wedge system Insights from of plate convergence, slip partitioning occurs within the Ryukyu accretionary wedge. A transcurrent fault

against the cohesive wedge (Figure 3a). Some minor back thrusts, related to the growth of the accretionary beneath the rear part of the accretionary wedge (Figure 3e). The old back thrusts, now located above of the experiment and are associated with the growth of the accretionary wedge. Curved back thrusts generated

In contrast to the ancient Proterozoic and Archean terranes of central and western Australia, eastern Australia consists of an outward stepping series of fold belts that largely formed between the Middle Cambrian and Triassic as a result of convergence along the proto-Pacific margin of east Gondwana. In southeast Australia, the Delamerian Orogen abuts the Precambrian cratons ...

Placing ore formation within the overall tectonic framework of an evolving orogenic system provides important constraints for the development of plate tectonic models. Distinct metallogenic associations across the Palaeozoic Lachlan Orogen in SE Australia are interpreted to be the manifestation of interactions between several microplates and three ...

A new geotectonic framework of the Taiwan orogen is presented in accordance with the hypothesis of an oblique arc-arc collision. The colliding Luzon arc is physically connected to the eastern Coastal Range in which a subduction complex remnant is preserved and backthrust with intra-arc sediments in a small retroforeland basin. A southern and extinct extension of the Ryukyu arc ...

Upper Messinian conglomerates in Calabria, southern Italy: Response to orogenic wedge adjustment as a result of the Messinian base-level falls. Along the Ionian coast of Calabria, southern Italy, these rocks part of the Cala- brian accretionary wedge. We propose that the upper Messinian deposits were produced

Four continental margin turbidite � black shale terranes of the Lachlan Orogen in the southern Tasmanides of eastern Australia formed in two major systems along the east Gondwana margin and constrain the Ordovician assembly of this accretionary orogen. Key features are the dissimilar stratigraphies of the adjacent Bendigo and ...

The global record of detrital zircon ages is frequently interpreted as reflecting supercontinent cycles. It was recently proposed that, on a global scale, distribution maxima in the detrital zircon age record and juvenile crust production do not always coincide, and that a link to supercontinent cycles may not exist. This disconnect, if real, should depend on the poor preservation potential of ...

This dissertation research addresses the tectonism of continental crust during ocean basin closure, suturing between continental landmasses, and collisional orogenesis. The new data and insights presented here were gathered through localized geologic investigations of the Tibetan Plateau of central Asia. This area of central Asia is an ideal location to study these fundamental ...

The main geological framework of the Ross Orogen may be subdivided along the c. ... give a deeper insight into critical aspects of the tectonic development of ... and magmatic evolution recorded in the pre-Devonian basement of the Ross ...

Two fundamentally different orogenic systems have existed on Earth throughout the Phanerozoic. Circum-Pacific accretionary orogens are the external orogenic system formed around the Pacific rim, where oceanic lithosphere semicontinuously subducts beneath continental lithosphere. In contrast, the internal ...

. Orogenic andesites and plate tectonics. Springer Verlag, Berlin, Heidelberg, New- York. GILLJ. B., SEALES C of upper plate material losses caused by tectonic erosion. Jolournal of Geo- physical Research 97, 217. & MALAVIEILLEJ. 1994. Coulomb theory applied to accretionary wedges - Possible causes for tectonic erosion and

The Kamchatsky Mts. accretionary complex in the Eastern Kamchatka orogenic belt was studied for identification of the oceanic and suprasubduction components into accretionary wedges. That complex is divided into two tectonic units. The Lower unit is formed sedimentary and tectonic melanges containing arc-related components (Late ...

Ar-Ar data from fabric-forming white mica in slates, syntectonic quartz veins and granitic mylonites constrain the timing of metamorphism, deformation, and exhumation in the Lachlan orogen, Australia. These data also help define the tectonic evolution of the Tasmanides during Paleozoic time. The Lachlan orogen formed by the progressive accretion of a thick ...

The Taiwan orogen has long been the focus of theoretical studies on the relationships between surface processes, tectonics and climate. As a result Taiwan has become famous as an example of the steady evolution of orogenic wedges where erosion triggered by seasonal tropical typhoons balances the accretionary influx. One main assumption ...

The processes that formed, thickened and thinned the early Earth's crust remain poorly known. The onset of modern plate tectonics, for example, could be as far back as the Hadean or as late as the Neoproterozoic. In many cratons, vertical processes are believed to have been dominant (dome-and-keel tectonics, e.g. Pilbara craton), while others are hypothesised to have formed by the progressive ...

The histories of the pre-Mesozoic landmasses in southern M�xico and their connections with Laurentia, Gondwana, and among themselves are crucial for the understanding of the Late Paleozoic assembly of Pangea. The Permian igneous and metamorphic rocks from the Chiapas massif as part of the southern Maya block, M�xico, were dated by U-Pb zircon geochronology employing the SHRIMP (sensitive high ...

The Lycian thrust belt is an important part of the Tethyan orogenic belt in the eastern Mediterranean region. It includes a unit of internally disrupted, thin-skinned thrust sheets (layered tectonic melange) and a melange rich in ophiolitic material (ophiolitic melange). The layered tectonic melange is dominated by Mesozoic distal deep-water sedimentary rocks, and the ...

Until recently, the importance of intense sea floor emissions of hydrocarbon-enriched fluids related to the ongoing movement and development of the olistostrome-accretionary wedge complex located in the Gulf of C�diz (Figure la), remained uncertain. The Gulf of C�diz is located in the transitional zone between the Gloria transform fault zone, which is the African-Eurasian ...

Seismic data, supplemented by field observations, indicate the presence of an accretionary complex in the frontal part of the Gibraltar arc. The complex can be subdivided into an inner complex represented by the classical Flysch units, and an outer complex made up by the Guadalquivir allochthonous units in the Betics and the Preifaine Nappe in the Rif. The inner complex ...

The Central Asian Orogenic Belt (CAOB) is the world's largest Paleozoic to Mesozoic accretionary orogen. It is characterized by the occurrence of large amount of juvenile crust. The Altai Mountains in NW China are a type terrane of CAOB. Our new zircon age data, along with the available age information, have established four Paleozoic ...

