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1

Naturally occurring arsenic in the Miocene Hawthorn Group, southwestern Florida: Potential implication  

E-print Network

Naturally occurring arsenic in the Miocene Hawthorn Group, southwestern Florida: Potential, and distribution of arsenic (As) in the Hawthorn Group, the chemical and mineralogical composition of 362 samples, the Hawthorn Group consisted primarily of a basal carbonate unit (the Arcadia For- mation) and an upper

Pichler, Thomas

2

Naturally occurring arsenic in the Miocene Hawthorn Group, southwestern Florida: Potential implication for phosphate mining  

Microsoft Academic Search

To understand the mineralogical association, concentration, and distribution of arsenic (As) in the Hawthorn Group, the chemical and mineralogical composition of 362 samples that were collected from 16 cores in southwestern Florida were examined in detail. In the study area, the Hawthorn Group consisted primarily of a basal carbonate unit (the Arcadia Formation) and an upper siliciclastic unit (The Peace

Olesya Lazareva; Thomas Pichler

2007-01-01

3

Natural Arsenic in the Miocene Hawthorn Group, Florida: Wide Ranging Implications for ASR, Phosphate Mining, Private Well  

Microsoft Academic Search

In order to understand the mineralogical association and distribution of arsenic (As) in the Hawthorn Group we examined in detail the chemical and mineralogical composition of 370 samples that were collected from 16 cores in central Florida. In our study area the Hawthorn group consists primarily of a basal carbonate unit (the Arcadia Formation) and an upper siliciclastic unit (The

O. V. Lazareva; T. Pichler

2004-01-01

4

Hawthorn  

MedlinePLUS

... Hawthorn is a spiny, flowering shrub or small tree of the rose family. The species of hawthorn discussed here are native to northern European regions and grow throughout the world. Historically, hawthorn fruit has been used for heart ...

5

Hawthorn  

Microsoft Academic Search

Hawthorn appears to be effective for the treatment of stage II congestive heart failure. The mechanism(s) by which hawthorn\\u000a exerts this positive effect is still unclear as results regarding changes in particular cardiovascular parameters are mixed.\\u000a Human clinical studies of the use of hawthorn in other cardiovascular conditions are lacking. Adverse effects of hawthorn\\u000a therapy appear to be mild and

Timothy S. Tracy

6

Hawthorn.  

PubMed

A review with 54 references covers all aspects of hawthorn, the genus Crataegus, including its traditional uses, chemical constituents, pharmacological activities, and clinical effects. Although the effectiveness of hawthorn on the treatment of cardiovascular diseases has received extensive attention worldwide, further scientific research on various areas such as pharmacokinetics, mechanism of actions will be necessary to ensure its safe and effective usage. PMID:12043949

Chang, Qi; Zuo, Zhong; Harrison, Francisco; Chow, Moses Sing Sum

2002-06-01

7

Hawthorn.  

PubMed

Crataegus monogyna Jacq (Lindm), C. laevigata (Poir) DC, or related Crataegus species, collectively known as hawthorn, have been used in the treatment of cardiovascular diseases. Clinical studies have found that standardized extracts show promise as adjunctive agents for the treatment of left ventricular dysfunction. Other trials consistently demonstrate its ability to improve exercise tolerance and symptoms of mild to moderate heart failure. Preliminary evidence indicates that it improves left ventricular performance, as measured by ejection fraction. In order to properly use hawthorn in the treatment of heart failure, a large, controlled, multicenter trial in which mortality serves as the primary endpoint is needed. PMID:12597258

Fong, Harry H S; Bauman, Jerry L

2002-07-01

8

Detailed geochemical and mineralogical analyses of naturally occurring arsenic in the Hawthorn Group  

Microsoft Academic Search

In order to understand the mineralogical association and distribution of arsenic (As) in the Hawthorn Group in central Florida, I examined in detail the chemical and mineralogical composition of 361 samples that were collected from 16 cores. Geochemical analyses were performed by hydride generation - atomic fluorescence spectrometry (HG-AFS) and inductively coupled plasma optical emission spectrometry (ICP-OES). The identification of

Olesya Lazareva

2004-01-01

9

M. FREDERICK HAWTHORNE Bibliography  

E-print Network

M. FREDERICK HAWTHORNE Bibliography #12;1 BIBLIOGRAPHY M. FREDERICK HAWTHORNE 1. Corwin Hansch and Fred Hawthorne, "Catalytic Synthesis of Thianapthene from Ethylbenzene," J. Am. Chem. Soc., 70, 2495 (1948). 2. Fred Hawthorne and Donald J. Cram, "Studies in Stereochemistry. XV. Effect of Configuration

Hawthorne, M. Frederick

10

The Phyllomedusa perinesos group (Anura: Hylidae) is derived from a Miocene Amazonian Lineage.  

PubMed

The Phyllomedusa perinesos group is composed of four species that inhabit cloud forests in the eastern Andean slopes. We estimated the phylogenetic relationships among them and their closest relatives using mitochondrial DNA sequences. Our results confirm the monophyly of the group and a close relationship with the Amazonian species Phyllomedusa atelopoides and Phyllomedusa tomopterna. A chronogram indicates that the group originated during the Miocene and the contemporary species diverged from their closest relatives during the Miocene and early Pliocene. The timing of the group's origin suggests that its evolution was linked to the rise of the eastern Andes. Based on the phylogeny we expand the species content of the group to include P. atelopoides and P. tomopterna. PMID:25112990

Ron, Santiago R; Almendariz, Ana; Cannatella, David C

2013-01-01

11

Hawthorne Control Procedures in Educational Experiments: A Reconsideration of Their Use and Effectiveness.  

ERIC Educational Resources Information Center

A descriptive analysis of research practices and a meta-analysis of control group effect sizes are used to address Hawthorne effects in educational experiments. The analysis of 86 studies and 256 treatment/Hawthorne/no-treatment control group effect size comparisons indicate that artifact controls have limited utility in dealing with the Hawthorne

Adair, John G.; And Others

1989-01-01

12

Hawthorne Control Procedures in Educational Experiments: A Reconsideration of Their Use and Effectiveness.  

ERIC Educational Resources Information Center

A meta-analysis was conducted on 44 educational studies that used either a (labelled) Hawthorne control group, a manipulation of Hawthorne effects, or a group designed to control for the Hawthorne effect. The sample included published journal articles, ERIC documents or unpublished papers, and dissertations. The studies were coded on 20 variables,…

Adair, John G.; And Others

13

Depositional environments and paleogeography of the Upper Miocene Wassuk Group, west-central Nevada  

USGS Publications Warehouse

Fluvial and lacustrine deposits of the Miocene Wassuk Group, exposed in Coal Valley, west-central Nevada, are divided into five lithofacies: (1) diatomite, claystone, siltstone, and carbonaceous siltstone deposited in a lake with paludal conditions at the margin; (2) upward-coarsening sequences of sandstone deposited on a delta and fan-delta; (3) channel-form sandstone deposited on a distal braided alluvial plain; (4) clast-supported conglomerate deposited on a proxial braided alluvial plain or distal alluvial fan; and (5) matrix-supported conglomerate deposited on a distal to middle alluvial fan. Petrographic analysis records an upsection change from a predominantly andesitic to a predominantly plutonic provenance. This change, combined with the overall upward-coarsening of the Wassuk Group and the great thickness (2400 m) of the sequence, suggests active uplift and rapid subsidence during deposition of the group. Facies relationships and paleocurrent directions indicate source areas to the south, southeast and west of Coal Valley. The Miocene Wassuk Group was deposited in an intra-arc basin with penecontemporaneous volcanism and tectonic activity. Syndepositional faulting at the southern margin of Coal Valley between 13 and 11 m.y. ago suggests an early episode of northeast-southwest extension prior to the onset of east-west basin and range extension. ?? 1984.

Golia, R.T.; Stewart, J.H.

1984-01-01

14

Health effects of hawthorn.  

PubMed

Hawthorn medicinal extract has long been a favored herbal remedy in Europe. The active components of this slow-acting cardiotonic agent are thought to be flavonoids and oligomeric procyanidins. The most studied hawthorn extracts are WS 1442 and LI 132. Reviews of placebo- controlled trials have reported both subjective and objective improvement in patients with mild forms of heart failure (New York Heart Association classes I through III). Other studies of hawthorn in patients with heart failure have revealed improvement in clinical symptoms, pressure-heart rate product, left ventricular ejection fraction, and patients' subjective sense of well-being. However, there is no evidence of a notable reduction in mortality or sudden death. Hawthorn is well tolerated; the most common adverse effects are vertigo and dizziness. Theoretic interactions exist with antiarrhythmics, antihypertensives, digoxin, and antihyperlipidemic agents. Proven conventional therapies for heart failure are still recommended until the safety and effectiveness of hawthorn has been proven in long-term studies. PMID:20148500

Dahmer, Stephen; Scott, Emilie

2010-02-15

15

Funalichnus bhubani isp. nov. from Bhuban Formation, Surma Group (Lower -Middle Miocene) of Aizawl, Mizoram, India  

PubMed Central

A new ichnospecies of the ichnogenus Funalichnus Pokorný is described from the Middle Bhuban Unit, Bhuban Formation, Surma Group (Lower - Middle Miocene) of Aizawl, Mizoram, India. Funalichnus bhubani isp. Nov. Is a large burrow displaying cylindrical segments that are oriented nearly perpendicular to the bedding plane. The new ichnospecies can be identified on the basis of general form, size, unlined passive filling and twisted rod-like structure. The association of Funalichnus bhubani isp. Nov. With Arenicolites, Diplocraterion, Ophiomorpha Psilonichnus Skolithos and Thalassinoides points to its bathymetric restriction. The deep extension of the burrow in clastic sediments provides a favourable condition for preservation in the shoreface environment and occurrence in fine- to medium-grained clastic sediments may be a preservational preference. PMID:24204992

Tiwari, Raghavendra Prasad; Rajkonwar, Chinmoy; Patel, Satish Jaychandbhai

2013-01-01

16

Process Writing with Hawthorne.  

ERIC Educational Resources Information Center

Teachers can use the process writing format for many assignments to teach and refine more skills than are often incorporated in older methods, and this is exemplified by a teaching unit comparing two short stories by Nathaniel Hawthorne. Peer conferences and peer editing in the revision stages, which are features of the process model, can lead to…

Edwards, Lita R.

17

Nathaniel Hawthorne Bicentennial Exhibition  

NSDL National Science Digital Library

Rightly regarded as one of the great figures of American letters, Nathaniel Hawthorne is best known for such works as The House of the Seven Gables, and of course one of America's oft-cited morality tales, The Scarlet Letter. He was part of a wide circle of other notable figures in 19th-century American literature that included Henry David Thoreau, Herman Melville, and Henry Wadsworth Longfellow. Given his strong connection with New England and his birth in Salem, Massachusetts, it is not surprising that the acclaimed Peabody Museum in that same town has mounted a significant exhibit to commemorate the bicentennial of Hawthorne's birth in 1804. For those who cannot make it to Salem in the coming months, this online exhibit is a true delight. The site includes the complete digitized images of "The Spectator", which was a hand-copied newspaper produced by Hawthorne when he was 16. Clearly, those with a penchant for learning about the life of Hawthorne will want to make several trips to this site.

18

Programmed Student Achievement: A Hawthorne Effect?  

ERIC Educational Resources Information Center

Three groups of college students were given instructions using different testing techniques to determine whether the superior performance obtained with Programed Student Achievement (PA) was due to a Hawthorne Effect. Results seem to preclude any attempt to interpret the effectiveness of PA on that basis. (Editor/JT)

Haddad, Nabil F.; And Others

1975-01-01

19

Late Miocene diversification and phylogenetic relationships of the huge toads in the Rhinella marina (Linnaeus, 1758) species group (Anura: Bufonidae).  

PubMed

We investigated the phylogeny and biogeography of the Rhinella marina group, using molecular, morphological, and skin-secretion data, contributing to an understanding of Neotropical faunal diversification. The maximum-parsimony and Bayesian analyzes of the combined data recovered a monophyletic R. marina group. Molecular dating based on Bayesian inferences and fossil calibration placed the earliest phylogenetic split within the R. marina group at ? 10.47 MYA, in the late Miocene. Two rapid major diversifications occurred from Central Brazil, first northward (? 8.08 MYA) in late Miocene and later southward (? 5.17 MYA) in early Pliocene. These results suggest that barriers and dispersal routes created by the uplift of Brazilian Central Shield and climatic changes explain the diversification and current species distributions of the R. marina group. Dispersal-vicariance analyzes (DIVA) indicated that the two major diversifications of the R. marina group were due to vicariance, although eleven dispersals subsequently occurred. PMID:20813190

Maciel, Natan Medeiros; Collevatti, Rosane Garcia; Colli, Guarino Rinaldi; Schwartz, Elisabeth Ferroni

2010-11-01

20

A zoophycos group trace fossil from miocene flysch in Southern Turkey: Evidence for a U?shaped causative burrow  

Microsoft Academic Search

Echinospira isp., a relatively small, lobate, trace fossil of the Zoophycos group, occurs in Miocene flysch deposits of the Cingöz Formation of southern Turkey. It displays a burrow system which contains U?shaped Rhizocorallium?like elements. The burrow system resulted from successive lateral shifts of a causative U?shaped burrow, which reworked most of the previously formed ones. More and less systematic patterns

Alfred Uchman; Huriye Demírcan

1999-01-01

21

Palynology and age of the Tadmor Group (Late Miocene-Pliocene) and Porika Formation (early Pleistocene), South Island, New Zealand  

Microsoft Academic Search

The Porika Formation, type formation of the Porikan glacial stage, contains palynomorphs of early Pleistocene (Hautawan) age. The underlying Tadmor Group consists of the Moutere Gravel overlying the Glenhope Formation. Palynomorphs from the Moutere Gravel are assigned to the Waipipian-Hautawan (middle Pliocene-early Pleistocene) and from the Glenhope Formation are assigned to the ?Kapitean-Opoitian (Late Miocene-Early Pliocene), although basal beds may

D. C. Mildenhall; R. P. Suggate

1981-01-01

22

Hawthorne Academy: The University Perspective  

ERIC Educational Resources Information Center

This article revisits the Trinity University and Hawthorne School partnership since the first case study written 10 years ago. This new perspective analyzes the teacher education program-particularly beliefs and attitudes about it and changes made to the program-with an eye to two primary themes: preparing future teachers and Hawthorne's Core…

Frazee, Bruce M.; Frazee, Felicia F.

2005-01-01

23

Sedimentology of the Navosa Group (Miocene-Pliocene), SW Viti Levu, Fiji (South Pacific)  

SciTech Connect

The Navosa Group consists of the Vunamaoli Conglomerate, newly defined Sovi Sandstone, and Tamanua Formation. The first two units are lateral-facies equivalents in a coarse-grained, volcaniclastic, slope apron-submarine fan depositional system. These marine rocks are restricted to a narrow, linear fault-bounded basin in southwest Viti Levu that opened and then deformed in an episode of late Miocene transform tectonics. The marine rocks are unconformably( ) overlain by the nonmarine, early Pliocene Tamanua Formation. Slope-apron deposits in the Vunamaoli Conglomerate consist of thick, laterally discontinuous, massive boulder diamictites, basement blocks, and slumps along the southern margin of the basin. The diamictites are interpreted as high-density gravelly mass-flow deposits resulting from basin-margin faulting. Along the basin edge these are interspersed with proximal submarine fan deposits. Inner fan regions contain prograding, lenticular, conglomeratic fan lobs composed of cobble-boulder diamictite, normal to inversely graded pebble-cobble conglomerate, pebbly mudstone, and coherent slump blocks with adjacent levee deposit and interdistributary channel thin-bedded turbidites. Mid-fan regions are composed of sheet-like to broadly lenticular high- and low-density sandy turbidites. Outer fan regions consist of poorly exposed, sheet-like, low-density sandy turbidites, and pelagic deposits. The Tamanua Formation represents deposits from north-flowing, gravel-bed load streams and colluvium. Recognizable features include channels, cutbanks, scours, cluster bed forms, cross-bedded gravels, intraclasts, overbank deposits, and paleosols. Paleocurrent and provenance data from the Tamanua Formation suggest there was little topographic relief across the faults that influenced earlier marine deposition.

Evans, J.E. (Bowling Green State Univ., OH (USA))

1990-05-01

24

The Hawthorne Misunderstanding (and How to Get the Hawthorne Effect in Action Research).  

ERIC Educational Resources Information Center

Examines the original Hawthorne relay-assembly research. Asserts the "Hawthorne misunderstanding" is common in criminology and criminal justice because authors have failed to properly attribute the explanation of increased work output to the Hawthorne effect. Describes the Hawthorne effect, how it is produced, and ways to achieve the Hawthorne

Gottfredson, Gary D.

1996-01-01

25

Hawthorn Extract Randomized Blinded Chronic Heart Failure (HERB CHF) Trial  

PubMed Central

Aims Hawthorn's efficacy when added to contemporary evidence-based heart failure therapy is unknown. We aimed to determine whether hawthorn increases submaximal exercise capacity when added to standard medical therapy. Methods and results We performed a randomized, double-blind, placebo-controlled trial in 120 ambulatory patients aged ?18 years with New York Heart Association (NYHA) class II-III chronic heart failure. All patients received conventional medical therapy, as tolerated, and were randomized to either hawthorn 450 mg twice daily or placebo for 6 months. The primary outcome was change in 6 min walk distance at 6 months. Secondary outcomes included quality of life (QOL) measures, peak oxygen consumption, and anaerobic threshold during maximal treadmill exercise testing, NYHA classification, left ventricular ejection fraction (LVEF), neurohormones, and measures of oxidative stress and inflammation. There were no significant differences between groups in the change in 6 min walk distance (P = 0.61), or on measures of QOL, functional capacity, neurohormones, oxidative stress, or inflammation. A modest difference in LVEF favoured hawthorn (P = 0.04). There were significantly more adverse events reported in the hawthorn group (P = 0.02), although most were non-cardiac. Conclusion Hawthorn provides no symptomatic or functional benefit when given with standard medical therapy to patients with heart failure. This trial is registered in ClinicalTrials.gov ID: NCT00343902. PMID:19789403

Zick, Suzanna M.; Vautaw, Bonnie Motyka; Gillespie, Brenda; Aaronson, Keith D.

2009-01-01

26

A Hawthorne strategy: implications for performance measurement and improvement.  

PubMed

The Hawthorne experiments are a backdrop for diverse studies assessing the impact of treatment and experimentation on human and organizational performance. The Hawthorne effect is used to describe the positive impact on behavior that sometimes occurs in a study or experiment as a result of the interest shown by the experimenter in humans who are being treated, studied, or observed. We propose that the Hawthorne effect can be viewed as an active construct to develop a coherent strategy for performance improvement. We propose a "Hawthorne strategy" that transcends the Hawthorne effect in that it offers an approach to improving performance indefinitely. This strategy uses external observations of performance to increase internal commitment to performance improvement. The focus of individual responsibility increases as does the perceived connection between individual efforts and external performance improvement. The sense of accountability is maintained by institutional recognition and periodic reinforcement of individual behaviors that contribute to performance improvement. A successful Hawthorne strategy encourages providers of care to be evaluators of their performance as individuals, as members of groups, and as members of institutions. PMID:10351289

Lied, T R; Kazandjian, V A

1998-01-01

27

What Caused the Hawthorne Effect?  

ERIC Educational Resources Information Center

Together, information feedback and differential reward could account for the gradually increasing productivity in the Hawthorne plant, especially in an explanatory framework of response shaping in operant conditioning. (Author/IRT)

Parsons, H. McIlvaine

1978-01-01

28

Hawthorn: pharmacology and therapeutic uses.  

PubMed

The uses, pharmacology, clinical efficacy, dosage and administration, adverse effects, and drug interactions of hawthorn are discussed. Hawthorn (Crataegus oxyacantha) is a fruit-bearing shrub with a long history as a medicinal substance. Uses have included the treatment of digestive ailments, dyspnea, kidney stones, and cardiovascular disorders. Today, hawthorn is used primarily for various cardiovascular conditions. The cardiovascular effects are believed to be the result of positive inotropic activity, ability to increase the integrity of the blood vessel wall and improve coronary blood flow, and positive effects on oxygen utilization. Flavonoids are postulated to account for these effects. Hawthorn has shown promise in the treatment of New York Heart Association (NYHA) functional class II congestive heart failure (CHF) in both uncontrolled and controlled clinical trials. There are also suggestions of a beneficial effect on blood lipids. Trials to establish an antiarrhythmic effect in humans have not been conducted. The recommended daily dose of hawthorn is 160-900 mg of a native water-ethanol extract of the leaves or flowers (equivalent to 30-169 mg of epicatechin or 3.5-19.8 mg of flavonoids) administered in two or three doses. At therapeutic dosages, hawthorn may cause a mild rash, headache, sweating, dizziness, palpitations, sleepiness, agitation, and gastrointestinal symptoms. Hawthorn may interact with vasodilating medications and may potentiate or inhibit the actions of drugs used for heart failure, hypertension, angina, and arrhythmias. The limited data about hawthorn suggest that it may be useful in the treatment of NYHA functional class II CHF. PMID:11887407

Rigelsky, Janene M; Sweet, Burgunda V

2002-03-01

29

Characterization of antioxidants present in hawthorn fruits  

Microsoft Academic Search

Hawthorn fruit extract has been shown to have many health benefits including being cardiovascular protective, hypotensive and hypocholesterolemic. The present study was carried out to characterize further the antioxidants of hawthorn fruit and their effect on the oxidation of human low density lipoprotein (LDL) and ?-tocopherol. The dry hawthorn fruit was extracted successively with ether, ethyl acetate, butanol and water.

Zesheng Zhang; Qi Chang; Min Zhu; Yu Huang; Walter K. K. Ho; Zhen-Yu Chen

2001-01-01

30

Harry Hawthorn Last revised October 2011  

E-print Network

Harry Hawthorn fonds Last revised October 2011 University of British Columbia Archives #12;Table Development Research series. - 1972. o Harry Hawthorn Project series. - 19--. o Audio series. - 1971. File List Catalogue entry (UBC Library catalogue) #12;Fonds Description Harry Hawthorn fonds. ­ 1947

Handy, Todd C.

31

Lowell on Hawthorne: A Summary Exercise.  

ERIC Educational Resources Information Center

Because Robert Lowell's poem "Hawthorne" focuses on Puritan New England, both as a setting and a subject, and shows the dark side of human nature, and Hawthorne as the alienated artist with a definite place in American literature, it is a most appropriate conclusion for a teaching unit on Hawthorne.

Fanning, Charles

1977-01-01

32

The Hawthorne Effect in community trials in developing countries  

Microsoft Academic Search

The Hawthorne Effect is relatively common in community intervention trials. Yet, very little is known about it in developing countries where poverty may play an important role in how and why people participate in studies. A quasi?experimental trial with a comparison group designed to evaluate the effectiveness of an indoor air pollution intervention showed evidence of reactivity in rural South

Brendon R. Barnes

2010-01-01

33

Placebo, Hawthorne, and Other Artifact Controls: Researchers' Opinions and Practices.  

ERIC Educational Resources Information Center

Mail surveys of 133 educational researchers were analyzed to determine practices concerning specially treated control groups. Although some consistency in practice was found, surveys revealed confusion among researchers over the definition of and relationship between both sources of artifact and placebo, Hawthorne, and attention-placebo controls.…

Adair, John G.; And Others

1989-01-01

34

An Observation of Hawthorne Effect in an Experiment in the Teaching of Reading in First Grade: A Hypothesis  

ERIC Educational Resources Information Center

Speculates about the presence of a negative Hawthorne effect on a control group in addition to a positive effect on the experimental group in an experiment involving 2 first-grade teachers and their classes, and draws implications for studies which seek to control for possible interference by positive and negative Hawthorne effects. Bibliography.…

McCracken, Robert A.

1968-01-01

35

THE HISTORY AND STATUS OF THE HAWTHORN SHIELDBUG ACANTHOSOMA HAEMORRHOIDALE  

E-print Network

THE HISTORY AND STATUS OF THE HAWTHORN SHIELDBUG ACANTHOSOMA HAEMORRHOIDALE (HEMIPTERA of the hawthorn shieldbug Acanthosoma haemorrhoidale (L.) in Scotland are discussed. The acanthosomatid is now The hawthorn shieldbug Acanthosoma haemorrhoidale (L.) (Acanthosomatidae) is a large and attractive shieldbug

Rider, David A.

36

The Hawthorne Effect: A Fresh Examination.  

ERIC Educational Resources Information Center

Reexamines definitions of and explanations for the Hawthorne Effect in research subjects. Notes that the Hawthorne Effect was tested in a study of the effectiveness of paired classroom reading among students. Challenges the notion that subject's behavior is modified by participation in research. Reviews various research studies that question the…

Diaper, Gordon

1990-01-01

37

The Hawthorne Effect: a randomised, controlled trial  

Microsoft Academic Search

BACKGROUND: The 'Hawthorne Effect' may be an important factor affecting the generalisability of clinical research to routine practice, but has been little studied. Hawthorne Effects have been reported in previous clinical trials in dementia but to our knowledge, no attempt has been made to quantify them. Our aim was to compare minimal follow-up to intensive follow-up in participants in a

Rob McCarney; James Warner; Steve Iliffe; Robbert van Haselen; Mark Griffin; Peter Fisher

2007-01-01

38

Student Services Multi Faith Facility Hawthorn Booking Form  

E-print Network

Student Services Multi Faith Facility Hawthorn Booking Form MULTI FAITH FACILITY HAWTHORN This form is to be used to apply to use space in the Multi Faith Facility at Hawthorn. It should be read in conjunction Equipment to be brought in? Yes No If yes, please list: MULTI FAITH FACILITY HAWTHORN CUPBOARDS Cupboards

Liley, David

39

Genetic relationships among some hawthorn (Crataegus spp.) species and genotypes.  

PubMed

The genus Crataegus is well distributed in Turkey as a wild plant, with numerous, inherently variable species and genotypes. RAPD markers were used to study 17 hawthorn genotypes belonging to Crataegus monogyna ssp. monogyna Jacq (2 genotypes), C. monogyna ssp. azarella Jacq (1), Crataegus pontica K.Koch (3), Crataegus orientalis var. orientalis Pallas Ex Bieb (3), Crataegus pseudoheterophylla Pojark (1), Crataegus aronia var. dentata Browicz (1), C. aronia var. aronia Browicz (4), and Crateagus x bornmuelleri Zabel (2). The 10 RAPD primers produced 72 polymorphic bands (88% polymorphism). A dendrogram based on Jaccard's index included four major groups and one outgroup according to taxa. The lowest genetic variability was observed within C. aronia var. aronia genotypes. The study demonstrated that RAPD analysis is efficient for genotyping wild-grown hawthorns. PMID:20640884

Yilmaz, Kadir Ugurtan; Yanar, Makbule; Ercisli, Sezai; Sahiner, Hatice; Taskin, Tuncer; Zengin, Yasar

2010-10-01

40

Mitigating the Hawthorne Effect Using Computer Simulations  

Microsoft Academic Search

\\u000a The Hawthorne studies by Roethlisberger and Dickson (1939) that investigated workplace behavior have maintained a consistent\\u000a presence in social science and education research literature (Chiesa & Hobbs, 2008). The Hawthorne Effect has been often noted\\u000a in social experiments describing participants modifying their behavior during the investigation because they know they are\\u000a being studied (G. Payne & J. Payne, 2004). This

Shawn Y. Holmes

41

75 FR 17406 - Hawthorn Oil Transportation; Notice of Filing  

Federal Register 2010, 2011, 2012, 2013, 2014

...Federal Energy Regulatory Commission [Docket No. AC10-62-000] Hawthorn Oil Transportation; Notice of Filing March 31, 2010. Take notice that on February 12, 2010, Hawthorn Oil Transportation submitted a request for the waiver of the...

2010-04-06

42

Pomological Characteristics of Hawthorns Species Found in Van Region  

Microsoft Academic Search

Hawthorns have not gained adequate importance in both Turkey and the World yet. This study aimed to determine the hawthorn species of the region of Van in Turkey to analyze fruit characteristics. Ninety eight hawthorn genotypes were determined by pre- selection in Geva? and Edremit towns of Van. However, fruit samples were only 31 types from Geva? and 18 types

Ahmet KAZANKAYA

43

The Lockean Thesis and the Logic of Belief James Hawthorne  

E-print Network

The Lockean Thesis and the Logic of Belief James Hawthorne 1 Introduction In a penetrating of consistent belief J. Hawthorne (B) Department of Philosophy, University of Oklahoma, Norman Oklahoma, 73019 USA e-mail: hawthorne@ou.edu 1 Foley cites Locke's An Essay Concerning Human Understanding, (1975

Fitelson, Branden

44

Harry Hawthorn Foundation Compiled by Christopher Hives (1986)  

E-print Network

Harry Hawthorn Foundation fonds Compiled by Christopher Hives (1986) Last revised October 2011 Library catalogue) #12;Fonds Description Harry Hawthorn Foundation fonds. ­ 1953-1986. 20 cm of textual records. 94 photographs. Administrative History The Harry Hawthorn Foundation was established in 1953

Handy, Todd C.

45

A "H--ll-Fired Story": Hawthorne's Rhetoric of Rumor.  

ERIC Educational Resources Information Center

Considers Nathaniel Hawthorne's literary technique of providing various, often conflicting, accounts of a narrative scene or event. Analyzes Hawthorne's rhetoric of rumor as featured in "The Scarlet Letter." Shows how Hawthorne tried to translate the dynamics of interpersonal communication into print in this novel. (HB)

Harshbarger, Scott

1994-01-01

46

The Hawthorne effect and energy awareness.  

PubMed

The feeling of being observed or merely participating in an experiment can affect individuals' behavior. Referred to as the Hawthorne effect, this inconsistently observed phenomenon can both provide insight into individuals' behavior and confound the interpretation of experimental manipulations. Here, we pursue both topics in examining how the Hawthorne effect emerges in a large field experiment focused on residential consumers' electricity use. These consumers received five postcards notifying, and then reminding, them of their participation in a study of household electricity use. We found evidence for a Hawthorne (study participation) effect, seen in a reduction of their electricity use--even though they received no information, instruction, or incentives to change. Responses to a follow-up survey suggested that the effect reflected heightened awareness of energy consumption. Consistent with that interpretation, the treatment effect vanished when the intervention ended. PMID:24003110

Schwartz, Daniel; Fischhoff, Baruch; Krishnamurti, Tamar; Sowell, Fallaw

2013-09-17

47

The Hawthorne effect and energy awareness  

PubMed Central

The feeling of being observed or merely participating in an experiment can affect individuals’ behavior. Referred to as the Hawthorne effect, this inconsistently observed phenomenon can both provide insight into individuals' behavior and confound the interpretation of experimental manipulations. Here, we pursue both topics in examining how the Hawthorne effect emerges in a large field experiment focused on residential consumers’ electricity use. These consumers received five postcards notifying, and then reminding, them of their participation in a study of household electricity use. We found evidence for a Hawthorne (study participation) effect, seen in a reduction of their electricity use—even though they received no information, instruction, or incentives to change. Responses to a follow-up survey suggested that the effect reflected heightened awareness of energy consumption. Consistent with that interpretation, the treatment effect vanished when the intervention ended. PMID:24003110

Schwartz, Daniel; Fischhoff, Baruch; Krishnamurti, Tamar; Sowell, Fallaw

2013-01-01

48

What Happened at Hawthorne?: New evidence suggests the Hawthorne effect resulted from operant reinforcement contingencies.  

PubMed

The Hawthorne effect in experimental research is the unwanted effect of the experimental operations themselves. Following the Hawthorne studies, various explanations have been proposed to account for rising rates of production. Although in the Relay Assembly Test Room experiment the experimental operations may have produced other extraneous variables, a reexamination based on new and neglected evidence has yielded a new interpretation. The new variable, made more plausible because research in other contexts has shown it to have similar effects, is a combination of information feedback and financial reward. It is an example of the control of behavior by its consequences. Although several approaches may be taken to explain the effects of response-consequence contingencies, I have favored operant conditioning because it seems to account for progressive increases in response rate-the Hawthorne phenomenon. Generalizing from the particular situation at Hawthorne, I would define the Hawthorne effect as the confounding that occurs if experimenters fail to realize how the consequences of subjects' performance affect what subjects do. But the Hawthorne effect need not be viewed solely as a problem in conducting experiments. The phenomenon that created it should be studied in its own right, as Sommer (67) suggested with a different phenomenon in mind. The study of response-consequence contingencies might well be extended to the examination of motivation in industrial workers. PMID:17756742

Parsons, H M

1974-03-01

49

Hawthorne Elementary School: The Evaluator's Perspective.  

ERIC Educational Resources Information Center

Provides an evaluator's view of the quantitative effects of the Core Knowledge Sequence, a content-based K-6 curriculum model, and other reforms at Hawthorne Elementary School (Houston, Texas). Pretest and posttest results show increased academic performance in reading, writing, and mathematics, based on Texas Assessment of Academic Skills…

Schubnell, Gail Owen

1996-01-01

50

The Hawthorne Effect: a fresh examination  

Microsoft Academic Search

This paper attempts to ascertain the authenticity of both definitions of and explanations for the Hawthorne Effect which are found in the literature. The term is alleged to derive from the earliest of a series of experiments between the years 1924 and 1932 designed to establish the relationship between levels of illumination and industrial production in the Western Electric Company

Gordon Diaper

1990-01-01

51

Quantitative determination of procyanidins in hawthorn fruits  

Microsoft Academic Search

The quantitative determination of procyanidins in hawthorn fruits by spectrophotometry is described. The method is characterized\\u000a by high accuracy, repeatability, and reproducibility and does not require standard samples. The proposed procedure can be\\u000a used for the analysis of both raw plant material and ready-to-use preparations.

O. M. Khishova; G. N. Buzuk

2006-01-01

52

Hawthorne Elementary School: The Teachers' Perspective.  

ERIC Educational Resources Information Center

Describes the Hawthorne Elementary School (Houston, Texas) reform efforts that targeted inner-city, low-income student academic improvement. The forceful use of national and local resources to implement teacher-initiated changes and to further a successful site-based school restructuring is presented. (GR)

Mentzer, Debra; Shaughnessy, Tricia

1996-01-01

53

Hawthorne Elementary School: The University Perspective.  

ERIC Educational Resources Information Center

Describes positive results coming from Trinity University's active support of educational reform efforts at Hawthorne Elementary School (Houston, Texas). Trinity's teacher education agenda focused on preparing teachers for the real world of the elementary school and pursuing a teacher-selected school reform project. (GR)

Frazee, Bruce M.

1996-01-01

54

Capillary electrophoretic analysis of flavonoids in single-styled hawthorn ( Crataegus monogyna Jacq.) ethanolic extracts  

Microsoft Academic Search

Flavonoids are an important group of natural compounds, which can prevent coronary heart disease and have antioxidant properties. Hawthorn is a well known and widely used medicinal plant due to its cardiotonic activity. Previous studies refer mostly to the HPLC analysis of the flavonoids: vitexin, quercetin, hyperoside, oligomeric procyanidins, which appear to be primarily responsible for the cardiac action of

A. Urbonavi?i?t?; V. Jakštas; O. Kornyšova; V. Janulis; A. Maruška

2006-01-01

55

Sedimentology of the Whiteclay Gravel Beds (Ogallala Group) in northwestern Nebraska, USA: Structurally controlled drainage promoted by Early Miocene uplift of the Black Hills Dome  

NASA Astrophysics Data System (ADS)

The newly recognized Whiteclay Gravel Beds (WGB) of the Miocene Ogallala Group crop out as a narrow, discontinuous ribbon of sands and gravels in Dawes and Sheridan Counties, northwestern Nebraska, USA. The WGB are exposed in a series of municipal gravel quarries and natural exposures that define a linear trench in underlying strata at least 20 m deep and up to 300 m wide, with short, southeast-trending reaches separating generally longer east-trending sections. This gravel-filled trench can be recognized from the Nebraska-South Dakota border near Whiteclay, Nebraska southeastward to east of Gordon, Nebraska, a distance of ˜ 30 km. The outcrop belt of the WGB is coincident in location and trend with the Whiteclay Fault Zone. Where exposed in quarries, the walls of the trench are steep-sided, vertical, or locally overhanging. Polished surfaces, slickensides, and parallel joint sets are common in the walls of the trench near Whiteclay, but uncommon in those to the east. The narrow belt defined by this trench is filled by stratified gravel (< 2.0 m, typically < 0.3 m) of sedimentary lithologies derived from various Cenozoic units (but principally Anderson Ranch Formation), and sand. Relatively small amounts of unrounded granitic, volcanic, and quartz gravel are preserved in places. Cross-bedding and clast imbrication indicate palaeoflow towards the east. The WGB are interpreted to have formed in response to tectonic upheaval associated with uplift of the Black Hills of South Dakota in Early Miocene times. Fault rupture topography facilitated formation of a steep-sided canyon, or valley, up to 20 m deep, being virtually straight with sharp bends at intervals of several km. An alluvial channel belt developed in the floor of the valley, filling the available accommodation space with coarse sand and gravel via aggradational stacking of the deposits of successive channels and channel belts. Channel belts were probably braided, with individual channels up to 4 m deep and a few tens of metres wide. The multi-storey character of the deposit indicates multiple episodes of cutting and filling. The coarse grain-size of the fill suggests energetic discharge with frequent bankfull flows, even though the system had a relatively low gradient (0.004). An abundance of reworked fossil debris is derived from several stratigraphic units, clasts of which have been identified in the fill. The presence of a contemporary merychippine horse and a primitive species of the oreodont Brachycrus constrain formation of the WGB to a short interval within the Early Miocene (c. 17.5 Ma). The mammal fauna suggests that this stream was a valuable source of water, while fragments of aquatic organisms such as turtles and fish indicate perennial discharge. The WGB provides a crucial window into a pluvial period in the Miocene that is largely unpreserved elsewhere in the basin, facilitated in part by fault rupture topography.

Fielding, Christopher R.; LaGarry, Hannan E.; LaGarry, Leigh Anne; Bailey, Bruce E.; Swinehart, James B.

2007-11-01

56

Secular variation of the middle and late Miocene geomagnetic field recorded by the Columbia River Basalt Group in Oregon, Idaho and Washington, USA  

NASA Astrophysics Data System (ADS)

This study of 118 discrete volcanic flows from the Columbia River Basalt Group is aimed to determine their distribution of geomagnetic field directions and virtual geomagnetic poles (VGPs) and to compare the inherent secular variation parameters with those from other studies. The magnetic signature of these rocks is uniformly carried by primary titanomagnetite, indicating that magnetic changes are due to variations in the magnetic field. Although most flows are flat lying, those that are tilted pass the Tauxe and Watson tilt test. Sequential flows with statistically similar site means were grouped, and directions that were considered outliers were evaluated and removed using the Vandamme cut-off method. Three normal-polarity (N-polarity) and three reversed-polarity (R-polarity) intervals are revealed by the stratigraphically ordered flows and have mean directions of N polarity (dec/inc = 6.6°/+61.2°, k = 29.3, ?95 = 4.2°), and R polarity (dec/inc = 178.2°/-59.2°, k = 16, ?95 = 5.5°). Regression analysis indicates that the secular variation analysis has not been affected by regional rotation, and that apparent polar wander is negligible. The VGP distribution is almost perfectly circular and supports the preference of VGP positions for the dispersion analysis. Dispersion parameters with corrections for within-site scatter (Sb) show a range of 14.3°-25.5°, including error limits, and were consistently higher for R-polarity results than for those of N polarity. Published dispersion parameters for extrusives <5 Ma show Sb values slightly lower than ours, yielding values of 16°-19°, although the difference is not statistically significant. In contrast, published dispersion parameters from high quality data from the Cretaceous Normal Superchron are lower than those for the Neogene, which suggests that the noisiness of the magnetic field correlates with the frequency of reversals. Our new results allow us to extend the Plio-Pleistocene palaeosecular variation database to the bottom of the middle Miocene. Many Miocene formations on a variety of continents are suitable targets for future analysis. Furthermore, the significant difference between the reversed and N-polarity dispersion parameters is intriguing and needs substantiation.