It has been recognized for many years that Early Proterozoic orogenic rocks in the western US range from 1.8 to 1.6 Ga, with a general distribution such that 1.8 to 1.7 Ga rocks underlie Colorado, northern Arizona, and northern New Mexico and 1.7 to 1.6 Ga rocks underlie southern Arizona and southern New Mexico. Recent U-Pb geochronologic and Sm-Nd isotopic studies by a ...

The integral 3D model of the deep structure of the Early Precambrian crust in the East European Craton is based on interpretation of the 1-EU, 4B, and TATSEIS seismic CDP profiles in Russia and the adjacent territory of Finland (FIRE project). The geological interpretation of seismic images of the crust is carried out in combination with consideration of geological and geophysical data on the ...

The Altaids is one of the largest accretionary orogenic collages in the world with the highest rate of Phanerozoic continental growth and significant metallogenic importance. It is widely accepted that subduction-related orogenesis of the Altaids started in the late Precambrian and gradually migrated southward (present coordinates). However, it is ...

The evolution of the North American, East European, and Siberian cratons is considered. The Paleoproterozoic juvenile associations concentrate largely within mobile belts of two types: (1) volcanic-sedimentary and volcanic-plutonic belts composed of low-grade metamorphic rocks of greenschist to low-temperature amphibolite facies and (2) granulite-gneiss belts with a predominance of high-grade ...

The Neogene tectonics of the central Mediterranean are related to the subduction and trench rollback of the Ionian basin under Eurasia, causing the opening of the Liguro-Provencal and Tyrrhenian back-arc basins and the formation of the Calabrian accretionary wedge. The Calabrian accretionary wedge is a partially submerged accretionary ...

This study provides an in situ geological perspective on fabrics produced by synconvergence lateral crustal flow of hot orogens. It is based on the example of the Neoarchean orogen of the Dharwar craton (India) and combines structural analysis and ion microprobe U-Pb zircon geochronology. We document a pervasive, three-dimensional flow mode of the lower ...

We investigate the thermo-mechanical properties beneath the young orogenic belt of Taiwan by constructing a shear strength profile from a vertical stratified rheological structure. The stratified rheological structure is estimated based on the recently developed thermal structure and its likely composition. Subduction collision in the young orogenic belts ...

The New England orocline lies within the Eastern Australian segment of the Terra Australis accretionary orogen and developed during the late Paleozoic to early Mesozoic Gondwanide Orogeny (310�230 Ma) that extended along the Pacific margin of the Gondwana supercontinent. The orocline deformed a pre-Permian arc assemblage consisting of a western magmatic ...

The Alps/Apennines system, as well as many collisional orogens through the world, shows a finite deformation produced during a long geological history which involves numerous superimposed tectonic events. As a result, complex and often contrasted reconstructions for the setting and tectonics of the different stages of the growing and interfering Alps/Apennines system have been ...

The Central Asia Orogenic belt (CAOB) is the largest accretionary orogen in the world which forms one third of the continental crust of Asia. This vast region was accreted from Late Proterozoic to Permian during several major tectonic pulses. The CAOB consists of vast regions represented by oceanic crust, domains of typical ...

The Southern Apennines chain is a fold-and-thrust belt resulting from the convergence of the African and European plates and simultaneous roll-back of SE-directed Ionian subduction (Upper Oligocene-Quaternary). Ophiolites in the Southern Apennines are related to northwest subduction of the oceanic lithosphere pertaining to the Ligurian sector of the Jurassic western Tethys. The ophiolitic ...

Orogenic wedges are standard elements of collisional plate tectonics, from accretionary prisms to retro-arc basins. Recent study of orogenic wedge development has focused on links between mechanisms of internal deformation and surface processes. Models of orogenic wedges are commonly presented in the cross-section ...

The northern Apennine orogenic wedge is one of several convergent orogens that exhibit syn-convergent extension. A number of geodynamic models have been proposed to explain this phenomenon, including slab retreat, slab detachment, orogenic collapse, and wedge underplating. However, no single model currently explains well all observed ...

Distinguishing between Cordilleran- vs. Tethyan-type ophiolites is a first-order tectonic problem in studying orogenic belts and their geodynamic evolution. Cordilleran ophiolites (CO) in accretionary-type orogenic belts structurally overlie subduction-accretion complexes and are incorporated into active continental margins via ...

Atokan strata of the Arkoma basin record the transition from sedimentation on a passive rifted margin to sedimentation in a foreland basin that developed as a result of convergent tectonic activity along the Ouachita orogenic belt. Sandstone compositions reveal how provenance and sediment dispersal patterns changed during Atokan sedimentation. The basal Atokan Spiro sandstone ...

In recent years, two end-member models for the formation of supercontinents have emerged. In the classical Wilson cycle, oceanic crust generated during supercontinent breakup (the interior ocean) is consumed during subsequent amalgamation so that the supercontinent turns �inside in� (introversion). Alternatively, following supercontinent breakup, the exterior margins of the dispersing ...

A synthesis of published work and preliminary results from a multidisciplinary study of the various crustal levels exposed in the island of Naxos in the Cyclades allows to propose a model for the evolution of the orogenic accretionary wedge in this region. Naxos is characterized by the juxtaposition of metamorphic rocks and Late Oligocene- Early Miocene to ...

Modern terranes interpretations and the controls on their constituent mineral systems require an understanding of the four-dimensional architecture of the crust. In this study, 3D geological model of the Tanami Orogen (Western Australia) was developed and constrained by geophysical potential field data in order to understand the tectonics and controls over the gold mineral ...

Accretionary orogenic systems (AOS) form at sites of subduction of oceanic lithosphere; these systems dominate during supercontinent break-up and dispersal. Collisional orogenic systems (COS) form where ocean basins close and subduction ultimately ceases; these systems dominate during crustal aggregation and assembly of ...

Sediment deformation, changes in physical properties, and fluid migration can be studied under well-defined conditions in accretionary prisms. Our investigations focused on the accretionary prisms of Barbados (Caribbean) and Nankai (Japan) to interpret the effects of compaction on different lithologies during accretion. The interpretation is based on very ...

High quality, digitally recorded and processed, water gun and air gun seismic reflection data collected seaward of the present position of the Washington-Norfolk canyon systems reveals new information on the development of the continental rise. This includes insight into the depositional history of the Washington-Norfolk fan system and the relative importance of gravity flow ...

We examined in eastern Pennsylvania, New York and Vermont (USA) various types of unmetamorphosed m�langes, which formed at an accretionary wedge-front of the Ordovician Taconic allochthon in the central and northern Appalachian orogenic belt. These m�lange occurrences display structural evidence for progressive deformation of a middle-late Ordovician ...

Mud volcanism is a global phenomenon in mostly convergent margin settings, whose nature has long been subject to scientific investigation. However, only recently its significance has been unravelled by quantitative studies in well-investigated submarine environments, like large accretionary complexes. The fluid flux through active mud volcanoes has been estimated to exceed ...

The Southern Central Andes of NW Argentina and the NW Himalaya are important orographic barriers that intercept moisture-bearing winds associated with monsoonal circulation. Changes in both atmospheric circulation systems on decadal to millennial timescales fundamentally influence differences in the amount and location of rainfall in both orogens. In India, the eastern arm of ...

Useful geodynamic distinction of continental collision zones can be based on the degree of rheological coupling of colliding plates. Coupled active collision zones (which can be either retreating or advancing) are characterized by a thick crustal wedge and compressive stresses (i.e. Himalaya and Western Alps), while decoupled end-members (which are always retreating) are defined by a thin crustal ...

We investigate the deformation of orogenic wedges that form in the early stages of continent-continent collisions using a two-dimensional numerical model limited to the upper lithosphere. Our models show that deformation at the plate margins is influenced by rheology, surface processes, and the balance between inward mass flux and outward subduction flux, as controlled by the ...

Preparation of the new 1:5M geologic map of North America as part of the Decade of North American Geology has entailed recompilation of the geology of the Appalachians. Any new Appalachian map must bear comparison with King's masterful compilation on the 1974 Geologic Map of the U.S. and with Williams' (1978) classic synthesis. The new compilation builds on these sources, but has ...

In the context of critical taper wedge mechanics, we analyze a new GPS-derived surface velocity field from the southern Subandean (SSA) range on the east flank of the central Andean Plateau. The SSA is one of the few active orogenic wedges located far enough from a plate boundary so that the geodetic signature of contractional processes may be isolated. We observe and model a ...

Variscan Central Iberian Zone lamprophyre dikes cut synorogenic to late orogenic peraluminous S-type granitoids marking an important shift in regional tectonic regime from earlier, 350�290 Ma, extension-related crustal melting to later, 265 Ma, transtension-related mantle melting. The mean trend of the camptonite and bostonite dikes strikes ?36� counterclockwise of the ...

Mafic rocks preserved in accretionary mountain belts often provide significant geologic information on the paleo-tectonic setting of the host litho-tectonic block. In the Appalachian orogen, studies of multiple generations and varieties of mafic rocks support models of the accretion of oceanic ophiolites, oceanic arcs, continental margin arcs as well as ...

The thickness of the Barbados accretionary prism varies along strike. The increased thickness of the prism to the south is believed to affect the transport of heat by fluids, resulting in anomalously high heat flow at the deformation front. We utilized a coupled three-dimensional numerical fluid flow and heat transport model to investigate the effect of variable ...

Detrital sedimentary records include vast archives of material that have been removed from developing tectonically active regions. These archives have been used to investigate challenging questions on continental deformation, exhumation and palaeodrainage using a variety of different techniques including heavy minerals, fission-track dating and palaeocurrent reconstructions. The Hengchun Peninsula ...

The accretionary prism of the Nankai Trough, Japan provides an excellent location to study the kinematics of a fold and thrust belt developed primarily in low permeability units. Recently acquired 3D reflection seismic data covering a 12 x 56 km area from the Kumano basin seaward to the deformation front reveals three structural domains within the frontal ...

Isotopic data from the Gurla Mandhata metamorphic core complex provide insight on the character of rocks exposed within it and permit possible correlations of these rocks to those exposed in the Himalayan thrust belt. Whole-rock Sr and Nd isotopic analyses show that rock units in the metamorphic core have isotopic signatures that correlate to those of Greater and Lesser ...

The southern portion of the Cobres Range is studied with an interdisciplinary, petrological geochemical and structural-cartographic approach. The Cobres Plutonic Complex (CPC) consists of two main plutons, a granodiorite and a monzogranite, as well as small bodies of gabbros, acidic dikes, and episyenite bands. Their mineralogy and geochemistry suggest a comagmatic character for both plutons, ...

The specific features of the oceanic lithosphere (the petrography, the mineral composition, and the petrochemistry of igneous rocks and restites) that indicate its formation at different spreading rates, from the extremely slow to fast, are considered. This evidence may be used for solution of the inverse problem of estimating, at least qualitatively, the rate of paleospreading from the structure ...

Arc-trench systems of the circum-Pacific orogenic belt contain voluminous sandstones within fore-arc terranes that include complexly deformed fore-arc basins of several types. Turbidites incorporated within subduction complexes include not only axially transported trench fill, but also abyssal-plain sediments deposited on the sea floor beyond the trench, and slope-basin ...

The contemporary presence of the Puli Topographic Embayment within the Taiwanese thrust belt provides insight into processes that initiate and maintain a subcritical state in a thin-skinned compressive wedge. Orogen-scale analyses of Taiwan have succeeded in describing the processes and interactions that affect overall development of the thrust belt; ...

The Taiwan orogen has long been regarded as a case example for studying exhumation and erosion processes in association with mountain building. In the recent years, the increasing number of thermochronometric data (mainly ZFT and AFT ages) has allowed to better understanding the deep-seated tectonic processes. For instance, using thermomechanical wedge modelling, up to 50% of ...

The Cache Creek terrane (CCT) of the Canadian Cordillera consists of accreted seamounts that originated adjacent to the Tethys Ocean in the Permian. We utilize Potential Translation Path plots to place quantitative constraints on the location of the CCT seamounts through time, including limiting the regions within which accretion events occurred. We assume a starting point for the CCT seamounts in ...

Eclogite lenses in the Agualada Unit (western Ordenes Complex, Spain) contain the peak mineral assemblage garnet (prograde rim: Alm = 48 mol%, Prp = 30 mol%), omphacite (Jd max = 36 mol%), quartz, rutile and rare zoisite, which equilibrated at T = 700 �C and P > 12 14 kbar. Garnet shows discontinuous growth zoning, with a pyrope-poor intermediate zone (Alm = 51 mol%, Prp = 10 mol%) between a ...