Dominguez, Ada R.; Van der Voo, Rob

2014-06-01

57

76 FR 67103 - Proposed Revision of Class D and Class E Airspace; Hawthorne, CA  

Federal Register 2010, 2011, 2012, 2013, 2014

...Proposed Revision of Class D and Class E Airspace; Hawthorne, CA AGENCY: Federal Aviation Administration...Class D and E airspace at Jack Northrop Field/Hawthorne Municipal Airport, Hawthorne, CA. Additional controlled airspace is...

2011-10-31

58

77 FR 7525 - Revision of Class D and Class E Airspace; Hawthorne, CA  

Federal Register 2010, 2011, 2012, 2013, 2014

...Revision of Class D and Class E Airspace; Hawthorne, CA AGENCY: Federal Aviation Administration...and Class E airspace at Jack Northrop Field/Hawthorne Municipal Airport, Hawthorne, CA. Additional controlled airspace is...

2012-02-13

59

The Burden of Secret Sin: Nathaniel Hawthorne's Fiction The fiction of Nathaniel Hawthorne has frequently been defined in musical terms on account of  

E-print Network

The Burden of Secret Sin: Nathaniel Hawthorne's Fiction The fiction of Nathaniel Hawthorne has be found throughout Hawthorne's writings, in his earliest as well as in his latest. It is The Scarlet. However, The House of the Seven Gables (1851) and a great number of Hawthorne's shorter works address

Paris-Sud XI, Université de

60

Editors' Introduction to the Hawthorne Case Study Series.  

ERIC Educational Resources Information Center

Introduces three perspectives on the Hawthorne Elementary School (Houston, Texas) reform effort. The case studies indicate that successful restructuring of schools serving highly disadvantaged communities is possible. (GR)

Stringfield, Samuel C.; Hollifield, John H.

1996-01-01

61

Impact of the Hawthorne effect in a longitudinal clinical study: the case of anesthesia.  

PubMed

Clinical research can be influenced by many factors that are capable of invalidating results, and one of these factors is known as the Hawthorne effect: the mere awareness of being under observation can alter the way in which a person behaves. In experimental research this effect can be the undesired effect of the experiments themselves, and the stronger its presence, the greater it can influence the results. In anesthesia practice, owing to the particular emotional condition of a patient facing a surgical operation, the Hawthorne effect could be especially strong. The aim of our study was to show the impact that the knowledge of being included in a study has (Hawthorne effect), by comparing the postoperative changes in psychological well-being in two groups of patients undergoing knee arthroscopy and receiving different information about the study from the anesthetist during the preoperative interview. Other signs and symptoms such as postoperative knee pain, nausea, vomiting (the most feared occurrences), headache, return of spontaneous diuresis, analgesic request, anesthesia complications, as well as the intensity of anxiety were also assessed as secondary endpoints. Our results show that subjects who were aware that they were part of a study scored significantly better on postoperative measures of psychological well-being and postoperative knee pain, compared to subjects who were unaware. The size of the effect, as measured by the odds ratio, remains unchanged when controlling for potential confounding factors. The study has enabled us to demonstrate the presence of the Hawthorne effect in clinical research. Therefore, the Hawthorne effect should be acknowledged and accounted for in the design of a study and in the interpretation of results. PMID:10715508

De Amici, D; Klersy, C; Ramajoli, F; Brustia, L; Politi, P

2000-04-01

62

A comparison of the composition of epicuticular wax from red raspberry (Rubus idaeus L.) and hawthorn (Crataegus monogyna Jacq.) flowers.  

PubMed

Epicuticular waxes have been characterised from the flowers of raspberry and hawthorn, on both of which adult raspberry beetles (Byturus tomentosus) can feed. The flower wax from both species had similar alkane profiles and also contained long-chain alcohols, aldehydes and fatty acids. The range of the carbon numbers detected for these classes of compounds was broadly similar in both but the relative amounts of each differed between species. Raspberry flower wax also contained fatty acid methyl esters, a group of compounds that has rarely been detected in plant epicuticular waxes, however, these were not observed in hawthorn flower wax. Long-chain alcohol-fatty acid esters with carbon numbers ranging from C36 to C48 were also detected in both plant species. However, an examination of their constituent acids indicated that in hawthorn the esters based on the C16 fatty acid predominated, whilst in raspberry flower wax, esters based on the C20 fatty acid were most abundant. Both species also contained pentacyclic triterpenoids, which accounted for, on average, over 16 and 48% of the total wax extracted from raspberry and hawthorn flowers respectively. In the former, ursolic and oleanolic acids accounted for over 90% of the pentacyclic triterpenes, whilst hawthorn flower wax, in addition to containing these acids, also contained high relative concentrations of both free and esterified alpha- and beta-amyrins. PMID:11065285

Griffiths, D W; Robertson, G W; Shepherd, T; Birch, A N; Gordon, S C; Woodford, J A

2000-09-01

63

AN OBSERVATION ABOUT HAWTHORNE EFFECT IN AN EXPERIMENT IN THE TEACHING OF READING IN FIRST GRADE--A HYPOTHESIS.  

ERIC Educational Resources Information Center

THE PURPOSE OF THIS STUDY WAS TO DETERMINE IF A HAWTHORNE EFFECT WERE PRESENT IN A 3-YEAR LONGITUDINAL STUDY WHICH COMPARED TWO METHODS OF TEACHING READING IN FIRST GRADE. THE INITIAL SUBJECTS WERE TWO TEACHERS AND FIVE FIRST-GRADE CLASSES OF RANDOMLY ASSIGNED STUDENTS WHO COMPOSED ONE EXPERIMENTAL, ONE CONTROL, AND THREE SUBCONTROL GROUPS.…

MCCRACKEN, ROBERT A.

64

Hawthorne Concept--Does It Affect Reading Progress?  

ERIC Educational Resources Information Center

Concludes that the extra attention paid to children during the administration of reading tests does not have a significant effect on test performance and that the Hawthorne effect does not influence reading test results. (RB)

Rubeck, Patricia A.

1975-01-01

65

UBC Museum of Anthropology Audrey & Harry Hawthorn Library & Archives  

E-print Network

UBC Museum of Anthropology Audrey & Harry Hawthorn Library & Archives Application Form for Use. Accreditation All images must be identified as specified by MOA, including the phrase "Courtesy of the Audrey

Strynadka, Natalie

66

Interview with Geoffrey Hawthorn on Malthus and population  

E-print Network

An interview with the sociologist Geoffrey Hawthorn in relation to Malthus and population, made in 1985 as part of the materials for the film 'The Mountebank Parson' made by Sofka Zinovieff, Rachel Riley and John Bell in that year...

Hawthorn, Geoffrey

2009-06-30

67

Interview with Geoffrey Hawthorn on Malthus and population  

E-print Network

An interview with Geoffrey Hawthorn in relation to Malthus and population, made in 1985 as part of the materials for the film 'The Mountebank Parson' by Sofka Zinovieff, Rachel Riley and John Bell in that year...

Hawthorn, Geoffrey

1985-01-01

68

Hawthorn (Crataegus spp.) in the treatment of cardiovascular disease  

PubMed Central

The medicinal properties of hawthorn (Crataegus spp., a genus comprising approximately 300 species) have been utilized by many cultures for a variety of therapeutic purposes for many centuries. In the Western world cardiovascular disease (CVD) has become one of the single most significant causes of premature death. Echoing this situation, more recent research into the therapeutic benefits of hawthorn preparations has focused primarily upon its cardiovascular effects. This review covers research into the various mechanisms of action proposed for Crataegus preparations, clinical trials involving Crataegus preparations, and the herb's safety profile. Clinical trials reviewed have been inconsistent in terms of criteria used (sample size, preparation, dosage, etc) but have been largely consistent with regard to positive outcomes. An investigation into data available to date regarding hawthorn preparations and herb/drug interactions reveals that theoretical adverse interactions have not been experienced in practice. Further, adverse reactions relating to the use of hawthorn preparations are infrequent and mild, even at higher dosage ranges. A recent retrospective study by Zick et al. has suggested a negative outcome for the long-term use of hawthorn in the prognosis of heart failure. These findings are examined in this paper. Although further research is needed in certain areas, current research to date suggests that hawthorn may potentially represent a safe, effective, nontoxic agent in the treatment of CVD and ischemic heart disease (IHD). PMID:22228939

Tassell, Mary C.; Kingston, Rosari; Gilroy, Deirdre; Lehane, Mary; Furey, Ambrose

2010-01-01

69

Hawthorn (Crataegus spp.) in the treatment of cardiovascular disease.  

PubMed

The medicinal properties of hawthorn (Crataegus spp., a genus comprising approximately 300 species) have been utilized by many cultures for a variety of therapeutic purposes for many centuries. In the Western world cardiovascular disease (CVD) has become one of the single most significant causes of premature death. Echoing this situation, more recent research into the therapeutic benefits of hawthorn preparations has focused primarily upon its cardiovascular effects. This review covers research into the various mechanisms of action proposed for Crataegus preparations, clinical trials involving Crataegus preparations, and the herb's safety profile.Clinical trials reviewed have been inconsistent in terms of criteria used (sample size, preparation, dosage, etc) but have been largely consistent with regard to positive outcomes. An investigation into data available to date regarding hawthorn preparations and herb/drug interactions reveals that theoretical adverse interactions have not been experienced in practice. Further, adverse reactions relating to the use of hawthorn preparations are infrequent and mild, even at higher dosage ranges. A recent retrospective study by Zick et al. has suggested a negative outcome for the long-term use of hawthorn in the prognosis of heart failure. These findings are examined in this paper.Although further research is needed in certain areas, current research to date suggests that hawthorn may potentially represent a safe, effective, nontoxic agent in the treatment of CVD and ischemic heart disease (IHD). PMID:22228939

Tassell, Mary C; Kingston, Rosari; Gilroy, Deirdre; Lehane, Mary; Furey, Ambrose

2010-01-01

70

THE WASON TASK(S) AND THE PARADOX OF CONFIRMATION BRANDEN FITELSON AND JAMES HAWTHORNE  

E-print Network

THE WASON TASK(S) AND THE PARADOX OF CONFIRMATION BRANDEN FITELSON AND JAMES HAWTHORNE Abstract . Date: 08/01/10. Draft: Final version to appear in Philosophical Perspectives, J. Hawthorne (ed.). 1 2 BRANDEN FITELSON AND JAMES HAWTHORNE Informally, (NC) asserts that "universal laws are confirmed

Fitelson, Branden

71

TO HAWTHORN CAMPUS! Tuesday 25 February 2014 Faculty of Health, Arts and Design (FHAD)  

E-print Network

welcome TO HAWTHORN CAMPUS! Tuesday 25 February 2014 Faculty of Health, Arts and Design (FHAD) We want to welcome you to Swinburne Hawthorn ­ join us for a full day of orientation activities! Speak Hawthorn. Learn about all the Swinburne services you can use You will also meet representatives of key

Liley, David

72

Anthropologist HarryHawthorn and artist Bill Reid, two pre-eminent  

E-print Network

Six to get honorary degrees Anthropologist HarryHawthorn and artist Bill Reid, two pre the University of B.C. in May. Prof.Hawthorn,whoretiresthis yearfrom UBC's Departmentof Anthropology the degree of Doctor of Laws. Prof.Hawthorn,whojoinedthe UBC facultyin 1947, washead of UBC's anthropology

Farrell, Anthony P.

73

Antarctic Miocene Climate  

NASA Astrophysics Data System (ADS)

Fossils from Antarctic Miocene terrestrial deposits, coupled with stratigraphic, geochemical and paleontological data from marine boreholes, provide new insights into the climatic history of the continent. During the Miocene, ice caps coalesced to form ice sheets and vegetated surfaces gave way to barren expanses. The cryospheric changes especially have global climatic implications. The fossil data consists of diatoms, pollen and spores, and macroscopic remains of plants, ostracods, insects, molluscs and a fish. Plant fossils include wood and leaves of Nothofagus (southern beech), seeds of several vascular plants, including Ranunculus (buttercup), Hippuris (mare's-tail) and Myriophyllum (watermilfoil), megaspores of Isoetes (quillwort), and moss species. The insect chitin consists of larval head capsules of Chironomidae (midges) and exoskeletal parts of Coleoptera (beetles). The molluscs include freshwater gastropods and bivalves. The majority of these taxa are likely descendants of taxa that had survived on the continent from the Paleogene or earlier. Even though early Miocene glaciations may have been large, the climate was never cold enough to cause the extinction of the biota, which probably survived in coastal refugia. Early Miocene (c. 20 Ma) macrofossils from the McMurdo Dry Valleys (77°S) support palynological interpretations from the Cape Roberts and ANDRILL marine records that the upland vegetation was a shrub tundra. Mean summer temperature (MST) in the uplands was c. 6°C and possibly higher at the coast. The climate was wet, supporting mires and lakes. By the mid-Miocene, even though the climate continued to be wet. MST was c. 4°C which was too cold to support Nothofagus and most vascular plant species. Stratigraphic evidence indicates that the time between the Early and Mid-Miocene was a time of repeated ice advances and retreats of small glaciers originating from ice caps. At c. 14 Ma there appears to have been a modal shift in climate to significantly colder and drier conditions that resulted in the extinction of the upland biota and a shift in glacial regimes from wet to cold-based. Paleontological and geochemical evidence from the deep marine record supports a major climatic event at this time. Based on pollen from the SHALDRIL cores a tundra biota survived until c. 12.8 Ma on the islands of the Antarctic Peninsula (65°S). Recently, sparse angiosperm pollen of chenopods or similar taxa, has been reported from deposits in the Prince Charles mountains (70°S) with a biostratigraphic age of Mid- to Late Miocene (12-9 Ma) making it possible that remnants of a tundra vegetation continued to exist on the edges of the continent after it had become extinct on the islands of the Antarctic Peninsula. Evidence for Pliocene warmth in the Ross Sea from thick diatomite sequence in ANDRILL cores is so far unsupported by terrestrial paleontological evidence. Pliocene wood-like structures reported from a DVDP core are interpreted as the remains of in situ shrubs but the evidence is unconvincing. Pliocene warmth in the Ross sea region, unaccompanied by an unambiguous terrestrial response can be explained in one of two ways: 1. Pliocene MSTs remained below the 3-4°C threshold needed to support shrub or herb tundra, or 2. Pliocene MSTs were warm enough but terrestrial taxa were unavailable because of extinction. Research supported by NSF 0739693,0947821.

Ashworth, A. C.; Lewis, A. R.

2013-12-01

74

Hawthorn (Crataegus monogyna Jacq.) extract exhibits atropine-sensitive activity in a cultured cardiomyocyte assay.  

PubMed

Hawthorn (Crataegus spp.) plant extract is used as a herbal alternative medicine for the prevention and treatment of various cardiovascular diseases. Recently, it was shown that hawthorn extract preparations caused negative chronotropic effects in a cultured neonatal murine cardiomyocyte assay, independent of beta-adrenergic receptor blockade. The aim of this study was to further characterize the effect of hawthorn extract to decrease the contraction rate of cultured cardiomyocytes. To test the hypothesis that hawthorn is acting via muscarinic receptors, the effect of hawthorn extract on atrial versus ventricular cardiomyocytes in culture was evaluated. As would be expected for activation of muscarinic receptors, hawthorn extract had a greater effect in atrial cells. Atrial and/or ventricular cardiomyocytes were then treated with hawthorn extract in the presence of atropine or himbacine. Changes in the contraction rate of cultured cardiomyocytes revealed that both muscarinic antagonists significantly attenuated the negative chronotropic activity of hawthorn extract. Using quinuclidinyl benzilate, L-[benzylic-4,4'-(3)H] ([(3)H]-QNB) as a radioligand antagonist, the effect of a partially purified hawthorn extract fraction to inhibit muscarinic receptor binding was quantified. Hawthorn extract fraction 3 dose-dependently inhibited [(3)H]-QNB binding to mouse heart membranes. Taken together, these findings suggest that decreased contraction frequency by hawthorn extracts in neonatal murine cardiomyocytes may be mediated via muscarinic receptor activation. PMID:18696181

Salehi, Satin; Long, Shannon R; Proteau, Philip J; Filtz, Theresa M

2009-01-01

75

In Praise of the Hawthorne Effect: Perspectives from the Profs.  

ERIC Educational Resources Information Center

Successful teacher education and effective teacher and student motivation may be obtainable through a positive approach to the Hawthorne Effect, which is the principle that increased attention to an operative situation leads to an increased productivity by that operation, regardless of all other surrounding variables. (LH)

Raywid, Mary Anne

1979-01-01

76

Is the Hawthorne Effect in Educational Experiments a Chimera?  

ERIC Educational Resources Information Center

Reports on an experimental study designed to investigate the relationship between two factors commonly regarded as components of the Hawthorne Effect on pupil performance and on intellectual task. These factors are (1) direct cue, or awareness of experimentation, as represented by an announcement that pupils were the subjects of an experiment; and…

Bauernfeind, Robert H.; Olson, Carl J.

1973-01-01

77

Yields of hawthorn Crataegus monogyna berries under different hedgerow management  

Microsoft Academic Search

Yields of hawthorn berries under different hedgerow management treatments were examined in experimental hedgerows at Monks Wood, Cambridgeshire, UK. Statistically significant differences existed between the management treatments with yields per unit area of hedgerows unmanaged for more than a decade out-yielding managed hedgerows by an order of magnitude. These differences were further inflated if yields were considered per unit length

T. H Sparks; T Martin

1999-01-01

78

Mozart, Hawthorne, and Mario Savio: Aesthetic Power and Political Complicity.  

ERIC Educational Resources Information Center

Discusses the false dichotomy pitting aesthetic power against political complicity in literary criticism. Considers the sexual politics of the household of Nathaniel Hawthorne in light of this opposition. Suggests how literary works keep warring voices and inner conflicts alive and at odds. (HB)

Herbert, T. Walter

1995-01-01

79

Fourth Period Discovers Hester as Mother: Hawthorne's Mother?  

ERIC Educational Resources Information Center

A teacher discusses how she used criticism of "The Scarlet Letter," when studying the book, in her honors class. The students were also intrigued by the biographical information they learned about Hawthorne, and eager to use it in interpreting his novel. (SRT)

Heginbotham, Eleanor

1986-01-01

80

Nathaniel Hawthorne's Garden of Eden Story: "Rappaccini's Daughter."  

ERIC Educational Resources Information Center

Presents a four-day lesson plan for secondary U.S. literature or Bible-and-literature classes, using the Garden of Eden story and Nathaniel Hawthorne's "Rappaccini's Daughter." Identifies objectives, materials, procedure, and evaluation measures. Develops students' ability to discover analogies and irony in literary texts. Lists teacher resources,…

Meixner, Linda L.

1990-01-01

81

Nathaniel Hawthorne and Herman Melville: A Research Guide.  

ERIC Educational Resources Information Center

This handout is a guide to library resources in the J. Murrey Atkins Library at the University of North Carolina-Charlotte for the study of the 19th-century American authors Nathaniel Hawthorne and Herman Melville. The guide details resources in Atkins library for biographical and critical material on the two authors. The guide is in four…

Van Noate, Judith, Comp.

82

Energy Engineering Analysis Program, limited energy study of steam distribution systems, Hawthorne Army Ammunition Depot, Hawthorne, Nevada. Programming documents  

SciTech Connect

The project is a significant part of Hawthorne Army Ammunition Depot`s effort to achieve a 20-percent reduction in energy consumption by FY2000 versus FY1985 baseline levels. The project will also assure that heating services are provided to Industrial Area facilities on a continuing basis, supporting mission requirements.

NONE

1995-09-01

83

Triterpenic Acids Present in Hawthorn Lower Plasma Cholesterol by Inhibiting Intestinal ACAT Activity in Hamsters  

PubMed Central

Hawthorn (Crataegus pinnatifida) is an edible fruit used in traditional Chinese medicine to lower plasma lipids. This study explored lipid-lowering compounds and underlying mechanisms of action of hawthorn. Hawthorn powder extracts inhibited acylCoA:cholesterol acyltransferase (ACAT) activity in Caco-2 cells. The inhibitory activity was positively associated with triterpenic acid (i.e., oleanolic acid (OA) and ursolic acid (UA)) contents in the extracts. Cholesterol lowering effects of hawthorn and its potential additive effect in combination with plant sterol esters (PSE) were further studied in hamsters. Animals were fed a semi-synthetic diet containing 0.08% (w/w) cholesterol (control) or the same diet supplemented with (i) 0.37% hawthorn dichloromethane extract, (ii) 0.24% PSE, (iii) hawthorn dichloromethane extract (0.37%) plus PSE (0.24%) or (iv) OA/UA mixture (0.01%) for 4 weeks. Compared to the control diet, hawthorn, PSE, hawthorn plus PSE and OA/UA significantly lowered plasma non-HDL (VLDL + LDL) cholesterol concentrations by 8%, 9%, 21% and 6% and decreased hepatic cholesterol ester content by 9%, 23%, 46% and 22%, respectively. The cholesterol lowering effects of these ingredients were conversely associated with their capacities in increasing fecal neutral sterol excretion. In conclusion, OA and UA are responsible for the cholesterol lowering effect of hawthorn by inhibiting intestinal ACAT activity. In addition, hawthorn and particularly its bioactive compounds (OA and UA) enhanced the cholesterol lowering effect of plant sterols. PMID:19228775

Lin, Yuguang; Vermeer, Mario A.; Trautwein, Elke A.

2011-01-01

84

Capillary electrophoretic analysis of flavonoids in single-styled hawthorn (Crataegus monogyna Jacq.) ethanolic extracts.  

PubMed

Flavonoids are an important group of natural compounds, which can prevent coronary heart disease and have antioxidant properties. Hawthorn is a well known and widely used medicinal plant due to its cardiotonic activity. Previous studies refer mostly to the HPLC analysis of the flavonoids: vitexin, quercetin, hyperoside, oligomeric procyanidins, which appear to be primarily responsible for the cardiac action of the plant. Aqueous ethanolic extracts of single-styled hawthorn (Crataegus monogyna Jacq., f.: Rosaceae Juss.) leaves and sprouts were analyzed by means of capillary zone electrophoresis (CZE). Influence of vegetation period on the extract qualitative composition and flavonoids quantities was evaluated. Sample preparation by extraction using different concentration of aqueous ethanol (40-96%, v/v) and the influence of extractant composition on the recovery of flavonoids are discussed in detail. The results obtained using CZE are compared to the results of spectrophotometric and HPLC analysis of the extracts. The effect of storage conditions of extracts (solar irradiation, temperature and duration) on degradation of flavonoids was investigated. PMID:16443232

Urbonavici?te, A; Jakstas, V; Kornysova, O; Janulis, V; Maruska, A

2006-04-21

85

Screening low fire blight susceptible Crataegus species for host suitability to hawthorn leaf-curling aphids (Dysaphis spp.).  

PubMed

The group of hawthorn leaf-curling aphids (Dysaphis spp.) hosted by the common hawthorn Crataegus monogyna Jacq. may play an important role in the biological control of the rosy apple aphid, Dysaphis plantaginea (Passerini), by increasing reproduction opportunities for the indigenous hymenopteran parasitoid Ephedrus persicae Froggatt. Unfortunately, most fruitgrowers hesitate to introduce the common hawthorn in their orchards because they fear fire blight infections which may be transmitted by this highly susceptible hawthron species. This potential hazard led us to investigate the suitability to leaf-curling aphids of alternative Crataegus species. As representative for these closely-related aphids, the species Dysaphis apiifolia petroselini (Börner) was used in the trials. Ten Crataegus species characterized by their very low susceptibility to fire blight were examined from two angles. Firstly, aphid sexuals were introduced in autumn onto the different species to verify whether egg laying could take place. Secondly, the development of fundatrices and gall formation were followed the next spring. Although eggs and mature fundatrices could be obtained on almost all species, no fundatrice-hosting galls were recorded in spring. The possible causes of these negative results with respect to the geographical origin of the particular Crataegus species involved in this work are discussed. PMID:12696414

Bribosia, E; Bylemans, D; Van Impe, G; Migon, M

2002-01-01

86

Miocene Antarctic Terrestrial Realm  

NASA Astrophysics Data System (ADS)

The discovery of several locations in the Transantarctic Mountains that contain macrofossils and pollen is transforming our understanding of late Cenozoic Antarctica. The most southerly location is on the Beardmore Glacier (85.1°S) about 500 km from the South Pole. The environment was an active glacial margin in which plants, insects and freshwater mollusks inhabited the sand and gravel bars and small lakes on an outwash plain. In addition to leaves and wood of dwarf Nothofagus (Southern Beech) shrubs, achenes of Ranunculus (Buttercup), in situ cushion growth forms of mosses and a vascular plant, the assemblages contains various exoskeletal parts of carabid and curculionid beetles and a cyclorrhaphan fly, the shells of freshwater bivalve and gastropod species and a fish tooth. Initially the deposits were assigned a Pliocene age (3.5 Ma) but a mid- to early Miocene age is more probable (c. 14 - 25 Ma) based on correlation of fossil pollen from the deposits with 39Ar/40Ar dated pollen assemblages from the McMurdo Dry Valleys locations. The oldest location within the Dry Valleys also involved an active ice margin but was part of a valley system that was completely deglaciated for intervals long enough for thick paleosols to develop. The Friis Hills fossil deposits of the Taylor Valley region (77.8°S) are at least 19.76 Ma based on the 39Ar/40Ar age of a volcanic ash bed. The valley floor during the non-glacial phases had poorly-drained soils and the extensive development of mossy mires. Wood and leaves of Nothofagus are abundant in lacustrine deposits. The silts of shallow fluvial channels contain abundant megaspores and spiky leaves of the aquatic lycopod Isoetes (Quillwort). Fossils of beetles are also present in these deposits. During the glacial phases, proglacial lakes were surrounded by dwarfed, deciduous Nothofagus shrubs. The youngest fossils recovered from the Dry Valleys are from the Olympus Range (77.5°S) with an age of 14.07 Ma. The environment was an alpine lake that formed behind a recessional moraine. The fossils are mostly those of freshwater organisms including numerous species of diatoms and an ostracod species in which the soft anatomy is preserved. The base of the lake is marked by a moss bed with exceptionally well-preserved stems and leaves of the extant species Drepanocladus longifolius. Pollen evidence from the Cape Roberts borehole in the Ross Sea basin suggests that tundra existed from the Oligocene to the Early Miocene. Fossil evidence from the Dry Valleys locations indicates that organisms that could not inhabit Antarctica today persisted until c. 14 Ma. At 14 Ma there was a shift in glacial regimes from wet- to cold-based, marking a profound and abrupt climatic shift. We hypothesize that this climate change from warmer and wetter to colder and drier conditions caused the extinction of the tundra biota. It seems probable that at least some of the mid-Miocene fossils are of organisms whose descendants evolved in Antarctica during the Paleogene or earlier. An important consequence of this hypothesis is that the Cenozoic climate of Antarctica was warm enough until the mid-Miocene to support vascular plants and insects. This research was funded by NSF OPP 0739693.

Ashworth, A. C.; Lewis, A.; Marchant, D. R.

2009-12-01

87

Calcareous Nannofossil Evolution Vs. Climatic Evolution In The Miocene  

NASA Astrophysics Data System (ADS)

Miocene times were characterized by major changes in ocean circulation and global climate that were driven by a complex set of factors operating on tectonic, orbital and suborbital timescales (Zachos et al., 2001). This time dependent development of Miocene paleo-environmental conditions is reflected in the distribution and evolutionary patterns, often expressed in terms of biostratigraphic resolution, among the dominant sediment-forming oceanic plankton groups (Kennett & Srinivasan, 1983; Baldauf & Barron, 1990; Perch-Nielsen, 1985) including calcareous nannofossils. In the Miocene through Pleistocene interval, calcareous nannofossil evolutionary appearances or extinctions provide eight biostratigraphically useful biohorizons between 23 Ma and 14 Ma, giving an average rate of 1.5 biohorizon per million years. In the next following eight million years (14-5 Ma), the number of biohorizons are 29 (3.6 biohorizons/million years), representing well over a doubling of the rate of taxonomic evolution among open ocean calcareous nannofossils compared with that of the early half of the Miocene. This observation demonstrates that a distinct evolutionary response to climatic evolution throughout the Miocene, specifically to changing conditions in the photic zone of the middle and late Miocene oceans. This assumption is supported by the behavior of some nannofossil groups, in particular by the representatives of the genus Discoaster, a key group that gives nearly half (14 of 29) of biohorizons in the younger half of the Miocene. The Discoaster's environmental distribution and abundance may provide some information about the complex interaction between climatic evolution and biotic evolution in the plankton realm.

Raffi, I.; Backman, J.; Ciummelli, M.

2013-12-01

88

Genetic Relationships Among Some Hawthorn ( Crataegus spp.) Species and Genotypes  

Microsoft Academic Search

The genus Crataegus is well distributed in Turkey as a wild plant, with numerous, inherently variable species and genotypes. RAPD markers were\\u000a used to study 17 hawthorn genotypes belonging to Crataegus monogyna ssp. monogyna Jacq (2 genotypes), C. monogyna ssp. azarella Jacq (1), Crataegus pontica K.Koch (3), Crataegus orientalis var. orientalis Pallas Ex Bieb (3), Crataegus pseudoheterophylla Pojark (1), Crataegus

Kadir Ugurtan Yilmaz; Makbule Yanar; Sezai Ercisli; Hatice Sahiner; Tuncer Taskin; Yasar Zengin

2010-01-01

89

Hawthorn ( Crataegus monogyna Jacq.) extract exhibits atropine-sensitive activity in a cultured cardiomyocyte assay  

Microsoft Academic Search

Hawthorn (Crataegus spp.) plant extract is used as a herbal alternative medicine for the prevention and treatment of various cardiovascular diseases.\\u000a Recently, it was shown that hawthorn extract preparations caused negative chronotropic effects in a cultured neonatal murine\\u000a cardiomyocyte assay, independent of beta-adrenergic receptor blockade. The aim of this study was to further characterize the\\u000a effect of hawthorn extract to

Satin Salehi; Shannon R. Long; Philip J. Proteau; Theresa M. Filtz

2009-01-01

90

Parasitism of the apple maggot, Rhagoletis pomonella , infesting hawthorns in Washington  

Microsoft Academic Search

Five species of larval parasitoids were reared fromRhagoletis pomonella (Walsh) infested fruit of hawthorn,Crataegus, collected from several locations in southwest Washington over a four year period. A braconid,Biosteres melleus (Gahan), parasitized larvae infesting fruits of a native hawthorn species,Crataegus douglasii Lindl. Another braconid,Opius downesi Gahan, emerged exclusively fromR. pomonella pupae reared from fruits of an introduced species of hawthorn,Crataegus monogyna

L. J. Gut; J. F. Brunner

1994-01-01

91

Metal characterization of white hawthorn organs and infusions.  

PubMed

Hawthorn is one of the most commonly used European and North American phytopharmaceuticals. Because there is no information on metals in seeds, and only rare data for leaves and flowers, the aim of the present study was elemental analysis of the white hawthorn (Crataegus monogyna) by inductively coupled plasma emission spectrometry (ICP-AES) or inductively coupled plasma mass spectrometry (ICP-MS) after digestion in a microwave-assisted system. The limits of detection are below 2 ?g/g for ICP-AES and 0.5 ?g/g for ICP-MS. Hawthorn leaves and flowers contain essential elements at concentrations (mean values, RSD 2-8%) in mg/g of Ca, 1-4; K, 4-5; Mg, 1-2; and Na, <0.2); and at ?g/g levels of Ba, 1-10; Co, <0.16; Cr, <1.4; Cu, 0.6-7; Fe, 1-37; Li, <0.5; Mn, 1-13; Mo, <0.17; Ni, <0.6; Sr, 0.2-2; and Zn, 1-31. Toxic elements were found in low quantities: As (<0.04), Cd (0.04-0.1), and Pb (0.1-2). Up to 10% of the metals is extracted into the infusions. The analyzed plant parts and infusions contain essential elements justifying its use as a medicinal plant, whereas the low quantities of harmful elements will not pose any risk to humans when consumed. PMID:25630398

Juranovi? Cindri?, Iva; Zeiner, Michaela; Mihajlov Konanov, Darija; Stingeder, Gerhard

2015-02-18

92

A macroecological glance at the structure of late Miocene rodent assemblages from Southwest Europe  

PubMed Central

Deep-time perspectives in macroecology are essential with regard to understanding the impact of climate forcing on faunal communities. Using late Miocene rodent faunas (12 to 5?Ma) from two different biogeographical provinces from southwestern Europe, we asked whether the waxing and waning of faunas with dissimilar ecological affinities tracked climate in different ways. The latest middle Miocene featured a fauna dominated by dormice with forest and mixed-habitat affinities. This group declined towards the Upper Miocene. Rodent taxa with the highest values of richness at the beginning of the Upper Miocene are generalists in the southern province and specialists of forested habitats in the northern province. Finally, we identified a third, increasingly significant group of rodents linked to open landscapes towards the end of the Miocene. These three broad ecological groups showed differential responses to a complex set of interconnected circumstances, including the biogeographic structure of the study area and climatic changes throughout time. PMID:25297009

Cano, Ana Rosa Gómez; Cantalapiedra, Juan L.; Álvarez-Sierra, M. Ángeles; Fernández, Manuel Hernández

2014-01-01

93

A macroecological glance at the structure of late Miocene rodent assemblages from Southwest Europe.  

PubMed

Deep-time perspectives in macroecology are essential with regard to understanding the impact of climate forcing on faunal communities. Using late Miocene rodent faunas (12 to 5 Ma) from two different biogeographical provinces from southwestern Europe, we asked whether the waxing and waning of faunas with dissimilar ecological affinities tracked climate in different ways. The latest middle Miocene featured a fauna dominated by dormice with forest and mixed-habitat affinities. This group declined towards the Upper Miocene. Rodent taxa with the highest values of richness at the beginning of the Upper Miocene are generalists in the southern province and specialists of forested habitats in the northern province. Finally, we identified a third, increasingly significant group of rodents linked to open landscapes towards the end of the Miocene. These three broad ecological groups showed differential responses to a complex set of interconnected circumstances, including the biogeographic structure of the study area and climatic changes throughout time. PMID:25297009

Gómez Cano, Ana Rosa; Cantalapiedra, Juan L; Álvarez-Sierra, M Ángeles; Hernández Fernández, Manuel

2014-01-01

94

A macroecological glance at the structure of late Miocene rodent assemblages from Southwest Europe  

NASA Astrophysics Data System (ADS)

Deep-time perspectives in macroecology are essential with regard to understanding the impact of climate forcing on faunal communities. Using late Miocene rodent faunas (12 to 5 Ma) from two different biogeographical provinces from southwestern Europe, we asked whether the waxing and waning of faunas with dissimilar ecological affinities tracked climate in different ways. The latest middle Miocene featured a fauna dominated by dormice with forest and mixed-habitat affinities. This group declined towards the Upper Miocene. Rodent taxa with the highest values of richness at the beginning of the Upper Miocene are generalists in the southern province and specialists of forested habitats in the northern province. Finally, we identified a third, increasingly significant group of rodents linked to open landscapes towards the end of the Miocene. These three broad ecological groups showed differential responses to a complex set of interconnected circumstances, including the biogeographic structure of the study area and climatic changes throughout time.

Cano, Ana Rosa Gómez; Cantalapiedra, Juan L.; Álvarez-Sierra, M. Ángeles; Fernández, Manuel Hernández

2014-10-01

95

Miocene reefs of Dominican Republic  

SciTech Connect

The reefs are overlain by conglomeratic strata. The stratigraphic setting of these reefs suggests that they have developed along the stalled portions of rapidly prograding fan deltas. Thickets and layers of coral debris are found seaward and stratigraphically above the well-developed reef. The matrix sediments are exclusively fine-grained sand to mud, and the fauna are suggestive of more open shelf conditions. In thickets, branched (porites spp., Pocillopora spp.), small massive (Montastrea spp., Siderastrea spp.), and foliose or plate like (Agaricia spp.) corals are found upright in the muddy sediment. Similarities in coral species and areal proximity suggest that thickets are the source of most layers of coralline debris. The association of coral debris with graded bedding and cross-bedding suggests that coral debris has been reworked by storms. The growth of corals and development of coral reefs in the Miocene-Pliocene Yaque Group is limited only by opportunities created by the slowing of siliciclastic sedimentation. Soft, muddy, terrigenous substrates and a continuing supply of terrigenous mud exert only a limited, indirect effect on reef growth.

Evans, C.C.

1988-01-01

96

Miocene-Oligocene sequence stratigraphy of the Malay Basin  

SciTech Connect

The Malay Basin has experienced extension of the Eocene ( ) through Oligocene, sag in the early Miocene, and compression in the middle Miocene through Pliocene-Pleistocene. The interaction of structurally induced and glacial-eustatic accommodation changes has resulted in complex, interrelated play elements, including multiple reservoirs, diverse nonmarine sources, discontinuous migration pathways, and thin seals. Extensional subbasins were filled with braided streams, associated coastal plain, lacustrine deltas, and thick lake shales (groups M-K). This initial rift fill comprises an overall second order progradational cycle punctuated by 3rd-order cycles. These 3rd-order cycles are capped by thick, source-rich, lacustrine shale packages. The lower Miocene section (groups I and J) consists of progradational to aggradational fluvial to tidally-dominated estuarine sands. Hydrocarbons are generated from interbedded coals and other coal-related lithologies.

Lovell, R.; Elias, M.R. (Esso Production Malaysia Inc., Kuala Lumpur (Malaysia)); Hill, R.E.; Feeley, M.H. (Exxon Production Research Co., Houston, TX (United States))

1994-07-01

97

NGC 300: AN EXTREMELY FAINT, OUTER STELLAR DISK OBSERVED TO 10 SCALE LENGTHS J. Bland-Hawthorn  

E-print Network

NGC 300: AN EXTREMELY FAINT, OUTER STELLAR DISK OBSERVED TO 10 SCALE LENGTHS J. Bland-Hawthorn of the formation process (Freeman & Bland-Hawthorn 2002; van der Kruit 1987; Ferguson & Clarke 2001). By mea

Draine, Bruce T.

98

An overview of Miocene reefs  

SciTech Connect

Miocene reefs lived approximately within the latitudes of 27{degree}S to 48{degree}N compared with 25{degree}S and 32{degree}N for Holocene reefs. This expansion of reef-growing environments was the result of warm Miocene climates, aided by a eustatic sea level rise and tectonic styles that provided numerous foundations for reef development. The majority of Miocene reefs are found in three main areas: (1) Southeast Asia and the western Pacific, (2) the Mediterranean-Middle East, and (3) Middle America and the Caribbean. These regions, with their distinctive suites of coral and foramineral species, formed three biological provinces; respectively, they are the Indo-Pacific, Tethyan, and Western Atlantic provinces. Miocene reefs in Southeast Asia occur in several foreland basins as patch reef complexes on paleohighs and as barrier reefs in back-arc basins. Those reefs in the Mediterranean occur as fringing reefs, middle-shelf patch reefs, or as barrier reefs on the edges of tectonic blocks associated with Alpine thrust belts. Most reefs in the Caribbean grew on isolated open-ocean highs of volcanic origin. Miocene reefs display a diversity of framework types: (1) coral-encrusting, red algal boundstones with diverse coral faunas, (2) branching coral-encrusting, red algal boundstones with a limited Poritid fauna, (3) encrusting red algal boundstones. Barrier reef systems are especially rich in encrusting red algae and robust corals; grainstones are common as interbedded sediment. Patch reef complexes, however, display muddy carbonate textures, may have less diverse coral faunas, and commonly have larger foraminifera. The global distribution of Miocene reefs is important because (1) it provides insight into a paleoclimatic view of the earth during a major greenhouse stage and (2) Miocene buildups, such as the Arun (EUR of 14 tcf) and Bima fields (EUR of about 100 MMBO), are exploration targets.

Jordan, C.F. Jr. (Mobil Research and Development Corp., Dallas, TX (USA)); Colgan, M.W. (College of Charleston, SC (USA)); Frost, S.H. (Unocal, Los Angeles, CA (USA)); Glenn, E.C. (Phillips Petroleum, Bartlesville, OK (USA)); Bosence, D. (Royal Holloway and Bedford New College, Egham (England)); Esteban, M. (ERICO Petroleum Information Ltd., London (England))

1990-05-01

99

Ctenodactyloid rodent assemblage from Kargil Formation, Ladakh Molasse Group: Age and palaeobiogeographic implications for the Indian subcontinent in the Oligo-Miocene  

Microsoft Academic Search

Two ctenodactyloid rodents, Fallomus razaeFlynn, Jacobs & Cheema and F. ladakhensis nov. sp., arebeing described from the Kargil Formation of the Ladakh Molasse Group of Kargil area. Fallomus (? Chapattimyidae) is considered an endemic offshoot of the South Asian Eocene ctenodactyloid stock. The new species is relatively larger and more hypsodont with an ectostylid borne on a separate pillar. At

Avinash C. Nanda; Ashok Sahni

1998-01-01

100

Development of an economic model to assess the cost-effectiveness of hawthorn extract as an adjunct treatment for heart failure in Australia  

PubMed Central

Objective An economic model was developed to evaluate the cost-effectiveness of hawthorn extract as an adjunctive treatment for heart failure in Australia. Methods A Markov model of chronic heart failure was developed to compare the costs and outcomes of standard treatment and standard treatment with hawthorn extract. Health states were defined by the New York Heart Association (NYHA) classification system and death. For any given cycle, patients could remain in the same NYHA class, experience an improvement or deterioration in NYHA class, be hospitalised or die. Model inputs were derived from the published medical literature, and the output was quality-adjusted life years (QALYs). Probabilistic sensitivity analysis was conducted. The expected value of perfect information (EVPI) and the expected value of partial perfect information (EVPPI) were conducted to establish the value of further research and the ideal target for such research. Results Hawthorn extract increased costs by $1866.78 and resulted in a gain of 0.02 QALYs. The incremental cost-effectiveness ratio was $85?160.33 per QALY. The cost-effectiveness acceptability curve indicated that at a threshold of $40?000 the new treatment had a 0.29 probability of being cost-effective. The average incremental net monetary benefit (NMB) was ?$1791.64, the average NMB for the standard treatment was $92?067.49, and for hawthorn extract $90?275.84. Additional research is potentially cost-effective if research is not proposed to cost more than $325 million. Utilities form the most important target parameter group for further research. Conclusions Hawthorn extract is not currently considered to be cost-effective in as an adjunctive treatment for heart failure in Australia. Further research in the area of utilities is warranted. PMID:22942231

Ford, Emily; Adams, Jon; Graves, Nicholas

2012-01-01

101

The Impact of the Hawthorne Effect in Experimental Designs in Educational Research. Final Report.  

ERIC Educational Resources Information Center

Project objectives included (1) establishing a body of knowledge concerning the role of the Hawthorne effect in experimental designs in educational research, (2) assessing the influence of the Hawthorne effect on educational experiments conducted under varying conditions of control, (3) identifying the major components comprising the effect, and…

Cook, Desmond L.

102

Metsulfuron spray drift reduces fruit yield of hawthorn ( Crataegus monogyna L.)  

Microsoft Academic Search

This study was carried out to investigate whether spray drift of metsulfuron has a potential to negatively affect hawthorn (Crataegus monogyna) hedgerows near agricultural fields. For this purpose four doses of metsulfuron ranging from 5% to 40% of the field dose (4 g metsulfuron per hectare) were sprayed on trees in seven different hawthorn hedgerows. The actual deposition on the

Christian Kjær; Morten Strandberg; Mogens Erlandsen

2006-01-01

103

THE HAWTHORNE EXPERIMENTS AND THE INTRODUCTION OF JEAN PIAGET IN AMERICAN INDUSTRIAL PSYCHOLOGY, 1929–1932  

Microsoft Academic Search

The Hawthorne interview program between 1929 and 1932 was one of the most significant industrial studies in the United States. The Hawthorne researchers applied Jean Piaget’s clinical method in their extensive interviews with tens of thousands of workers. Chiefly responsible for the program’s methodology was Elton Mayo, an Australian who saw interviewing as a means to promote social cooperation. Previous

Yeh Hsueh

2002-01-01

104

Hawthorn extract for treating chronic heart failure: meta-analysis of randomized trials  

Microsoft Academic Search

The aim of this meta-analysis was to assess the evidence from rigorous clinical trials of the use of hawthorn extract to treat patients with chronic heart failure. We searched the literature using MEDLINE, EMBASE, the Cochrane Library, CINAHL, CISCOM, and AMED. Experts on and manufacturers of com- mercial preparations containing hawthorn extract were asked to contribute published and unpublished studies.

Max H. Pittler; S. Schmidt; Edzard Ernst

2003-01-01

105

Student Houses: The Hawthorns All the key information you need for arrivals weekend for your residence, including how to  

E-print Network

Student Houses: The Hawthorns Moving in All the key information you need for arrivals weekend The official arrivals day The Hawthorns is Saturday 20 September between 9am and 4pm and all your events car parking available at The Hawthorns, so it is very important that you try to stick to your

Bristol, University of

106

43J. Environ. Hort. 25(1):4346. March 2007 Residual Toxicity of Imidacloprid to Hawthorn Lace Bug,  

E-print Network

43J. Environ. Hort. 25(1):43­46. March 2007 Residual Toxicity of Imidacloprid to Hawthorn Lace Bug Cotoneasters are important and valuable landscape plants. They are severely attacked by hawthorn lace bug of imidacloprid in landscapes and containers remained toxic to hawthorn lace bugs for more than one growing season

Eubanks, Micky

107

A Revised Interpretation of 3D Seismic Data, Hawthorne Army Depot, Nevada: FaultedBasin Reflections or Sill Intrusions?  

E-print Network

A Revised Interpretation of 3D Seismic Data, Hawthorne Army Depot, Nevada: Faulted Programs Office, U.S. Navy China Lake Naval Weapons Center, Ridgecrest, CA, USA The Hawthorne as seen in Long Valley, California (Bursik & Sieh, 1989) (figure 1). Figure 1: (A) Shows Hawthorne

108

The 2011 Hawthorne, Nevada, Earthquake Sequence; Shallow Normal Faulting  

NASA Astrophysics Data System (ADS)

An energetic sequence of shallow earthquakes that began in early March 2011 in western Nevada, near the community of Hawthorne, has slowly decreased in intensity through mid-2011. To date about 1300 reviewed earthquake locations have been compiled; we have computed moment tensors for the larger earthquakes and have developed a set of high-precision locations for all reviewed events. The sequence to date has included over 50 earthquakes ML 3 and larger with the largest at Mw 4.6. Three 6-channel portable stations configured with broadband sensors and accelerometers were installed by April 20. Data from the portable instruments is telemetered through NSL's microwave backbone to Reno where it is integrated with regional network data for real-time notifications, ShakeMaps, and routine event analysis. The data is provided in real-time to NEIC, CISN and the IRIS DMC. The sequence is located in a remote area about 15-20 km southwest of Hawthorne in the footwall block of the Wassuk Range fault system. An initial concern was that the sequence might be associated with volcanic processes due to the proximity of late Quaternary volcanic flows; there have been no volcanic signatures observed in near source seismograms. An additional concern, as the sequence has proceeded, was a clear progression eastward toward the Wassuk Range front fault. The east dipping range bounding fault is capable of M 7+ events, and poses a significant hazard to the community of Hawthorne and local military facilities. The Hawthorne Army Depot is an ordinance storage facility and the nation's storage site for surplus mercury. The sequence is within what has been termed the 'Mina Deflection' of the Central Walker Lane Belt. Faulting along the Whiskey Flat section of the Wassuk front fault would be primarily down-to-the-east, with an E-W extension direction; moment tensors for the 2011 earthquake show a range of extension directions from E-W to NW-SE, suggesting a possible dextral component to the Wassuk Range front fault at this latitude. At least two faults have been imaged within the sequence; these structures are at shallow depth (3-6 km), strike NE, and dip ~NW. Prior to temporary station installation event depths were poorly constrained, with the nearest network station 25 km from the source area. Early sequence moment tensor solutions show depths are on the order of 2-6 km and locations using the near source stations also confirm the shallow depths of the Hawthorne sequence. S-P times of 0.5 sec and less have been observed on a near-source station, illustrating extremely shallow source depths for some events. Along with the 2011 Hawthorne activity, very shallow depths in Nevada have been observed from near source stations in the 2008 west Reno earthquake sequence (primarily strike-slip faulting; main shock Mw 5.0) and the 1993 Rock Valley sequence in southern NNSS (strike-slip faulting; main shock Mw 4.0). These shallow sequences tend to include high rates of low magnitude earthquakes continuing over several months duration.

Smith, K. D.; Johnson, C.; Davies, J. A.; Agbaje, T.; Knezevic Antonijevic, S.; Kent, G.

2011-12-01

109

The "Hawthorne effect" is a myth, but what keeps the story going?  

PubMed

The Hawthorne studies became famous because of the discovery of the "Hawthorne effect": "a marked increase in production related only to special social position and social treatment". They mark the beginning of the Human Relations School. This article demonstrates that the Hawthorne research does not pass a methodological quality test. Even if methodological shortcomings were waived, there is no proof of a Hawthorne effect in the original data. The following five myths are debunked: (i) scientific worth, (ii) continuous improvement, (iii) social factors prevailing over physical factors and pay, (iv) wholehearted cooperation, and (v) the neurotic worker. The following five factors are held responsible for the creation and survival of the Hawthorne myth: (i) a story too good to be untrue, (ii) bias and selective accounts by original researchers and "laziness" among later scientists, (iii) social factors do matter, and (iv) a story that fits the cognitive world and interests of psychologists, and (v) management. PMID:17091208

Kompier, Michiel A J

2006-10-01

110

Miocene waterfowl and other birds from central Otago, New Zealand  

Microsoft Academic Search

Abundant fossil bird bones from the lower Bannockburn Formation, Manuherikia Group, an Early?Middle Miocene lacustrine deposit, 16–19 Ma, from Otago in New Zealand, reveal the “St Bathans Fauna” (new name), a first Tertiary avifauna of land and freshwater birds from New Zealand. At least 23 species of birds are represented by bones, and probable moa, Aves: Dinornithiformes, by eggshell. Anatids

T. H. Worthy; A. J. D. Tennyson; C. Jones; J. A. McNamara; B. J. Douglas

2007-01-01

111

1, 167188, 2006 Late Miocene River  

E-print Network

eED 1, 167­188, 2006 Late Miocene River Euphrates T. Demir et al. Title Page Abstract Introduction is the access reviewed discussion forum of eEarth Location of the River Euphrates in the Late Miocene; dating Miocene River Euphrates T. Demir et al. Title Page Abstract Introduction Conclusions References Tables

Boyer, Edmond

112

Energy Engineering Analysis Program, limited energy study of steam distribution systems, Hawthorne Army Ammunition Depot, Hawthorne, Nevada. Energy report  

SciTech Connect

This report summarizes all work of the Limited Energy Study of Steam Distribution Systems, Energy Engineering Analysis Program, Hawthorne Army Ammunition Depot (HWAAD), Nevada. The purpose of this limited energy study is to evaluate steam distribution and condensate collection systems in both the Industrial Area and Ordnance Area of HWAAD to develop a set of replacement actions that will reduce energy consumption and operating costs. These efforts consist of corrections and revisions to previously submitted funding requests. A number of facilities covering over 140,000 acres constitute HWAAD; however, this study was limited to the Industrial and Ordnance Areas.

NONE

1995-07-01

113

Outpatient process quality evaluation and the Hawthorne Effect.  

PubMed

We examine the evidence that the behavior of clinicians is impacted by the fact that they are being observed by a research team. Data on the quality of care provided by clinicians in Arusha region of Tanzania show a marked fall in quality over time as new patients are consulted. By conducting detailed interviews with patients who consulted both before and after our research team arrived we are able to show strong evidence of the Hawthorne effect. Patient-reported quality is steady before we arrive, rises significantly (by 13 percentage points) at the moment we arrive and then falls steadily thereafter. We show that quality after we arrive begins to look similar to quality before we arrived between the 10th and 15th consultations. Implications for quality measurement and policy are discussed. PMID:16887245

Leonard, Kenneth; Masatu, Melkiory C

2006-11-01

114

The Hawthorne experiments and the introduction of Jean Piaget in American industrial psychology, 1929-1932.  

PubMed

The Hawthorne interview program between 1929 and 1932 was one of the most significant industrial studies in the United States. The Hawthorne researchers applied Jean Piaget's clinical method in their extensive interviews with tens of thousands of workers. Chiefly responsible for the program's methodology was Elton Mayo, an Australian who saw interviewing as a means to promote social cooperation. Previous discussions of the Hawthorne experiments have ignored the influence of Piaget in the social sciences. This article provides an account of Mayo's and the Hawthorne researchers' efforts to fuse Piaget's innovation with burgeoning American industrial psychology. The endeavor was not an isolated event but rather drew on the theories and practice of Janet-Piaget psychology, on the support of the Laura Spelman Rockefeller Memorial Foundation, and on the discourse among social scientists about Piaget's work. PMID:12096759

Hsueh, Yeh

2002-05-01

115

Radioprotective effects of hawthorn against genotoxicity induced by gamma irradiation in human blood lymphocytes  

Microsoft Academic Search

The radioprotective effect of hawthorn (Crataegus microphylla) fruit extract was investigated in cultured blood lymphocytes from human volunteers. Peripheral blood samples were collected\\u000a from five human volunteers 10 min before and 1, 2 and 3 h after a single oral ingestion of 500 mg hawthorn powder extract.\\u000a At each time point, the whole blood was exposed in vitro to 150 cGy of cobalt-60 gamma

Seyed Jalal Hosseinimehr; Aziz Mahmoudzadeh; Mohammad Azadbakht; Shahram Akhlaghpoor

2009-01-01

116

Hawthorn fruit increases the antioxidant capacity and reduces lipid peroxidation in senescence-accelerated mice  

Microsoft Academic Search

Hawthorn fruit has long been used as a folk medicine with many medicinal benefits. HPLC analysis revealed that hawthorn fruit\\u000a extract (HFE) contained 19.86% procyanidin B2, 15.27% epicatechin, 3.10% chlorogenic acid, 2.91% hyperoside, and 1.34% isoquercitrin.\\u000a Antioxidants are essential for protection of the bodies against the damaging action of free radicals. And we hypothesized\\u000a that HFE could enhance antioxidant defenses

Hao WangZesheng; Zesheng Zhang; Ying Guo; Ping Sun; Xiaoling Lv; Yanbo Zuo

2011-01-01

117

Hawthorn extract for treating chronic heart failure: meta-analysis of randomized trials.  

PubMed

The aim of this meta-analysis was to assess the evidence from rigorous clinical trials of the use of hawthorn extract to treat patients with chronic heart failure. We searched the literature using MEDLINE, EMBASE, the Cochrane Library, CINAHL, CISCOM, and AMED. Experts on and manufacturers of commercial preparations containing hawthorn extract were asked to contribute published and unpublished studies. There were no restrictions about the language of publication. Two reviewers independently performed the screening of studies, selection, validation, data extraction, and the assessment of methodological quality. To be included, studies were required to state that they were randomized, double-blind, and placebo controlled, and used hawthorn extract monopreparations. Thirteen trials met all inclusion criteria. In most of the studies, hawthorn was used as an adjunct to conventional treatment. Eight trials including 632 patients with chronic heart failure (New York Heart Association classes I to III) provided data that were suitable for meta-analysis. For the physiologic outcome of maximal workload, treatment with hawthorn extract was more beneficial than placebo (weighted mean difference, 7 Watt; 95% confidence interval [CI]: 3 to 11 Watt; P < 0.01; n = 310 patients). The pressure-heart rate product also showed a beneficial decrease (weighted mean difference, -20; 95% CI: -32 to -8; n = 264 patients) with hawthorn treatment. Symptoms such as dyspnea and fatigue improved significantly with hawthorn treatment as compared with placebo. Reported adverse events were infrequent, mild, and transient; they included nausea, dizziness, and cardiac and gastrointestinal complaints. In conclusion, these results suggest that there is a significant benefit from hawthorn extract as an adjunctive treatment for chronic heart failure. PMID:12798455

Pittler, Max H; Schmidt, Katja; Ernst, Edzard

2003-06-01

118

Mediterranean Miocene carbonates: facies models and diagenesis  

SciTech Connect

Miocene carbonates can bridge the gap between Holocene and older carbonate sequences, thus enhancing understanding of depositional and diagenetic patterns. Miocene carbonates can bridge this gap because of their similarity to Holocene counterparts and the ease of using these carbonates to reconstruct tectonic, paleogeographic, and paleoclimatic settings. In the Mediterranean, the Miocene provides a superb set of exposures and a wide variety of facies models in different geologic settings.

Esteban, M.E.

1987-11-01

119

Apatite (U-Th)/He Thermochronometry as an innovative Geothermal Exploration Tool - A case study from the Wassuk Range, Hawthorne, Nevada  

NASA Astrophysics Data System (ADS)

A utility-grade geothermal system requires increased, near-surface temperatures (>120°C), water to transfer heat, and structural or sedimentological fluid conduits. In extensional tectonic settings, geothermal anomalies often occur in areas with recent, high strain accumulation and complex faulting (i.e., cross-faults, accommodation zones) where exhumation and uplift of footwall rocks transfer heat, via advection, to the near-surface which is further carried by water through structural fluid conduits. Apatite helium (AHe) thermochronometric footwall age mapping can be used in conjunction with these genetic occurrence models to further focus regional-scale geothermal exploration efforts to areas of probabilistic increased fracture permeability and most recent, rapid footwall exhumation. Furthermore, partially reset apatites resulting from interaction with hydrothermal fluids (>40°C) will show which areas have been hottest most recently. This case study in the Wassuk Range, Hawthrone, NV confirms the utility of AHe thermochronometry as a geothermal exploration tool. A dense grid of footwall samples were collected adjacent to the Hawthorne geothermal anomaly (>85°C BHT) located in the hanging wall of the Wassuk Range block. Our data show that the location of the present-day geothermal anomaly correlates with the location of 1) the most recent episode of rapid footwall exhumation at 3.5-4 Ma, 2) km scale accommodation zones between differentially tilted Wassuk Range blocks, and 3) an elevated Miocene geothermal gradient. Furthermore, anomalously young AHe ages (<3.5 Ma) mimic the lateral extent of the Hawthorne geothermal anomaly and likely resulted from interaction with a deep-seated geothermal cell or hot hydrothermal fluids.

Gorynski, K. E.; Stockli, D. F.; Walker, J. D.

2010-12-01

120

MIOCENE AND PLIOCENE VERTEBRATES FROM ARIZONA  

Microsoft Academic Search

We present an overview of the Miocene and Pliocene vertebrates of Arizona, spanning the time period from about 2 to 20 Ma. The best known Miocene faunas are Wellton and Anderson Mine from the late Arikareean or Hemingfordian North American land-mammal \\

GARY S. MORGAN; RICHARD S. WHITE

2005-01-01

121

The Effects of Using In-Class Focus Groups on Student Course Evaluations.  

ERIC Educational Resources Information Center

Student course evaluations were collected from four sections of finance course (two included focus groups). Student recommendations were implemented in all four. Students in focus group sections reported higher satisfaction with the course, perhaps due to the Hawthorne Effect. (SK)

Hamilton, Diane M.; Pritchard, Robert E.; Welsh, Carol N.; Potter, Gregory C.; Saccucci, Michael S.

2002-01-01

122

Intentional use of the Hawthorne effect to improve oral hygiene compliance in orthodontic patients.  

PubMed

The purpose of this study was to evaluate whether the home care of noncompliant adolescent orthodontic patients with "poor" oral hygiene could be improved through the use of a deception strategy designed to intentionally induce the Hawthorne effect. This effect is often cited as being responsible for oral health improvements of control groups that receive placebo treatments. It is thought that participating in and fulfilling the requirements of a study alters subjects' behavior, thereby contributing to the improvement. Forty patients with histories of poor oral hygiene were assigned, in a quasi-random fashion, to two groups. Experimental subjects (n = 20) were presented with a situation that simulated participation in an experiment. These included the use of a consent form; distribution of tubes of toothpaste labeled "experimental"; instructions to brush twice a day for two minutes using a timer; and a request to return unused toothpaste. Control subjects (n = 20) had no knowledge of study participation. Tooth surface area covered with plaque was used as a proxy measure of home care behavior. It was measured at baseline, three months, and six months. Mean percentages of tooth surface covered with plaque for the experimental and control groups were 71 (+/- 11.52) and 74 (+/- 11.46) at baseline; 54 (+/- 13.79) and 78 (+/- 12.18) at three months; and 52 (+/- 13.04) and 79 (+/- 10.76) at six months. No statistically significant difference (p > .05) was obtained between groups at baseline. Statistically significant differences (p < .05) were found between groups at three and six months. Significant differences (p < .05) were also found only for the experimental subjects between baseline and each of the two subsequent observation periods. The efficiency and potential effectiveness of this strategy suggest that additional research be conducted to assess oral health improvements and possible applications to the private practice setting. PMID:12449206

Feil, Philip H; Grauer, Jennifer Sherah; Gadbury-Amyot, Cynthia C; Kula, Katherine; McCunniff, Michael D

2002-10-01

123

Miocene reefs in western Mediterranean  

SciTech Connect

Coral reefs were particularly abundant and well developed during the late Tortonian and Messinian in southeastern Spain, the Balearic Islands, Italy, Sicily, Algeria, and Morocco. These reefs occurred just before and during the deposition of the thick Messinian evaporite units in the basinal areas and disappeared completely from Mediteranean during the early Pliocene. Most of the coral reefs are fringing terrigenous coastal fan complexes with very small lagoons and show progradation of less than 2 km. Some of the reefs occur on, or are intercalated with, Neogene volcanics or Messinian evaporites. Barrier-reef complexes are less common, have extensive lagoons behind them, and show complex progradational geometries more than 10 km wide. Excellent outcrops allow detailed reconstruction of paleogeography and sea level changes. Progradation predominated during phases of relative sea level drops and stillsands, while significant retrogradation occurred during sea level rises. The coral reef wall framework is commonly less than 20 m thick and is dominated by Porites and, locally, Tarbellastrae. Older Miocene reefs are less well developed, but show greater diversity of corals and reef organisms. Younger Miocene reef complexes occurring in open ocean settings are formed by only one branching coral genus (Porites or, locally, Tarbellastraea) with branching colonies up to 7 m high. Halimeda sands are particularly abundant in the upper reef slopes with occasional intercalations of red algae pavements that most likely coincide with episodes of terrigenous influx.

Esteban, M.

1988-01-01

124

Regulation of lipoprotein lipase expression by effect of hawthorn flavonoids on peroxisome proliferator response element pathway.  

PubMed

To investigate the possibility that natural medicines affect lipid metabolism by regulating lipoprotein lipase (LPL) expression, a green fluorescent protein (GFP) gene was constructed downstream of the peroxisome proliferator response element (PPRE) and the constructed plasmid was microinjected into Xenopus oocytes to establish a PPRE regulatory reporter system. Using this system, hawthorn flavonoids were quickly selected from a panel of natural medicines and found to up-regulate GFP expression by an effect on PPRE. To confirm the effect of hawthorn flavonoids, we treated mice orally with water (control), hawthorn flavonoids, and pioglitazone and measured the LPL levels in serum, adipose tissue, and muscle by an enzyme-linked immunosorbent assay. The serum LPL levels were no different from the controls after treatment with either hawthorn flavonoids or pioglitazone, but LPL increased significantly in muscular tissues and decreased in adipose tissues. These results demonstrate that hawthorn flavonoids meditate LPL expression in mice with tissue-specific differences. A novel PPRE regulatory report system was established for rapid and effective selection and evaluation of LPL-mediating drugs. PMID:16404131

Fan, Chunlei; Yan, Jin; Qian, Ying; Wo, Xingde; Gao, Liping

2006-01-01

125

Comparative Protective Effect of Hawthorn Berry Hydroalcoholic Extract, Atorvastatin, and Mesalamine on Experimentally Induced Colitis in Rats  

PubMed Central

Abstract The protective effect of hydroalcoholic extract of hawthorn berries (HBE) on acetic acid (AA)–induced colitis in rats was investigated. Forty-two Wistar rats were divided into seven groups, including control and test groups (n=6). The control animals received saline, and the test animals were treated with saline (sham group), mesalamine (50?mg/kg; M group), atorvastatin (20?mg/kg; A group), HBE (100?mg/kg; H group), mesalamine and HBE (HM group), or atorvastatin plus HBE (HA group), 3 days before and a week after colitis induction. Colitis was induced by administration of 1?mL AA (4%) via a polyethylene catheter intrarectally. High-performance liquid chromatography analyses showed that HBE contained 0.13% and 0.5% oleanolic acid and ursolic acid, respectively. Elevated myeloperoxidase activity and lipid peroxidation were attenuated in the HA group. The H and HM groups showed marked reductions in colitis-induced decreases in total thiol molecules and body weight. The histopathological studies revealed that HBE decreased colitis-induced edema and infiltration of neutrophils. Our data suggest the anti-inflammatory and antioxidant effects of HBE and atorvastatin protect against AA-induced colitis. The anti-inflammatory effect of HBE may be attributable to its ability to decrease myeloperoxidase activity as a biomarker of neutrophil infiltration. PMID:23875899

Shafie-Irannejad, Vahid; Hobbenaghi, Rahim; Tabatabaie, Seyed Hamed; Moshtaghion, Seyed-Mehdi

2013-01-01

126

Energy Engineering Analysis Program, limited energy study of steam distribution systems, Hawthorne Army Ammunition Depot, Hawthorne, Nevada  

SciTech Connect

This report summarizes all work of the Limited Energy Study of Steam Distribution Systems, Energy Engineering Analysis Program, Hawthorne Army Ammunition Depot (HWAAD), Nevada. The project is authorized under Contract No. DACA05-92-C-0155 with the U.S. Army Corps of Engineers, Sacramento District, California. The purpose of this limited energy study is to evaluate steam distribution and condensate collection systems in both the Industrial Area and Ordnance Area of HWAAD to develop a set of replacement actions that will reduce energy consumption and operating costs. These efforts consist of corrections and revisions to previously submitted funding requests. Amended DD Forms 1391 and supporting documentation are prepared for: (1) Project 40667, Modernize Steam Distribution System, Industrial Area, and (2) Project 42166, Modernize Ordnance Area Steam Distribution, Ordnance Area. HWAAD is located next to Highway 95 near the center of Nevada`s border with California, about 130 miles southeast of Reno. The elevation is about 4,100 feet. The location is depicted on Figure 1-1. A number of facilities covering over 140,000 acres constitute HWAAD; however, this study was limited to the Industrial and Ordnance Areas.

NONE

1995-12-31

127

Headspace solid-phase microextraction analysis of volatile compounds in hawthorn vinegars fermented by two strains of Acetobacter  

Microsoft Academic Search

Hawthorn (Crataegus oxyacantha), which is wildly distributed in northern China, has a long history as a medicinal substance, for the treatment of digestive ailments, dyspnea, kidney stones and cardiovascular disorders, etc. Today, it is currently used for the juice production and is used as the raw material for hawthorn wine and vinegar production. However, the flavor of fruit vinegars diversifies

Yu Zheng; Hongxiang Liu; Keping Zhang; Min Wang

2010-01-01

128

Effect of hawthorn ( Crataegus oxycantha) crude extract and chromatographic fractions on multiple activities in a cultured cardiomyocyte assay  

Microsoft Academic Search

Extracts of hawthorn (Crataegus oxycantha) have become popular herbal supplements for their well-recognized cardiotonic effects. Many commercial preparations have been used successfully in the treatment of congestive heart failure, although the active principles within these extracts have yet to be conclusively identified. Several hawthorn preparations were studied and found to have negative chronotropic effects in a cultured neonatal murine cardiomyocyte

S. R. Long; R. A. Carey; K. M. Crofoot; P. J. Proteau; T. M. Filtz

2006-01-01

129

Identification of host fruit volatiles from domestic apple (Malus domestica), native black hawthorn (Crataegus douglasii) and introduced ornamental hawthorn (C. monogyna) attractive to Rhagoletis pomonella flies from the western United States.  

PubMed

The apple maggot fly, Rhagoletis pomonella, infests apple (Malus domestica) and hawthorn species (most notably the downy hawthorn, Crataegus mollis) in the eastern USA. Evidence suggests that the fly was introduced into the western USA sometime in the last 60 years. In addition to apple, R. pomonella also infests two species of hawthorns in the western USA as major hosts: the native black hawthorn (C. douglasii) and the introduced ornamental English hawthorn, C. monogyna. Apple and downy hawthorn-origin flies in the eastern USA use volatile blends emitted from the surface of their respective ripening fruit to find and discriminate among host trees. To test whether the same is true for western flies, we used coupled gas chromatography and electroantennographic detection (GC-EAD) and developed a 7-component apple fruit blend for western apple-origin flies, an 8-component black hawthorn fruit blend for flies infesting C. douglasii, and a 9-component ornamental hawthorn blend for flies from C. monogyna. Crataegus douglasii and C. monogyna-origin flies showed similar levels of upwind directed flight to their respective natal synthetic fruit blends in flight tunnel assays compared to whole fruit adsorbent extracts, indicating that the blends contain all the behaviorally relevant fruit volatiles to induce maximal response levels. The black and ornamental hawthorn blends shared four compounds in common including 3-methylbutan-1-ol, which appears to be a key volatile for R. pomonella populations in the eastern, southern, and western USA that show a preference for fruit from different Crataegus species. However, the blends also differed from one another and from domesticated apple in several respects that make it possible that western R. pomonella flies behaviorally discriminate among fruit volatiles and form ecologically differentiated host races, as is the case for eastern apple and hawthorn flies. PMID:22399441

Cha, Dong H; Yee, Wee L; Goughnour, Robert B; Sim, Sheina B; Powell, Thomas H Q; Feder, Jeffrey L; Linn, Charles E

2012-03-01

130

Changes in physicochemical characteristics and free amino acids of hawthorn (Crataegus pinnatifida) fruits during maturation.  

PubMed

In this study, changes in physicochemical characteristics associated with fruit quality and free amino acids were investigated during maturation of hawthorn fruits. Significant differences in these parameters were found during maturation. The color turned progressively from mature green to semi-red, to reach bright red; the shape changed gradually from oval to round or approached round; the size, weight, and edible part (flesh/core ratio) of hawthorns increased while the density of intact fruits did not change. The content of moisture, total soluble sugars, soluble pectin, reduced ascorbic acid, total ascorbic acid, fructose, and sucrose increased while crude protein content decreased significantly. The levels of starch, sucrose, titratable acidity, protopectin, pectin, total free amino acids, and total essential amino acids initially increased and then decreased gradually during maturation. The outcomes of this study provide additional and useful information for fresh consumption and processing as well as utilization of dropped unripe hawthorn fruits. PMID:25577050

Li, Wei-Qin; Hu, Qing-Ping; Xu, Jian-Guo

2015-05-15

131

Applied environmental stresses to enhance the levels of polyphenolics in leaves of hawthorn plants.  

PubMed

In this investigation, two species of Crataegus (hawthorn) were chosen because their polyphenolic constituents have recently received greater attention for the treatment of patients with severe heart disease. One-year-old plants of hawthorn (Crataegus laevigata and C. monogyna) were subjected to water-deficit (continuous water deprivation), cold (4 degrees C), flooding (immersion of roots of plants in water) or herbivory (leaf removal) stress treatments (each of 10 days duration) in order to assess their effects on levels of polyphenolics, namely (-)-epicatechin, catechin, chlorogenic acid, vitexin, vitexin-2"-O-rhamnoside, acetylvitexin-2"-O-rhamnoside, hyperoside, quercetin, and rutin in the leaves. The working hypothesis followed is that one or more of these stress treatment will elicit increases in the levels of these polyphenolics. Cold stress causes increases in levels of vitexin-2"-O-rhamnoside, acetylvitexin-2"-O-rhamnoside, hyperoside, and quercetin in both Crataegus species. Water-deficit stress increased the productivity of chlorogenic acid, catechin, and (-)-epicatechin in both hawthorn species. Flooding and herbivory caused no net increases, and in some cases, decreases in levels of polyphenolics. These studies indicate that either water-deficit stress or cold stress treatments, or a combination of the two, can be used to enhance the levels of desired polyphenolics in the leaves of these two hawthorn species in a photobioreactor system. These results may have significance for hawthorn in adapting to water-deficit or cold stress and are important considerations for the use of hawthorn in the treatment of heart disease in humans. PMID:15153184

Kirakosyan, Ara; Kaufman, Peter; Warber, Sara; Zick, Suzanna; Aaronson, Keith; Bolling, Steven; Chul Chang, Soo

2004-06-01

132

Panafrican distribution of Lower Miocene Hominoidea  

NASA Astrophysics Data System (ADS)

Palaeontological survey of the Neogene littoral deposits of the Namaqualand coastal strip, Northern Cape Province, South Africa, has resulted in the collection of the first Lower Miocene faunas from South Africa. Among the mammals from Ryskop and Hondeklip Bay is a gorilla-sized hominoid. This discovery greatly increases the geographic range of early Miocene hominoids and suggests that even at this remote epoch, the superfamily had a Panafrican distribution.

Senut, Brigitte; Pickford, Martin; Wessels, Dudley

1997-11-01

133

Energy Engineering Analysis Program, energy survey of Army Industrial Facilities, Western Area Demilitarization Facility Hawthorne Ermy Ammunition Plant Hawthorne, Nevada. Volume 1. Final report  

SciTech Connect

This report summarizes all work for the Energy Survey of Army Industrial Facilities, Energy Engineering Analysis Program (EEAP) at the Western Area Demilitarization Facility (WADF) of the Hawthorne Army Ammunition Plant (HWAAP), Hawthorne, Nevada, authorized under Contract No. DACA03-92-C-0155 with the U.S. Army Corps of Engineers, Sacramento District, California. The purpose of this energy survey is to develop a set of projects and actions that will reduce energy consumption and operating costs of selected facilities at the WADF. A preliminary inspection of facilities at WADF by Keller Gannon that identified potential retrofit opportunities was submitted as the EEAP Study and Criteria Review in December 1993. This document formed the basis of the Detailed Scope of Work for this study. Facilities included in the survey and study, together with operational status, are listed in Table 1 - 1. The complete scope of work appears in Appendix.

NONE

1995-03-17

134

Energy Engineering Analysis Program, energy survey of Army Industrial Facilities, Western Area Demilitarization Facility, Hawthorne Army Ammunition Plant, Hawthorne, Nevada; Volume 1 - energy report. Final report  

SciTech Connect

This report summarizes all work for the Energy Survey of Army Industrial Facilities, Energy Engineering Analysis Program (EEAP) at the Western Area Demilitarization Facility (WADF) of the Hawthorne Army Ammunition Plant (HWAAP), Hawthorne, Nevada, authorized under Contract No. DACA05-92-C-0155 with the U.S. Army Corps of Engineers, Sacramento District, California. The purpose of this energy survey is to develop a set of projects and actions that will reduce energy consumption and operating costs of selected facilities at the WADF. A preliminary inspection of facilities at WADF by Keller Gannon that identified potential retrofit opportunities was submitted as the EEAP Study and Criteria Review in December 1993. This document formed the basis of the Detailed Scope of Work for this study. Facilities included in the survey and study, together with operational status.

NONE

1995-03-17

135

Allopolyploidy, diversification, and the Miocene grassland expansion.  

PubMed

The role of polyploidy, particularly allopolyploidy, in plant diversification is a subject of debate. Whole-genome duplications precede the origins of many major clades (e.g., angiosperms, Brassicaceae, Poaceae), suggesting that polyploidy drives diversification. However, theoretical arguments and empirical studies suggest that polyploid lineages may actually have lower speciation rates and higher extinction rates than diploid lineages. We focus here on the grass tribe Andropogoneae, an economically and ecologically important group of C4 species with a high frequency of polyploids. A phylogeny was constructed for ca. 10% of the species of the clade, based on sequences of four concatenated low-copy nuclear loci. Genetic allopolyploidy was documented using the characteristic pattern of double-labeled gene trees. At least 32% of the species sampled are the result of genetic allopolyploidy and result from 28 distinct tetraploidy events plus an additional six hexaploidy events. This number is a minimum, and the actual frequency could be considerably higher. The parental genomes of most Andropogoneae polyploids diverged in the Late Miocene coincident with the expansion of the major C4 grasslands that dominate the earth today. The well-documented whole-genome duplication in Zea mays ssp. mays occurred after the divergence of Zea and Sorghum. We find no evidence that polyploidization is followed by an increase in net diversification rate; nonetheless, allopolyploidy itself is a major mode of speciation. PMID:25288748

Estep, Matt C; McKain, Michael R; Vela Diaz, Dilys; Zhong, Jinshun; Hodge, John G; Hodkinson, Trevor R; Layton, Daniel J; Malcomber, Simon T; Pasquet, Rémy; Kellogg, Elizabeth A

2014-10-21

136

Allopolyploidy, diversification, and the Miocene grassland expansion  

PubMed Central

The role of polyploidy, particularly allopolyploidy, in plant diversification is a subject of debate. Whole-genome duplications precede the origins of many major clades (e.g., angiosperms, Brassicaceae, Poaceae), suggesting that polyploidy drives diversification. However, theoretical arguments and empirical studies suggest that polyploid lineages may actually have lower speciation rates and higher extinction rates than diploid lineages. We focus here on the grass tribe Andropogoneae, an economically and ecologically important group of C4 species with a high frequency of polyploids. A phylogeny was constructed for ca. 10% of the species of the clade, based on sequences of four concatenated low-copy nuclear loci. Genetic allopolyploidy was documented using the characteristic pattern of double-labeled gene trees. At least 32% of the species sampled are the result of genetic allopolyploidy and result from 28 distinct tetraploidy events plus an additional six hexaploidy events. This number is a minimum, and the actual frequency could be considerably higher. The parental genomes of most Andropogoneae polyploids diverged in the Late Miocene coincident with the expansion of the major C4 grasslands that dominate the earth today. The well-documented whole-genome duplication in Zea mays ssp. mays occurred after the divergence of Zea and Sorghum. We find no evidence that polyploidization is followed by an increase in net diversification rate; nonetheless, allopolyploidy itself is a major mode of speciation. PMID:25288748

Estep, Matt C.; McKain, Michael R.; Vela Diaz, Dilys; Zhong, Jinshun; Hodge, John G.; Hodkinson, Trevor R.; Layton, Daniel J.; Malcomber, Simon T.; Pasquet, Rémy; Kellogg, Elizabeth A.

2014-01-01

137

Additional material of the enigmatic Early Miocene mammal Kelba and its relationship to the order Ptolemaiida  

PubMed Central

Kelba quadeemae, a fossil mammal from the Early Miocene of East Africa, was originally named on the basis of three isolated upper molars. Kelba has previously been interpreted as a creodont, a pantolestid, an insectivoran, and a hemigaline viverrid. The true affinities of this taxon have remained unclear because of the limited material and its unique morphology relative to other Miocene African mammals. New material of Kelba from several East African Miocene localities, most notably a skull from the Early Miocene locality of Songhor in Western Kenya, permits analysis of the affinities of Kelba and documents the lower dentition of this taxon. Morphological comparison of this new material clearly demonstrates that Kelba is a member of the order Ptolemaiida, a poorly understood group whose fossil record was previously restricted to the Oligocene Fayum deposits of northern Egypt. Phylogenetic analysis supports the monophyly of the Ptolemaiida, including Kelba, and recovers two monophyletic clades within the order. We provide new family names for these groups and an emended diagnosis for the order. The discovery of ptolemaiidans from the Miocene of East Africa is significant because it extends the known temporal range of the order by >10 million years and the geographic range by >3,200 km. Although the higher-level affinities of the Ptolemaiida remain obscure, their unique morphology and distribution through a larger area of Africa (and exclusively Africa) lend support to the idea that Ptolemaiida may have an ancient African origin. PMID:17372202

Cote, Susanne; Werdelin, Lars; Seiffert, Erik R.; Barry, John C.