It is well-known that the Pacific superplume has been episodically active to form a number of oceanic Lips in the Pacific. During the middle Cretaceous time, it has formed Ontong-Jawa, Caribbean plateau, Mid-Pacific seamount chains and others. Moreover, several accreted fragments of those equivalents have been recently recognized as accreted fragments in accretionary ...

We investigate the structure of the accretionary wedge of the Caledonian orogen, the underlying autochthonous/parautochthonous carbonaceous alum shales and the Precambrian basement. We have conducted 60 broad-band magnetotelluric soundings along a 180 km long profile in J�mtland, Sweden, across the eastern section of the Central Scandinavian Caledonides. ...

The thermotectonic evolution of the East Alpine Rhenodanubian flysch zone (RDFZ) and the collisional history along the orogenic front is reconstructed using apatite fission-track (FT) thermochronology. The apatite FT data provides evidence for a burial depth of at least 6 km for the samples, which were totally reset. Burial was not deeper than 11 km, since the zircon ...

New insights into the tectonic evolution of the buried Precambrian basement in the north-central United States have come from a compilation of drill hole data, which was recently prepared in cooperation with the respective state geological surveys. The data reveal an Early Proterozoic orogen (Central Plains; 1.64-1.75 Ga) more than 1000 km long and 500 km ...

The assembly of Gondwana was the result of a major collision orogen, the East African Orogen, between East and West Gondwana during Neoproterozoic times. Madagascar, which represents a fragment of East Gondwana, is located in a key area of this Pan-African orogen. Granites of unambiguous tectonic setting have been dated using the U-Pb ...

Accretionary wedges and foreland thrust belts exhibit structural associations at their respective deformation fronts that can be grouped in distinct families. At accretionary margins, one style involves major forethrusts with regular spacing and foreland-directed thrust propagation such as at Nankai or Barbados. A contrasting, rather rare style is ...

Paleontological and isotopic age data from the Franciscan complex in the Ortigalita Peak quadrangle, Diablo Range, California, provide new insight into the tectonic evolution of at least part of the Franciscan complex. Graywacke, shale, pillowed greenstone, and chert in the quadrangle were deposited in Late Jurassic (Tithonian) time, about 135 to 150 m.y. ago, on the basis of ...

Characterization of the protoliths of a subduction-accretion complex can provide major insights into the dynamics of the subduction channel. Geochemistry of eclogites found as boulders in a Tertiary conglomerate from the Guajira Peninsula, Colombia, indicate that these rocks are mainly metamorphosed basalts. A negative Nb-anomaly and flat to enriched REE patterns suggest that ...

Accurate orogenic models are nedded to reconstruct complex tectonic histories of long lived convergent margins. Integrated zircon U-Pb geochronology on igneous, sedimentary and metasedimentry rocks within single crustal domains is a powerful tool, as it can be used to trace the timing of rock forming events, magmatic style and episodity, and identify crustal recycling. U-Pb ...

Ongoing paleomagnetic work on Early and Middle Paleozoic units provides quantitative data on paleogeography, latitudinal separation and latitudinal drift rates of tectonic elements that characterize the history of the northern segment of the Appalachian orogen. Following rifting and opening of Iapetus, the southern margin of Laurentia moved from ca 15S in the Ordovician to ca. ...

Sandstones in the Taconic, Acadian and Alleghanian clastic wedges in the Appalachian Orogenic Belt provide evidence for changing provenances during the late Ordovician through pennsylvanian, Neoproterozoic-Early Cambrian, synrift sandstones are predominantly feldspathic arenites, whereas quartz arenites typify sandstones in the Cambrian passive-margin prism. In contrast, ...

A polyphase tectonothermal evolution appears to characterize allochthonous sequences within the Scandinavian Caledonides. Late Cambrian consumption of Iapetus oceanic crust occurred outboard of the Blatoscandian margin with development of an island arc terrane above a west-dipping subduction complex. Imbrication, polydeformation, and variably high-grade metamorphism (including eclogite formation) ...

The ongoing oblique arc-continent collision in Taiwan between the Eurasian continental margin and the Luzon island-arc of the Philippine Sea Plate provides a classic spatial view of the temporal evolution of an orogen from accretion to collision. We have constructed crustal-scale geologic cross sections through the Taiwan orogen at various latitudes, ...

The 1.90-1.89 billion year old Rocknest Formation in the Northwest Territories is a west-facing, passive-margin carbonate terrace in the foreland of Wopmay orogen. Initial outbuilding of an accretionary stromatolite rim over downslope facies was followed by upbuilding of the rim, local backstepping of the rim, and terminal subduction-related drowning of ...

The Paleoproterozoic Svecofennian accretionary orogen is characterized by thick layered crust with large thickness variations of the lower crust. The upper, middle and lower crustal layers are distinguished by their characteristic velocity and reflectivity properties on deep seismic refraction (SVEKA, FEENIA), reflection (FIRE1-3) and tomographic ...

The Rehamna massif is a part of the Morocco Variscan belt where the metamorphic infrastructure has been exhumed in a continental accretionary wedge. The relationships between infra- and supra-structure tectonics originate by thickening of intra-continental Devonian and Carboniferous (Mississipian) basin. Two superposed deformations probably related to plate configuration ...

High Pressure - Low Temperature (HP-LT) rocks testify for burying and exhumation of crustal material in subduction zones. Their complete exhumation is the result of processes acting during (syn-orogenic) and after (post-orogenic) subduction is active, the latter partly obliterating the first. In the Aegean domain, the Attic-Cycladic Blueschist unit (ACBU) ...

Tectonic accretion of island arc terranes is the process widely developed in Pacific Rim in the present and in the past. The mode and nature of crustal growth of continental margins during arc accretion are various and essentially determined by deformation of the margin. The Cenozoic Kamchatka orogen formed by the accretion of two island arc terranes: Achaivayam-Valaginskaya ...

The metamorphic core complexes are commonly associated with regions of orogenic collapse and refer to crustal thinning induced by the gravitational instability of a thickened crust. Similar domal structure can be also found in the convergent accretionary wedge system resulting in formation of the purely convergent metamorphic core complex: the Vepor Unit ...