2007-01-01

138

Curtobacterium flaccumfaciens Septic Arthritis following Puncture with a Coxspur Hawthorn Thorn ?  

PubMed Central

Curtobacterium species are recognized plant pathogens. We report the first well-documented case of Curtobacterium human infection, a child with septic arthritis following puncture with a Coxspur Hawthorn plant thorn. The organism isolated from synovial tissue and the plant thorn was identified as Curtobacterium flaccumfaciens by 16S rRNA gene sequence analysis. PMID:21562106

Francis, Michelle J.; Doherty, Richard R.; Patel, Minoo; Hamblin, John F.; Ojaimi, Samar; Korman, Tony M.

2011-01-01

139

Curtobacterium flaccumfaciens septic arthritis following puncture with a Coxspur Hawthorn thorn.  

PubMed

Curtobacterium species are recognized plant pathogens. We report the first well-documented case of Curtobacterium human infection, a child with septic arthritis following puncture with a Coxspur Hawthorn plant thorn. The organism isolated from synovial tissue and the plant thorn was identified as Curtobacterium flaccumfaciens by 16S rRNA gene sequence analysis. PMID:21562106

Francis, Michelle J; Doherty, Richard R; Patel, Minoo; Hamblin, John F; Ojaimi, Samar; Korman, Tony M

2011-07-01

140

Fruit fate, frugivory, and fruit characteristics: a study of the hawthorn, Crataegus monogyna (Rosaceae)  

Microsoft Academic Search

The fate of fruits from a population of European hawthorn (Crataegus monogyna) in western Oregon, USA, was examined over a two-year period. Only one frugivore, the American robin (Turdus migratorius) foraged on the C. monogyna fruits, making this an unusually straightforward fruit-frugivore system. Dispersal efficiency was low, with an average 21% of seeds being dispersed (carried away from parent plants)

Rex Sallabanks

1992-01-01

141

Gall production on hawthorns caused by Gymnosporangium spp.in Hatay province, Turkey  

Technology Transfer Automated Retrieval System (TEKTRAN)

Three hawthorn and related rust diseases caused by Gymnosporangium confusum on Crataegus monogyna, G. clavariiforme on C. orientalis, and G. sabinae on Pyrus communis were detected in Hatay province, Turkey. Gymnosporangium confusum was also found causing telial galls on Juniperus communis. Gymnospo...

142

Radioprotective effects of Hawthorn against genotoxicity induced by gamma irradiation in human blood lymphocytes.  

PubMed

The radioprotective effect of hawthorn (Crataegus microphylla) fruit extract was investigated in cultured blood lymphocytes from human volunteers. Peripheral blood samples were collected from five human volunteers 10 min before and 1, 2 and 3 h after a single oral ingestion of 500 mg hawthorn powder extract. At each time point, the whole blood was exposed in vitro to 150 cGy of cobalt-60 gamma irradiation, and then the lymphocytes were cultured with mitogenic stimulation to determine the micronuclei in cytokinesis-blocked binucleated cell. The lymphocytes in the blood samples collected after extract ingestion exhibited a significant decrease in the incidence of binucleated cells containing micronuclei as compared to similarly irradiated lymphocytes collected prior to extract ingestion. The maximum decrease in the frequency of micronuclei-containing cells was observed at 1 h after ingestion of Hawthorn extract (on average a 44% decrease). These data suggest that it may be possible to use Hawthorn extracts in personnel exposed to radiation in order to protect lymphocytes from radiation effects. PMID:18769933

Hosseinimehr, Seyed Jalal; Mahmoudzadeh, Aziz; Azadbakht, Mohammad; Akhlaghpoor, Shahram

2009-02-01

143

The Repressive Nature of the Past: Hawthorne's "House of the Seven Gables."  

ERIC Educational Resources Information Center

"The House of the Seven Gables" describes the problems that emerge when a family allows itself to become so locked into the traditions and sins of the past that each new generation becomes a slightly degenerated facsimile of the previous generation. Nathaniel Hawthorne manages this task by comparing Clifford, a descendent of a long line of…

Loges, Max L.

144

Characteristics of Students Attending the Hawthorne and Northeast Centers. Volume 12, No. 10.  

ERIC Educational Resources Information Center

A study was conducted at William Rainey Harper College (WRHC) to develop a profile of students attending the college's new Northeast Center and to compare these students with those attending classes at the old Hawthorne Center and the college's main campus. Surveys were mailed to 103 degree credit students and 97 continuing education students…

Howard, William; And Others

145

The late early Miocene Sabine River  

SciTech Connect

Work on a new late early Miocene vertebrate fossil site, in a paleochannel deposit of the upper Carnahan Bayou Member of the lower Fleming Formation, has revealed unexpected data on the course and nature of the Sabine River of that time. Screen washing for smaller vertebrate remains at the site, just west of the Sabine River in Newton County, central eastern Texas, has resulted in the recovery of early Permian, Early Cretaceous, Late Cretaceous (Maestrichtian), Paleocene/Eocene, late Eocene, and Oligocene/Miocene fossils, in addition to the main early Miocene fauna. The reworked fossils, as well as distinctive mineral grains, show that the late early Miocene Sabine River was connected to the Texas/Oklahoma/Arkansas boundary section of the Red River, as well as to rivers draining the southern Ouachita Mountains. These rivers must have joined the Texas/Louisiana boundary section of the Sabine River somewhere in northwest Louisiana at that time. This suggests that the Louisiana section of the present Red River pirated the Texas/Oklahoma/Arkansas boundary section of the river some time after the early Miocene. The preservation of recognizable fossils transported hundreds of miles in a large river itself requires explanation. It is speculated here that the late early Miocene Sabine River incorporated a large amount of the then recently deposited volcanic ash from the Trans-Pecos Volcanic Field. Montmorillonite clay from the altered volcanic ash would have made the river very turbid, which could have allowed coarse sand-sized particles to be carried in the suspended load of the river, rather than in its bed load (where they would have been destroyed by the rolling chert gravel). Additional evidence for such long-distance fossil transport in the late early Miocene rivers of the western Gulf Coastal Plain comes from the abundant Cretaceous fossils of the upper Oakville Formation of southeast Texas and the Siphonina davisi zone of the southeast Texas subsurface.

Manning, E. (Louisiana State Univ., Baton Rouge (USA))

1990-09-01

146

Assessment of phenolic acid content and in vitro antiradical characteristics of hawthorn.  

PubMed

The infusions and extracts obtained from leaves with flowers, fruit peel, and seed from hawthorn (Crataegus monogyna Jacq., Family Rosaceae) were subjected to evaluation as potential sources of antioxidant phytochemicals on the basis of their total content of phenolics, levels of phenolic acids, and in vitro antiradical activity. Total phenolic content of extracts was determined using the modified Folin-Ciocalteau method. Antioxidant activity was determined for phenolic extracts by a method involving the use of the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). Phenolic acids containing extracts and infusions from hawthorn leaves, fruit peel, and seeds were obtained using different polarity solvents and separated by reverse-phase high-performance liquid chromatography, which enabled improved separation by the use of a C(18) column, an acidic mobile phase, and gradient elusion. The highest total phenolic content (343.54?mg of gallic acid equivalents/g) and the highest DPPH radical scavenging activity as the inhibition percentage (60.36%) were obtained in ethyl acetate extract from hawthorn leaves with flower. Also, the highest phenolic acid content was measured in the extracts of hawthorn leaves with flowers: protocathechuic (108-128?mg/100?g), p-hydroxy benzoic (141-468?mg/100?g), caffeic (137-3,580?mg/100?g), chlorogenic (925-4,637?mg/100?g), ferulic (3,363-3,462?mg/100?g), vanillic (214?mg/100?g), and syringic (126?mg/100?g) acids. The results indicate that hawthorn is a promising plant because of its high antioxidant activity. PMID:21554133

Öztürk, Nilgün; Tunçel, Muzaffer

2011-06-01

147

Shark-bitten vertebrate coprolites from the Miocene of Maryland  

NASA Astrophysics Data System (ADS)

Coprolites (fossilized feces) preserve a wide range of biogenic components, from bacteria and spores to a variety of vertebrate tissues. Two coprolites from the Calvert Cliffs outcrop belt (Miocene-aged Chesapeake Group), MD, USA, preserve shark tooth impressions in the form of partial dental arcades. The specimens are the first known coprolites to preserve vertebrate tooth marks. They provide another example of trace fossils providing evidence of prehistoric animal behaviors that cannot be directly approached through the study of body fossils. Shark behaviors that could account for these impressions include: (1) aborted coprophagy, (2) benthic or nektonic exploration, or (3) predation.

Godfrey, Stephen J.; Smith, Joshua B.

2010-05-01

148

Ecology in relation to speciation rates: some case histories of Miocene-Recent mammal clades  

Microsoft Academic Search

Summary Some African mammal clades are used to analyse evolutionary processes. The clades chosen are especially suitable for this purpose because they include both extant species, for which there is an abundant literature, and fossil records from various Miocene-Recent strata mainly in Eastern and Southern Africa. The monophyletic groups in this sample differ considerably in speciation rates and in the

E. S. Vrba

1987-01-01

149

Aquifer characteristics and water quality of Miocene–Pleistocene sediments, Kuwait  

Microsoft Academic Search

Al-Atraf is one of the water well fields of Kuwait supplying Kuwait City with the brackish groundwater obtained from the Kuwait Group aquifer of Miocene–Pleistocene age. The study determined the hydrogeological and hydrochemical characteristics of the groundwater in order to identify the major chemical processes that influence the groundwater quality of the study area. The results of the aquifer test

F. M. Al-Ruwaih; H. A. Qabazard

2005-01-01

150

Miocene sediments distribution in the central and northern parts of the Vienna Basin, central Europe  

NASA Astrophysics Data System (ADS)

The Vienna Basin is a Miocene sedimentary basin situated at the Alpine-Carpathian transition and spreading from Austria in the South to the Czech Republic and Slovakia in the north. The basin primarily developed as a piggy-back basin during the Lower Miocene (~18 - 16 Ma) on top of the NW-ward moving Eastern Alpine and West Carpathians thrust sheets. In the late Lower Miocene, the local stress regime changed by the lateral extrusion of the Eastern Alps towards the Pannonian area. It leads to the developing of the basin between two left stepping sinistral strike-slip faults of the Vienna Basin faults system during the Middle and Upper Miocene (~16 - 8 Ma). Structures related with this pull-apart stage are extensional sinistral strike-slip duplexes connected with large scale listric normal fraults. Our study area mainly covers the central and northern Vienna Basin that is not yet studied well for the stratigraphy. The goal of this study is the characterization and distribution of the Miocene sediments. For this purpose we investigated approximately 200 wells in 17 well-groups in order to obtain details on the Miocene sediments. Among them 84 wells drilled down to the Northern Calcareous Alps and the flysch units in the pre-Neogene basin subcrop. The initial phase of the Miocene deposition was related to the transgression and is characterized by the deposition of coarse clastic and marly clay sediments. These sediments are distributed locally in the northern part of the basin. The overlying sediments are more widely distributed than the underlying ones. During the late Lower Miocene, the depocenters shifted towards the south and sedimentation was dominated by marly clay intercalated with sand. An unconformity depicted for the regional stage boundary fits well with the regressive phase and the subsequent transgression. From Middle to Upper Miocene, sediments were deposited over a wide area of the Vienna Basin. The sedimentation was governed by combination of pull-apart kinematics, eustatic global sea-level changes and sediment supply mostly from deltas. Figure 1. Tectonic sketch map of the Vienna Basin and location of studied area.

Lee, E.; Wagreich, M.; Decker, K.

2012-12-01

151

Ammonium carbonate is more attractive than apple and hawthorn fruit volatile Lures to Rhagoletis pomonella (Diptera: Tephritidae) in Washington State.  

PubMed

The apple maggot fly, Rhagoletis pomonella (Walsh), is an introduced, quarantine pest of apple (Malus domestica Borkhausen) in the Pacific Northwest of the United States. In the eastern United States where the fly is native, fruit volatiles have been reported to be more attractive than ammonia compounds to R. pomonella. However, the opposite may be true in the western United States. Here, we determined whether newly identified western apple and western hawthorn fruit volatiles are more attractive than ammonium carbonate (AC) to R. pomonella in apple, black hawthorn, and ornamental hawthorn trees in western Washington State. In all three host trees, sticky red sphere or yellow panel traps baited with AC generally caught more flies than traps baited with lures containing the four newly developed fruit blends (modified eastern apple, western apple, western ornamental hawthorn, and western black hawthorn) or two older blends (eastern apple and eastern downy hawthorn). Fruit volatiles also displayed more variation among trapping studies conducted at different sites, in different host trees, and across years than AC. The results imply that traps baited with AC represent the best approach to monitoring R. pomonella in Washington State. PMID:24915519

Yee, Wee L; Nash, Meralee J; Goughnour, Robert B; Cha, Dong H; Linn, Charles E; Feder, Jeffrey L

2014-08-01

152

Effect of hawthorn (Crataegus oxycantha) crude extract and chromatographic fractions on multiple activities in a cultured cardiomyocyte assay.  

PubMed

Extracts of hawthorn (Crataegus oxycantha) have become popular herbal supplements for their well-recognized cardiotonic effects. Many commercial preparations have been used successfully in the treatment of congestive heart failure, although the active principles within these extracts have yet to be conclusively identified. Several hawthorn preparations were studied and found to have negative chronotropic effects in a cultured neonatal murine cardiomyocyte assay using unpaced cells. As compared to conventional cardiac drugs (i.e., epinephrine, milrinone, ouabain, or propranolol), hawthorn extract has a unique activity profile. Hawthorn extract appears to be anti-arrhythmic and capable of inducing rhythmicity in quiescent cardiomyocytes. Hawthorn extract does not cause beta-adrenergic receptor blockade at concentrations which cause negative chronotropic effects. Commercial hawthorn preparations, extracts prepared from dried leaves and those made from dried berries have similar chronotropic activities. When crude extracts are separated using size-exclusion chromatography, several fractions retain multiple cardiac activities. Assays with chromatographic fractions reveal that multiple dissimilar cardioactive components may exist within the extract, making the identification of individual active constituents more challenging. PMID:16487691

Long, S R; Carey, R A; Crofoot, K M; Proteau, P J; Filtz, T M

2006-11-01

153

B. F. Skinner and T. N. Whitehead: a brief encounter, research similarities, hawthorne revisited, what next?  

PubMed

B. F. Skinner and T. N. Whitehead recalled a personal interaction in 1934, with differing memories of the event. No evidence of other subsequent interactions or mutual citations has been found. Although they went their separate ways, three similarities in their research strategies have been found and are discussed. Elements of Whitehead's Hawthorne study and Skinner's concurrent, parallel work reveal that they both (a) introduced the cumulative curve to report data, (b) used a small number of subjects studied over time, and (c) used highly accurate recording devices. A few "afterwords" are offered on their lives and writings, and again, on the Hawthorne effect. A suggestion is made that a Skinner-Whitehead research approach might be useful in studying gambling behavior. PMID:22478490

Claus, Calvin K

2007-01-01

154

B. F. Skinner and T. N. Whitehead: A Brief Encounter, Research Similarities, Hawthorne Revisited, What Next?  

PubMed Central

B. F. Skinner and T. N. Whitehead recalled a personal interaction in 1934, with differing memories of the event. No evidence of other subsequent interactions or mutual citations has been found. Although they went their separate ways, three similarities in their research strategies have been found and are discussed. Elements of Whitehead's Hawthorne study and Skinner's concurrent, parallel work reveal that they both (a) introduced the cumulative curve to report data, (b) used a small number of subjects studied over time, and (c) used highly accurate recording devices. A few “afterwords” are offered on their lives and writings, and again, on the Hawthorne effect. A suggestion is made that a Skinner–Whitehead research approach might be useful in studying gambling behavior. PMID:22478490

Claus, Calvin K

2007-01-01

155

Antarctic hydrology during mid-Miocene warmth  

NASA Astrophysics Data System (ADS)

The Middle Miocene Climatic Optimum (MMCO) represents a period of global warmth 17-15 million years ago which resulted in the regrowth of vegetation on regions of Antarctica that were ice-covered since the Oligocene. A recent drilling campaign on the Antarctic ice shelf (ANDRILL SMS program) recovered middle Miocene sediments provided a first glimpse of a vegetated Antarctica at this time (Warny et al., 2009). However the hydrological regimes of Middle Miocene climate that enabled this vegetation expansion are not yet precisely known. Here we report leaf wax hydrogen isotope values of -170 to -120% indicate dD values for precipitation of -80 to -20% during the Middle Miocene. These values are significantly less negative than modern precipitation and together with microfossil evidence for warm, sea ice-free conditions, suggest an enhanced moisture flux. Experiments with isotopic tracers in idealized models under warm, ice free conditions indicate physical and dynamical support for 'heavy' polar precipitation isotopes reconstructed here. Pollen and biomarker abundances indicate peak conditions at 16.4 and 15.7Ma coeval with global anomalies of the MMCO (Zachos et al., 2001). Our results indicate increased moisture delivery to the Antarctic continent and an invigoration of meridional circulation and poleward latent heat flux during global warmth.

Feakins, S. J.; Warny, S.; Lee, J.

2011-12-01

156

Oxygen species scavenging activity of phenolic extracts from hawthorn fresh plant organs and pharmaceutical preparations.  

PubMed

Different extracts of fresh vegetative and reproductive organs from Crataegus monogyna harvested during a whole season and from some pharmaceutical hawthorn preparations exhibit in vitro antioxidant activities using three different models of oxygen reactive species generation (superoxide anion, hydrogen peroxide and hypochlorous acid). All the tested samples show low IC50 values, the most efficient being fresh young leaves, fresh floral buds and pharmaceutical dried flowers. The activities seem to be especially bound to the total phenolic proanthocyanidin and flavonoid contents. PMID:8955870

Bahorun, T; Gressier, B; Trotin, F; Brunet, C; Dine, T; Luyckx, M; Vasseur, J; Cazin, M; Cazin, J C; Pinkas, M

1996-11-01

157

A unique Middle Miocene European hominoid and the origins of the great ape and human clade  

PubMed Central

The great ape and human clade (Primates: Hominidae) currently includes orangutans, gorillas, chimpanzees, bonobos, and humans. When, where, and from which taxon hominids evolved are among the most exciting questions yet to be resolved. Within the Afropithecidae, the Kenyapithecinae (Kenyapithecini + Equatorini) have been proposed as the sister taxon of hominids, but thus far the fragmentary and scarce Middle Miocene fossil record has hampered testing this hypothesis. Here we describe a male partial face with mandible of a previously undescribed fossil hominid, Anoiapithecus brevirostris gen. et sp. nov., from the Middle Miocene (11.9 Ma) of Spain, which enables testing this hypothesis. Morphological and geometric morphometrics analyses of this material show a unique facial pattern for hominoids. This taxon combines autapomorphic features—such as a strongly reduced facial prognathism—with kenyapithecine (more specifically, kenyapithecin) and hominid synapomorphies. This combination supports a sister-group relationship between kenyapithecins (Griphopithecus + Kenyapithecus) and hominids. The presence of both groups in Eurasia during the Middle Miocene and the retention in kenyapithecins of a primitive hominoid postcranial body plan support a Eurasian origin of the Hominidae. Alternatively, the two extant hominid clades (Homininae and Ponginae) might have independently evolved in Africa and Eurasia from an ancestral, Middle Miocene stock, so that the supposed crown-hominid synapomorphies might be homoplastic. PMID:19487676

Moyà-Solà, Salvador; Alba, David M.; Almécija, Sergio; Casanovas-Vilar, Isaac; Köhler, Meike; De Esteban-Trivigno, Soledad; Robles, Josep M.; Galindo, Jordi; Fortuny, Josep

2009-01-01

158

Paleomagnetism of Miocenic Rocks Around Chalcatzingo, Morelos, Mexico: A Revaluation  

NASA Astrophysics Data System (ADS)

The Chalcatzingo domes southeast of Mexico City have been recently 40Ar/39Ar dated to be around 20.7 Ma old. These rocks and the surrounding Tepexco Volcanic Group are defined in a previous study as showing strongly discordant paleomagnetic directions, about 50 west from the expected Miocene geomagnetic field direction; which prompted the hypothesis of a counter clockwise crustal block rotation, related to a regional left lateral fault system along the Transmexican Volcanic Belt. This rotation is the largest proposed so far for central Mexico, and it is in contrast to data from the nearby Basin of Mexico, which are concordant with the expected field directions. In view of the limited previous sampling and relatively complex remanence record, we have re-sampled the Chalcatzingo and Tepexco rocks to verify the validity of the proposed block rotation. For that purpose samples were collected from 26 sites. Reflected light and scanning electron microscopy were used to determine composition and texture of magnetic minerals, and IRM acquisition and thermomagnetic experiments to determine the rock magnetic properties. Detailed demagnetization was carried out using mainly the AF method to determine the characteristic remanence directions, to calculate site mean directions and VGPs. These are compared to the Miocene reference direction and pole for stable North America, and interpreted in terms of potential tectonic movements of the study area.

Vazquez-Duarte, A.; Bohnel, H.; Yutsis, V.

2009-05-01

159

The comparison of anti-oxidative kinetics in vitro of the fluid extract from maidenhair tree, motherwort and hawthorn.  

PubMed

The aim of the study was to perform a quantitative analysis of fluid extracts of maidenhair tree (Ginkgo biloba L.), motherwort (Leonurus cardiaca L.) and hawthorn (Crataegus monogyna Jacq.), to evaluate their antioxidant activity and to compare their ability to inactivate free radicals. The antioxidant activity was measured using the DPPH*and the ABTS*+ radical scavenging reaction systems. The study showed that the manifestation of the radical scavenging capacity in the DPPH* reaction system was in the following order: the fluid extract of hawthorn (70.37 +/- 0.80%) > the fluid extract of maidenhair tree (82.63 +/- 0.23%) > the fluid extract of motherwort (84.89 +/- 0.18%), while in the ABTS*+ reaction system, the manifestation of the radical scavenging capacity was in the following order: the fluid extract of hawthorn (87.09 +/- 0.55%) > the fluid extract of motherwort (88.28 +/- 1.06%) > the fluid extract of maidenhair tree (88.39 +/- 0.72%). The results showed that in the DPPH* reaction system, fluid extract of motherwort manifested higher antioxidant activity, compared to the fluid extracts of maidenhair tree and hawthorn. By contrast, in the ABTS*+ reaction system, higher antioxidant activity was found in the fluid extract of maidenhair tree, compared to the fluid extracts of motherwort and hawthorn. This would suggest that preparations manufactured from these herbal raw materials could be used as effective preventive means and valuable additional remedies in the treatment of diseases caused by oxidative stress. PMID:19702174

Bernatoniene, Jurga; Kucinskaite, Agne; Masteikova, Ruta; Kalveniene, Zenona; Kasparaviciene, Giedre; Savickas, Arunas

2009-01-01

160

Miocene reef carbonates of Mariana Islands  

Microsoft Academic Search

Miocene carbonates in the southern Mariana Islands are impressive for their lithologic diversity, thicknesses (over 250 m), and geographic extent (> 20% combined outcrop coverage over four major high islands: Guam, Rota, Tinian and Saipan). Sections are dominated either by lagoonal algal-foraminiferal wackestones and mudstones with locally abundant high-energy shelly-skeletal facies, or by rubbly to muddy, fore-reef-to-bank deposits of packstones

Siegrist; H. G. Jr

1988-01-01

161

Miocene reef carbonates of Mariana Islands  

Microsoft Academic Search

Miocene carbonates in the southern Mariana Islands are impressive for their lithologic diversity, thicknesses (over 250 m), and geographic extend (>20% combined outcrop coverage over four major high islands: Guam, Rota, Tinian and Saipan). Sections are dominated either by lagoonal algal-foraminiferal wackestones and mudstones with locally abundant high-energy shelly-skeletal facies, or by rubbly to muddy, fore-reef-to-bank deposits of packstones and

Siegrist; H. G. Jr

1988-01-01

162

Miocene cercopithecoidea from the Tugen Hills, Kenya.  

PubMed

Miocene to Pleistocene fossiliferous sediments in the Tugen Hills span the time period from at least 15.5 Ma to 0.25 Ma, including time periods unknown or little known elsewhere in Africa. Consequently, the Tugen Hills deposits hold the potential to inform us about crucial phylogenetic events in African faunal evolution and about long-term environmental change. Among the specimens collected from this region are a number of discoveries already important to the understanding of primate evolution. Here, we describe additional cercopithecoid material from the Miocene deposits in the Tugen Hills sequence, including those from securely dated sites in the Muruyur Beds (16-13.4 Ma), the Mpesida Beds (7-6.2 Ma) and the Lukeino Formation (? 6.2-5.7 Ma). We also evaluate previously described material from the Ngorora Formation (13-8.8 Ma). Identified taxa include Victoriapithecidae gen. et sp. indet., cf. Parapapio lothagamensis, and at least two colobines. Specimens attributed to cf. Pp. lothagamensis would extend the species' geographic range beyond its type locality. In addition, we describe specimens sharing derived characters with modern African colobines (Tribe: Colobina), a finding that is congruent with previous molecular estimates of colobine divergence dates. These colobine specimens represent some of the earliest known members of the modern African colobine radiation and, in contrast to previous hypotheses, suggest that early African colobines were mainly arboreal and that semi-terrestrial Late Miocene and Plio-Pleistocene colobine taxa were secondarily derived in their locomotor adaptations. PMID:20889183

Gilbert, Christopher C; Goble, Emily D; Hill, Andrew

2010-11-01

163

New hominoid skull material from the Miocene of Pakistan  

Microsoft Academic Search

Neogene hominoid cranial material is regrettably scarce, especially from the middle and late Miocene. Between the 18-Myr-old virtually complete early Miocene Proconsul africanus skull from Rusinga1 and the 3-4-Myr-old Hadar hominoid cranial material2, the only significant large (non-hylobatid) hominoid facial or cranial specimens are those from the late Miocene Salonika in Greece3, Yassiören in Turkey4, Lufeng in China5, the possibly

David Pilbeam

1982-01-01

164

Petrogenesis of the Miocene volcanism along the ?zmir-Bal?kesir Transfer Zone in western Anatolia, Turkey: Implications for origin and evolution of potassic volcanism in post-collisional areas  

NASA Astrophysics Data System (ADS)

The Miocene volcanic rocks along the ?zmir-Bal?kesir Transfer Zone along the western margin of the Menderes Core Complex (MCC) in western Anatolian Volcanic Province (WAVP), where strike-slip deformation is dominant, comprise: (Group 1) early-middle Miocene high-K to shoshonitic rocks with high-Mg# and relatively low SiO2, (Group 2) middle Miocene phonolitic rocks with low-Mg# and intermediate SiO2, (Group 3) early-middle Miocene medium- to high-K series from andesites to rhyolites, (Group 4) middle Miocene rhyolites with distinct trace element compositions; and (Group 5) late Miocene high-MgO basalts, K-trachybasalts and (Group 6) late Miocene high-MgO basaltic andesites. The geochemical features of these rocks are comparable with the other Oligocene to Miocene volcanic rocks, but differ from the Eocene volcanic rocks in WAVP. The geochemical features of the most primitive early-middle Miocene Group 1 rocks indicate that they were derived from an anomalously metasomatized lithospheric mantle. The mineralogical and geochemical properties of garnet-amphibole peridotite from the Ulten Zone (UZP), Eastern Alps, which is thought to represent a fossil metasomatic mantle wedge contaminated by continental subduction, is similar to the model mantle composition previously proposed for the genesis of the mafic rocks. Together with the presence of Eocene to early Miocene continental subduction beneath the Aegean-west Anatolia region, this strongly suggests that continental subduction was an important factor in the genesis of the high-MgO shoshonitic to ultrapotassic volcanism in this post-collisional area. The origin of the Group 3 andesitic to rhyolitic rocks includes; (1) lower crustal melting, (2) mixing between lower crustally-derived and mantle-derived melts, and (3) FC-AFC processes. The late Miocene Group 5 and 6 rocks, however, derived from a more depleted mantle source, indicating that the mantle became depleted over time. The rhyolites of Group 4 are most probably crustally-derived. OIB-type Quaternary Kula volcanics (QKV) were emplaced near the centre of the MCC. Among the late Miocene basalts in the region, only the basalts located close to the QKV show transitional geochemistry between the Miocene volcanic rocks and QKV, indicating that asthenospheric contribution to lavas in the region occurred only near the centre of the MCC.

Ersoy, Yalç?n E.; Helvac?, Cahit; Uysal, ?brahim; Karao?lu, Özgür; Palmer, Martin R.; Dindi, Fulya

2012-10-01

165

Miocene mollusks from the Simojovel area in Chiapas, southwestern Mexico  

NASA Astrophysics Data System (ADS)

The fauna of gastropods and bivalves from the amber-bearing lithostratigraphic units of the Simojovel area, Chiapas is reported, including the description of two new species and one subspecies: Turbinella maya new species, Melongena corona tzeltal new subspecies and Agladrillia ( Eumetadrillia) vermeiji new species. Stratigraphic affinities of the previously described species suggest an Early Miocene age for the Mazantic Shale, and a Middle Miocene age for the overlying Balumtum Sandstone. One specimen of gastropod, with a relatively large piece of amber attached to the adapertural part of the shell is representative for an Early Miocene age and estuarine paleoenvironmental interpretation for the Mazantic Shale. Mollusca, Miocene, Chiapas, Amber, Mexico.

del Carmen Perrilliat, María; Vega, Francisco J.; Coutiño, Marco A.

2010-11-01

166

Influence of extraction technique on the anti-oxidative potential of hawthorn (Crataegus monogyna) extracts in bovine muscle homogenates.  

PubMed

Six extracts were prepared from hawthorn (Crataegus monogyna) leaves and flowers (HLF) and berries (HB) using solid-liquid [traditional (T) (HLFT, HBT), sonicated (S) (HLFS, HBS)] and supercritical fluid (C) extraction (HLFC, HBC) techniques. The antioxidant activities of HLF and HB extracts were characterised using in vitro antioxidant assays (TPC, DPPH, FRAP) and in 25% bovine muscle (longissimus lumborum) homogenates (lipid oxidation (TBARS), oxymyoglobin (% of total myoglobin)) after 24h storage at 4°C. Hawthorn extracts exhibited varying degrees of antioxidant potency. In vitro and muscle homogenate (TBARS) antioxidant activity followed the order: HLFS>HLFT and HBT>HBS. In supercritical fluid extracts, HLFC>HBC (in vitro antioxidant activity) and HLFC?HBC (TBARS). All extracts (except HBS) reduced oxymyoglobin oxidation. The HLFS extract had the highest antioxidant activity in all test systems. Supercritical fluid extraction (SFE) exhibited potential as a technique for the manufacture of functional ingredients (antioxidants) from hawthorn for use in muscle foods. PMID:25170819

Shortle, E; O'Grady, M N; Gilroy, D; Furey, A; Quinn, N; Kerry, J P

2014-12-01

167

Isotope geochemistry of the Miocene and Quaternary carbonate rocks in Rabigh area, Red Sea coast, Saudi Arabia  

NASA Astrophysics Data System (ADS)

The Rabigh area, a coastal region north of Jeddah city, Saudi Arabia contains raised Quaternary coral reefal terraces and reworked coral fragments mixed with sand and gravel. This area has a thin exposure Lower Miocene shallow marine carbonate rocks that laterally pass into evaporites. The Miocene carbonate and evaporite rocks conformably overly the Lower Miocene siliciclastic sequence, are in turn capped by the Harrat basaltic boulders. The Miocene carbonates are made up of dolomitic packstone, wackestone and mudstone, whereas the overlying Quaternary reefal terraces are composed of coral boundstone and grainstones. The Quaternary reefal terraces of Rabigh area have been dated using the uranium-series dating method to obtain precise dates for these corals. The calculated ages (128, 212 and 235 ka) indicate that deposition took place during high sea level stands associated with interglacial times during Oxygen Isotope Stages (OIS) 5 and 7. The youngest age (128 ka) clearly corresponds to stage 5e of the last interglacial period. The obtained ages correlate well with those of the emerged reefs on the Sudanese and Egyptian coasts at the western side of the Red Sea. The broad distribution of wet climate, pluvial deposits on the continents and high sea level stands indicate a wide geographical range of the interglacial events of the Oxygen Isotope Stages (OIS) 5 and 7. The oxygen and carbon isotopic composition of the Miocene and Quaternary carbonate rocks in Rabigh area show a broad range of ?13C and ?18O. The Quaternary carbonate rocks have significantly higher ?13C than the Miocene ones, but low ?13C values of the Miocene samples likely indicate a high contribution of carbon from organic sources at the time of deposition. Linear trends are evident in both groups of samples supporting the likelihood of secondary alteration.

Dawood, Yehia H.; Aref, Mahmoud A.; Mandurah, Mohammed H.; Hakami, Ahmed; Gameil, Mohammed

2013-11-01

168

Preliminary plan for the development of geothermal energy in the town of Hawthorne, Nevada  

NASA Astrophysics Data System (ADS)

Site characteristics pertinent to the geothermal development are described, including: physiography, demography, economy, and goals and objectives of the citizens as they relate to geothermal development. The geothermal reservoir is characterized on the basis of available information. The probable drilling depth to the reservoir, anticipated water production rates, water quality, and resource temperature are indicated. Uses of the energy that seem appropriate to the situation both now and in the near future at Hawthorne are described. The essential institutional requirements for geothermal energy development are discussed, including the financial, environmental, and legal and regulatory aspects. The various steps that are necessary to accomplish the construction of the geothermal district heating system are described.

1981-11-01

169

Anti-inflammatory, gastroprotective, free-radical-scavenging, and antimicrobial activities of hawthorn berries ethanol extract.  

PubMed

Hawthorn [Crataegus monogyna Jacq. and Crataegus oxyacantha L.; sin. Crataegus laevigata (Poiret) DC., Rosaceae] leaves, flowers, and berries are used in traditional medicine in the treatment of chronic heart failure, high blood pressure, arrhythmia, and various digestive ailments, as well as geriatric and antiarteriosclerosis remedies. According to European Pharmacopoeia 6.0, hawthorn berries consist of the dried false fruits of these two species or their mixture. The present study was carried out to test free-radical-scavenging, anti-inflammatory, gastroprotective, and antimicrobial activities of hawthorn berries ethanol extract. Phenolic compounds represented 3.54%, expressed as gallic acid equivalents. Determination of total flavonoid aglycones content yielded 0.18%. The percentage of hyperoside, as the main flavonol component, was 0.14%. With respect to procyanidins content, the obtained value was 0.44%. DPPH radical-scavenging capacity of the extract was concentration-dependent, with EC50 value of 52.04 microg/mL (calculation based on the total phenolic compounds content in the extract). Oral administration of investigated extract caused dose-dependent anti-inflammatory effect in a model of carrageenan-induced rat paw edema. The obtained anti-inflammatory effect was 20.8, 23.0, and 36.3% for the extract doses of 50, 100, and 200 mg/kg, respectively. In comparison to indomethacin, given in a dose producing 50% reduction of rat paw edema, the extract given in the highest tested dose (200 mg/kg) showed 72.4% of its activity. Gastroprotective activity of the extract was investigated using an ethanol-induced acute stress ulcer in rats with ranitidine as a reference drug. Hawthorn extract produced dose-dependent gastroprotective activity (3.8 +/- 2.1, 1.9 +/- 1.7, and 0.7 +/- 0.5 for doses of 50, 100, and 200 mg/kg, respectively), with the efficacy comparable to that of the reference drug. Antimicrobial testing of the extract revealed its moderate bactericidal activity, especially against gram-positive bacteria Micrococcus flavus, Bacillus subtilis, and Lysteria monocytogenes, with no effect on Candida albicans. All active components identified in the extract might be responsible for activities observed. PMID:18698794

Tadi?, Vanja M; Dobri?, Silva; Markovi?, Goran M; Dordevi?, Sofija M; Arsi?, Ivana A; Menkovi?, Nebojsa R; Stevi?, Tanja

2008-09-10

170

The Late Miocene paleogeography of the Amazon Basin and the evolution of the Amazon River system  

E-print Network

The Late Miocene paleogeography of the Amazon Basin and the evolution of the Amazon River system Keywords: Amazon basin Amazon River Late Miocene Paleogeography Paleoecology fossil vertebrates palinology

Bermingham, Eldredge

171

Paleomagnetism of the Miocene Columbia River Basalt Group in Oregon and Washington from the Pacific Coast to the Columbia Plateau: Magnetostratigraphy, Vertical-Axis Rotations, Paleosecular Variation, and Remagnetization  

NASA Astrophysics Data System (ADS)

Identification of individual flows within the Columbia River Basalt Group (CRBG) has mostly relied on minor differences in geochemistry, but magnetic polarity has also proved useful in differentiating flows and establishing a temporal framework. Within the thick, rapidly erupted Grande Ronde Basalt four major polarity chrons (R1 to N2) have been identified. Because cooling times of CRBG flows are brief compared to rates of paleosecular variation (PSV), within-flow paleomagnetic directions are expected to be constant across the extensive east-west reaches of these flows. Vertical-axis rotations in OR and WA, driven by northward-oblique subduction of the Juan de Fuca plate, thus can be measured by comparing directions for western sampling localities to directions for the same flow units on the relatively stable Columbia Plateau. Clockwise rotations calculated for outcrop locations within the Coast Range (CR) block are uniformly about 30° (N=102 sites). East of the northwest-trending en échelon Mt. Angel-Gales Creek, Portland Hills, and northern unnamed fault zones, as well as north of the CR block's northern boundary (~Columbia River), clockwise rotations abruptly drop to about 15° (N=39 sites), with offsets in these bounding fault zones corresponding to the Portland and Willamette pull-apart basins. The general agreement of vertical- axis rotation rates estimated from CRBG magnetizations with those determined from modern GPS velocities indicates a relatively steady rate over the last 10 to 15 Myr. Unusual directions due to PSV, field excursions, or polarity transitions could provide useful stratigraphic markers. Individual flow directions, however, have not been routinely used to identify flows. One reason this has been difficult is that remagnetization is prevalent, particularly in the Coast Ranges, coupled with earlier demagnetization techniques that did not completely remove overprint components. Except for the Ginkgo and Pomona flows of the Wanapum and Saddle Mountains Basalts, reference Plateau directions for the CRBG are poorly known. Moreover, field and drill- core relations indicate that flows with different chemistries were erupted at the same time. Renewed sampling, therefore, has been undertaken eastward from the Portland area into the Columbia River Gorge and out onto the Plateau. Resampling of the Patrick Grade section (23 flows) in southeastern WA has shown that overprint magnetizations were not successfully removed in many flows at this locality in an earlier study [1]. This brings into question blanket demagnetization studies of the CRBG as well as polarity measurements routinely made in the field with hand-held fluxgate magnetometers. [1] Choiniere and Swanson, 1979, Am. J. Sci., 279, p. 755

Hagstrum, J. T.; Wells, R. E.; Evarts, R. C.; Niem, A. R.; Sawlan, M. G.; Blakely, R. J.

2008-12-01

172

Preliminary plan for the development of geothermal energy in the town of Hawthorne, Nevada  

SciTech Connect

The results of the analyses as well as a plan for the development of the geothermal resource are described. Site characteristics pertinent to the geothermal development are described. These characteristics include physiography, demography, economy, and goals and ojectives of the citizens as they would relate to geothermal development. The geothermal resource is described. The reservoir is characterized on the basis of available information. The probable drilling depth to the reservoir, anticipated water production rates, water quality, and resource temperatures ae indicated. Uses of the energy that seem appropriate to the situation both now and in the near future at Hawthorne are described. The amounts and types of energy currently consumed by end users are estimated. Using this data base, conceptual engineering designs and cost estimates for three alternative district heating systems are presented. In addition, the results of a life cycle cost analysis for these alternatives are discussed. The essential institutional requirements for geothermal energy development, including the financial, environmental, and legal and regulatory aspects are discussed. The various steps that are necessary to accomplish the construction of the geothermal district heating system at Hawthorne are described. A time-line chart shows the tasks, the time estimated to be required for each, and the interrelationships among the activities.

Not Available

1981-11-04

173

Metsulfuron spray drift reduces fruit yield of hawthorn (Crataegus monogyna L.).  

PubMed

This study was carried out to investigate whether spray drift of metsulfuron has a potential to negatively affect hawthorn (Crataegus monogyna) hedgerows near agricultural fields. For this purpose four doses of metsulfuron ranging from 5% to 40% of the field dose (4 g metsulfuron per hectare) were sprayed on trees in seven different hawthorn hedgerows. The actual deposition on the leaves was measured by means of a tracer (glycine). Spraying was conducted both at the bud stage and at early flowering. Leaves, flowers, green berries and mature berries were harvested and the number and weight of each were measured. The spraying at the bud stage caused a highly significant reduction in number and dry weight of berries, whereas it had no effects on leaf and flower production. The berry reduction was close to 100% at actual depositions relevant for spray drift under normal conditions. Spraying at early flowering also significantly reduced berries although the effect was smaller than for the spraying at bud stage. The early flower stage spraying caused no reduction in number and size of leaves. The possible ecological consequence is that metsulfuron spray drift from agricultural fields has a potential to reduce the amount of berries available for frugivorous birds in nearby hedgerows. A potential need for regulatory measures to reduce herbicide spray drift to hedgerows situated near agricultural fields with herbicide use is also indicated. PMID:15893364

Kjaer, Christian; Strandberg, Morten; Erlandsen, Mogens

2006-03-01

174

Optimization of ultrasound-assisted extraction (UAE) of flavonoids compounds (FC) from hawthorn seed (HS).  

PubMed

Hawthorn seed (HS), an important by-product of the Hawthorn industry, is rich in potentially health-promoting flavonoids compounds. In this paper, the ultrasound-assisted extraction (UAE) of FC from HS was investigated. Important variables and their levels were obtained using Plackett-Burman (PB) design and Box-Behnken (BB) design. A mathematical model was developed to show the effects of each variable and their combinatorial interactions on extraction yield of FC. A high coefficient of determination (R(2) = 91.26%) indicated good agreement between the experimental and predicted values of FC yield. The optimum levels of these significant parameters were determined using response surface methodology (RSM), which revealed these as follows: ultrasound temperature 65 °C, ultrasonic time 37 min, extraction temperature 91 °C, extraction time 1.5h, solid-liquid ratio of 1:18, and 72% ethanol. Under the optimum condition, the UAE rate of FC was up to 91.7%, and the yield of FC was 16.45 ± 0.02 mg/g (P<0.05) that was 1.32-fold the yield of conventional reflux extraction (CRE). PMID:22142939

Pan, Guangyan; Yu, Guoyong; Zhu, Chuanhe; Qiao, Julin

2012-05-01

175

The dietary adaptations of European Miocene catarrhines.  

PubMed Central

European Miocene "apes" have been known for nearly a century and a half but their phylogenetic significance is only now becoming apparent with the recent discovery of many relatively complete remains. Some appear to be close in time and morphology to the last common ancestor of modern great apes and humans. The current study is an attempt to reconstruct the diets of these fossils on the basis of quantitative data. Results suggest that these primates varied more greatly in their diets than modern apes, with adaptations ranging from hard-object feeding to soft-object frugivory to folivory. PMID:7777533

Ungar, P S; Kay, R F

1995-01-01

176

Miocene-Oligocene sequence stratigraphy of the Malay Basin  

Microsoft Academic Search

The Malay Basin has experienced extension of the Eocene ( ) through Oligocene, sag in the early Miocene, and compression in the middle Miocene through Pliocene-Pleistocene. The interaction of structurally induced and glacial-eustatic accommodation changes has resulted in complex, interrelated play elements, including multiple reservoirs, diverse nonmarine sources, discontinuous migration pathways, and thin seals. Extensional subbasins were filled with braided

R. Lovell; M. R. Elias; R. E. Hill; M. H. Feeley

1994-01-01

177

Upper Miocene hominoid distribution and the origin of hominids revisited  

Microsoft Academic Search

The geographic origin of African apes and humans is a major issue in modern paleoprimatology: did these hominoids originate in Eurasia or in Africa? Despite the commonly accepted view that Africa was devoid of hominoids in the late Middle Miocene and Upper Miocene, at least 10 different lineages have now been identified on this continent (three in the late Middle

Brigitte Senut

2010-01-01

178

The Solar Activity in the Miocene Period In this Subthesis we study the solar activity in the Miocene (or Triassic)  

E-print Network

in the Miocene (or Triassic) period. Measurements of the thickness of the annual tree­rings of petrified trees Triassic) period show solar cycles with a period of 6:8 \\Gamma 8:4 years in contradiction to the recentThe Solar Activity in the Miocene Period In this Subthesis we study the solar activity

179

A farm-scale evaluation of the influence of hedgerow cutting frequency on hawthorn ( Crataegus monogyna) berry yields  

Microsoft Academic Search

Hawthorn Crataegus monogyna is the dominant hedgerow species in the UK and has the potential to produce an abundance of berries (haws). These berries provide an important food resource for many animals through the winter. Experimental studies have shown a strong influence of hedgerow management on berry production and this study examines whether that influence extends to farm-scale hedgerow management.

P. J Croxton; T. H Sparks

2002-01-01

180

A comparison of the composition of epicuticular wax from red raspberry ( Rubus idaeus L.) and hawthorn ( Crataegus monogyna Jacq.) flowers  

Microsoft Academic Search

Epicuticular waxes have been characterised from the flowers of raspberry and hawthorn, on both of which adult raspberry beetles (Byturus tomentosus) can feed. The flower wax from both species had similar alkane profiles and also contained long-chain alcohols, aldehydes and fatty acids. The range of the carbon numbers detected for these classes of compounds was broadly similar in both but

D. Wynne Griffiths; Graeme W Robertson; Tom Shepherd; A. Nicholas E Birch; Stuart C Gordon; J. A. Trefor Woodford

2000-01-01

181

Transcript Assembly and Quantification by RNA-Seq Reveals Differentially Expressed Genes between Soft-Endocarp and Hard-Endocarp Hawthorns  

PubMed Central

Hawthorn (Crataegus spp.) is an important pome with a long history as a fruit, an ornamental, and a source of medicine. Fruits of hawthorn are marked by hard stony endocarps, but a hawthorn germplasm with soft and thin endocarp was found in Liaoning province of China. To elucidate the molecular mechanism underlying the soft endocarp of hawthorn, we conducted a de novo assembly of the fruit transcriptome of Crataegus pinnatifida and compared gene expression profiles between the soft-endocarp and the hard-endocarp hawthorn varieties. De novo assembly yielded 52,673 putative unigenes, 20.4% of which are longer than 1,000 bp. Among the high-quality unique sequences, 35,979 (68.3%) had at least one significant match to an existing gene model. A total of 1,218 genes, represented 2.31% total putative unigenes, were differentially expressed between the soft-endocarp hawthorn and the hard-endocarp hawthorn. Among these differentially expressed genes, a number of lignin biosynthetic pathway genes were down-regulated while almost all the flavonoid biosynthetic pathway genes were strongly up-regulated, concomitant with the formation of soft endocarp. In addition, we have identified some MYB and NAC transcription factors that could potentially control lignin and flavonoid biosynthesis. The altered expression levels of the genes encoding lignin biosynthetic enzymes, MYB and NAC transcription factors were confirmed by quantitative RT-PCR. This is the first transcriptome analysis of Crataegus genus. The high quality ESTs generated in this study will aid future gene cloning from hawthorn. Our study provides important insights into the molecular mechanisms underlying soft endocarp formation in hawthorn. PMID:24039819

Zhang, Feng; Liu, Zhongchi; Li, Xiaoming; Li, Wenran; Ma, Yue; Li, He; Liu, Yuexue; Zhang, Zhihong

2013-01-01

182

Subsurface Miocene sequence stratigraphic framework in the Nile Delta, Egypt  

NASA Astrophysics Data System (ADS)

The Miocene depositional history of the Nile Delta is dominated by fluvial-deltaic, marginal marine and marine shelf sedimentation. It exhibits radical lateral facies changes due to its tectonic setting. Different attributions in age assignments characterise the Miocene Nile Delta due to the lack of large vertical facies changes, which consists mainly of siliciclastic with different environments. This study uses integrating lithologic, biostratigraphic, gamma-ray log and benthic foraminiferal biofacies, at four boreholes (Tanta-1, Rommana-1X, El-Fayrouz and Rosetta-7) in the Nile Delta, Egypt. Planktonic foraminifera allow subdivision of the Miocene Nile Delta succession into 12 planktonic biozones and benthic species are used in paleobathymetic estimates.

Farouk, Sherif; Ziko, Abdelmohsen; Eweda, Shehtta A.; Said, Ali E.

2014-03-01

183

Paleotopography of the Miocene European Central Alps  

NASA Astrophysics Data System (ADS)

Reconstructing the surface elevation, surface uplift, and relief evolution histories is fundamental to understanding the growth of mountain ranges, to explore their topographic limits, and relate these to geodynamic and Earth surface processes. Recent geologic and geodynamic models for the Central European Alps propose that the bulk of topography was built through the Pliocene, mainly based on the observation of a strong increase in sedimentation and erosion rates during the last 5-6 Ma, suggesting that the Alps never attained elevations as high as today. Here, we aim to quantify the Miocene (20-14 Ma) paleoelevation of the Central Alps through stable isotope paleoaltimetry. The novelty of the approach presented here, which renders it rather insensitive to past climate change, is to analyze stable isotope proxies of identical age, both from high internal parts of the Alpine orogen and from the adjacent foreland basin that was at or near sea level. We first exploit the hydrogen isotopic ratio in phyllosilicates (mica and chlorite) that interacted with meteoric water during activity of the Simplon detachment, a major normal fault that developed during orogen-parallel extension in high elevation regions. We then contrast the resulting meteoric water compositions with those recorded in carbonate-bearing paleosols of the North-Alpine foreland basin to provide an estimate of relative elevation differences. In the North-Alpine foreland basin, we present oxygen and carbon isotopic compositions of pedogenic mudstones and carbonate concretions. These terrestrial paleosols, dated with ca. 100 ka precision, serve as our point of reference for stable isotope paleoaltimetry, since they formed at or near sea level. Here, ?18O and ?13C values vary between +19 to +25% (SMOW) and -7 to +1% respectively and show close correspondence to global climate change during the mid-Miocene climatic optimum. In the Simplon fault zone, detachment-related muscovite (-126%) and chlorite (-135%) ?D values from the brittle hanging wall provide unequivocal evidence for syntectonic meteoric water interaction. This result is supported by a strongly localized pattern of meteoric water interaction in the footwall mylonites where recrystallized muscovite and biotite have ?D values of -108% and -140%, respectively. Detailed 40Ar/39Ar and fission track geochronology constrains the timing of isotopic exchange during the ductile to brittle transition of the detachment to ca. 14-15 Ma. Using the relative differences between meteoric water composition in the foreland and internal regions of the orogen, our isotope data are consistent with an average altitude difference of 2300 m ± 500 m during the mid-Miocene. Our results do not necessarily agree with the proposition that the main formation of topography started only 5-6 Ma ago, since the Alpine elevations were similar or even higher than those of today already in the mid-Miocene. This implies that the bulk of Alpine topography was built during the construction stage of the Alpine orogenic wedge when accretion rates outpaced erosion and sediment evacuation rates.

Campani, M.; Mulch, A.; Kempf, O.; Schlunegger, F.; Mancktelow, N.

2011-12-01

184

Phytochemical characterization of several hawthorn (Crataegus spp.) species sampled from the Eastern Mediterranean region of Turkey  

PubMed Central

Background: We evaluated the total phenolic content, antioxidant capacity as well as antioxidant activity of five Crataegus species (A1, A2, Y1, Y2, Y4 accessions of Crataegus aronia var. aronia; B2, B3, B5, B6, B7, B9, Y5 accessions of C. aronia var. dentata; B10 accession of C. aronia var. minuta; Y3 accession of Crataegus orientalis var. orientalis and A3 accession of Crataegus monogyna subsp. azarella). Materials and Methods: Antioxidant activity and total phenolic content of fruits were determined by ?-carotene bleaching and Folin–Ciocalteu assays. Antioxidant capacity was determined by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Results: C. monogyna subsp. azarella had the highest total phenol, antioxidant activity and antioxidant capacity of 55.2 mg gallic acid equivalents (GAE)/g dry weight (DW), 81.9% and 31.2%, respectively. C. aronia var. aronia was found to have the lowest total phenolic content (35.7 mg GAE/g DW). The antioxidant activities of fruit extracts increased in the order of C. orientalis var. orientalis < C. aronia var. minuta < C. aronia var. dentata < C. aronia var. aronia < C. monogyna subsp. azarella according to ?-carotene/linoleic acid assay. In recent years, C. aronia var. dentata has gained importance as a commercial species in this region. B3 and B7 accessions had fruit weight more than 14 g, and considerable total phenol content, antioxidant activity and antioxidant capacity. Conclusion: This investigation shows the potential value of hawthorn fruit species as a good source of natural antioxidants and that consumption of hawthorn fruit or its products may contribute substantial amounts of antioxidants to the diet. PMID:22438658

Çali?kan, O?uzhan; Gündüz, Kazim; Serçe, Sedat; Toplu, Celil; Kamilo?lu, Önder; ?engül, Memnune; Erci?li, Sezai

2012-01-01

185

Chaungtha, a new Middle Miocene mammal locality from the Irrawaddy Formation, Myanmar  

NASA Astrophysics Data System (ADS)

We describe here a mammalian assemblage originating from the locality of Chaungtha (Irrawaddy Formation, Myanmar). It represents one of the rare descriptions of a precisely located, in space, vertical section and time, fossil mammal fauna from the Irrawaddy Formation. Classically the fossil record of Irrawaddy Formation is essentially known from isolated fossils of imprecise or unknown provenance, especially concerning the stratigraphic position of the fossils along several hundred meter thick sections. The Chaungtha faunal association consists of the rhino Brachypotherium fatehjangense, the pig Conohyus thailandicus, the ruminants cf. Siamotragulus sanyathanai, cf. Siamotragulus sp. and a gomphotheriid proboscidean. This assemblage indicates that the locality is Miocene in age, and not Late Eocene as previously claimed, and roughly contemporaneous with the Chinji Formation of India-Pakistan (ca. 14-11 Ma) and with the Mae Moh Group of northern Thailand. The Chaungtha fauna, even if it displays regional characteristics, shows a strong resemblance to those of the Middle Miocene of India-Pakistan and of Thailand and reinforces the idea that South-East Asia and Pakistan were part of the same biogeographical province during the Middle Miocene.

Chavasseau, Olivier; Chaimanee, Yaowalak; Tun, Soe Thura; Soe, Aung Naing; Barry, John C.; Marandat, Bernard; Sudre, Jean; Marivaux, Laurent; Ducrocq, Stéphane; Jaeger, Jean-Jacques

2006-12-01

186

Ostracods (Crustacea) and their palaeoenvironmental implication for the Solimões Formation (Late Miocene; Western Amazonia/Brazil)  

NASA Astrophysics Data System (ADS)

Western Amazonia's landscape and biota were shaped by an enormous wetland during the Miocene epoch. Among the most discussed topics of this ecosystem range the question on the transitory influx of marine waters. Inter alia the occurrence of typically brackish water associated ostracods is repeatedly consulted to infer elevated salinities or even marine ingressions. The taxonomical investigation of ostracod faunas derived from the upper part of the Solimões Formation (Eirunepé; W-Brazil) documents a moderately diverse assemblage (19 species). A wealth of freshwater ostracods (mainly Cytheridella, Penthesilenula) was found co-occurring with taxa (chiefly Cyprideis) usually related to marginal marine settings today. The observed faunal compositions as well as constantly very light ?18O- and ?13C-values obtained by measuring both, the freshwater and brackish water ostracod group, refer to entirely freshwater conditions. These results corroborate with previous sedimentological and palaeontological observations, which proposed a fluvial depositional system for this part of western Amazonia during the Late Miocene. We demonstrate that some endemic, “brackish” water ostracods (i.e., Cyprideis) have been effectively adapted to freshwater conditions. Thus, their occurrence is no univocal evidence for the influence of brackish or marine waters in western Amazonia during the Miocene.

Gross, Martin; Ramos, Maria Ines; Caporaletti, Marco; Piller, Werner E.

2013-03-01

187

Early Miocene hippopotamids (Cetartiodactyla) constrain the phylogenetic and spatiotemporal settings of hippopotamid origin  

PubMed Central

The affinities of the Hippopotamidae are at the core of the phylogeny of Cetartiodactyla (even-toed mammals: cetaceans, ruminants, camels, suoids, and hippos). Molecular phylogenies support Cetacea as sister group of the Hippopotamidae, implying a long ghost lineage between the earliest cetaceans (?53 Ma) and the earliest hippopotamids (?16 Ma). Morphological studies have proposed two different sister taxa for hippopotamids: suoids (notably palaeochoerids) or anthracotheriids. Evaluating these phylogenetic hypotheses requires substantiating the poorly known early history of the Hippopotamidae. Here, we undertake an original morphological phylogenetic analysis including several “suiform” families and previously unexamined early Miocene taxa to test previous conflicting hypotheses. According to our results, Morotochoerus ugandensis and Kulutherium rusingensis, until now regarded as the sole African palaeochoerid and the sole African bunodont anthracotheriid, respectively, are unambiguously included within the Hippopotamidae. They are the earliest known hippopotamids and set the family fossil record back to the early Miocene (?21 Ma). The analysis reveals that hippopotamids displayed an unsuspected taxonomic and body size diversity and remained restricted to Africa during most of their history, until the latest Miocene. Our results also confirm the deep nesting of Hippopotamidae within the paraphyletic Anthracotheriidae; this finding allows us to reconstruct the sequence of dental innovations that links advanced selenodont anthracotheriids to hippopotamids, previously a source of major disagreements on hippopotamid origins. The analysis demonstrates a close relationship between Eocene choeropotamids and anthracotheriids, a relationship that potentially fills the evolutionary gap between earliest hippopotamids and cetaceans implied by molecular analyses. PMID:20547829

Orliac, Maeva; Boisserie, Jean-Renaud; MacLatchy, Laura; Lihoreau, Fabrice

2010-01-01

188

Application of (U-Th)/He thermochronometry as a geothermal exploration tool in extensional tectonic settings: the Wassuk Range, Hawthorne, Nevada  

E-print Network

with hot geothermal fluids. Apatite cooling ages from the footwall of the Wassuk Range, Hawthorne, Nevada have identified the presence of a known geothermal anomaly and associated struc- tural complexities. The most recent pulse of exhumation along... during rapid uplift and exhumation of the footwall in normal faults (Walker et al., 2005). Application of (U-th)/He thermochronometry as a Geothermal Exploration tool in Extensional tectonic settings: the Wassuk range, Hawthorne, Nevada Kyle E...

Gorynski, Kyle; Stockli, Daniel F.; Walker, J. Douglas; Sabin, Andrew

2010-01-01

189

Fossil Woodwardia virginica Foliage From the Middle Miocene Yakima Canyon  

NSDL National Science Digital Library

Fossil Woodwardia virginica foliage from the middle Miocene Yakima Canyon flora of central Washington State, USA. Vegetative and fertile features of this fossil are remarkably similar to those of the modern ""Virginia chain fern"" of the Atlantic coastal region, USA.

Kathleen B. Pigg (Arizona State University;Department of Plant Biology ADR;POSTAL)

2004-03-09

190

Miocene deformation of the central Vienna Basin (Austria-Slovakia)  

NASA Astrophysics Data System (ADS)

The project KARPATIAN TECTONICS SLOVAKIA aims at the creation of a comprehensive geologic model of the structural evolution of the Vienna Basin area before the onset of major subsidence related to pull-apart deformation, i.e., during the Lower Miocene. Seismic data acquired by OMV from the central Vienna Basin and from the region east fo the Drösing depression, as well as outcrop data provide the basis for structural geologic interpretation of the entire central Vienna Basin. In this study, we focus on the complex structural evolution that can be mapped from these seismic datasets complementing the deformation geometry and history of the region east of the Spannberg ridge. The structural inventory found in the central Vienna Basin consist of (i) ENE and WSW dipping normal faults, (ii) SE- to ESE-dipping thrust faults, (iii) NW - SE-striking sinistral strike-slip faults (Hölzel et al., in press). These structural features can be found above the nappes of the Austroalpine Calcareous Alps, the nappes of the Tirolic and Bajuvaric superunits. In this study, we can complement the structures from East to West as follows: (1) The continution of the Lassee negative flower structure reaches up along the Lab fault system to the Laksary elevation. Here, it widens and branches off into at least two major branches engulfing the Laksary elevation. (2) N - S striking strike-slip faults penetrating the accoustic basement as well as Karpatian strata possibly form a continuing system that branches off of the Zwerndorf transform fault system. (3) In the center of the Gajary depression, normal faults offset the accoustic basement above sediments of the Upper Cretaceous Gosau Group. These features can be dated by Karpatian growth strata. However, the normal faults were not always active at the same time as indicated by the geometry of the sedimentary strata bounded by the normal faults. (4) At the western boundary of the Gajary depression, smaller scale normal faults deform the Aderklaa Conglomerate (Top Karpatian). (5) NW - SE trending grabens in the basement and Karpatian strata occur in the center and SE corner of the Gajary depression. (6) The entire Karpatian sedimentary stack including the Top Karpatian is tilted towards the West forming the central part of the Levare depression to the North of the Gajary depression. Hölzel, M., Decker, K., Zámolyi, A., Strauss, P., Wagreich, M. (in press): Lower Miocene structural evolution of the central Vienna Basin (Austria). Marine and Petroleum Geology

Zámolyi, András.; Lee, Eun Young; Beidinger, Andreas; Hoprich, Maria; Strauss, Philipp; Decker, Kurt

2010-05-01

191

Is patient satisfaction sensitive to changes in the quality of care? An exploitation of the Hawthorne effect.  

PubMed

We introduce a new instrument to evaluate the impact of behavior on outcomes when the behavior may be a function of unobserved variables that also affect outcomes. The instrument is introduced through a test of patient sensitivity to increases in the quality of care provided by doctors. We utilize the Hawthorne effect, in which the very presence of a research team causes doctors to provide measurably superior quality care for any type of patient to show that patients respond to this increased quality and are more likely to be very satisfied. Using the Hawthorne effect as an instrument allows us to examine the responsiveness of satisfaction to improvements in quality despite the fact that patient satisfaction is subjective and jointly produced with quality during the course of a consultation. PMID:18192043

Leonard, Kenneth L

2008-03-01

192

Antioxidant capacity of polyphenolic extracts from leaves of Crataegus laevigata and Crataegus monogyna (Hawthorn) subjected to drought and cold stress.  

PubMed

Crataegus laevigata and Crataegus monogyna (hawthorn) were subjected to drought and cold stress treatments, and polyphenolic extracts from control and stress-treated plants were assayed for antioxidant capacities using a modified version of the Total Antioxidant Status Assay (Randox, San Francisco, CA). In addition, these plants were analyzed for levels of flavanol-type substance [(-)-epicatechin] and flavonoid (vitexin 2' '-O-rhamnoside, acetylvitexin 2' '-O-rhamnoside, and hyperoside) constituents that are important metabolites in hawthorn herbal preparations used to treat patients with heart disease. Drought and cold stress treatments caused increases in levels of (-)-epicatechin and hyperoside in both Crataegus species. Such treatments also enhanced the antioxidant capacity of the extracts. The results from this study thus indicate that these kinds of stress treatments can enhance the levels of important secondary metabolites and their total antioxidant capacities in leaves of Crataegus. PMID:12822932

Kirakosyan, Ara; Seymour, Elisabeth; Kaufman, Peter B; Warber, Sara; Bolling, Steven; Chang, Soo Chul

2003-07-01

193

Miocene-Pleistocene tectono-sedimentary evolution of Bah?´a Concepción region, Baja California Sur (México)  

NASA Astrophysics Data System (ADS)

Bah?´a Concepción is one of the largest fault-bound bays in the Gulf of California. It is one of the area's best examples of an extensional basin, and an accommodation zone related to the Late Miocene extension in the Gulf of California region. Extensional tectonics in the Gulf region initiated from middle to early Late Miocene, in a simple east-west manner. The units within the Comondú Group are tilted between 14 and 45° in opposite directions (E/W), as a direct result of a single main extensional episode. This event produced subsidence that created the depocenters for nearshore marine basins. The oldest sedimentary units present in the region are assigned to the Late Miocene-early Pliocene Tirabuzón Formation. Up-faulted granodiorite basement occurs on the Peninsula Concepción, and at Punta San Antonio as a direct result of the Late Miocene extensional episode. Extension on the Bah?´a Concepción zone was responsible for development of a divided half-graben structure first flooded in Late Pliocene time. The tectono-sedimentary evolution of Bah?´a Concepción is recorded by three stratigraphic stages: (1) pre-rift strata represented by the Comondú Group, (2) a syn-rift unconformity, and (3) a post-rift strata represented by the Late Miocene to Pliocene flat laying sedimentary units. This triad of stratigraphic stages clearly varies from other basins along the margin of the Gulf of California. Upper Pleistocene terrace deposits generally conform to the 6-12 m elevation regionally associated with substage 5e. Their uniformity in elevation inside and outside Bah?´a Concepción indicates that tectonic uplift was locked in step throughout the immediate region at least since that time.

Ledesma-Vázquez, J.; Johnson, Markes E.

2001-10-01

194

Miocene reef facies of Pelagian Block, central Mediterranean  

SciTech Connect

Miocene reefs outcrop in the Maltese Islands, southeastern Sicily, and the pelagian island of Lampedusa. Several rapid eustatic sea level fluctuations affected these late Tortonian-early Messinian build-ups; normal salinities appear to have been maintained during these events. Substrate, topography, sedimentation rate, and tectonic/eustatic events controlled reef development, which can be grouped into three settings: The most stable situation, the oldest Maltese and southeastern Sicilian reefs, has a ramp profile 15-30 km wide. The outermost zone consists of a broad belt of the large benthic foraminifer Heterostegina (compared with the underyling Oligocene beds rich in Lepidocyclina). Coralline algal carbonates, commonly rhodolitic, form a broad biostromal up-ramp association, kilometers in width, which commonly extends into the shallowest parts of the shelf. Scattered across the shallower ramp areas, in water depths generally less than 10 m, are coral-algal patch reefs, rarely larger than 20-50 m in diameter, commonly with truncated tops, and dominated by crustose coralline algae and the corals Porites and Tarbellastraea.

Pedley, H.M.

1988-01-01

195

Functional response of the predator Scolothrips takahashii to hawthorn spider mite, Tetranychus viennensis : effectof age and temperature  

Microsoft Academic Search

A leaf disc bioassay was employed to examine the effects of temperature and predator age on functional response of an acarophagous\\u000a thrips, Scolothrips takahashii Priesner, to hawthorn spider mite, Tetranychus viennensis Zacher, in the laboratory. The results indicated that the predatory thrips exhibited type-II functional responses against\\u000a the mites under various temperatures, and that females are more voracious than males.

Li Ding-Xu; Tian Juan; Shen Zuo-Rui

2007-01-01

196

Simultaneous determination of three polyphenols in rat plasma after orally administering hawthorn leaves extract by the HPLC method  

Microsoft Academic Search

A simple and sensitive HPLC method was developed to simultaneously determine three active compounds, vitexin-4?-O-glucoside (VG), vitexin-2?-O-rhamnoside (VR) and hyperoside (HP), in rat plasma after administering the hawthorn leaves extract (HLE). An HPLC assay with baicalin as the internal standard was carried out using a Phenomsil C18 analytical column with UV detection at 332?nm. The mobile phase consisted of methanol–acetonitrile–tetrahydrofuran–1%

Xixiang Ying; Xiansheng Meng; Siyuan Wang; Dong Wang; Haibo Li; Bing Wang; Yang Du; Xun Liu; Wenjie Zhang; Tingguo Kang

2012-01-01

197

Simultaneous determination of three polyphenols in rat plasma after orally administering hawthorn leaves extract by the HPLC method  

Microsoft Academic Search

A simple and sensitive HPLC method was developed to simultaneously determine three active compounds, vitexin-4?-O-glucoside (VG), vitexin-2?-O-rhamnoside (VR) and hyperoside (HP), in rat plasma after administering the hawthorn leaves extract (HLE). An HPLC assay with baicalin as the internal standard was carried out using a Phenomsil C18 analytical column with UV detection at 332?nm. The mobile phase consisted of methanol–acetonitrile–tetrahydrofuran–1%

Xixiang Ying; Xiansheng Meng; Siyuan Wang; Dong Wang; Haibo Li; Bing Wang; Yang Du; Xun Liu; Wenjie Zhang; Tingguo Kang

2011-01-01

198

The Effect of Group Counseling upon the Classroom Behavior and on the Manifest Anxiety of Elementary School Student Teachers. Final Report.  

ERIC Educational Resources Information Center

This study assesses the effectiveness of a group counseling treatment on the classroom behaviors and on the manifest anxiety levels of elementary school student teachers. The subjects were 44 volunteer student teachers, randomly assigned to three groups: 1) an experimental counseling group, 2) a Hawthorne seminar control group, and 3) a control…

Eder, Sidney Charles

199

Marine Biotic Responses to Miocene Climate Change  

NSDL National Science Digital Library

This activity is part of a collection under development by participants in a June 2006 workshop. Tested versions will be available in Spring 2007. During the Miocene the Earth plunged into its present "icehouse" state, with glaciers at North and South Poles. In this activity, students investigate biotic responses to this climate change using microfossil data from the Deep Sea Drilling Project (DSDP) and Ocean Drilling Program (ODP). These data are analyzed and displayed using the CHRONOS information technology system, building information technology skills while strengthening understanding of biostratigraphic principles. The activity integrates geochemical and biotic data, reinforcing the notion that understanding Earth History requires a multidisciplinary approach. Students use Time Scale Creator to examine how sediments are correlated and dated. DSDP and ODP core data in the Neptune database is used to create age-distribution histograms for foraminifers and calcareous nannofossils, and compare these data to the record of climate change based on oxygen isotope analyses. Students synthesize and compare their discoveries regarding marine microfossil responses to global climate change, and evaluate the assumptions and biases inherent in these results. Step-by-step instructions for using the CHRONOS interface are provided, formatted as a student handout. References to related primary literature are included, and may be used to adapt the exercise for more advanced undergraduates or graduate students.

Grossman, Ethan; Mccarville, Katherine; Clark, Kendra; Hemmesch, Nikki T.

200

Oligocene-Miocene deformational and depositional history of the Andean hinterland basin in the northern Altiplano plateau, southern Peru  

NASA Astrophysics Data System (ADS)

basin fill of the northern Altiplano plateau records the tectonic development of the flanking Western Cordillera magmatic arc and Eastern Cordillera fold-thrust belt. The Ayaviri hinterland basin of southern Peru contains a ~2300 m thick succession of fluvial sandstones and overbank siltstones (upper Oligocene Puno Group and lower Miocene lower Tinajani Formation) capped by ~400 m of alluvial fan conglomerates (middle Miocene upper Tinajani Formation). New U-Pb zircon chronostratigraphic constraints from ~30 to 15 Ma yield sediment accumulation rates of 110-660 m/Myr. Newly dated growth strata highlight the genetic role played by thrust displacement in basin evolution. A several phase accumulation history derived from chronostratigraphic, provenance, and structural data reveals Oligocene basin filling by fluvial sand and mud that changes provenance from Western Cordillera Mesozoic-Cenozoic volcanic rocks to Paleozoic-Mesozoic Eastern Cordillera sedimentary rocks driven by deformation along the southwest directed, northeastern basin margin Ayaviri thrust at 28-26 Ma. Continued early Miocene fluvial deposition was sourced solely from the Eastern Cordillera. An abrupt middle Miocene shift to coarse alluvial fan deposition sourced from the Western Cordillera was driven by out-of-sequence deformation along the northeast directed, southwestern basin margin Pasani thrust at 18-16 Ma. This northern Altiplano out-of-sequence deformation was coincident with increased Eastern and Western Cordillera exhumation and thrusting and may be symptomatic of changes in critical wedge dynamics. The overall record of basin sedimentation and syndepositional fold-thrust deformation emphasizes the role of regional shortening in governing crustal thickening and basin evolution in the central Andes during the Oligocene to Miocene.

Perez, Nicholas D.; Horton, Brian K.

2014-09-01

201

A molecular organic carbon isotope record of miocene climate changes  

SciTech Connect

The difference in carbon-13 ([sup 13]C) contents of hopane and sterane biomarkers in the Monterey formation (Naples Beach, California) parallels the Miocene inorganic record of the change in [sup 18]O ([delta][sup 18]O), reflecting the Miocene evolution from a well-mixed to a highly stratified photic zone (upper 100 meters) in the Pacific. Steranes ([delta][sup 13]C = 25.4 [+-] 0.7 per mil versus the Pee Dee belemnite standard) from shallow photic-zone organisms do not change isotopically throughout the Miocene. In contrast, sulfur-bound C[sub 35] hopanes (likely derived from bacterial plankton living at the base of the photic zone) have systematically decreasing [sup 13]C concentrations in Middle and Late Miocene samples ([delta][sup 13]C = 29.5 to [minus]31.5 per mil), consistent with the Middle Miocene formation of a carbon dioxide-rich cold water mass at the base of the photic zone.

Schoell, M. (Chevron Petroleum Technology Co., La Habra, CA (United States)); Schouten, S.; Sinninghe Damste', J.S.; Leeuw, J.W. de (Netherlands Institute of Sea Research, Texel (Netherlands)); Summons, R.E. (Australian Geological Survey Organization, Canberra (Australia))

1994-02-25

202

Late Miocene “washhouse” climate in Europe  

NASA Astrophysics Data System (ADS)

We present two eight-million year long proxy records of precipitation for Southwest and Central Europe, covering the middle to late Miocene (5.3-13 Ma) at a temporal resolution of about 60 kyr and 150 kyr, respectively. The estimates of precipitation are based on the ecophysiological structure of herpetological assemblages (amphibians and reptiles). From 13.0 Ma until about 9 Ma, both records show a similar trend, evolving from a long dry period (13-11 Ma) into a "washhouse climate" (10.2-9.8 Ma), characterized by global warm conditions and several times more precipitation than present. The transition from washhouse to a dryer climate between 9.7 and 9.5 Ma and the concomitant cooling episode appear to have triggered a severe biotic event known as the Vallesian crisis, which included the extinction of hominoids in Western Europe. A second washhouse period (9.0-8.5 Ma), coeval with a global warm episode, was unprecedentedly intense in Southwest Europe, but less pronounced in Central Europe. From 8 Ma onward, a divergence in the two precipitation records is observed, with Southwest Europe staying wetter and Central Europe becoming dryer than present. Both precipitation records are combined into a common run-off curve as a measure of the relative intensity of the hydrological cycle for moderate latitudes of continental Europe. The run-off curve shows a remarkable positive correlation with Atlantic deep-water temperatures from Ceará Rise by Lear et al. (2003), which are significantly higher (up to + 3 °C) during the two washhouse periods and show no other positive excursion of comparable magnitude. We discuss potential links and the role of the coeval temporary restriction of the Central American Seaway on ocean and atmosphere circulation.

Böhme, Madelaine; Ilg, August; Winklhofer, Michael

2008-11-01

203

Miocene shallow-water carbonates on the Eratosthenes Seamount, easternmost Mediterranean Sea   

E-print Network

Miocene shallow-water limestones of the Eratosthenes Seamount add considerably to the picture of widespread and heterogeneous Mediterranean Miocene reef development. Shallow-water limestones were cored at two sites on the ...

Robertson, Alastair H F

1998-01-01

204

On the Miocene Cyprideis species flock (Ostracoda; Crustacea) of Western Amazonia (Solimões Formation): Refining taxonomy on species level.  

PubMed

The Miocene mega-wetland of western Amazonia holds a diverse, largely endemic ostracod fauna. Among them, especially the genus Cyprideis experienced a remarkable radiation. Micropalaeontologic investigations of a 400 m long sediment core (~62 km SW Benjamin Constant, Amazonia, Brazil) permitted a taxonomic revision of about two-thirds of hitherto described Cyprideis species. We evaluate the diagnostic value of shell characters and provide an extensive illustration of the intraspecific variability of species. Based on comparative morphology, the 20 recorded Cyprideis species are arranged in groups and subgroups. The "smooth" group comprises C. amazonica, C. kotzianae, C. kroemmelbeini, C. machadoi, C. multiradiata, C. olivencai, C. paralela and C. simplex; the "ornate" group C. curucae nom. nov., C. cyrtoma, C. aff. graciosa, C. inversa, C. ituiae n. sp., C. matorae n. sp., C. minipunctata, C. munoztorresi nom. nov., C. pebasae, C. reticulopunctata, C. schedogymnos and C. sulcosigmoidalis. Five species have been revalidated, two renamed, two synonymised and two are new descriptions. Along with 10 further formally established species, for which a review is pending, Cyprideis keeps at least 30 endemic species in that region during Miocene times. Up to 12 Cyprideis species have been found to occur sympatrically, representing >90 % of the entire ostracod fauna. Ostracod index species enable a biostratigraphic allocation of the well succession to the Cyprideis minipunctata to Cyprideis cyrtoma biozones, corresponding to a late Middle to early Late Miocene age (late Serravallian-early Tortonian).  PMID:25543674

Gross, Martin; Ramos, Maria Ines F; Piller, Werner E

2014-01-01

205

Paleomagnetic Evidence for Spatially Distributed Post-Miocene Rotation of Western Washington and Oregon  

NASA Astrophysics Data System (ADS)

Anomalous paleomagnetic directions have been determined for 17 sites in the Frenchmans Springs member of the Wanapum basalt formation, Columbia River basalt group. These sites are located in the Ginkgo flows from near Vantage, Washington, to Portland, Oregon, a distance of approximately 300 km. The average paleomagnetic direction for six of these sites, centered around Vantage is D = 147°, I = 41°, ?95 = 4.5°. The expected Miocene field direction is D = 355°, I = 65°. At some localities there are two distinct Ginkgo flows, in direct stratigraphic succession, with statistically identical anomalous directions. Their anomalous paleomagnetic direction makes these flows a valuable marker horizon in the Columbia River basalt group. The nondipole field direction of the Ginkgo flows correlates well with available results from the Miocene Cape Foulweather basalts of Oregon. This correlation strongly supports the hypothesis that these coastal basalts of Oregon are the distal ends of Columbia Plateau derived basalt flows. The spatial distribution of these anomalous field directions suggests about 14° of clockwise rotation between Vantage and Portland. Combining these data with data from the Oregon Coast basalts allows a maximum declination difference of about 35°. The increase in declination can be best explained by clockwise rotation, about nearby vertical axes, increasing to the southwest across the Columbia Plateau and Oregon coast.

Sheriff, Steven D.

1984-06-01

206

Occlusal enamel complexity in middle miocene to holocene equids (Equidae: Perissodactyla) of North America.  

PubMed

Four groups of equids, "Anchitheriinae," Merychippine-grade Equinae, Hipparionini, and Equini, coexisted in the middle Miocene, but only the Equini remains after 16 Myr of evolution and extinction. Each group is distinct in its occlusal enamel pattern. These patterns have been compared qualitatively but rarely quantitatively. The processes influencing the evolution of these occlusal patterns have not been thoroughly investigated with respect to phylogeny, tooth position, and climate through geologic time. We investigated Occlusal Enamel Index, a quantitative method for the analysis of the complexity of occlusal patterns. We used analyses of variance and an analysis of co-variance to test whether equid teeth increase resistive cutting area for food processing during mastication, as expressed in occlusal enamel complexity, in response to increased abrasion in their diet. Results suggest that occlusal enamel complexity was influenced by climate, phylogeny, and tooth position through time. Occlusal enamel complexity in middle Miocene to Modern horses increased as the animals experienced increased tooth abrasion and a cooling climate. PMID:24587267

Famoso, Nicholas A; Davis, Edward Byrd

2014-01-01

207

Phenolic constituents and antioxidant capacities of Crataegus monogyna (Hawthorn) callus extracts.  