The Grenville orogenic cycle, between ~1190 and 980 Ma, involved accretion of magmatic arcs and/or continental terranes to the Laurentian craton. A transect across the western Central Gneiss Belt, Georgian Bay, Ontario, which crosses the boundary between parautochthonous and allochthonous units at an inferred orogenic depth of 20-30 km, offers some ...

Piston-cylinder experiments in the granite system demonstrate that a variety of isotopically distinct melts can arise from progressive melting of a single source. The relation between the isotopic composition of Sr and the stoichiometry of the observed melting reactions suggests that isotopic signatures of anatectic magmas can be used to infer melting reactions in natural systems. Our results also ...

The Damara orogen developed during the pan-African orogeny that led to the assembly of Gondwana at the end of Neoproterozoic. Interpreted as a collision belt, it is divided into a N-S trending coastal arm (the Kaoko belt) and a NE-SW striking inland branch with a width of ca. 400 km, which can be traced for more than 1500 km from Namibia into Botswana and Zambia (Miller, ...

This paper discusses the nature and origin of subsurface sediment mobilization processes in deep marine clay-rich environments. In the studied area of the southern Barbados accretionary prism, new geophysical acquisitions have emphasized the spectacular widespread development of mud volcanoes that are well-developed along ramp anticlines and along sigmoidal rises with trends ...

On a global scale, most passive margins are located within crustal segments which were stressed by compressive tectonics and crustal thickening in their previous geological past. These margin types can be referred as "orogen - passive continental margin systems". There older orogenic structural anisotropies were reactivated during the later passive margin ...

The dynamic coupling between tectonics and surface processes is particularly evident in compressional mountain belts. Numerical models clearly demonstrate the fundamental control exerted by surface processes on orogen evolution, with recent studies emphasising the importance of sedimentation and mass redistribution in determining the style and timescale of landscape response ...

The Pyrenees and the Cantabrian Mountains are two E-W trending mountain chains located in the northern border of the Iberian Peninsula that grew during the Alpine orogenesis in Late Cretaceous-Tertiary times. The Pyrenees run along the isthmus separating the Iberian Peninsula from the rest of continental Europe, and were initiated by the inversion of a wide and elongated Mesozoic basin located ...

Scaled sandbox models based on field and seismic data were used to simulate Miocene evolution of the Carpathian orogenic front. The experiments investigated the influence of synorogenic deposition on the geometry and kinematics of growing tectonic structures. The deposition introduced at the foreland of an active fold-thrust wedge resting on top of a weak ductile detachment ...

New insights into episodic deformation at the Nankai trough subduction zone are provided by data from two Ocean Drilling Program borehole hydrologic observatories drilled into the Philippine Sea plate (Site 1173) and the seaward part of the Nankai accretionary prism off southwestern Japan (Site 808), and from an array of high-sensitivity borehole ...

Along the eastern border of the Caribbean plate the Lesser Antilles islands form an active volcanic arc above the Atlantic subducting lithosphere. The crustal structure of this convergent margin is presented here from first arrival tomographic inversion of a 3D wide-angle seismic dataset acquired offshore Dominica and Martinique islands by a network of 27 Ocean Bottom Seismometers (OBS). The ...

There are very close relationships between chains building and contemporaneous basins formation in terms of spatial and structural interdependence, mutual compensation of sediments, tectonic interaction and simultaneous evolution. In fact, extensional tectonics has been worldwide documented as a process that contributes to the evolution of orogenic belts. The dynamics of wedge ...

We investigate changes in the elastic properties of deforming core materials recovered from the Nankai Trough Accretionary Prism along the IODP NanTroSEIZE transect. We shear clastic marine sediments while simultaneously making ultrasonic velocity measurements across the deforming layers. Examining the resulting changes in elastic moduli at the laboratory scale allows us to ...

Faults reactivation (positive, oblique or negative inversions) often drives mountain building processes, from basin formation to accretionary wedge emplacement and its syn- and post-orogenic modifications. Several analytical studies on faults reactivation highlighted the importance of pre-existing fault orientation in the stress field, even though ...

UHPM is the petrologic record (min. P-T equivalent to Coe stability) of transport of continental lithosphere to asthenospheric depth, and return to crustal depth and incorporation into continents. The record of UHPM is scale- independent, but the issue of unit size (boudin/slice/terrane) and whether UHPM is recorded are important. Although the requirement for external hydration may limit ...

The Elbow-Cranberry-Iskwasum lakes area comprises a large portion of the eastern Amisk collage in the Palaeoproterozoic Flin Flon Belt (southern Trans-Hudson Orogen) of Manitoba, Canada. Deformation episodes recorded in the Flin Flon Belt are divided into pre-, early, late and post-Hudsonian orogeny, and are distinguished by the orientation of structures and changes in ...

The surfaces of atmosphereless bodies are subjected to a variety of chemical, thermal, accretionary,

... Title : Processes and Signatures of Sediment Supply, Redistribution, and Accumulation on an Accretionary Continental Margin. ...

... accreted oceanic rocks and pre- and post-accretionary plutonic rocks that are overlain in places by younger depositional ... ...

The orogenic belt of the central Mediterranean, which extends from northern Africa to the southern Apennines across Sicily and the Calabrian Arc (Apenninic-Maghrebian Orogen), is a orocline located between a new oceanic area, the Tyrrhenian Basin and a foreland structural domain. The latter is represented by an oceanic area, the Ionian Basin, bounded by ...

Analysis of stable isotopes and fluid inclusions in centimeter-scale fibrous quartz-calcite strain fringes from the Taconic thrust belt in Vermont and New York allows reconstruction of fluid conditions and sources over the course of strain-fringe growth. Oxygen isotope ratios in quartz show regular variations in ?18O, ranging between 19.2� and 20.0� in different parts of strain fringes. Fluid ...

High mountains with a steep topographic gradient subsists in the Longmen Shan (Sichuan, China) at the eastern boundary of the Tibetan plateau. However, there is almost no significant present day horizontal shortening (< 3mm/yr) across this range as shown by GPS measurements (Chen et al., 2000 ; Gan et al., 2007 ; Shen et al., 2009). Two main crustal models for the uplift and the evolution of ...