PubMed

Crataegus (Hawthorn) has long been used as a folk medicine and is widely utilized in pharmaceutical preparations mainly because of its neuro- and cardiosedative actions and its low toxicity. The pharmacological effects of Crataegus have mainly been attributed to the polyphenolic contents. In this study, the production of polyphenols by ten-year-old Crataegus monogyna calli was studied in relation to growth variation and antioxidant capacity within a subculture period. Assays based on the Trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP) and stability in oil-in-water emulsion were used to characterize the antioxidant actions of the callus cultures. High TEAC (3.66 micromol/g dry weight) and FRAP (208.19 micromol Fe2+/g dry weight) values were observed when maximal growth was reached(days 30-35), and this seemed to be influenced by optimum total phenol (47.40 mg/g dry weight), proanthocyanidin (20.81 mg/g dry weight), flavonoid (7.01 mg/g dry weight), anthocyanin (6.18 mg/g dry weight), (-)-epicatechin (1.77 mgl/g dry weight), procyanidin B2 (3.97 mg/g dry weight), and chlorogenic acid (1.11 mg/g dry weight) production during that period. The TEAC values were strongly associated with total flavonoids and to a lesser extent with total phenols, anthocyanins and total proanthocyanidins. The FRAP antioxidant values correlated to total phenols, proanthocyanidins and flavonoids, respectively. The polyphenolic rich calli were as effective as butylated hydroxytoluene (BHT) in preventing hydroperoxide and conjugated diene formation in a 30% oil-in-water emulsion prepared with stripped sunflower oil, during 7days storage at 30 degrees C. Crataegus monogyna cell culture represents an important alternative source for natural antioxidants. PMID:12866623

Bahorun, Theeshan; Aumjaud, Esha; Ramphul, Hemlata; Rycha, Maheshwaree; Luximon-Ramma, Amitabye; Trotin, Francis; Aruoma, Okezie I

2003-06-01

208

Scale-dependent effects of habitat fragmentation on hawthorn pollination, frugivory, and seed predation.  

PubMed

Habitat fragmentation is a major cause of functional disruption in plant-animal interactions. The net effect on plant regeneration is, however, controversial because a given landscape change can simultaneously hamper mutualism and attenuate antagonism. Furthermore, fragmentation effects may emerge at different spatial scales, depending on the size of the foraging range of the different interacting animals. We studied pollination by insects, frugivory by birds acting as seed dispersers, and postdispersal seed predation by rodents in 60 individual hawthorn (Crataegus monogyna Jacq.) trees in relation to structural fragmentation in the surrounding habitat. We evaluated fragmentation at three spatial scales by measuring the percentage of forest cover in three concentric areas around each tree of, respectively, 10-m, 20- to 50-m, and 50- to 100-m radius. The number of developing pollen tubes per flower style and fruit set decreased in proportion to the decrease of forest cover. Similarly, the magnitude of frugivory in focal trees was negatively affected by habitat loss. In contrast, seed predation was higher under plants in highly fragmented contexts. The effect of fragmentation was additive in terms of reducing the potential of plant regeneration. Moreover, the functional scale of response to habitat loss differed among interactions. Fragmentation effects on pollination emerged at the largest scale, whereas seed predation was mostly affected at the intermediate scale. In contrast to expectations from the larger foraging range of birds, fragmentation effects on frugivory mainly operated at the finest scale, favored by the ability of birds to cope hierarchically with spatial heterogeneity at different scales. Given that two opposing demographic forces (frugivory and seed predation) would be potentially affected by fine-scale features, we propose structural scale as the primary spatial dimension of fragmentation effects on the process of plant regeneration. PMID:17391190

García, Daniel; Chacoff, Natacha P

2007-04-01

209

Chemical evolution of Miocene wood: Example from the Belchatow brown coal deposit, central Poland  

USGS Publications Warehouse

Miocene conifer wood samples from the Belchatow brown coal deposit in Poland were studied in order to discuss a range of chemical variations that occur as a result of biochemical coalification. Petrographic analysis, ultimate analysis, electron microprobe technique, and FTIR spectroscopy were used in this study. Our data show several progressive trends in functional groups distribution that take place during the wood transformation from group 1 to group 4, such as an overall increase in aromaticity, an increase in lignin/cellulose ratio, and an increase in oxygen functionalities. Other observations include an increase in aliphatic stretching and bending functionalities from groups 1 to 3; followed by a decrease in the wood of group 4; appearance of aliphatic out-of-plane bands in group 3 and increase in group 4; an increase in CH2/CH3 in group 4 compared to the other groups; and decrease in O-H groups in group 4 compared to other groups. These observations, together with other chemical and petrological observations, indicate that the progressive elimination of cellulose and modification of lignin are dominant processes of the wood transformation. ?? 2005 Elsevier B.V. All rights reserved.

Drobniak, A.; Mastalerz, M.

2006-01-01

210

"The most important technique …": Carl Rogers, Hawthorne, and the rise and fall of nondirective interviewing in sociology.  

PubMed

In the 1940s, interviewing practice in sociology became decisively influenced by techniques that had originally been developed by researchers in other disciplines working within a number of therapeutic or quasi-therapeutic contexts, in particular the "nondirective interviewing" methods developed by Carl Rogers and the interviewing procedures developed during the Hawthorne studies. This article discusses the development of nondirective interviewing and looks at how in the 1930s and '40s the approach came to be used in sociology. It examines the factors leading to both the popularity of the method and its subsequent fall from favor. PMID:21462193

Lee, Raymond M

2011-01-01

211

Nitellopsis (Charophyta) from the Miocene of northern Thailand  

Microsoft Academic Search

Charophyte gyrogonites from two Miocene sites in northern Thailand are studied and compared for population variation. Morphometrical differences between the two populations, determined as Nitellopsis merianii and N. meriani globula, correspond to variation at the interpopulation level and do not justify the distinction of two separate species as made by previous authors. The first exhaustive synonymy for both taxa is

I. Soulié-Märsche; P. Gemayel; Y. Chaimanee; V. Suteethorn; J.-J. Jaeger; S. Ducrocq

1997-01-01

212

Fossil Hominoid Vertebra from the Miocene of Uganda  

Microsoft Academic Search

THE Miocene site of Moroto II in Karamoja, Uganda, was first described by Bishop and Whyte in 1962 (ref. 1). The only primate specimens so far recorded from this site are dental and cranial remains that have been assigned to Proconsul major, Le Gros Clark and Leakey2,3. Among fragmentary specimens from Moroto II in the Uganda Museum, Kampala, eight can

Alan Walker; M. D. ROSE

1968-01-01

213

The lithostratigraphy of Miocene series from Tunisia, revisited  

NASA Astrophysics Data System (ADS)

In the Mediterranean region, the Miocene is a rather particular tectonic, eustatic and climatic epoch. In Tunisia, the complex distribution of the sedimentary sequences has been controlled by the interaction of these factors. These sequences are composed mostly of silici-clastic packages filling usually rim-syncline, graben and half-graben basins. In the absence of a solid biostratigraphic framework, the dating and correlation of certain formations are not yet clearly perceived. In spite of the availability of some elements of dating (planktonic foraminifera, vertebrates), the solution remains as a whole unclear. The question thus remains as to the significance of the frequency and occurrence of discontinuities, and consequently of those hiatuses between Miocene Formations. Thus, in the light of the recent palynologic, sedimentological and vertebrate biostratigraphical data, a new reading of the paleogeography and paleoenvironment of the Miocene from Tunisia is essential. In this work, the results of multi-field studies supported by the compilation of the literature, enable sensible discussion of the proposed ages, analyze the depositional environments, and concomitantly support correlations between the Miocene Formations recognized to the South-East of the Eastern Dorsale of Tunisia. It is demonstrated that the Beglia and Saouaf Formations are partially equivalent rather than being superposed, as it has been previously surmised. A new, marine formation, the "Kef Ettir Formation", is also proposed.

Mannaï-Tayech, Beya

2009-06-01

214

Miocene terrestrial climate of southern New Zealand from floral proxies  

NASA Astrophysics Data System (ADS)

Southern New Zealand is situated in the mid-latitude south-west Pacific near the convergence zone of the Sub-Antarctic Front and the Subtropical Front. Climate records from this region are therefore of considerable importance for the understanding of the development of the Antarctic Ice Sheet and the consequences of the possible future retreat of the West Antarctic Ice Sheet. Well-preserved, diverse floral assemblages from several Miocene lake deposits have been discovered in southern New Zealand: they include one from the Aquitanian (23 Ma), two from the Burdigalian (16-18 Ma) and two from the Serravallian-Early Tortonian (10-12 Ma). Climatic proxies such as Climate Leaf Analysis Multivariate Program (CLAMP) and Bioclimatic Analysis provide a robust framework with which to reconstruct the terrestrial climate of southern New Zealand through the Miocene. CLAMP employs a set of physiognomic characteristics of fossil leaves and correlates these with a large physiognomic dataset of modern floral collections and associated climate variables. Bioclimatic Analysis is a mutual climate range method using the climatic envelopes of the nearest living relatives of a fossil flora to determine the climatic range in which the flora could co-occur. It employs a comprehensive dataset of modern living taxa of the major floral components from Australia, New Zealand and New Caledonia. New Zealand was a low-lying landmass throughout the Miocene, most likely of a comparable size to modern day New Zealand. Most floral assemblages were deposited close to sea-level and climate would have been regulated by the surrounding ocean. Subtropical climatic conditions prevailed throughout the Early and Middle Miocene with mean annual temperatures (MAT) around 18-20°C and precipitation rates at around 1500-2000 mm-yr. By comparison modern day coastal southern New Zealand has a MAT of between 8-10°C and annual precipitation ranges from 600-900 mm-yr on the east coast, to well over 4000 mm-yr on the southwest coast. The temperature difference between summer and winter in the Early to Middle Miocene was less than 10°C. Towards the Late Miocene, the MAT dropped to around 15°C and the temperature during the cold season was significantly cooler, with a cold month mean of ~13-14°C in the Early and Middle Miocene and ~6°C in the Late Miocene; close to modern day New Zealand winter temperatures. Precipitation rates remained the same at around 1500-2000mm-yr. The development of the West Antarctic Ice Sheet in the Miocene was the main driver that pushed the Sub-Antarctic Front northward, while southern New Zealand's latitudinal position remained stable at close to 45°S. Antarctic southerlies would not have played a role in New Zealand's climatic system during the Early and Middle Miocene, when the average temperature of the coldest months very rarely dropped below 10°C. By the Tortonian, Antarctic southerlies would have played a significant role in cooling southern New Zealand during winter.

Reichgelt, T.; Kennedy, E.; Conran, J. G.; Lee, D.

2013-12-01

215

The early to mid-Miocene environment of Antarctica  

NASA Astrophysics Data System (ADS)

Paleoecological studies in the Transantarctic Mountains of the McMurdo region provide evidence that the climate was both warmer and wetter in the early to mid-Miocene than it was during the late Miocene. The climate change was accompanied by a shift from wet- to cold-based glaciation in the TAM and the probable growth of the polar ice sheet. Terrestrial and freshwater aquatic fossil assemblages from the Friis Hills (77°S) and the Olympus Range (77°S), with endpoint 40Ar/39Ar ages on tephras of 19.76 Ma and 14.07 Ma, respectively, indicate climatic cooling during the interval. At c.14 Ma, the temperature dropped below the threshold required to support the plants and insects of a tundra biome, and they became extinct. This interpretation is supported by pollen studies from Ross Sea cores. The extinction of the tundra biota on the continent appears to have been time-transgressive, occurring at 12.8 Ma on the Antarctic Peninsula. Evidence of climatic cooling from early to mid-Miocene is based on a decrease in biodiversity. During interglacial phases of the early Miocene, the poorly drained valley of the Friis Hills supported a sexually-reproducing moss community dominated by Campylium cf. polygamum, which today grows on the margins of lakes and in soil between boulders. Wood and leaves of Nothofagus (Southern Beech), and the seeds of at least five other angiosperm species are preserved as fossils. In addition, there are abundant megaspores and spiny, curved leaves of the aquatic lycopod Isoetes (Quillwort), as well as chitinous remains of curculionid beetles and Chironomidae (midges). During glacial phases, the only fossils found are Nothofagus leaves of a species which appears to be different than that associated with the interglacial phases. Pollen supports the interpretation that there was more than one species of Nothofagus in the vegetation. The types and numbers of species indicate that the vegetation was a shrub tundra. The closest modern analog for the fossil assemblage is at treeline and higher on Isla Navarino (55°S) at the southern tip of South America. By mid-Miocene, the upland tundra biota was less diverse, most notably in the number of angiosperm taxa. Based on the autecology and geographic distributions of the descendants of the fossil biota which survive in the subantarctic islands, South America and Tasmania, there was a decline of mean summer temperatures from c. 6°C to c. 4°C from the early to the mid-Miocene. During the early Miocene, the MST of the TAM was c.19°C warmer than today. A paleotemperature estimate based on leaf waxes from a Ross Sea core is for a MST 11°C warmer than today which seems low considering it is based on a near sea-level vegetation. A recent paper utilizing a salt-hydration process to provide adequate moisture to support a Miocene tundra biota is based on erroneous data. The Miocene climate was wet with an annual precipitation of at least 3000 mm. A recent report of the possible survival of vegetation in the Taylor Valley until the Pliocene, based on the discovery of 5 Ma wood-like forms in a DVDP core, is improbable. Even if wood can be definitively identified from the Pliocene deposits it is likely to be reworked Miocene wood from uplands in the TAM (e.g. Friis Hills). Research supported by NSF OPP 0739693.

Ashworth, A. C.; Lewis, A.

2012-12-01

216

Coarse-grained deltaic sedimentation in the Miocene Cuyama strike-slip basin, California Coast Ranges  

USGS Publications Warehouse

The Cuyama basin, located in the southern Coast Ranges of California southwest of the San Andreas fault, developed early in the history of the San Andreas transform system. The Miocene marine basin formed in a transtensional setting along a dextral strike-slip fault of the transform system following Oligocene non-marine basin formation in an extensional setting. The lower and middle Miocene Vaqueros Formation in the northwestern part of the basin, which represents the first of two transgressive-regressive cycles, is described here in terms of nine facies in two broad facies groups. The 400-m-thick Soda Lake Shale Member (of the Vaqueros) comprises deep-basin and starved-basin facies. A thin transgressive facies occurs locally at the base of the formation. The overlying Painted Rock Sandstone Member (of the Vaqueros), which is more than 2200 m thick and consists mostly of coarse-grained sandstone and pebbly sandstone, constitutes a delta complex of prodelta, slope channel, delta front, tide-influenced distributary channel, interdistributary bay, and fluvial channel facies. The basinal depositional system consisted of turbidite mud and sand, and hemipelagic and pelagic sediments of the basinal facies deposited in a rapidly subsiding basin. The delta depositional system consisted of the delta complex facies that prograded into the deep basin and had a steep prodelta slope that extended to bathyal depths. The delta is inferred to be a mixed fluvial-wave-dominated fan delta, analogous in its delta-front morphology and processes to a fjord delta, in which coarse sediment delivered to the delta front by braided streams was transported down the prodelta slope into deep water by sediment gravity flows. Transgression and rapid deepening of the basin in the early Miocene coincided with rapid tectonic subsidence. Deepening culminated with deposition of a starved-basin facies or condensed section at the time of maximum transgression, which was followed by the beginning of a regression and basin shallowing. The overall basin history and geometry of the northwestern Cuyama basin are typical of strike-slip basins. The initial rapid subsidence to bathyal depths at rates of more than 500 m/m.y. in the early Miocene is interpreted to be a result of extension at the releasing bend of a dextral strike-slip fault. ?? 1990.

Alan, Bartow J.

1990-01-01

217

C4 expansion in the central Inner Mongolia during the latest Miocene and early Pliocene  

NASA Astrophysics Data System (ADS)

The emergence of C4 photosynthesis in plants as a significant component of terrestrial ecosystems is thought to be an adaptive response to changes in atmospheric CO 2 concentration and/or climate during Neogene times and has had a profound effect on the global terrestrial biosphere. Although expansion of C4 grasses in the latest Miocene and Pliocene has been widely documented around the world, the spatial and temporal variations in the C4 expansion are still not well understood and its driving mechanisms remain a contentious issue. Here we present the results of carbon and oxygen isotope analyses of fossil and modern mammalian tooth enamel samples from the central Inner Mongolia. Our samples represent a diverse group of herbivorous mammals including deer, elephants, rhinos, horses and giraffes, ranging in age from the late Oligocene to modern. The ?13C values of 91 tooth enamel samples of early late-Miocene age or older, with the exception of two 13 Ma rhino samples (- 7.8 and - 7.6‰) and one 8.5 Ma suspected rhino sample (- 7.6‰), were all less than - 8.0‰ (VPDB), indicating that there were no C4 grasses present in their diets and thus probably few or no C4 grasses in the ecosystems of the central Inner Mongolia prior to ~ 8 Ma. However, 12 out of 26 tooth enamel samples of younger ages (~ 7.5 Ma to ~ 3.9 Ma) have ?13C values higher than - 8.0‰ (up to - 2.4‰), indicating that herbivores in the area had variable diets ranging from pure C3 to mixed C3-C4 vegetation during that time interval. The presence of C4 grasses in herbivores' diets (up to ~ 76% C4) suggests that C4 grasses were a significant component of the local ecosystems in the latest Miocene and early Pliocene, consistent with the hypothesis of a global factor as the driving mechanism of the late Miocene C4 expansion. Today, C3 grasses dominate grasslands in the central Inner Mongolia area. The retreat of C4 grasses from this area after the early Pliocene may have been driven by regional climate change associated with tectonic processes in central Asia as well as global climate change.

Zhang, Chunfu; Wang, Yang; Deng, Tao; Wang, Xiaoming; Biasatti, Dana; Xu, Yingfeng; Li, Qiang

2009-10-01

218

A new pitheciin primate from the middle Miocene of Argentina.  

PubMed

We report here a new fossil primate from the middle Miocene of Argentina. The material consists of isolated teeth, mandibular fragments, and a talus. The fossils were collected in the Collón Cura formation at Cañadón del Tordillo in Neuquén Province. An age of 15.71 +/- 0.07 Ma has been reported for the Pilcaniyeu Ignimbrite, which lies just below the paleosols in which the fossils were found. This material is thus the youngest occurrence of fossil primates in Argentina (hitherto documented in the Santacrucian and older land mammal ages) but still is older than the middle Miocene platyrrhine primates from La Venta, Colombia, in particular the pitheciins Nuciruptor and Cebupithecia. The material is recognized as a new genus and species of Pitheciinae, Propithecia neuquenensis. The mesiodistally compressed, high-crowned incisors are specialized and similar to species in the tribe Pithecini and to the nonpitheciin Soriacebus (early Miocene, Patagonia). We rule out a phylogenetic relationship to the latter because of differences in molar morphology. Propithecia does, however, fit well into the pattern of pitheciin evolution, being more derived than the middle Miocene pitheciin Nuciruptor but not as much as another middle Miocene taxon, Cebupithecia. As such, this makes Propithecia the oldest taxon that can be confidently placed within this modern New World monkey subfamily. By analogy with the molar structures and diets of extant platyrrhines, Propithecia has a molar structure consistent with a variety of low-fiber diets ranging from fruit and gum to seeds. Its incisors suggest seed-eating in much the same way as extant pitheciins, like Pithecia. The talus resembles that of Callicebus, suggesting arboreal quadrupedal locomotion. PMID:9702279

Kay, R F; Johnson, D; Meldrum, D J

1998-01-01

219

A study of uranium favorability of Cenozoic sedimentary rocks, Basin and Range Province, Arizona: Part I, General geology and chronology of pre-late Miocene Cenozoic sedimentary rocks  

USGS Publications Warehouse

This study focuses attention on Cenozoic sedimentary rocks in the Basin and Range Province of Arizona. The known occurrences of uranium and anomalous radioactivity in these rocks are associated with sediments that accumulated in a low energy environment characterized by fine-grained clastics, including important tuffaceous materials, and carbonate rocks. Most uranium occurrences, in these rocks appear to be stratabound. Emphasis was placed on those sedimentary materials that pre-date the late Cenozoic Basin and Range disturbance. They are deformed and crop out on pedimented range blocks and along the province interface with the Transition Zone. Three tentative age groups are recognized: Group I - Oligocene, pre-22 m.y., Group II - early Miocene - 22 m.y. - 16 m.y., and Group III - middle Miocene - 16 m.y. to 13--10 m.y. Regionally, these three groups contain both coarse to fine-grained red clastics and low energy lighter colored 'lacustrine' phases. Each of the three groups has been the object of uranium exploration. Group II, the early Miocene strata, embraces the Anderson Mine - Artillery region host rocks and also the New River - Cave Creek early Miocene beds-along the boundary with the Transition Zone. These three groups of rocks have been tectonically deformed to the extent that original basins of deposition cannot yet be reconstructed. However, they were considerably more extensive in size than the late Cenozoic basins the origin of which deformed the former. Group II rocks are judged to be of prime interest because of: (1) the development and preservation of organic matter in varying lithologies, (2) apparent contemporaneity with silicic volcanic centers, (3) influence of Precambrian crystalline rocks, and (4) relative outcrop continuity near the stable Transition Zone. The Transition Zone, especially along its boundary with the Basin and Range Province, needs additional geologic investigation, especially as regards the depositional continuity of Group II sediment s.

Scarborough, Robert Bryan; Wilt, Jan Carol

1979-01-01

220

Interpretation of a 3D Seismic-Reflection Volume in the Basin and Range, Hawthorne, Nevada  

NASA Astrophysics Data System (ADS)

A collaborative effort by the Great Basin Center for Geothermal Energy at the University of Nevada, Reno, and Optim Inc. of Reno has interpreted a 3d seismic data set recorded by the U.S. Navy Geothermal Programs Office (GPO) at the Hawthorne Army Depot, Nevada. The 3d survey incorporated about 20 NNW-striking lines covering an area of approximately 3 by 10 km. The survey covered an alluvial area below the eastern flank of the Wassuk Range. In the reflection volume the most prominent events are interpreted to be the base of Quaternary alluvium, the Quaternary Wassuk Range-front normal fault zone, and sequences of intercalated Tertiary volcanic flows and sediments. Such a data set is rare in the Basin and Range. Our interpretation reveals structural and stratigraphic details that form a basis for rapid development of the geothermal-energy resources underlying the Depot. We interpret a map of the time-elevation of the Wassuk Range fault and its associated splays and basin-ward step faults. The range-front fault is the deepest, and its isochron map provides essentially a map of "economic basement" under the prospect area. There are three faults that are the most readily picked through vertical sections. The fault reflections show an uncertainty in the time-depth that we can interpret for them of 50 to 200 ms, due to the over-migrated appearance of the processing contractor’s prestack time-migrated data set. Proper assessment of velocities for mitigating the migration artifacts through prestack depth migration is not possible from this data set alone, as the offsets are not long enough for sufficiently deep velocity tomography. The three faults we interpreted appear as gradients in potential-field maps. In addition, the southern boundary of a major Tertiary graben may be seen within the volume as the northward termination of the strong reflections from older Tertiary volcanics. Using a transparent volume view across the survey gives a view of the volcanics in full, providing a clear picture of prominent structures. Potential drill targets and areas of development are defined within the data volume by the intersections of the fault surfaces with the tracked, strong stratigraphic reflections. Target volumes for drilling and development are defined by the intersections of the faults and bright-spot stratigraphy, and their uncertainty bounds. There are a few such intersections present within the 3d volume. Analyzing seismic attributes gives the opportunity to identify characteristics common in geothermal environments.

Louie, J. N.; Kell, A. M.; Pullammanappallil, S.; Oldow, J. S.; Sabin, A.; Lazaro, M.

2009-12-01

221

Mid Miocene Terrestrial Ecosystems: Information from Mammalian Herbivore Communities.  

NASA Astrophysics Data System (ADS)

In present day ecosystems the numbers and proportions of different kinds of ecologically distinct ungulates (hoofed mammals) provide an indicator of the nature of the vegetation in the habitat. Different vegetation types (such as forest, savanna, or grassland) are characteristically associated with different arrays of ungulates, with species exhibiting differences in diet, body size, and type of digestive fermentation system. These biological attributes can also be inferred for fossil ungulate species, the first two from quantitative assessment of skull and dental anatomy, and the last from phylogenetic affinity. Thus fossil ungulate communities may be used as indicators of the vegetation types of the habitats in which they lived. Vegetation types, in turn, are determined largely by a number of physical environmental factors. Typical ungulate communities of the late early to early middle Miocene (17 - 15 Ma) from the Great Plains of North America contained a diversity of browsing (leaf-eating) and grazing (grass-eating) species, with proportions of dietary types and a diversity of body sizes indicative of a woodland savanna habitat. Paleobotanical evidence also indicates a woodland savanna type of vegetation. However, these communities included a much larger number of ungulate species than can be found in any present-day community. The "excess" ungulate species were primarily browsers. Throughout the rest of the middle Miocene both species numbers and the proportion of browsers in ungulate communities appear to have declined steadily. During this decline in browser species the numbers of grazer species remained relatively constant. Within-community species numbers comparable to the present day were attained by the late Miocene. We suggest that the early Miocene browser-rich communities, and their subsequent decline, carry an important paleoenvironmental signal. In particular, communities "over rich" in browsers may reflect higher levels of primary productivity in mid Miocene vegetation types in comparison with corresponding, structurally equivalent present-day vegetation types. The observed decline in species numbers may represent a gradual decline in terrestrial primary productivity, which would be consistent with one current hypothesis of a mid-Miocene decrease in atmospheric carbon dioxide concentrations from higher mid-Cenozoic values.

Janis, C. M.; Damuth, J.; Theodor, J. M.

2001-05-01

222

300. Schwartz, D., B. Fischhoff, T. Krishnamurti, and F. Sowell, The Hawthorne Effect and Energy Awareness. Proceedings of the National Academy of Sciences of the United  

E-print Network

from the development, production and processing of Marcellus Shale natural gas. Journal of the Air300. Schwartz, D., B. Fischhoff, T. Krishnamurti, and F. Sowell, The Hawthorne Effect and Energy, Economic implications of thermal energy storage for concentrated solar thermal power. Renewable Energy

223

Giant Miocene landslides and the evolution of Fuerteventura, Canary Islands  

NASA Astrophysics Data System (ADS)

Fuerteventura is the oldest island in the Canaries archipelago; following the growth of a pre-Miocene seamount, its shield stage began 20.6 Ma ago, and ended in the mid-Miocene. There followed a very extended period of quiescence, then very minor Quaternary post-erosional volcanism. The shield stage produced volcanoes up to 3000 m above sea level which were rapidly eroded by 17.5 Ma. Both Fuerteventura and Lanzarote, the older eastern-most islands, are in a post-erosional stage and have subdued topography with elevations rarely rising above 400 m. The western islands, La Palma and El Hierro, together with Tenerife, are the youngest in the archipelago, and are still in their shield stage which began at most 7.5 Ma ago. They have a rugged topography with peaks rising to several thousand metres. Volcanic activity persists in these islands and in Lanzarote. The shield-stage construction of the volcanically active western islands demonstrates that recent eruptive activity has concentrated in volcanic centres aligned in well-defined rift zones in which major dyke emplacement has taken place, and that volcano flank collapse has occurred with giant landslides initiated on the rifts. In Fuerteventura, most of the shield-stage volcanic rocks have been removed; however, evidence has now been advanced to show that major dyke swarms were emplaced in the Oligocene and Miocene. These belonged to a line of intrusive complexes above which, by the early to mid-Miocene, volcanic peaks had been constructed. Three volcanic centres have been identified and in the central one, a peak as high as the present Mount Teide on Tenerife was rapidly denuded in less than 2 Ma. In the west of the island, this erosion has exposed a window of more than 300 km 2 of submarine volcanics and sediments belonging to the pre-shield phase seamount. The principal mechanism of erosion seems to have been the generation of giant landslides analogous to those seen in the younger islands. These appear to have removed some 3500 km 3 of lavas and volcaniclastics, stripping the western sectors of the Miocene volcanoes down to the pre-shield phase "Basal Complex", and transporting the mass of volcanic material into the Atlantic ocean as debris flows. Remnants of the shield volcanoes still exist in the eastern part of the island. Present day topographic variation indicates that the Miocene base level of erosion is still visible in a "Central Depression" which runs through the axis of the island, the eastern hills are composed of the Miocene shield-stage volcanics which still preserve a drainage pattern initiated on these peaks, and the "Basal Complex" in the west has a juvenile landscape suggesting incision on a post-Miocene domal uplift of the volcano core. Structural links between intra-island volcano-tectonic events and the South Atlas Fault zone are not thought to be likely.

Stillman, C. J.

1999-12-01

224

Late Miocene biogeography and paleoclimatology of the central North Atlantic  

USGS Publications Warehouse

Quantitative analyses of planktonic foraminiferal assemblages from Deep Sea Drilling Project (DSDP) Holes 334 and 410 demonstrate that subpolar and subtropical faunal provinces existed in the North Atlantic during the late Miocene. Climatic oscillations are clearly recorded in Hole 410 by variations in abundance of the Neogloboquadrina subpolar assemblage. These climatic oscillations have a period of about 1 m.y. Higher frequency oscillations with a periodicity of one to several hundred thousand years are evident from about 6.5 to 7.5 m.y. and are probably present throughout the entire late Miocene. A revised age of 7.0 m.y. is proposed for the first occurrence of the calcareous nannofossil Amaurolithus primus (the Amaurolithus datum). ?? 1981.

Poore, R.Z.

1981-01-01

225

Across the Pacific: Climate Evolution in the Middle Miocene  

NASA Astrophysics Data System (ADS)

We present the first high-resolution (3 kyr) astronomically-tuned record of ?18O and ?13C from planktonic foraminifera for the equatorial Pacific Ocean (16.5-13.5 Myr). Our data provides exciting new information on sea surface temperatures and primary productivity changes at the tropics during the middle Miocene at a resolution not achieved in any previous study, which sheds new light on the middle Miocene climatic transition (MMCT) and associated carbon-isotope excursion. Reliable sea surface temperature estimates are crucial to any reconstruction and modelling of past ocean salinity and density, water column stratification, thermohaline circulation, and ice volume. Despite extensive studies of benthic foraminifera, existing planktonic foraminiferal records of this interval are extremely scarce and of low resolution, with samples representing time intervals of 2x105and 5x105 years. Previous studies have been hindered by the absence of biogenic carbonate (e.g., Leg 199). Consequently the impact of global warming and cooling on tropical surface waters and the propagation of orbital cycles in the Earth System are unknown. In 2009 Integrated Ocean Drilling Program Expedition 320/321 recovered lower-middle Miocene sediments with high sedimentation rates (30m/myr), continuous recovery, and orbital cyclicity from the east equatorial Pacific Ocean. At Site U1338 planktonic foraminifera are abundant and diverse in the lower and middle Miocene sediments and exceptionally well preserved. Scanning electron microscope studies revealed open pore spaces, little evidence of calcitic overgrowth on the wall surface and in many cases preserved spines (Fox and Wade, 2013). We compare our data from Site U1338 to Site 1146 in the western equatorial Pacific Ocean, to reconstruct bottom and surface water conditions and changes in ocean dynamics across the equatorial Pacific during this highly complex interval of climate history.

Fox, Lyndsey; Wade, Bridget; Holbourn, Ann; Leng, Melanie

2014-05-01

226

Across the Pacific: Climate Evolution in the Middle Miocene  

NASA Astrophysics Data System (ADS)

We present the first high-resolution (3 kyr) astronomically-tuned record of ?18O and ?13C from planktonic foraminifera for the equatorial Pacific Ocean (16.5-13.5 Myr). Our data provides exciting new information on sea surface temperatures and primary productivity changes at the tropics during the middle Miocene at a resolution not achieved in any previous study, which sheds new light on the middle Miocene climatic transition (MMCT) and associated carbon-isotope excursion. Reliable sea surface temperature estimates are crucial to any reconstruction and modelling of past ocean salinity and density, water column stratification, thermohaline circulation, and ice volume. Despite extensive studies of benthic foraminifera, existing planktonic foraminiferal records of this interval are extremely scarce and of low resolution, with samples representing time intervals of 2x105 and 5x105 years. Previous studies have been hindered by the absence of biogenic carbonate (e.g., Leg 199). Consequently the impact of global warming and cooling on tropical surface waters and the propagation of orbital cycles in the Earth System are unknown. In 2009 Integrated Ocean Drilling Program Expedition 320/321 recovered lower-middle Miocene sediments with high sedimentation rates (30m/myr), continuous recovery, and orbital cyclicity from the east equatorial Pacific Ocean. At Site U1338 planktonic foraminifera are abundant and diverse in the lower and middle Miocene sediments and exceptionally well preserved. Scanning electron microscope studies revealed open pore spaces, little evidence of calcitic overgrowth on the wall surface and in many cases preserved spines (Fox and Wade, in press). We compare our data from Site U1338 to Site 1146 in the western equatorial Pacific Ocean, to reconstruct bottom and surface water conditions and changes in ocean dynamics across the equatorial Pacific during this highly complex interval of climate history.

Fox, L. R.; Wade, B.; Holbourn, A. E.; Leng, M. J.

2013-12-01

227

Preservation of Miocene glacier ice in East Antarctica  

Microsoft Academic Search

ANTARCTIC climate during the Pliocene has been the subject of considerable debate. One view holds that, during part of the Pliocene, East Antarctica was largely free of glacier ice and that vegetation survived on the coastal mountains1á¤-4. An alternative viewpoint argues for the development of a stable polar ice sheet by the middle Miocene, which has persisted since then5á¤-10. Here

David E. Sugden; David R. Marchant; Noel Potter; Roland A. Souchez; George H. Denton; Carl C. Swisher III; Jean-Louis Tison

1995-01-01

228

Early Miocene rodents and insectivores from northeastern Colorado  

E-print Network

THE UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS VE RTE B RATA ARTICLE 7 Pages 1-92, Figures 1-131 EARLY MIOCENE RODENTS AND INSECTIVORES FROM NORTHEASTERN COLORADO By ROBERT W. WILSON ARTICLE 8 Pages 1-24, Figures 1-21 A NEW ARMORED DINOSAUR... AND INSECTIVORES FROM NORTHEASTERN COLORADO By ROBERT W. WILSON (Contribution from the Museum of Natural History) THE UNIVERSITY OF KANSAS PUBLICATIONS November 21, 1960 PRINTED BY THE UNIVERSITY OF KANSAS PRESS LAWRENCE THE UNIVERSITY OF KANSAS PALEONTOLOGICAL...

Wilson, R. W.

1960-11-21

229

Human evolution from the Miocene to the Present  

Microsoft Academic Search

Based on morphological, palaeoanthropological and molecular biological studies, human evolution from the Miocene to the Present\\u000a has been reviewed. The initial divergence of orangutan from the hominoid stock, the divergence of man from the last common\\u000a ancestor with the African apes, the origin and expansion ofHomo lineage and the advent of modern man have been discussed.

Shama Barnabas

1990-01-01

230

Paleoproductivity And Carbon Cycling During The Middle Miocene Monterey Excursion  

NASA Astrophysics Data System (ADS)

A prominent middle Miocene (17.5 to 13.5 Ma) carbon-isotope excursion (the so-called Monterey event) is punctuated by six distinct carbon isotope maxima (CM). Orbital tuning of carbon isotope records links each CM event with the long term component of eccentricity (400 kyr) highlighting the importance of insolation control on the global carbon cycle (Holbourn et al., 2008). Here we use proxy reconstructions (benthic foraminiferal accumulation rates) from six sites in the Atlantic and Pacific Oceans combined with geochemical modelling to investigate whether there is a link between long term insolation forcing and the marine carbon isotope record via marine productivity and thus atmospheric CO2 levels. Our results show that none of the CM events are associated with distinctly large changes in paleoproductivity. This observation is consistent with our previous finding that the overall mid Miocene carbon isotope maximum is not associated with a change in marine productivity (Diester-Haass et al., 2009). There are, albeit minor, fluctuations in productivity that can be related to the 400 kyr variability in the carbon isotope records with several productivity maxima between CM events, whereas CM events often show minima in productivity. Only the last of the CM events (CM 6), which occurs in close association with the major step in mid Miocene Antarctic ice growth, is accompanied by an ocean-wide increase in paleoproductivity. To tentatively explain the observed 400 kyr variability of the deep ocean carbon isotope record an improved version of the geochemical box model used Diester-Haass et al. (2009) has been forced by sealevel fluctuations reconstructed for the middle Miocene (Holbourn pers. comm., 2009). Calculations indicate that the induced changes in weathering rates and carbon cycle can explain the temporal variability of the carbon isotope record, but not the observed amplitude.

Billups, K.; Diester-Haass, L.; Emeis, K.; François, L.; Jacquemin, I.; Lefebvre, V.

2010-05-01

231

North Atlantic Deep Water formed by the later middle Miocene  

Microsoft Academic Search

There is evidence that in Mesozoic and Palaeogene times both north and south subpolar areas had a mild climate1,2. Unlike the present day climatic symmetry, with warm equatorial regions and ice-covered polar regions, a strong planetary asymmetry developed in the middle Miocene, when the Antarctic ice cap was established while the northern high latitudes remained unglaciated3. The symmetry was restored

P.-L. Blanc; D. Rabussier; C. Vergnaud-Grazzini; J.-C. Duplessy

1980-01-01

232

Oligo-Miocene syn-rift and Miocene post-rift sedimentary records: the tectono-stratigraphic development of the northern proximal margin of the Gulf of Aden  

NASA Astrophysics Data System (ADS)

The northern margin of the Gulf of Aden results from the Oligo-Miocene rifting (34Ma) leading to continental break-up and the oceanic spreading since the Burdigalian (17.6 Ma). We, here, investigate in detail the tectono-stratigraphy development of the Ashawq Graben belonging to the proximal part of northern margin (southern Oman, Dhofar). This graben exhibits sedimentary records of syn-rift and post-rift sequences, so-called Dhofar (Rupelian-Burdigalian) and Fars (middle Miocene-Pliocene) Groups respectively. Analyzing the deposit conditions and sequences geometries provide fundamental inputs for the whole margin understanding. An accurate sedimentological and biostratigraphical analysis evidences two second-order sea level cycles corresponding to the syn-rift and the post-rift units separated by an erosive surface with paleo-karst cavities. The first stage of the rifting expresses as a regional uplift which led to set up of an early Oligocene mix platform system (Ashawq Fm., Shizar Mb.) overlying the proximal platform (Aydim Fm.) and continental (Zalumah Fm.) system deposit of the late Eocene to earliest Oligocene time. Then, the rift extension process during early Oligocene leads to verticals movements along normal faults and increase of the accommodation rate in the Ashawq graben. Such increase of accommodation is fully compensated by an important carbonate production leading to the aggradation of a thick reefal carbonate platform (Ashawq Fm., Nakhlit Mb.). An acceleration of the extension processes during late Oligocene time reaches an increase of the tectonic subsidence associated to the partial drowning and collapsing of the platform and to the set up of carbonate gravity-flow deposits in a deep basin (Mughsayl Fm.). In the most proximal realm, the sedimentation rate attempts to compensate the accommodation rate resulting in a differential aggradation of the reefal carbonate platform, sometimes in the form of patch reef. At the early Miocene time, the progradation of a conglomeratic fan delta system testifies the decrease of the accommodation rate and a strong basinward system shift controlled by a general uplift of the margin. This surrection phase leading to a subaerial exposure is interpreted as the consequence of the continental breakup at the Burdigalian time (17.6 Ma) and the set up of Ocean-Continent Transition (OCT). At the middle Miocene time, new subsidence phase is associated with a partial marine incursion and to the set up of proximal shallow marine carbonate deposits (Adawnib Fm.) and the lateral equivalent conglomeratic alluvial fan deposits (Nar Fm.). This post-rift unit records a progressive decrease of the tectonic activity, which may be related to the migration of the deformation towards the distal margin up to the oceanic spreading in the Gulf of Aden. Late deformation phases (erosive paleo-surface at the top the post-rift conglomerates, preservation of uplifted paleo-beach deposits) may imply a large-scale geodynamic processes.