Taiwan represent the subaerial part of an active, bivergent thrust belt resulting from the oblique collision between the Luzon island arc of the Philippine Sea Plate and the passive margin of the Eurasian Plate since about 4 to 6.5 Ma. This collision followed the initially intraoceanic subduction of the South China Sea lithosphere below the Philippine Sea Plate, which commenced c. 15 Ma ago and ...

Mantle rocks exposed at Earth's surface provide insight to the physical processes which brought them there. While ophiolites may be representative of oceanic upper mantle, orogenic peridotites are thought to originate from continental lithosphere. Because lithosphere is not homogeneous, variations in composition may have important implications if detected ...

How does decoupling occur at depth in the intermediate to lower continental crust? Insight is obtained from the TRANSALP, NFP, and ECORP-CROP geological-geophysical transects of the Periadriatic Fault System (PFS), an exhumed, late-orogenic fault bounding the retro-wedge of the Alpine orogen. The PFS accommodated 100+ km of ...

We present a comparative analysis of on-land examples of ancient m�langes and diverse modern tectonic environments where m�lange-forming processes are currently operating, and discuss: (1) possible relationships between the m�lange types and their tectonic setting of formation; (2) contribution of mass-transport versus contractional deformation processes at the onset of m�lange formation, ...

The Lepontine Dome is investigated regarding faulting and paleostress, which allows to constrain the late brittle deformation of this gneissic core. Its tectonic evolution under brittle conditions was determined using fault mapping and paleostress inversions. Three brittle phases were reconstructed. The older phase is a NW-SE extension restricted to the eastern parts of the Dome. The second phase ...

The Taiwan Mountain Belt is one of the youngest mountain belts on Earth surface. It results from the NW-directed oblique convergence between the Eurasian plate and the Philippine Sea plate. The accretion of the Luzon arc propagates southward and results in the continental growth of Asian continent. Foliation and lineation traces in the Central Range of Taiwan outline the shape of the foreland ...

Active eclogitization has recently been inferred at depth beneath the Himalaya from geophysical observations, and the mechanical consequences of eclogitization can be observed in the field in the eroded and extended nappe stack of the Scandinavian Caledonides. There, Proterozoic metastable granulites and igneous protoliths underwent partial eclogitization during the collision of Baltica with ...

Interaction between surface processes and deep tectonic processes plays a key role in the structural evolution, kinematics and exhumation of rocks in orogenic wedges. The deformation patterns observed in analogue models applied to natural cases of present active or ancient mountain belts reflect several first order processes that result of these interactions. Internal strain ...

The Big Creek Gneiss, southern Sierra Madre, southeastern Wyoming, is a heterogeneous suite of upper-amphibolite-facies metamorphic rocks intruded by post-metamorphic pegmatitic granite. The metamorphic rocks consist of three individual protolith suites: (1) pre- to syn-1780-Ma supracrustal rocks including clastic metasedimentary rocks, calc-silicate paragneiss, and metavolcanic rocks; (2) a ...

ICLO (intra-collisional landlocked ocean) subduction (proposed by Edwards and Grasemann 2009) provides a mantle dynamics mechanism by which to explain key differences in the nature of continental extension at convergent margin settings. We present a new model that identifies why salient differences are present in the three greater Africa-Eurasia collision components of (1) The Hellenic - Western ...

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 ...

The Central Asian orogenic belt (CAOB) is a major accretionary belt, and is a natural laboratory to study Phanerozoic continental growth. The southern Tianshan orogen is the southern boundary of the CAOB. It resulted from the closure of the south Tianshan ocean following collision of the Tarim and Kazakhstan-Yili blocks. We have ...

The North Tien Shan microcontinent is the most prominent tectonic unit forming the basement of the northeastern Kyrgyz Tien Shan orogen. The microcontinent can be traced further north through Kazakhstan, to the Stepnyak terrane, and in fact seems to form a continuous continental fragment, the Stepnyak-North Tien Shan microcontinent (SNT). The SNT is underlain by Precambrian ...

In this contribution, we present new Petrological and U-Pb SHRIMP dating data for metasedimentary rocks from the North Qilian (NQL) orogenic belt, in which typical early-Paleozoic ophiolitic sequences and HP/LT metamorphic rocks have been previously recognized. The studied metasedimentary rocks contain eclogitic facies assemblages reflecting PT conditions of 450-520 �C and ...

Novaya Zemlya is a banana-shaped set of islands stretching northward from the Polar Urals and separating the Barents and Kara Seas. The southernmost part of the islands is an integral component of the Timanides, a Neoproterozoic orogenic belt, which broadly follows the Urals along the eastern and northeastern margin of Baltica. The Timanian event at ca. 600-550 Ma created a ...

In recent collisional processes the occurrences of basic magmatism are considered to be postcollisional. But in the ancient orogens the pre-, syn- and post-collisional magmatism is observed. The recently obtained geochronological data on magmatic and metamorphic associations of the western part of Central Asian Folded Belt allowed to distinguish a distinct Cambrian-Ordovician ...

Ellesmere Island, in Canada's Arctic, comprises a series of ~SW-NE trending tectonic provinces, the crustal structure and geological expression of which represent a combination of interplate, accretionary orogenesis in the Palaeozoic (Caledonian equivalent and Ellesmerian orogenies) and intraplate orogenesis in the Tertiary (Eurekan Orogeny). The present-day topography of ...

The Neoproterozoic-Eoplalaeozoic Brasiliano orogeny at the eastern margin of the Rio de la Plata craton in southernmost Brazil and Uruguay comprises a complex tectonic history over 300 million years. The southern Brazilian Shield consists of a number of tectono-stratigraphic units and terranes. The S�o Gabriel block in the west is characterized by c.760�690 Ma supracrustal rocks and ...

The Gorny Altai region in southern Siberia is one of the key areas in reconstructing the tectonic evolution of the western segment of the Central Asian Orogenic Belt (CAOB). This region features various orogenic elements of Late Neoproterozoic Early Paleozoic age, such as an accretionary complex (AC), high-P/T metamorphic (HP) rocks, ...

The Central Asian Orogenic Belt (CAOB) extends 800 km separating the Siberia craton in the north from the Tarim and North China Cratons in the south, and spans 3000 km from the Urals in the west to the Pacific in the east, making the largest Phanerozoic orogenic belt in the world. It was formed by subduction and accretion of island arcs, ophiolites, ...

Tectonic reconstructions performed in recent years are increasingly based on petrographic (Dickinson & Suczek, 1979; Garzanti et al., 2007) and geochronological (Brandon et al., 1998; DeCelles et al., 2004) analyses of detrital systems. Detrital age patterns are traditionally interpreted as a result of cooling induced by exhumation (J�ger, 1967; Dodson, 1973). Such an approach can lead to ...

The Zagros-Makran syntaxis marks the limit between the present day collision and subduction of the Arabian plate. Several torsions are observed at different scales that suggest vertical axis rotations. 1) The continental prism of Zagros and accretionary prism of Makran show both an arcuate shape; 2) The syntaxis makes a reentrant, which mimics the Oman peninsula. This led some ...

Understanding what controls the detachment and migration of oceanic crustal slices along the subduction channel is crucial to constrain subduction mechanics. For this reason, we compiled key information pertaining to the burial and exhumation of oceanic blueschists and eclogites worldwide (shape of exhumation P-T-t paths, exhumation velocities, timing of exhumation with respect to the convergence ...

The continental heat flow map can be used to reconstruct regional thermal structure of lithosphere and understands tectonic evolution with evaluations of fission track results, especially for an active collision orogen. From the tectonic framework view of the Taiwan, the ongoing oblique arc-continental collision has been propagating southward and causes different exhumation ...

The conventional view of the climatic influence on weathering is that weathering rates are strongly temperature-dependent due to the near exponential relationship (Clausius-Clapeyron) between temperature and the saturation vapor pressure of water, and hence precipitation and runoff. This is a central theme in the Earth thermostat model, i.e., weathering of aluminosilicate rocks on continents acts ...

The Great Falls tectonic zone (GFTZ) separates the Archean Wyoming province from the Hearne/Medicine Hat craton. Its northeastern limit is a high angle intersection with the Trans-Hudson orogen and marks the site of the Williston basin. Its southwestern extent probably reaches the Neoproterozoic margin of Laurentia. Though long recognized as a fundamental boundary in the ...

Many parallels exist between the Caucasus region, shaped as the Eurasian and Arabian-African plates converged during the Cenozoic Alpine orogeny, and California, where the North American and Pacific plates interact. The Forecaucasian platform hosts many large oil and gas fields in molasse-filled foredeeps of high heat flow. Production is from Permian to Pliocene tight anticlines on reverse faults, ...

The Cook Inlet, lying between the Aleutian Trench and the Alaska-Aleutian batholith, has often been cited as a typical forearc basin. Upper (northeast) Cook Inlet Tertiary sediments have produced oil for over 25 years. Lower (southwest) Cook Inlet exploration, however, has been unsuccessful; previous studies have noted extensive zeolitization of potential Jurassic reservoirs. Geohistory analysis ...

The Upper Carboniferous Qingshuijian Formation in the Western Hill, NE China, was deposited disconformably on a Lower Paleozoic platformal carbonate sequence. The provenance and the tectonic setting of the source area of the Qingshuijian Formation were studied using sandstone petrography and mudstone geochemistry. Sandstones consist mainly of quartz and (meta) sedimentary lithic fragments and are ...

Pre-Mesozoic rocks beneath the Gulf Coastal Plain reflect the late Precambrian (Pc)-Cambrian (Cb) rifted continental margin and the late Paleozoic Appalachian-Ouachita orogen (AOO). The AL promontory of Pc continental crust is bounded by a NW-striking transform margin (AL-OK transform) and a NE-striking rifted margin (southern Blue Ridge rift). Terrane accretion during the AOO ...

COCORP recently collected 1100 km of new deep reflection data along two transects crossing the portion of the Appalachian orogen buried beneath the Georgia/Florida coastal plain, the superjacent Triassic/Early Jurassic South Georgia basin, and the southernmost Piedmont. On all profiles the base of the crust is marked by discontinuous patches of reflections at 11 to 12 s, which ...

The Proterozoic orogen in Arizona consists of structural blocks separated by NE trending shear zones. The Gneiss Canyon Shear Zone (GCSZ) is important because it appears to define in part the boundary between the amphibolite facies Yavapai Province and the granulite facies Mojave Province. An early NW striking foliation is clearly visible in many samples from the Lower Granite ...

The paradox of how horizontal contraction and extension can occur simultaneously in convergent mountain belts remains a fundamental and largely unresolved problem in continental dynamics. The Apennines represent one of the most accessible "type locality" areas of syn-convergent extension. Rollback - which describes the tendency of a subducting plate to retreat from the ...

A detailed survey was conducted of the Nd-isotope compositions of Precambrian metamorphic rocks both within and adjacent to the Cheyenne belt, a metamorphosed crustal segment in southeastern Wyoming that defines the Proterozoic suture zone between the Archean Wyoming craton and accreted Proterozoic island arc(s). The results of the study indicate that Proterozoic miogeoclinal sedimentary rocks ...

Exhumation mechanisms for metamorphic rocks include (a) erosion, (b) extension, (c) extrusion by channel flow, simple or pure shear, and - recently suggested - (d) slab extraction. Distinguishing in a particular case of a metamorphic complex between the different exhumation mechanisms is a much discussed subject in modern geodynamics. In order to add to this discussion, we adopt an ...

The Turfan Basin extends approximately 550 km east-west by 100 km north-south within northwest China and is located between branches of the intracontinental Tien Shan orogenic belt. At present it is an intermontane foreland basin loaded by southward transported thrust sheets at its northern margin. This deformation is a long-distance manifestation of the India-Asia collision, ...

Taiwan is situated along the collision boundary between the Eurasian plate and Philippine Sea plate and the ongoing subduction with different polarity occurs in northeastern and southwestern offshore area near Taiwan. The northward extension of Manila trench loses its subduction signature and connects to the deformation front of an accretionary wedge offshore southwestern ...

The Western-Eastern Blue Ridge boundary involved formation by premetamorphic thrusting of an oceanic fragment/accretionary wedge/island arc upon Laurentian basement and metasedimentary cover. Detailed outcrop-scale mapping, structural and petrographic analysis reveal both terranes experienced the same deformation at the same metamorphic grade. Early F1 and F2 isoclinal folds ...