Robinet, J.; Razin, P.; Serra Kiel, J.; Gallardo Garcia, A.; Grelaud, C.; Roger, J.; Leroy, S.; Malaval, M.

2012-04-01

233

12. STRONTIUM-ISOTOPIC CORRELATION OF OLIGOCENE TO MIOCENE SEQUENCES, NEW JERSEY AND FLORIDA1  

Microsoft Academic Search

We use Sr-isotopic age estimates to date siliciclastic, carbonate, and mixed siliciclastic-carbonate Oligocene and Miocene sequences for the New Jersey Coastal Plain and Florida Peninsula and to correlate sequence boundaries with the deep-sea ?18O record and the inferred eustatic record of Exxon. The New Jersey onshore Oligocene to lower Miocene sequences correlate rea- sonably well with the Florida Miocene sequences.

Peter J. Sugarman; Lucy McCartan; Kenneth G. Miller; Mark D. Feigenson; Stephen Pekar; Ronald W. Kistler; A. G. Robinson

234

Middle Miocene paleoaltimetry of the southern Altiplano, central Andes  

NASA Astrophysics Data System (ADS)

The central Andean plateau is both high (mean elevation ~4 km) and broad (>300 km wide). Constraining the elevation history of the Andes is necessary to understand the effects of a high, broad mountain range on regional and global climate and the tectonic processes responsible for the creation and maintenance of such mountain plateaus. Recent paleoelevation estimates based on paleobotanical, stable isotope, and geomorphologic data suggest that the northern part of the central Andes experienced ~2.5 ± 1 km of surface uplift since ca. 10 Ma. Middle Miocene sedimentary sections were measured in two localities in the southern Altiplano and Eastern Cordillera. The depositional environment of Cerdas (~4000 m, ~16.3 to <15.105 Ma) in the Altiplano basin was dominantly fluvial floodplain and volcaniclastic-rich gravity flows; Quebrada Honda (~3500 m, >12.83 to <11.96 Ma) in the Eastern Cordillera consists of fluvial floodplain and ephemeral lacustrine environments. Sedimentation rates are on the order of 100-200 m/Myr, which is comparable to other middle Miocene basins in the central Andes. Carbonate nodules from paleosols within floodplain deposits were analyzed for stable isotopes. We employ a ?18O-altitude relationship based on modern rainfall (Gonfiantini et al., 2001) and surface water data to estimate paleoelevation from pedogenic carbonates. Data from Cerdas yield a mean ?18O of -10.8‰ and a paleoelevation estimate of 2458 ± 1000 m; data from Quebrada Honda produce a mean of -7.2‰ and a paleoelevation estimate of 757 ± 1000 m. These low elevations (relative to the modern elevations) in the southern Altiplano are consistent (within error) with published middle Miocene elevations for the northern Altiplano, suggesting a common plateau-wide elevation history prior to <11.96 Ma. If changes in paleoelevation of the southern Altiplano show synchronous late Miocene surface uplift as compared with the northern Altiplano, this would suggest that a regional tectonic process was responsible for the ~2 km of surface uplift since middle Miocene time.

Auerbach, D. J.; Garzione, C. N.; Smith, J. J.; MacFadden, B. J.

2008-12-01

235

Miocene Global Carbon Isotope Shifts and Marine Biological Productivity.  

NASA Astrophysics Data System (ADS)

The Miocene contains two major global carbon isotope shifts: a negative shift during the late Miocene (~8-6 Ma) and a positive shift during the mid-Miocene (16-14 Ma). We aim at deciphering possible changes in marine biological export productivity during these shifts by calculating paleoproductivity in gC/cm*ky from benthic foraminiferal numbers and accumulation rates at a number of sites spanning the world oceans. Our previous work has illustrated that the onset of the late Miocene negative d 13C shift, which has been attributed to enhanced erosion of terrestrial biomass and expansion of C4 plants, is also accompanied by an increase in marine export productivity from lower than present day values up to 2-3 times modern values at six sites (982, 1088, 721, 846, 1146, 1172; Diester-Haass et al, in press; Diester-Haass et al., in preparation). The Mid-Miocene 'Monterey Event', on the other hand, has been attributed to sequestration of organic material in circum-Pacific basins (Vincent and Berger, 1985) or wide spread deposition of brown coal and drowning of carbonate platforms (Föllmi et al., 2005) . For this particular time interval, our initial results from Site 608 (Atlantic Ocean) reveal relatively constant paleoproductivity values similar to modern ones ( about 10 gC/cm*ky) until 16.5 Ma, after which time paleoproductivity begins to increase until the end of our record at 11 Ma. Superimposed on the trend of generally increasing productivity, there are a number of productivity minima spaced roughly 0.5 million years apart. The long term trend in the paleoproductivity finds some similarities in the global composite benthic foraminiferal d 13C record as both proxies show an overall increase until ~14 Ma. Thereafter, however, paleoproductivity continues to increase while d 13C values decrease marking the end of the Monterey excursion. Stable isotope analyses from these same intervals will show to what extend the smaller scale fluctuations in paleoproductivity can be related to changes in the d13C of the oceanic reservoir or regional water masses. Diester-Haass, L., Billups, K., Emeis, K-C., 2005, Paleoceanography, in press. Vincent, E. and Berger, W., 1985, In: The carbon cycle and atmospheric CO2: Natural variations Archaen to present, edited by Sunquist, E.T. and Broecker, W.S., Am.Geophys. Union Monogr. 32,455-468 Föllmi, K.B. et al., 2005, Geol.Soc.Am.Bull., 117/5, 589-619.

Diester-Haass, L.; Billups, K.

2005-12-01

236

PALAEONTOLOGICAL STUDY OF THE ORDER LAMNIFORMES IN THE MIOCENE MEDITERRANEAN BASIN.  

E-print Network

??A palaeontological study of the lamniform assemblage of the Miocene Mediterranean Sea, based on systematic, statistical and of palaeopathological approaches, is proposed. The systematic revision… (more)

SORCE, BARBARA

2010-01-01

237

Life-History Traits of the Miocene Hipparion concudense (Spain) Inferred from Bone Histological Structure  

PubMed Central

Histological analyses of fossil bones have provided clues on the growth patterns and life history traits of several extinct vertebrates that would be unavailable for classical morphological studies. We analyzed the bone histology of Hipparion to infer features of its life history traits and growth pattern. Microscope analysis of thin sections of a large sample of humeri, femora, tibiae and metapodials of Hipparion concudense from the upper Miocene site of Los Valles de Fuentidueña (Segovia, Spain) has shown that the number of growth marks is similar among the different limb bones, suggesting that equivalent skeletochronological inferences for this Hipparion population might be achieved by means of any of the elements studied. Considering their abundance, we conducted a skeletechronological study based on the large sample of third metapodials from Los Valles de Fuentidueña together with another large sample from the Upper Miocene locality of Concud (Teruel, Spain). The data obtained enabled us to distinguish four age groups in both samples and to determine that Hipparion concudense tended to reach skeletal maturity during its third year of life. Integration of bone microstructure and skeletochronological data allowed us to identify ontogenetic changes in bone structure and growth rate and to distinguish three histologic ontogenetic stages corresponding to immature, subadult and adult individuals. Data on secondary osteon density revealed an increase in bone remodeling throughout the ontogenetic stages and a lesser degree thereof in the Concud population, which indicates different biomechanical stresses in the two populations, likely due to environmental differences. Several individuals showed atypical growth patterns in the Concud sample, which may also reflect environmental differences between the two localities. Finally, classification of the specimens’ age within groups enabled us to characterize the age structure of both samples, which is typical of attritional assemblages. PMID:25098950

Martinez-Maza, Cayetana; Alberdi, Maria Teresa; Nieto-Diaz, Manuel; Prado, José Luis

2014-01-01

238

Palaeoenvironmental Shifts Drove the Adaptive Radiation of a Noctuid Stemborer Tribe (Lepidoptera, Noctuidae, Apameini) in the Miocene  

PubMed Central

Between the late Oligocene and the early Miocene, climatic changes have shattered the faunal and floral communities and drove the apparition of new ecological niches. Grassland biomes began to supplant forestlands, thus favouring a large-scale ecosystem turnover. The independent adaptive radiations of several mammal lineages through the evolution of key innovations are classic examples of these changes. However, little is known concerning the evolutionary history of other herbivorous groups in relation with this modified environment. It is especially the case in phytophagous insect communities, which have been rarely studied in this context despite their ecological importance. Here, we investigate the phylogenetic and evolutionary patterns of grass-specialist moths from the species-rich tribe Apameini (Lepidoptera, Noctuidae). The molecular dating analyses carried out over the corresponding phylogenetic framework reveal an origin around 29 million years ago for the Apameini. Ancestral state reconstructions indicate (i) a potential Palaearctic origin of the tribe Apameini associated with a major dispersal event in Afrotropics for the subtribe Sesamiina; (ii) a recent colonization from Palaearctic of the New World and Oriental regions by several independent lineages; and (iii) an ancestral association of the tribe Apameini over grasses (Poaceae). Diversification analyses indicate that diversification rates have not remained constant during the evolution of the group, as underlined by a significant shift in diversification rates during the early Miocene. Interestingly, this age estimate is congruent with the development of grasslands at this time. Rather than clade ages, variations in diversification rates among genera better explain the current differences in species diversity. Our results underpin a potential adaptive radiation of these phytophagous moths with the family Poaceae in relation with the major environmental shifts that have occurred in the Miocene. PMID:22859979

Toussaint, Emmanuel F. A.; Condamine, Fabien L.; Kergoat, Gael J.; Capdevielle-Dulac, Claire; Barbut, Jérôme; Silvain, Jean-François; Le Ru, Bruno P.

2012-01-01

239

Miocene Vetigastropoda and Neritimorpha (Mollusca, Gastropoda) of central Chile  

NASA Astrophysics Data System (ADS)

Species of Vetigastropoda (Fissurellidae, Turbinidae, Trochidae) and one species of Neritimorpha (Neritidae) from the Navidad area, south of Valpara?´so, and the Arauco Peninsula, south of Concepción, are described. Among these, the Fissurellidae comprise Diodora fragilis n. sp., Diodora pupuyana n. sp., two additional unnamed species of Diodora, and a species resembling Fissurellidea. Turbinidae are represented by Cantrainea sp., and Trochidae include Tegula (Chlorostoma) austropacifica n. sp., Tegula (Chlorostoma) chilena n. sp., Tegula (Chlorostoma) matanzensis n. sp., Tegula (Agathistoma) antiqua n. sp., Bathybembix mcleani n. sp., Gibbula poeppigii [Philippi, 1887] n. comb., Diloma miocenica n. sp., Fagnastesia venefica [Philippi, 1887] n. gen. n. comb., Fagnastesia matanzana n. gen. n. sp., Calliostoma mapucherum n. sp., Calliostoma kleppi n. sp., Calliostoma covacevichi n. sp., Astele laevis [Sowerby, 1846] n. comb., and Monilea riorapelensis n. sp. The Neritidae are represented by Nerita (Heminerita) chilensis [Philippi, 1887]. The new genus Fagnastesia is introduced to represent low-spired trochoideans with a sculpture of nodes below the suture, angulated whorls, and a wide umbilicus. This Miocene Chilean fauna includes genera that have lived at the coast and in shallow, relatively warm water or deeper, much cooler water. This composition therefore suggests that many of the Miocene formations along the central Chilean coast consist of displaced sediments. A comparison with different fossil and Recent faunas from around the Pacific and South America indicates that the vetigastropod and neritid fauna from the Miocene of Chile has only minor affinities with taxa living near New Zealand, Argentina, and the tropical eastern Pacific at that time.

Nielsen, Sven N.; Frassinetti, Daniel; Bandel, Klaus

2004-09-01

240

Multiple Miocene Melastomataceae dispersal between Madagascar, Africa and India.  

PubMed Central

Melastomataceae sensu stricto (excluding Memecylaceae) comprise some 3000 species in the neotropics, 1000 in Asia, 240 in Africa, and 230 in Madagascar. Previous family-wide morphological and DNA analyses have shown that the Madagascan species belong to at least three unrelated lineages, which were hypothesized to have arrived by trans-oceanic dispersal. An alternative hypothesis posits that the ancestors of Madagascan, as well as Indian, Melastomataceae arrived from Africa in the Late Cretaceous. This study tests these hypotheses in a Bayesian framework, using three combined sequence datasets analysed under a relaxed clock and simultaneously calibrated with fossils, some not previously used. The new fossil calibration comes from a re-dated possibly Middle or Upper Eocene Brazilian fossil of Melastomeae. Tectonic events were also tentatively used as constraints because of concerns that some of the family's fossils are difficult to assign to nodes in the phylogeny. Regardless of how the data were calibrated, the estimated divergence times of Madagascan and Indian lineages were too young for Cretaceous explanations to hold. This was true even of the oldest ages within the 95% credibility interval around each estimate. Madagascar's Melastomeae appear to have arrived from Africa during the Miocene. Medinilla, with some 70 species in Madagascar and two in Africa, too, arrived during the Miocene, but from Asia. Gravesia, with 100 species in Madagascar and four in east and west Africa, also appears to date to the Miocene, but its monophyly has not been tested. The study afforded an opportunity to compare divergence time estimates obtained earlier with strict clocks and single calibrations, with estimates based on relaxed clocks and different multiple calibrations and taxon sampling. PMID:15519967

Renner, Susanne S

2004-01-01

241

The beaver Anchitheriomys from the Miocene of Central Europe  

SciTech Connect

New finds of teeth and mandibles of Anchitheriomys from the Hambach opencast lignite mine in Northwest Germany and the first detailed descriptions of other mandibles from South Germany and Switzerland allow a review of the Central European specimens of this rare beaver genus. The metric variation of cheek teeth and especially the great differences in dimensions of incisors can be much better assessed. The observed range in size can be attributed to ontogenetic changes, and all material is assigned to Anchitheriomys suevicus. Stratigraphically, this species is restricted to the early middle Miocene, European Mammalian Neogene biozones MN 5-6.

Stefen, C.; Mors, T. [Museum Tierkunde, Dresden (Germany)

2008-09-15

242

Ostracoda (Arthropoda, Crustacea) in a Miocene oxygen minimum zone, Trinidad, West Indies: A test of the Platycopid Signal Hypothesis  

NASA Astrophysics Data System (ADS)

Studies of Recent ostracodes around the area of South America shed little light on the paleoenvironmental interpretation of Miocene assemblages. Consequently, interpretations of the Miocene ostracode assemblages must be supplemented using evidence from better documented taxa. Benthic foraminifera in samples from the Lower to Middle Miocene Brasso Formation at Brasso Village, Trinidad, have previously been used to distinguish three sample groupings (Beneath, Within and Above) around an oxygen minimum zone (OMZ), this being a layer of water within which dissolved oxygen concentrations can be as low as 0.1-1.0 mL/L. Using these same samples and the foraminiferal assemblage demarcations relative to the OMZ, this paper examines the associated and rich ostracode fauna of the Brasso Formation. The mean recovery of ostracode valves per sample was approximately three times greater in the Within OMZ sample group than in either of the Beneath OMZ or Above OMZ groups, perhaps reflecting the exclusion of macro-predators from within the OMZ. Individual rarefaction of species richness S to N = 300 valves was conducted for each sample group. This showed that S did not differ between the sample groups, ranging from 22.4 to 24.8. We used all ostracode species to model group separation. Based upon the Mahalanobis' criterion, we obtained significant group separation using a model with four taxa: Munseyella ex gr. minuta, Argilloecia posterotruncata, Munseyella sp. and Xestoleberis sp., while a fifth, Argilloecia spp., provided a significant but minor increase in separation probabilities over all groups. The two most abundant species (Bradleya sp., Gangamocytheridea reticulata) were thus not the best species for detecting the OMZ. Platycopid ostracodes of the genus Cytherella were found throughout the section, rather than concentrated within the OMZ, which contradicts the Platycopid Signal Hypothesis that OMZs are characterized by platycopid dominance. The total distribution and turnover of both ostracodal and foraminiferal assemblages were compared and contrasted quantitatively using a total assemblage turnover index (ATI) and the paleoenvironmental importance evaluated. The correlated between-sample ATI is for both groups lowest within the OMZ.

Wilson, Brent; Coimbra, João C.; Hayek, Lee-Ann C.

2014-10-01

243

PRELIMINARY ASSESSMENT OF THE LATE MIOCENE AVIFAUNA FROM LEMUDONG'O, KENYA  

Microsoft Academic Search

The small collection of avian skeletal remains, including those of an eagle, an owl, and possibly a pheasant, from Lemudong'o provides additional information about terrestrial late Miocene avifaunas in east Africa. Large phasianids are known elsewhere in the Miocene of Africa, but pheasants are naturally absent today from the continent. The presence of two predatory bird species at the locality

THOMAS A. STIDHAM

244

Long-period eccentricity control on sedimentary sequences in the continental Madrid Basin (middle Miocene, Spain)  

E-print Network

Miocene, Spain) Hemmo A. Abels a,b, , Hayfaa Abdul Aziz a,b , Wout Krijgsman b , Sander J.B. Smeets Madrid Basin (central Spain) is dated bio-magnetostratigraphically between 15.2 Ma and 11.5 Ma-dominated intervals is similar to a previously documented Late Miocene shift in the Teruel Basin of northeast Spain

Utrecht, Universiteit

245

Sr-isotopic, paleomagnetic, and biostratigraphic calibration of horse evolution: Evidence from the Miocene of Florida  

Microsoft Academic Search

During the middle Miocene an explosive adaptive radiation resulted in the advent of grazing horses with high-crowned teeth in North America. New Sr isotopic, paleomagnetic, and biostratigrahic evidence from the Miocene marine and nonmarine sequence of the Florida panhandle calibrates the base of this adaptive radiation. The transition from the primitive outgroup species 'Parahippus' leonensis to the most primitive high-crowned

Bruce J. MacFadden; J. Daniel Bryant; Paul A. Mueller

1991-01-01

246

A Miocene tectonic inversion in the Ionian Sea (central Mediterranean): Evidence from  

E-print Network

A Miocene tectonic inversion in the Ionian Sea (central Mediterranean): Evidence from multichannel 23 December 2011. [1] It is widely accepted that the Central and Eastern Mediterranean are remnants (2011), A Miocene tectonic inversion in the Ionian Sea (central Mediterranean): Evidence from

Brest, Université de

247

Wetland paradise lost: Miocene community dynamics in large herbivorous mammals from the German Molasse Basin  

Microsoft Academic Search

Questions: What was the distribution of fossil mammal taxa in the Miocene German Molasse Basin? Were there changes in community structure during the terrestrial development of the Molasse Basin? Were community dynamics similar in the Molasse Basin to those in the rest of Europe? Data: We gathered the available Miocene large mammal herbivore occurrences from the southern German Molasse Basin

Jussi T. Eronen; Gertrud E. Rössner

2007-01-01

248

High-resolution palynological analysis in late earlymiddle Miocene core from the Pannonian Basin, Hungary  

E-print Network

High-resolution palynological analysis in late early­middle Miocene core from the Pannonian Basin-resolution palynological analysis in the Karpatian­Sarmatian (late early­middle Miocene) interval of the borehole Tengelic reserved. Keywords: Palynology; Climatic quantification; Cyclostratigraphy; Eustatic changes; Early

Jiménez-Moreno, Gonzalo

249

Drilling and Dating New Jersey Oligocene-Miocene Sequences: Ice Volume,  

E-print Network

REPRINT Drilling and Dating New Jersey Oligocene-Miocene Sequences: Ice Volume, Global Sea Level of the New Jersey Coastal Plain Drilling Project Oligocene to middle Miocene sequence boundaries on the New global sea-level lowerings. The ages of New Jersey sequence boundaries and global 1 8 increases also

250

THE OLIGOCENE-MIOCENE TRANSITION ON CORAL REEFS IN THE FALCON BASIN (NW VENEZUELA)  

Microsoft Academic Search

The Oligocene-Miocene Transition (OMT) was an interval of region- al environmental and biotic change on Caribbean reefs. During the late Oligocene, a diverse Tethyan biota contributed to extensive reef building across the region, but by the early Miocene, reef building had declined, and a regional extinction had removed up to 50% of the late Oligocene diversity. The general decline in

KENNETH G. JOHNSON; MARCELO R. SANCHEZ-VILLAGRA; ORANGEL A. AGUILERA

2009-01-01

251

Regional climate model experiments to investigate the Asian monsoon in the Late Miocene  

Microsoft Academic Search

The Late Miocene (11.6-5.3 Ma) is a crucial period for the Asian monsoon evolution. However, the spatiotemporal changes of the Asian monsoon system in the Late Miocene are still ambiguous, and the mechanisms responsible for these changes are debated. Here, we present a simulation of the Asian monsoon climate (0 to 60° N and 50 to 140° E) in the

H. Tang; A. Micheels; J. Eronen; M. Fortelius

2011-01-01

252

27. MIOCENE BENTHIC FORAMINIFER OXYGEN AND CARBON ISOTOPES, SITE 709, INDIAN OCEAN1  

Microsoft Academic Search

The benthic isotopic record of Miocene Cibicidoides from Site 709 provides a record of conditions in the Indian Ocean at a depth of about 3200 mbsf. As expected, the record qualitatively resembles those of other Deep Sea Drilling Project and Ocean Drilling Program sites. The data are consistent with the scenario for the evolution of thermohaline circulation in the Miocene

Fay Woodruff; Samuel M. Savin; Linda Abel

253

Composition and provenance of the Puente Formation (Miocene), Los Angeles Basin  

SciTech Connect

The Puente Formation (PFm) is a middle to upper Miocene clastic unit lying unconformably on the middle to lower Miocene El Modeno Volcanics and Topanga Group, within the Los Angeles basin (LAB). The PFm, about 3900m thick, is composed of sandstone, conglomerate, and mudrock deposited on a submarine fan at bathyal depths. Several intrabasinal discordances suggest active tectonics during deposition. The succession consists of two main upward thickening and coarsening megacycles reflecting submarine fan progradation. The PFm is characterized up-section by: (1) thin-bedded fine sandstone and shale (La Vida M.) grading to thick-bedded coarse sandstone an conglomerate (soquel M.); (2) thin-bedded siltstone, mudrock and sandstone (Yorba M.) grading to thick- to very thick-bedded coarse-grained sandstone and conglomerate (Sycamore Canyon M.). Sandstones of the PFm are quartzofeldspathic and suggest a probable local provenance from the plutonic, volcanic, and metamorphic rocks of the San Gabriel Mountains. Petrological parameters, however, suggest variable contribution of these source rock units through time. Coarse-grained plutonic rock fragments are abundant for the entire succession and consist of plagioclase-rich plutonic rocks perhaps sourced from the Lowe granodiorite. Microlitic, lathwork to felsitic volcanic lithic grains are also present in the lower and middle part. In the Yorba M. there is a local increase of volcanic detritus (Lv/L - 0.80), represented by larger volcanic lithics and abundant volcaniclastic matrix. Metamorphic detritus is not very abundant; it is concentrated in the La Vida M. the PFm represents sedimentation during tectonically active time in the evolution of southern California.

Critelli, S. (Instituto de Rierca per la Protezione Idrogeologica Nell'Italia Meridionale ed Insulare, Roges de Rende (Italy)); Rumelhart, P.E.; Ingersoll, R.V. (Univ. of California, Los Angeles, CA (United States))

1994-04-01

254

Relationship of Mediterranean type lamproites to large shoshonite volcanoes, Miocene of Lesbos, NE Aegean Sea  

NASA Astrophysics Data System (ADS)

Shoshonites, which are high-K trachyandesitic rocks, are found in many orogenic belts and are commonly of post-collisional origin. The petrogenesis of shoshonites has been widely debated. Small lava flows and dykes of lamproite and related lamproitic rocks of early Miocene age in Lesbos are coeval with voluminous shoshonite volcanoes. Their distinctive petrology and isotope geochemistry provide an exceptional opportunity to assess the petrogenetic relationship between lamproites and shoshonites. The lamproitic rocks contain phenocrysts of forsteritic olivine (as high as Fo93) and clinopyroxene, both with inclusions of chrome spinel (Cr# ~ 0.9 or ~ 0.6) and carbonate melt inclusions, indicating the presence of carbonatite melts. Some complexly zoned clinopyroxene from lamproitic rocks have salite cores with chemical composition suggesting they formed in the upper mantle in a melt strongly enriched in LILE and LREE. Both lamproites and shoshonites show continuous trends of trace elements and their isotopic compositions overlap. Lack of variation in K with Mg# or SiO2 for particular temporal-spatial groups of shoshonites suggests derivation from particular inhomogeneous mantle rather than fractionation processes. In contrast to other peri-Mediterranean lamproites, the Lesbos lamproites and shoshonites have unusual Pb isotope composition that requires a common origin from subcontinental lithospheric mantle enriched in LILE in the Paleozoic. This enrichment process involved partial melting of subducted carbonate-bearing pelites. Triassic rift-related volcanism and formation of Jurassic small ocean basins produced extreme depletion of parts of the mantle. Lamproitic magma was derived from melting of enriched refractory harzburgite, whereas enriched lherzolite, wehrlite and pyroxenite partially melted to supply larger volumes of shoshonitic and related magmas. The NE Aegean Miocene shoshonite province is thus not directly related to contemporary subduction, but may have been triggered by related back-arc extension.

Pe-Piper, Georgia; Zhang, Yuanyuan; Piper, David J. W.; Prelevi?, Dejan

2014-01-01

255

Isolation and Purification of Three Flavonoids from the Hawthorn Leaves by High Speed Countercurrent Chromatography, Combined with Isocratic Preparative Reversed-Phase High Performance Liquid Chromatography  

Microsoft Academic Search

Three flavonoids including 4??-O-rhamnosylrutin, 2?-O-rhamnosylvitexin, and 4?-O-glucosylvitexin were isolated and purified from the hawthorn leaves by high speed countercurrent chromatography (HSCCC), combined together with isocratic preparative reversed-phase high performance liquid chromatography. Analytical HSCCC was used for the preliminary selection of a suitable solvent system composed of n-butanol-water (1:1, v\\/v). After two useful fractions were obtained by HSCCC using the optimal

Honglei Xu; Tingting Zhou; Jun Wen; Guorong Fan; Yutian Wu

2009-01-01

256

Early Miocene sequence development across the New Jersey margin  

USGS Publications Warehouse

Sequence stratigraphy provides an understanding of the interplay between eustasy, sediment supply and accommodation in the sedimentary construction of passive margins. We used this approach to follow the early to middle Miocene growth of the New Jersey margin and analyse the connection between relative changes of sea level and variable sediment supply. Eleven candidate sequence boundaries were traced in high-resolution multi-channel seismic profiles across the inner margin and matched to geophysical log signatures and lithologic changes in ODP Leg 150X onshore coreholes. Chronologies at these drill sites were then used to assign ages to the intervening seismic sequences. We conclude that the regional and global correlation of early Miocene sequences suggests a dominant role of global sea-level change but margin progradation was controlled by localized sediment contribution and that local conditions played a large role in sequence formation and preservation. Lowstand deposits were regionally restricted and their locations point to both single and multiple sediment sources. The distribution of highstand deposits, by contrast, documents redistribution by along shelf currents. We find no evidence that sea level fell below the elevation of the clinoform rollover, and the existence of extensive lowstand deposits seaward of this inflection point indicates efficient cross-shelf sediment transport mechanisms despite the apparent lack of well-developed fluvial drainage. ?? 2008 The Authors. Journal compilation ?? 2008 Blackwell Publishing.

Monteverde, D.H.; Mountain, Gregory S.; Miller, K.G.

2008-01-01

257

Upper Miocene reef complex of Mallorca, Balearic Islands, Spain  

SciTech Connect

The late Tortonian-Messinian coral reef platform of south Mallorca onlaps a folded middle late Miocene carbonate platform on which progradation of up to 20 km occurs. Vertical sea cliffs (up to 100 m high) superbly show the last 5 km of this progradation and complement the numerous water-well cores from the island interior. The coral reef platform consists of a series of progradational-accretional sequences and erosion surfaces of different orders of magnitude. The first-order sequence is bounded by significant erosion surfaces with breccias, major facies shifts, and vertical accretion. The second-order sequences show accretional events of up to 100 m thick with 1 to 2 km of progradation, and the third-order sequences occur in packages of tens of meters. Individual reef units are bounded by minor erosional surfaces and define the fourth-order sequences. This composite accretional-progradational architecture implies cyclic variations of relative sea level. Episodes of sea level rise were responsible for the vertical accretion. Sea level falls produced the erosional surfaces; most progradation occurred during lowering sea level episodes. This sedimentological framework of the Mallorca reef suggests late Miocene glacio-eustatic fluctuations of sea level similar to the Quaternary.

Pomar, L.

1988-01-01

258

Alkenone producers during late Oligocene-early Miocene revisited  

NASA Astrophysics Data System (ADS)

This study investigates ancient alkenone producers among the late Oligocene-early Miocene coccolithophores recorded at Deep Sea Drilling Project (DSDP) Site 516. Contrary to common assumptions, Reticulofenestra was not the most important alkenone producer throughout the studied time interval. The comparison between coccolith species-specific absolute abundances and alkenone contents in the same sedimentary samples shows that Cyclicargolithus abundances explain 40% of the total variance of alkenone concentration and that the species Cyclicargolithus floridanus was a major alkenone producer, although other related taxa may have also contributed to the alkenone production at DSDP Site 516. The distribution of the different alkenone isomers (MeC37:2, EtC38:2, and MeC38:2) remained unchanged across distinct changes in species composition, suggesting similar diunsaturated alkenone compositions within the Noelaerhabdaceae family during the late Oligocene-early Miocene. However, the overall larger cell size of Cyclicargolithus may have implications for the alkenone-based reconstruction of past partial pressure of CO2. Our results underscore the importance of a careful evaluation of the most likely alkenone producers for periods (>1.85 Ma) predating the first occurrence of contemporary alkenone producers (i.e., Emiliania huxleyi and Gephyrocapsa oceanica).

Plancq, Julien; Grossi, Vincent; Henderiks, Jorijntje; Simon, Laurent; Mattioli, Emanuela

2012-03-01

259

Plate-induced Miocene extension in southern California  

SciTech Connect

Miocene crustal extension in southern California can be explained by the interaction of tectonic plates in relative motion. The Pacific, Juan de Fuca, and Farallon (Guadalupe) plates are represented by flat elastic plates surrounded by an infinite elastic plate, the eastern part of which represents the North America plate. Forcing is by assigned subduction pull, and tractions at all plate boundaries satisfy a viscous constitutive law. Plate bottoms are stress-free. In the first part of the solution plate velocities and boundary tractions are found from static equilibrium. Then principal horizontal stresses and strains in plate interiors caused by tractions and subduction pull are found by a boundary element procedure. Using plate boundary geometry from Stock and Hodges for early- and mid-Miocene times, it is found that the portion of the North America plate margin between the Mendocino and Rivera triple junctions has maximum extensional strain directed westward. This result is generally consistent with directions associated with metamorphic core complex formation in southern California. The model is also consistent with extensional strain and rotation sense of crustal blocks in the vicinity of Los Angeles, as inferred by Luyendyk and others from paleomagnetic data. In the model the greatest extensional strain of the North America plate occurs near the Pacific-North America transform, in the area above the absent Farallon slab. Extension direction varies from northwest to southwest according to plate geometry, subduction pull (Juan de Fuca and Guadalupe), and plate boundary tractions.

Stuart, W.D. (Geological Survey, Pasadena, CA (United States) Univ. of California, Santa Barbara, CA (United States))

1992-01-01

260

Preliminary assessment of injection, storage, and recovery of freshwater in the lower Hawthorn aquifer, Cape Coral, Florida  

USGS Publications Warehouse

A preliminary assessment of subsurface injection, storage and recovery of fresh canal water was made in the naturally brackish lower Hawthorn aquifer in Cape Coral, southwestern Florida. A digital modeling approach was used for this preliminary assessment, incorporating available data on hydrologic conditions, aquifer properties, and water quality to simulate density-dependent ground-water flow and advective-dispersive transport of a conservative ground-water solute (chloride ion). A baseline simulation was used as reference to compare the effects of changing various operational factors on the recovery efficiency. A recovery efficiency of 64 percent was estimated for the baseline simulation. Based on the model, the recovery efficiency increases if the injection rate and recovery rates are increased and if the ratio of recovery rate to injection rate is increased. Recovery efficiency decreases if the amount of water injected is increased; slightly decreases if the storage time is increased; is not changed significantly if the water is injected to a specific flow zone; increases with successive cycles of injection, storage, and recovery; and decreases if the chloride concentrations in either the injection water or native aquifer water are increased. In everal hypothetical tests, the recovery efficiency fluctuated between 22 and about 100 percent. Two successive cycles could bring the recovery efficiency from 60 to about 80 percent. Interlayer solute mass movement across the upper and lower boundaries seems to be the most important factor affecting the recovery efficiency. A sensitivity analysis was performed applying a technique in which the change in the various factors and the corresponding model responses are normalized so that meaningful comparisons among the responses could be made. The general results from the sensitivity analysis indicated that the permeabilities of the upper and lower flow zones were the most important factors that produced the greatest changes in the relative sensitivity of the recovery efficiency. Almost equally significant changes occurred in the relative sensitivity of the recovery efficiency when all porosity values of the upper and lower flow zones and the leaky confining units and the vertical anisotropy ratio were changed. The advective factors are the most important in the Cape Coral area according to the sensitivity analysis. However, the dispersivity values used in the model were extrapolated from studies conducted at the nearby Lee County Water Treatment Plant, and these values might not be representative of the actual dispersive characteristics of the lower Hawthorn aquifer in the Cape Coral area.

Quinones-Aponte, Vicente; Wexler, Eliezer J.

1995-01-01

261

Drivers and Dynamics of Ecological Responses to Abrupt Environmental Change on the Early Miocene Oregon Shelf  

NASA Astrophysics Data System (ADS)

We know that the biosphere responds to abrupt climate change, but know less about the dynamics of those changes and their proximal drivers. Studies of well-preserved fossil time-series spanning past climate events that utilize multiple environmental proxies and examine multiple taxonomic groups can provide critical insight into (a) the specific environmental factors to which the biota respond, (b) the rate and tempo of those responses, and (c) whether taxonomic groups respond similarly or differently to the same stresses. I examine the drivers and dynamics of ecological changes in continental shelf benthic foraminifera and molluscs from the Early Miocene Newport Member of the Astoria Formation in Oregon (20.3-16.3 mya), which spans a time of global warming leading into the Middle Miocene Climate Optimum. Stable isotope (?18O) data from three species of benthic foraminifera from the Astoria sediments indicate that the region abruptly warmed by 2-4°C approximately 19 mya. In addition, ?13C values from epifaunal and infaunal foraminifera indicate an increase in productivity and organic carbon flux over time. Further, an increase in ?15N from bulk sediment and an increase in sedimentary laminations suggest oxygen levels declined. Multivariate analyses demonstrate a strong correlation between foraminiferal community metrics and ?15N suggesting that the foraminiferal community is tracking oxygenation levels while correlations to productivity changes appear indirect. Molluscan community metrics also have an approximately linear relationship to ?15N. Temperature itself had little direct influence on community composition. Changes in community composition and structure of both the foraminifera and the molluscs are abrupt relative to the duration of community states, but each group responds differently to the climate change. The foraminiferal community increases in the number of species and the evenness of species abundances while the molluscan community decreases in diversity, evenness, and body size suggesting the molluscs experienced greater stress. This difference in response may be explained by the shorter life cycles of benthic foraminifera and their ability to respond to seasonal changes in upwelling or oxygen stress. On the Oregon shelf in the last decade, low-oxygen conditions have increased in occurrence due to intensified wind-driven upwelling tied to modern warming. Faunal patterns from the Newport Member suggest that the benthic faunas may change in response to oxygenation and be less directly affected by productivity and temperature changes. Taxonomic groups may also to respond differently to the same environmental stresses due to physiological and ecological dissimilarities.

Belanger, C. L.

2012-12-01

262

A mantle plume beneath California? The mid-Miocene Lovejoy Flood Basalt, northern California  

USGS Publications Warehouse

The Lovejoy basalt represents the largest eruptive unit identified in California, and its age, volume, and chemistry indicate a genetic affinity with the Columbia River Basalt Group and its associated mantle-plume activity. Recent field mapping, geochemical analyses, and radiometric dating suggest that the Lovejoy basalt erupted during the mid-Miocene from a fissure at Thompson Peak, south of Susanville, California. The Lovejoy flowed through a paleovalley across the northern end of the Sierra Nevada to the Sacramento Valley, a distance of 240 km. Approximately 150 km3 of basalt were erupted over a span of only a few centuries. Our age dates for the Lovejoy basalt cluster are near 15.4 Ma and suggest that it is coeval with the 16.1-15.0 Ma Imnaha and Grande Ronde flows of the Columbia River Basalt Group. Our new mapping and age dating support the interpretation that the Lovejoy basalt erupted in a forearc position relative to the ancestral Cascades arc, in contrast with the Columbia River Basalt Group, which erupted in a backarc position. The arc front shifted trenchward into the Sierran block after 15.4 Ma. However, the Lovejoy basalt appears to be unrelated to volcanism of the predominantly calc-alkaline Cascade arc; instead, the Lovejoy is broadly tholeiitic, with trace-element characteristics similar to the Columbia River Basalt Group. Association of the Lovejoy basalt with mid-Miocene flood basalt volcanism has considerable implications for North American plume dynamics and strengthens the thermal "point source" explanation, as provided by the mantle-plume hypothesis. Alternatives to the plume hypothesis usually call upon lithosphere-scale cracks to control magmatic migrations in the Yellowstone-Columbia River basalt region. However, it is difficult to imagine a lithosphere-scale flaw that crosses Precambrian basement and accreted terranes to reach the Sierra microplate, where the Lovejoy is located. Therefore, we propose that the Lovejoy represents a rapid migration of plume-head material, at ??20 cm/yr to the southwest, a direction not previously recognized. ?? 2008 The Geological Society of America.

Garrison, N.J.; Busby, C.J.; Gans, P.B.; Putirka, K.; Wagner, D.L.

2008-01-01

263

Scope and construction of a gas and oil atlas series of the Gulf of Mexico: Examples from Texas offshore lower Miocene plays  

SciTech Connect

An atlas series about the offshore northern Gulf of Mexico will group gas and oil reservoirs into subregional plays and will display reservoir data on a computerized geographical information system. The atlas series will provide critically compiled reservoir engineering data to help the private sector explore and develop hydrocarbons and to help the public sector analyze the hydrocarbon endowment in this basin. In this report, we cover aspects of the play-analysis procedure and provide specific examples of lower Miocene plays from the upper Texas coast and Federal Outer Continental Shelf (OCS). Play analysis emphasizes using broad classes of structural style, depositional style and environments, and defining attributes to group reservoirs into plays. To date, we have identified 4 Oligocene and 25 Miocene plays in Texas State offshore waters and 115 plays in the Federal OCS. Texas State offshore plays are gas prone (cumulative production 3.7 TcF) and are preferentially trapped in rollover anticlines. Miocene plays include submarine-fan Lenticulina sandstones; progradational Dicorbis b., Siphonina d., Marginulina a., and Lenticulina sandstones; transgressive sandstones associated with a barrier-bar system in the Matagorda Area; and transgressive Amphistegina B sandstones. Particularly productive gas-prone plays are progradational Sihonina d. deltas in the High Island Area and progradational Marginulia a. shelf and deltaic sandstones in the Matagorda Island and Brazos Areas.

Seni, S.J.; Desselle, B.A.; Standen, A. [Univ. of Texas, Austin, TX (United States)

1994-12-31

264

Simultaneous Determination of Seven Components from Hawthorn Leaves Flavonoids in Rat Plasma by LC-MS/MS.  