During dextral oblique translation along Laurentia in western Idaho, the Blue Mountains superterrane underwent clockwise rotation and impinged into the Syringa embayment at the northern end of the Salmon River suture. Along the suture, the superterrane is juxtaposed directly against western Laurentia, making this central Cordilleran accretionary-margin segment unusually ...

During dextral oblique translation along Laurentia in western Idaho, the Blue Mountains superterrane underwent clockwise rotation and impinged into the Syringa embayment at the northern end of the Salmon River suture. Along the suture, the superterrane is juxtaposed directly against western Laurentia, making this central Cordilleran accretionary-margin segment unusually ...

Each Circum-Pacific Tectonic Map sheet gives a tectonic synopsis of one-eighth of the earth's surface and contains enough detail to illustrate specifics of individual regions. The maps show the active plate margins and the contrasting oceanic and continental crustal domains. Crustal domains are further subdivided into cover rocks and basement complexes. In the oceanic crustal domain, ...

development. Surface processes at the orogen are assumed to be glacially dominated, and tectonic activity regimes. Table 1 summarizes the dependencies between erosional yield, orogen width, tectonic activity of observations concerning glacial erosion and wedge tectonics. Firstly, both tectonic activity and the rate

The Himalayan orogen is commonly divided into orogen-parallel, faultbound structural units that extend along the entire length of the orogen. However, significant along-strike variations of the Himalayan architecture occure, and topography, local relief and the distribution of precipitation vary from west to east. We apply apatite ...

Analysis of new and existing field, structural, petrologic, and geochronologic data in the northern Inner Piedmont (IP), southern Appalachians, provide insight into the processes and kinematics of Neoacadian (Late Devonian Mississippian) crustal flow. The IP is characterized by 360 345 Ma middle to upper amphibolite facies metamorphism, gentle dip of the dominant S2 foliation, ...

The thrust-related Imbricate Zone and the sinistral strike-slip Storstr�mmen Shear Zone (SSZ) are two major orogen-parallel ductile shear zones that mark the western limit of intense Caledonian deformation in northeast Greenland and transect the orogenic hinterland, respectively. Detailed microstructural analysis of associated mylonitic fault rocks from ...

Steady-state orogens must balance lateral as well as vertical rock motions by erosion, but how this balance is effected and what its topographic signature might be are open questions. Here we explore the conditions necessary to achieve a topographic steady state above fault-bend folds, a major class of topography-forming orogenic structures in which ...

Recent petrological, structural and geochronological studies of the eastern margin of the Bohemian Massif (Czech Republic) suggest a new conceptual geodynamical model to explain exhumation of high grade (20 kbar, 800�C) rocks. This conceptual model involves indentation of a weak orogenic lower crust by adjacent rigid mantle lithosphere, resulting in crustal scale buckling of ...

Seamount sudbuction is a common feature at convergent plate margins and several examples can also be seen at the Nankai wedge, but its impact on methane hydrate accumulation has not fully described. In order to understand the accumulation mechanism of methane hydrate, the key issue would be the fluid flow within the sediments. The fluid flow can be classified into two types; the diffusive flow by ...

Concepts have been developed that explain the changeover from tectonically to erosionally controlled exhumation processes in the tectonic evolution of the Himalayan orogen. However, the degree to which climate-driven erosion controls the late Cenozoic development of the southern Himalayan front is still a matter of debate. The Himalaya forms an orographic barrier with strong ...

This paper presents magnetic fabric analysis to examine the internal structure of the accretionary prism toe in the Nankai Trough, off the east coast of Japan. Two sites (C0006 and C0007) drilled during Integrated Ocean Drilling Program (IODP) Expedition 316 penetrated the sediment section, including intra wedge thrusts and the frontal thrust. Anisotropy of magnetic ...

In September, 2007, we deployed an array of ocean bottom seismometers from the NSF OBSIP across the central Oregon continental margin from the continental shelf to the abyssal plain. The Central Oregon Locked Zone Array (COLZA) was designed to span the subduction zone from the deformation front to deeper zone of ductile slip across a segment where moderate-size, low-angle thrust earthquakes have ...

Studies at oceanic convergent margins show unambiguously that large volumes of continental material are recycled into the mantle by sediment subduction and forearc subduction erosion. The fate of this subducted continental material is poorly known; mass balance consideration suggest that at least 95 percent of this material is recycled to deep mantle circulation. The Late Cretaceous La ...

S-type Devonian acidic intrusives in northern Vermont occur scattered throughout the turbiditic flysch sequence and pervasive horizon of mafic Standing Pond Volcanics of the Connecticut Valley--Gaspe Trough (CVGT). These granitoids formed in a successor basin that opened over the stalled Taconic subduction zone located between the Bronson Hill--Boundary Mountain Volcanic arc (east) and the ...

Subduction zones account for 90% of global seismic moment release, generating damaging earthquakes and tsunamis, with potentially disastrous effects on heavily populated coastal areas. Understanding the processes that govern the strength of earthquakes, and nature and distribution of slip along these plate boundary fault systems, are crucial steps toward evaluating and mitigating geohazards, ...

The new findings of PF in quartzs in sandstone from the rim of the structure, along with accretionary lapilli from soil inside the structure, and the presence of coesite in these lapilli, suggest that Ramgarh is an impact crater.

Accretionary lapilli from the Pompeii and Avellino Plinian ash deposits of Vesuvius consist of centimeter-sized spheroids composed of glass, crystal, and lithic fragments of submillimeter size. The typical structure of the lapilli consists of a central ma...

Sediments containing components produced by accretionary events should contain sufficient geochemical evidence to constrain several of the variables involved in modeling the environmental consequences of such events. We consider the geochemical record exp...

youngest unit of the Chugach accretionary complex in southeastern Alaska. Using laser-ablation inductively coupled plasma mass spectroscopy, we obtained 492 detrital-zircon ages on...

The paper reports measurements of solar-flare tracks, microcraters, and glass accretionary particles

... WHS- Washington Headquarters Service ... processes, magma genesis, and tectonic and erosional ... evolution of accretionary plate boundary structure ...

Although geochemical and mineralogical evidence indicate that a major accretionary event occurred at