PubMed

In this study, a simple, sensitive, and throughout liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous determination of seven flavonoid compounds, namely, rutin, vitexin-4?-O-glucoside, vitexin-2?-O-rhamnoside, hyperoside, vitexin, shanyenoside A and quercetin in rat plasma after intravenous administration of hawthorn leaves flavonoids (HLF) using lysionotin as an internal standard (IS). The target compounds were extracted using protein precipitation by methanol. The detection was achieved by LC-MS/MS in multiple reaction monitoring mode. The optimal mass transition ion pairs (m/z) for quantitation were 609.3/300.1 for rutin, 593.1/413.2 for vitexin-4?-O-glucoside, 577.3/413.2 for vitexin-2?-O-rhamnoside, 463.2/300.1 for hyperoside, 431.2/311.2 for vitexin, 407.2/245.1 for shanyenoside A, 301.1/151.1 for quercetin and 343.2/313.1 for the IS, respectively. The method was fully validated with respect to specificity, sensitivity, linearity, precision, accuracy, recovery and stability experiments. A sufficiently sensitive and selective LC-MS/MS method was first developed in this study to simultaneously evaluate the pharmacokinetics of seven flavonoids in rat plasma following intravenous administration of HLF. PMID:25368407

Zhu, Shourong; Yan, Huiyu; Niu, Kai; Zhang, Sixi

2014-11-01

265

Porosity evolution of upper Miocene reefs, Almeria Province, southern Spain  

USGS Publications Warehouse

Sea cliffs 40 km east of Almeria, southeastern Spain, expose upper Miocene reefs and patch reefs of the Plomo formation. These reefs are formed of scleractinian corals, calcareous algae, and mollusks. The reef cores are as much as 65 m thick and several hundred meters wide. Fore-reef talus beds extend 1,300 m across and are 40 m thick. The reefs and reef breccias are composed of calcific dolomite. They lie on volcanic rocks that have a K-Ar date of 11.5 m.y. and in turn are overlain by the upper Miocene Vicar Formation. In the reef cores and fore-reef breccia beds, porosity is both primary and postdepositional. Primary porosity is of three types: (a) boring clam holes in the scleractinian coral heads, cemented reef rocks, and breccias; (b) intraparticle porosity within the corals, Halimeda plates, and vermetid worm tubes; and (c) interparticle porosity between bioclastic fragments and in the reef breccia. Postdepositional moldic porosity was formed by the solution of aragonitic material such as molluscan and coral fragments. The Plomo reef carbonate rocks have high porosity and permeability, and retain a great amount of depositional porosity. Pores range in size from a few micrometers to 30 cm. The extensive intercrystalline porosity and high permeability resulted from dolomitization of micritic matrix. Dolomite rhombs are between 10 and 30 ? across. More moldic porosity was formed by the dissolution of the calclte bioclasts. Some porosity reduction has occurred by incomplete and partial sparry calcite infilling of interparticular, moldic, and intercrystalline voids. The high porosity and permeability of these reefs make them important targets for petroleum exploration in the western Mediterranean off southern Spain. In these offshore areas in the subsurface the volcanic ridge and the Plomo reef complex are locally onlapped or overlapped by 350 m or more of Miocene(?) and Pliocene fine-grained sedimentary rocks. The possibility exists that the buried Plomo reef deposits may form traps for oil and gas in the offshore areas southwest of the type locality. Stratigraphic traps also may occur where the Neogene sequence above the Plomo reef complex onlaps the volcanic ridge.

Armstrong, A.K.; Snavely, P.D.; Addicott, W.O.

1980-01-01

266

Late Miocene shortening of the Northern Apennines back-arc  

NASA Astrophysics Data System (ADS)

The inner Northern Apennines (western Tuscany and Tyrrhenian basin) is characterized by a relatively thin continental crust (˜20-25 km), high heat flow (>100 mW m-2), and the presence of relevant tectonic elision of stratigraphic sequences, a setting known as Serie Ridotta. These features are normally ascribed to an extensional deformation that affected the back-arc area above the subducting Adria plate since the Early-Middle Miocene (˜16 Ma). However, various geophysical studies image the continental crust to be currently affected by W-dipping thrust faults (and associated basement uplifts) that have not been obliterated by this claimed long-lasting extensional process. These observations raise the question whether the thrusts are older or younger than the continental extension. To address this question we have reprocessed and interpreted the deep seismic reflection profile CROP03/c that crosses the onshore hinterland sector, and investigated the structural setting of some of the Late Miocene-Pliocene hinterland basins (Cinigiano-Baccinello, Siena-Radicofani, Tafone, Albegna and Radicondoli basins) that are situated at the front or in-between the basement uplifts. The analysis of field structures and commercial seismic profiles has allowed the recognition that both substratum and basins' infill have been intensely shortened. These findings and the architecture of the basins suggest that the latter developed under a contractional regime, which would have started around 8.5 Ma with the onset of the continental sedimentation. This compressive stress state followed an earlier phase of continental extension that presumably started at ˜16 Ma (with the blocking of the Corsica-Sardinia rotation), and thinned both the continental crust and sedimentary cover producing most of the Serie Ridotta. The main phases of basin shortening are bracketed between 7.5 and 3.5 Ma, and thus overlap with the increase in the exhumation rate of the metamorphic cores at ˜6-4 Ma determined through thermochronological data. We therefore propose a correlation between the basin deformation and the activity of the nearby basement thrusts, which would have thus shortened a previously thinned continental crust. This chronology of deformation may suggest a geodynamic model in which the back-arc and hinterland sector of the Northern Apennines was recompressed during Late Miocene-Early Pliocene times. This evolution may be explained through different speculative scenarios involving a blockage of the subduction process, which may vary between end members of complete slab detachment and stalled subduction.

Bonini, Marco; Sani, Federico; Stucchi, Eusebio M.; Moratti, Giovanna; Benvenuti, Marco; Menanno, Giovanni; Tanini, Chiara

2014-03-01

267

Gulf of Mexico Miocene CO2 Site Characterization Mega Transect  

SciTech Connect

This project characterized the Miocene-age sub-seafloor stratigraphy in the near-offshore portion of the Gulf of Mexico adjacent to the Texas coast. The large number of industrial sources of carbon dioxide (CO2) in coastal counties and the high density of onshore urbanization and environmentally sensitive areas make this offshore region extremely attractive for long-term storage of carbon dioxide emissions from industrial sources (CCS). The study leverages dense existing geologic data from decades of hydrocarbon exploration in and around the study area to characterize the regional geology for suitability and storage capacity. Primary products of the study include: regional static storage capacity estimates, sequestration “leads” and prospects with associated dynamic capacity estimates, experimental studies of CO2-brine-rock interaction, best practices for site characterization, a large-format ‘Atlas’ of sequestration for the study area, and characterization of potential fluid migration pathways for reducing storage risks utilizing novel high-resolution 3D (HR3D) seismic surveys. In addition, three subcontracted studies address source-to-sink matching optimization, offshore well bore management and environmental aspects. The various geologic data and interpretations are integrated and summarized in a series of cross-sections and maps, which represent a primary resource for any near-term commercial deployment of CCS in the area. The regional study characterized and mapped important geologic features (e.g., Clemente-Tomas fault zone, the regionally extensive Marginulina A and Amphistegina B confining systems, etc.) that provided an important context for regional static capacity estimates and specific sequestration prospects of the study. A static capacity estimate of the majority of the Study area (14,467 mi2) was estimated at 86 metric Gigatonnes. While local capacity estimates are likely to be lower due to reservoir-scale characteristics, the offshore Miocene interval is a storage resource of National interest for providing CO2 storage as an atmospheric emissions abatement strategy. The natural petroleum system was used as an analog to infer seal quality and predict possible migration pathways of fluids in an engineered system of anthropogenic CO2 injection and storage. The regional structural features (e.g., Clemente-Tomas fault zone) that exert primary control on the trapping and distribution of Miocene hydrocarbons are expected to perform similarly for CCS. Industrial?scale CCS will require storage capacity utilizing well?documented Miocene hydrocarbon (dominantly depleted gas) fields and their larger structural closures, as well as barren (unproductive, brine?filled) closures. No assessment was made of potential for CO2 utilization for enhanced oil and gas recovery. The use of 3D numerical fluid flow simulations have been used in the study to greatly assist in characterizing the potential storage capacity of a specific reservoir. Due to the complexity of geologic systems (stratigraphic heterogeneity) and inherent limitations on producing a 3D geologic model, these simulations are typically simplified scenarios that explore the influence of model property variability (sensitivity study). A specific site offshore San Luis Pass (southern Galveston Island) was undertaken successfully, indicating stacked storage potential. Downscaling regional capacity estimates to the local scale (and the inverse) has proven challenging, and remains an outstanding gap in capacity assessments. In order to characterize regional seal performance and identify potential brine and CO2 leakage pathways, results from three high-resolution 3D (HR3D) seismic datasets acquired by the study using novel HR3D (P-Cable) acquisition system showed steady and significant improvements in data quality because of improved acquisition and processing technique. Finely detailed faults and stratigraphy in the shallowest 1000 milliseconds (~800 m) of data allowed for the identification and mapping of unconformable surfaces including what is probably

Meckel, Timothy; Trevino, Ramon

2014-09-30

268

Ruminant diets and the Miocene extinction of European great apes  

PubMed Central

The successful evolutionary radiations of European hominoids and pliopithecoids came to an end during the Late Miocene. Using ruminant diets as environmental proxies, it becomes possible to detect variations in vegetation over time with the potential to explain fluctuations in primate diversity along a NW–SE European transect. Analysis shows that ruminants had diverse diets when primate diversity reached its peak, with more grazers in eastern Europe and more browsers farther west. After the drop in primate diversity, grazers accounted for a greater part of western and central European communities. Eastwards, the converse trend was evident with more browsing ruminants. These opposite trends indicate habitat loss and an increase in environmental uniformity that may have severely favoured the decline of primate diversity. PMID:20519220

Merceron, Gildas; Kaiser, Thomas M.; Kostopoulos, Dimitris S.; Schulz, Ellen

2010-01-01

269

A Miocene submarine volcano at Low Layton, Jamaica  

NASA Technical Reports Server (NTRS)

A submarine fissure eruption of Upper Miocene age produced a modest volume of alkaline basalt at Low Layton, on the north coast of Jamaica. The eruption occurred in no more than a few hundred meters of water and produced a series of hyaloclastites, pillow breccias and pillow lavas, massive lavas, and dikes with an ENE en echelon structure. The volcano lies on the trend of one of the island's major E-W strike-slip fault zones; the Dunavale Fault Zone. The K-Ar age of the eruption of 9.5 plus or minus 0.5 Ma. B.P. corresponds to an extension of the Mid-Cayman Rise spreading center inferred from magnetic anomalies and bathymetry of the Cayman Trough to the north and west of Jamaica. The Low Layton eruption was part of the response of the strike-slip fault systems adjacent to this spreading center during this brief episode of tectonic readjustment.

Wadge, G.

1982-01-01

270

Miocene reef and nonreef carbonate rocks in Japan  

SciTech Connect

Japan's main islands experienced temperature climates throughout the Neogene with a tropical invasion around 16 Ma (early middle Miocene). This climatic warming, accompanied by a eustatic sea level rise, caused the unusual occurrence of reef facies, mangrove deposits, and lateritic beds in Japan. In cooler climates both before and after reef growth, sediments rich in bryozoan and algal material were widespread. Reef rocks emplaced as penecontemporaneous olistoliths in deep-water clastics at the Pacific coast of central Honshu are characterized by a wide lithologic spectrum, ranging from grainstone to bindstone. These rocks include rudstone and floatstone, which are rich in coralline algae (encrusting forms such as Lithophyllum and Mesophyllum and articulate forms such as Amphiroa) and codiacean algae (Halimeda) with hermatypic corals and large benthic formainifera (e.g., Nephrolepidina and Miogypsina) being less common. Two types of dolomite occur: (1) limpid dolomite with O/sup 18/ = -5.77 and with bipyramidal quartz and (2) microcrystalline dolomite with O/sup 18/ = 2.00 and with length-slow chalcedony. While microcrystalline dolomite tends to predominate in muddy matrix material, limpid dolomite appears to fill pores, some of which are moldic. Younger nonreef carbonate rocks, as occur on the Noto Peninsula of central Honshu, are commonly cross-bedded, contain Bryozoa, mollusks, small foraminifera, and echinoids, and are locally dolomitized. These dolomites are ascribed to a mixed-water origin. A different type of nonreef, yet reservoir-forming, dolostone occurs in the late middle Miocene of northeast Honshu and is interpreted to have formed as a transformation from bathyal opal.

Konishi, K.

1988-01-01

271

Herds Overhead: Nimbadon lavarackorum (Diprotodontidae), Heavyweight Marsupial Herbivores in the Miocene Forests of Australia  

PubMed Central

The marsupial family Diprotodontidae (Diprotodontia, Vombatiformes) is a group of extinct large-bodied (60–2500 kg) wombat-like herbivores that were common and geographically widespread in Cenozoic fossil deposits of Australia and New Guinea. Typically they are regarded to be gregarious, terrestrial quadrupeds and have been likened in body form among placental groups to sheep, rhinoceros and hippopotami. Arguably, one of the best represented species is the zygomaturine diprotodontid Nimbadon lavarackorum which is known from exceptionally well-preserved cranial and postcranial material from the middle Miocene cave deposit AL90, in the Riversleigh World Heritage Area, northwestern Queensland. Here we describe and functionally analyse the appendicular skeleton of Nimbadon lavarackorum and reveal a far more unique lifestyle for this plesiomorphic and smallest of diprotodontids. Striking similarities are evident between the skeleton of Nimbadon and that of the extant arboreal koala Phascolarctos cinereus, including the powerfully built forelimbs, highly mobile shoulder and elbow joints, proportionately large manus and pes (both with a semi-opposable digit I) and exceedingly large, recurved and laterally compressed claws. Combined with the unique (among australidelphians) proportionately shortened hindlimbs of Nimbadon, these features suggest adept climbing ability, probable suspensory behaviour, and an arboreal lifestyle. At approximately 70 kg, Nimbadon is the largest herbivorous mammal to have occupied the forest canopies of Australia - an ecological niche that is no longer occupied in any Australian ecosystem and one that further expands the already significant niche diversity displayed by marsupials during the Cenozoic. PMID:23185250

Black, Karen H.; Camens, Aaron B.; Archer, Michael; Hand, Suzanne J.

2012-01-01

272

A new genus of the family Jaculinidae (Cheilostomata, Bryozoa) from the Miocene of the tropical western Atlantic.  

PubMed

Pirabasoporella gen. nov. is introduced for three new bryozoan species from the Early Miocene of the tropical western Atlantic. The genus is placed in the family Jaculinidae Zabala, a peculiar group of cheilostome bryozoans characterised by reticulate colonies formed by uni- or biserial branches that are connected by kenozooidal struts. This colonial morphology superficially resembles colonies of the Paleozoic order Fenestrata (Stenolaemata) and some Recent Cyclostomata. As jaculinid colonies are anchored to soft sediments via rhizoids, however, they differ in life habit from Paleozoic and modern fenestrate colonies, which are firmly attached to stable substrata by an encrusting base.        The three new species are Pirabasoporella atalaiaensis n. sp. from the Brazilian Pirabas Formation, Pirabasoporella baitoae n. sp. from the Baitoa Formation (Dominican Republic), and Pirabasoporella chipolae n. sp. from the Floridan Chipola Formation. Their presence in the Early Miocene western Atlantic represents the earliest record of Jaculinidae, and suggests that the origin of the family, the only living species of which are known from the eastern Atlantic and Mediterranean Sea, extends well into the Paleogene.        The Jaculinidae is here transferred from the lepraliomorph superfamily Schizoporelloidea Jullien to the umbonulomorph Lepralielloidea Vigneaux owing to the partly umbonuloid frontal shield and non-schizoporelloid ovicell. PMID:25081761

Zágoršek, Kamil; Ramalho, Laís V; Berning, Björn; De Araújo Távora, Vladimir

2014-01-01

273

Phylogeny and rapid northern and southern hemisphere speciation of goldfinches during the Miocene and Pliocene epochs.  

PubMed

Mitochondrial cytochrome b (cyt b) from 25 out of 31 extant goldfinches, siskins, greenfinches and redpolls (genus Carduelis) has been sequenced from living samples taken around the world, specimens have also been photographed. Phylogenetic analysis consistently gave the same groups of birds, and this grouping was generally related to geographical proximity. It has been supposed that Pleistocene glaciations played a crucial role in the origin of extant diversity and distribution of Northern Hemisphere vertebrates. Molecular comparison of most extant songbird species belonging to the genus Carduelis does not support this assertion. The fossil record of chicken and pheasant divergence time has been used to calibrate the molecular clock; cyt b DNA dendrograms suggest that speciation in Carduelinae birds occurred during the Miocene and Pliocene Epochs (9-2 million years ago) in both the Northern and Southern Hemispheres. Only about 4% average amount of nucleotide substitution per lineage is found between the most distant Carduelis species; this suggests a remarkably rapid radiation when compared with the radiation of other passerine songbird genera. In addition, a continuum of small songbird speciation may be found during the Miocene Epoch in parallel with speciation of other orders (i.e. Galliformes, chicken/pheasant). Pleistocene glaciations may have been important in subspeciation (i.e. Eastern European grey-headed goldfinches/Western European black-headed goldfinches) and also in ice-induced vicariance (isolation) (i.e. siskin in Western Europe vs. siskin in Far East Asia) around the world. European isolated Serinus citrinella (citril finch) is not a canary, but a true goldfinch. South American siskins have quickly radiated in the last 4 million years coinciding with the emergence of the Isthmus of Panama; probably, a North American siskin related to C. notata invaded a suitable and varied biotope (the South American island) for Carduelis birds. North American goldfinches may be renamed as siskins, because they have a distant genetic relationship with European goldfinches. Genus Acanthis could be dropped, and thus redpolls should be separated from twite and linnet, the latter (Europeans) probably being related to American goldfinches. Also, reproductive barriers are observed between closely related species and not between other more distant ones. Finally, a tentative classification for genus Carduelis species is suggested. PMID:9791543

Arnaiz-Villena, A; Alvarez-Tejado, M; Ruíz-del-Valle, V; García-de-la-Torre, C; Varela, P; Recio, M J; Ferre, S; Martínez-Laso, J

1998-09-01

274

Miocene climate seasonality in southern India - first direct evidence for a weak Indian monsoon during the Middle Miocene Climate Optimum  

NASA Astrophysics Data System (ADS)

The Asian monsoon is an integral component of the global climate system. This large-scale atmospheric circulation comprises the East Asian summer and winter monsoon and the Indian monsoon subsystems, all characterized by seasonal reversing winds and precipitation changes associated with asymmetric heating of land and sea. The Neogene monsoon history is mainly reconstructed from chemical and physical weathering rates recorded in widely continuous marine sequences of the Indus Fan, Bengal Fan and South China Sea, which, depending on the source, physiography and sediment, indicate drier or wetter climates. These indirect climate proxies display an unusually dry period during the Middle Miocene Climate Optimum (MMCO, 16.5-15 Ma). As part of the FWF-projects P18189, P21414 and P23492, we present an Early/Middle Miocene coastal palynoflora record from the siliciclastic Ambalapuzha Formation at the coastal cliff of Varkala (Kerala Basin, SW India). Pollen assemblages and facies document a coastal wetland with mangrove vegetation. The Coexistence Approach was applied for palaeoclimatic reconstructions. This method uses climatic tolerances of all nearest living relatives known for a fossil flora by assuming that the tolerances of a fossil taxon are not significantly different from its modern counterpart. The maximum overlap of the environmental tolerances of all nearest living relatives (coexistence interval) is then regarded as being indicative of the most likely palaeoenvironment. By enquiring the Palaeoflora Database (http://www.palaeoflora.de/), the palaeoclimatic parameters of the pollen flora were calculated. The reconstructed climatic parameters for the MMCO show a seasonal precipitation pattern with a dry and a wet period and moderate rainfalls during the warmest period, which is comparable to the present day annual precipitation cycle in coastal Kerala, and affirms the presence of a monsoon-like atmospheric circulation over South India during the MMCO. However, the precipitation amounts during the wet (average 75%) and the warmest period (average 68%) were significantly reduced compared to today, while the rainfalls during the dry seasons are in the same order. This implies a weak Indian monsoon during the MMCO and a low thermal land - sea gradient between the Eurasian landmass and the Indian Ocean. Although a ~3°C warmer global climate during the MMCO and a weaker monsoon accounts for a higher near-surface air temperature during summer, the calculated mean annual temperature (MAT; 24.4°C) is 2.7°C lower than at present. The estimated warmest month temperature is, however, in the same range as today. Therefore, the low coldest month temperature (CMT; 20.6-22.8°C) in the Miocene has to account for the high MAT difference. This parameter represents the lower temperature threshold of the Varkala flora, and displays only the minimum temperature during the coldest month, which is significantly lower than the average CMT. Accordingly, the Miocene CMT approximates the present 24-h minimum temperature during the coldest month in Kerala (22.4°C). The reconstructed seasonal temperature cycle supports climate models, which suggest a higher temperature increase in mid-latitudes than in low-latitudes as well as warmer equatorial sea surface temperatures during the MMCO.

Piller, W. E.; Reuter, M.; Kern, A. K.; Harzhauser, M.

2012-04-01

275

A new termite bug in Miocene amber from the Dominican Republic (Hemiptera, Termitaphididae)  

E-print Network

A new species of the termite bug genus Termitaradus Myers (Aradoidea: Termitaphididae) is described and figured based on a single female preserved in Early Miocene (Burdigalian) amber from the Dominican Republic. Termitaradus mitnicki sp. n. differs...

Engel, Michael S.

2009-10-23

276

The genus Macroteleia Westwood in Middle Miocene amber from Peru (Hymenoptera, Platygastridae s.l., Scelioninae)  

E-print Network

al. 2006) that is exposed on the eastern bank of the Amazon River in the Tamshiyacu locality, 30 km The genus Macroteleia Westwood in Middle Miocene amber from Peru... 121 upstream of Iquitos in northeastern Peru. The age and paleobiota...

Perrichot, Vincent; Antoine, Pierre-Olivier; Salas-Gismondi, Rodolfo; Flynn, John J.; Engel, Michael S.

2014-06-17

277

Deformation of the late Miocene to Pliocene Inyo Surface, eastern Sierra region, California  

USGS Publications Warehouse

A middle and late Miocene erosion surface, the Inyo Surface, underlies late Miocene mafic flows in the White Mountains and late Miocene and (or) early Pliocene flows elsewhere in the eastern Sierra region. The Inyo Surface is correlated with an erosion surface that underlies late Miocene mafic flows in the central and northern Sierra Nevada. The mafic flows had outpourings similar to flood basalts, although of smaller volume, providing paleohorizontal and paleolowland indicators. The flows filed and locally topped the existing landscape forming broad plateau-like flats. Topographic relief in the region was characterized by weathered and rounded slopesp rior to late Miocene mafic magmatism. Relicts of the older landscape lie adjacent to late Miocene and early Pliocene basalt-covered lowlands that now occur within the crests of ranges that have 2500-3000 m relief and dramatically steep escarpments. Late Miocene mafic flows that lie on the crest of the Sierra Nevada adjacent to the White Mountains predate significant activity on the Sierra Nevada frontal fault zone. These deposits and accompanying erosion surfaces provide excellent strain markers for reconstructing part of the Walker Lane north of the Garlock fault and west of the Amargosa drainage, here referred to as the eastern Sierra region. The Inyo Surface is a compound erosional surface that records at least four major erosion events during the Cenozoic. These four surfaces were first recognized on the Kern Plateau and named from oldest to youngest, the Summit Upland, the Subsummit Plateau, the Chagoopa Plateau, and the Canyon. The three older surfaces have also been subsequently modifi ed by Pleistocene glaciation. The compound erosion surface, which is locally overlain by late Miocene mafic flows in the northern and central Sierra Nevada, is here referred to as the Lindgren Surface. Correlatives in the eastern Sierra region are found in the White Mountains, Inyo Mountains, Darwin Plateau, Coso Range, and nearby ranges. Copyright ?? 2009 The Geological Society of America.

Jayko, A.S.

2009-01-01

278

Miocene fossil hydrothermal system associated with a volcanic complex in the Andes of central Chile  

Microsoft Academic Search

Cenozoic deposits in the Andes of central Chile have been affected by very low-grade burial metamorphism. At about 33°S in the Cuesta de Chacabuco area, approximately 53 km north of Santiago, two Oligocene and Miocene volcanic units form a ca. 1300-m-thick rock pile. The Miocene unit corresponds to a volcanic complex composed of two eroded stratovolcanoes. Secondary mineral assemblages in

Francisco Fuentes; Luis Aguirre; Mario Vergara; Leticia Valdebenito; Eugenia Fonseca

2004-01-01

279

New Catarrhine fossils from Moroto II, Early Middle Miocene (ca 17.5 Ma) Uganda  

Microsoft Academic Search

During the 1998–2003 field seasons of the Uganda Palaeontology Expedition, dental remains of three catarrhine species were recovered from Moroto II, Uganda. Micromammals from the locality indicate a late Early Miocene to basal Middle Miocene (ca 17.5–17 Ma) age, younger than Rusinga (17.8 Ma), but similar in age to Buluk (17.2 Ma) and Kalodirr (17.2 Ma). This paper describes and interprets new catarrhines from

Martin Pickford; Brigitte Senut; Dominique Gommery; Ezra Musiime

2003-01-01

280

A Tortonian (Late Miocene, 11.61–7.25 Ma) global vegetation reconstruction  

Microsoft Academic Search

For the Tortonian age of the Miocene Epoch (11.6–7.25Ma) we present a global palaeobotanical and palaeoecologically-based vegetation dataset, combined with a best-fit Late Miocene climate-vegetation model experiment to create an advanced global data–model hybrid biome reconstruction. This new palaeoecological database and global vegetation reconstruction can be used both for the purposes of validating future palaeoclimate model simulations, as well as

Matthew J. Pound; Alan M. Haywood; Ulrich Salzmann; James B. Riding; Daniel J. Lunt; Stephen J. Hunter

2011-01-01

281

Middle Miocene latitudinal climatic gradient in Western Europe: Evidence from pollen records  

Microsoft Academic Search

Pollen analysis of sections spanning the Middle Miocene (Langhian and Serravallian) from southern Spain to Switzerland has been carried out with the aim of reconstructing the existing latitudinal environmental gradient.Floral assemblages indicate a tropical–subtropical to warm–temperate climate for the entire area during the Middle Miocene. The presence, in all pollen spectra, of taxa with high temperature requirements demonstrates that the

Gonzalo Jiménez-Moreno; Jean-Pierre Suc

2007-01-01

282

Miocene karst drainage system: seismic stratigraphy of the continental shelf west of Florida  

SciTech Connect

High-resolution geophysical data recorded on the continental shelf west of Tampa Bay, Florida show three stratigraphic units: Holocene, Plio-Pleistocene, and Miocene. Within the Miocene unit is an expansive drainage system extending about 80 kilometers offshore. In most areas, a system such as this would typically be characterized as a paleo-fluvial system. Although this drainage system probably initiated fluvially, geophysical data showing much evidence of karstification suggest that this system probably formed on the inner shelf as a result of large scale dissolution and collapse of Miocene limestones during lowered sea-level. The overlying Plio-Pleistocene unit infills the Miocene drainage system, while exiguously covering Miocene rocks in areas where the system is absent. Deposition of this unit probably took place during high-stands of sea-level, followed by erosion and transport of sediment farther offshore, exposing Miocene rocks. The Holocene unit sporadically covers underlying units throughout the study area. Sediments making up this unit have been reworked into several bedform types probably resulting from various boundary layer flow events such as hurricanes, storms, currents and tides. This scenario is probably not unique to the continental shelf west of Tampa Bay, Florida, but may also characterize other karstic shelves where paleo-fluvial processes were previously thought to be the dominant mechanism forming paleo-coastal drainage systems.

Herbert, J.A.

1985-01-01

283

Simultaneous determination and pharmacokinetic comparisons of multi-ingredients after oral administration of radix salviae miltiorrhizae extract, hawthorn extract, and a combination of both extracts to rats.  

PubMed

A simple and sensitive HPLC method was developed for simultaneous determination of danshensu (DSS), rosmarinic acid (RA), lithospermic acid (LA), salvianolic acid B (SAB), and hyperoside (HP) in rat plasma. This method validated was successfully applied to the pharmacokinetic study of the main active ingredients after oral administration of Radix Salviae Miltiorrhizae extract (SME), hawthorn extract (HTE), and a combination of both extracts (2.5?:?1) to rats. The results indicated that there have been great differences in pharmacokinetics between a single extract and a combination of both extracts. A combination of both extracts can enhance their bioavailabilities and delay the elimination of SAB and DSS in rats. PMID:24660090

Liu, Yu-Qiang; Cai, Qian; Liu, Chang; Bao, Feng-Wei; Zhang, Zhen-Qiu

2014-01-01

284

Screening and structural characterization of ? -glucosidase inhibitors from hawthorn leaf flavonoids extract by ultrafiltration LC-DAD-MS n and SORI-CID FTICR MS  

Microsoft Academic Search

In vitro ?-glucosidase inhibition assays and ultrafiltration liquid chromatography with photodiode array detection coupled to electrospray\\u000a ionization tandem mass spectrometry (ultrafiltration LC-DAD-ESI-MS\\u000a n\\u000a ) were combined to screen ?-glucosidase inhibitors from hawthorn leaf flavonoids extract (HLFE). As a result, four compounds\\u000a were identified as ?-glucosidase inhibitors in the HLFE, and their structures were confirmed to be quercetin-3-O-rha- (1-4)-glc-rha\\u000a and C-glycosylflavones

Huilin Li; Fengrui Song; Junpeng Xing; Rong Tsao; Zhiqiang Liu; Shuying Liu

2009-01-01

285

Simultaneous Determination and Pharmacokinetic Comparisons of Multi-Ingredients after Oral Administration of Radix Salviae Miltiorrhizae Extract, Hawthorn Extract, and a Combination of Both Extracts to Rats  

PubMed Central

A simple and sensitive HPLC method was developed for simultaneous determination of danshensu (DSS), rosmarinic acid (RA), lithospermic acid (LA), salvianolic acid B (SAB), and hyperoside (HP) in rat plasma. This method validated was successfully applied to the pharmacokinetic study of the main active ingredients after oral administration of Radix Salviae Miltiorrhizae extract (SME), hawthorn extract (HTE), and a combination of both extracts (2.5?:?1) to rats. The results indicated that there have been great differences in pharmacokinetics between a single extract and a combination of both extracts. A combination of both extracts can enhance their bioavailabilities and delay the elimination of SAB and DSS in rats. PMID:24660090

Liu, Yu-Qiang; Cai, Qian; Liu, Chang; Bao, Feng-Wei; Zhang, Zhen-Qiu

2014-01-01

286

Subcellular preservation in giant ostracod sperm from an early Miocene cave deposit in Australia.  

PubMed

Cypridoidean ostracods are one of a number of animal taxa that reproduce with giant sperm, up to 10 000 µm in length, but they are the only group to have aflagellate, filamentous giant sperm. The evolution and function of this highly unusual feature of reproduction with giant sperm are currently unknown. The hypothesis of long-term evolutionary persistence of this kind of reproduction has never been tested. We here report giant sperm discovered by propagation phase contrast X-ray synchrotron micro- and nanotomography, preserved in five Miocene ostracod specimens from Queensland, Australia. The specimens belong to the species Heterocypris collaris Matzke-Karasz et al. 2013 (one male and three females) and Newnhamia mckenziana Matzke-Karasz et al. 2013 (one female). The sperm are not only the oldest petrified gametes on record, but include three-dimensional subcellular preservation. We provide direct evidence that giant sperm have been a feature of this taxon for at least 16 Myr and provide an additional criterion (i.e. longevity) to test hypotheses relating to origin and function of giant sperm in the animal kingdom. We further argue that the highly resistant, most probably chitinous coats of giant ostracod sperm may play a role in delaying decay processes, favouring early mineralization of soft tissue. PMID:24827442

Matzke-Karasz, Renate; Neil, John V; Smith, Robin J; Symonová, Radka; Mo?kovský, Libor; Archer, Michael; Hand, Suzanne J; Cloetens, Peter; Tafforeau, Paul

2014-07-01

287

The record of Miocene impacts in the Argentine Pampas  

NASA Astrophysics Data System (ADS)

Argentine Pampean sediments represent a nearly continuous record of deposition since the late Miocene (˜10 Ma). Previous studies described five localized concentrations of vesicular impact glasses from the Holocene to late Pliocene. Two more occurrences from the late Miocene are reported here: one near Chasicó (CH) with an 40Ar/39Ar age of 9.24 ± 0.09 Ma, and the other near Bahía Blanca (BB) with an age of 5.28 ± 0.04 Ma. In contrast with andesitic and dacitic impact glasses from other localities in the Pampas, the CH and BB glasses are more mafic. They also exhibit higher degrees of melting with relatively few xenoycrysts but extensive quench crystals. In addition to evidence for extreme heating (>1700 °C), shock features are observed (e.g., planar deformation features [PDFs] and diaplectic quartz and feldspar) in impact glasses from both deposits. Geochemical analyses reveal unusually high levels of Ba (˜7700 ppm) in some samples, which is consistent with an interpretation that these impacts excavated marine sequences known to be at depth. These two new impact glass occurrences raise to seven the number of late Cenozoic impacts for which there is evidence preserved in the Pampean sediments. This seemingly high number of significant impacts over a 106 km2 area in a time span of 10 Myr is consistent with the number of bolides larger than 100 m expected to enter the atmosphere but is contrary to calculated survival rates following atmospheric disruption. The Pampean record suggests, therefore, that either atmospheric entry models need to be reconsidered or that the Earth has received an enhanced flux of impactors during portions of the late Cenozoic. Evidence for the resulting collisions may be best preserved and revealed in rare dissected regions of continuous, low-energy deposition such as the Pampas. Additionally, the rare earth element (REE) concentrations of the target sediments and impact melts associated with the Chasicó event resemble the HNa/K australites of similar age. This suggests the possibility that those enigmatic tektites could have originated as high-angle, distal ejecta from an impact in Argentina, thereby accounting for their rarity and notable chemical and physical differences from other Australasian impact glasses.

Schultz, Peter H.; Zárate, Marcelo; Hames, Willis E.; Harris, R. Scott; Bunch, T. E.; Koeberl, Christian; Renne, Paul; Wittke, James

2006-05-01

288

Porosity evolution of upper Miocene reefs, Almeria Province, Southern Spain  

SciTech Connect

In the reef cores and fore-reef breccia beds, porosity in both primary and postdepositional. Primary porosity is of three types: (a) boring clam holes in the scleractinian coral heads, cemented reef rocks, and breccias; (b) intraparticle porosity within the corals, Halimeda plates, and vermetid worm tubes; and (c) interparticle porosity between bioclastic fragments and in the reef breccia. Postdepositional moldic porosity was formed by the solution of aragonitic material such as molluscan and coral fragments. The Polomo reef carbonate rocks have high porosity and permeability, and retain a great amount of depositional porosity. Pores range in size from a few micrometers to 30 cm. The extensive intercrystalline porosity and high permeability resulted from dolomitization of micritic matrix. Some porosity reduction has occured by incomplete and partial sparry calcite infilling of interparticular, moldic, and intercrystalline voids. The high porosity and permeability of these reefs make them important targets for petroleum exploration in the western Mediterranean off southern Spain. In these offshore areas in the subsuface the volcanic ridge and the Plomo reef complex are locally onlapped or overlapped by 350 m or more of Miocene and Pliocene fine-grained sedimentary rocks. The possibility exists that the buried Plomo reef deposits may form traps for oil and gas in the offshore areas southwest of the type locality. Stratigraphic traps also may occur where the Neogene sequence above the Plomo reef complex onlaps the volcanic ridge. 17 figures.

Armstrong, A.K.; Snavely, P.D. Jr.; Addicott, W.O.

1980-02-01

289

Late Miocene calcareous nannofossil genus Catinaster: taxonomy, evolution and magnetobiochronology  

USGS Publications Warehouse

A systematic study on the evolution and stratigraphic distribution of the species of Catinaster from several DSDP/ODP sites with magnetostratigraphic records is presented. The evolution of Catinaster from Discoaster is established by documentation of a transitional nannofossil species, Dicoaster transitus. Two new subspecies, Catinaster coalitus extensus and Catinaster calyculus rectus are defined which appear to be intermediates in the evolution of Catinaster coalitus coalitus to Catinaster calyculus calyculus. The first occurrence of C. coalitus is shown to be in the lower part of C5n.2n at 10.7-10.9 Ma in the low to mid-latitude Atlantic and Pacific oceans. The last occurrence of C. coalitus coalitus varies from the upper part of C5n.2n to the lower portion of C4A. Magnetobiostratigraphic evidence suggests that the FO of C. calyculus rectus is diachronous. Catinaster mexicanus occurs in the late Miocene and has been found only in the eastern equatorial Pacific, the Indian Ocean and the Gulf of Mexico.

Peleo-Alampay, A.; Bukry, D.; Liu, L.; Young, J.R.

1998-01-01

290

Age structure, residents, and transients of Miocene rodent communities.  

PubMed

The age structures of two successive rodent communities are studied on the basis of a rich record from well-dated Miocene sections (17-10 Ma) in north-central Spain. Community age is defined as the mean of the residence times of the community members at the time of the locality age. Community ages are negatively correlated with the numbers of community members. These members are divided into residents (with continuous membership times > or =1.54 million years) and transients (with membership times <1.54 million years). During episodes of species loss, there is a preferential disappearance of transients while residents are retained, a pattern referred to as the "seniority rule." The residents define the studied communities. They are associated with early successional stages of vegetation, and transients are associated with later stages. Under stable conditions, early arrivals in succession are "transient" and replaced by competitive later arrivals. The reversed roles of transients and residents in the studied fossil record are explained by assuming high degrees of disturbance. We view the system within the context of nonequilibrium metapopulation theory, in which competitively superior species become transients because of their dependence on ephemeral late successional habitats. PMID:15791531

van der Meulen, Albert J; Peláez-Campomanes, Pablo; Levin, Simon A

2005-04-01

291

Miocene ungulates and terrestrial primary productivity: Where have all the browsers gone?  

PubMed Central

Progressive changes are observed in both the composition of mammal faunas and vegetation during the Miocene epoch [24–5 mega-annum (Ma)]. These changes are usually interpreted as a response to climatic changes. In the traditional view, forests or woodlands gradually gave way to more open habitats, with grazing (grass-eating) ungulate (hoofed) mammal species replacing the browsing (leafy-vegetation-eating) species as grasslands expanded. However, data from fossil assemblages in the Great Plains region of North America show that this faunal change was not a one-for-one replacement of browsers by grazers, as usually thought. Typical late early Miocene (17 Ma) fossil communities included extraordinarily high numbers of browsing ungulate species, comprising a fauna that cannot be directly analogized with any present-day community. Both maximum species richness of all ungulates and the proportion of browsers declined steadily in ungulate communities through the middle Miocene, to levels comparable to those of the present by the late Miocene. The resulting dramatic, cumulative loss of browsing species constitutes one of the strongest faunal signals of the late Tertiary (but was not a single “event”). We suggest that the early Miocene browser-rich communities may reflect higher levels of primary productivity in Miocene vegetation, compared with equivalent present-day vegetation types. The observed decline in species richness may represent a gradual decline in primary productivity, which would be consistent with one current hypothesis of a mid-Miocene decrease in atmospheric CO2 concentrations from higher mid-Cenozoic values. PMID:10884422

Janis, Christine M.; Damuth, John; Theodor, Jessica M.

2000-01-01

292

New insights to the middle Miocene pCO2 problem (Invited)  

NASA Astrophysics Data System (ADS)

The climate of the middle Miocene was substantially different to today with a much warmer world with boundary conditions (plate configurations, ocean circulation etc) that were very different to the present. The sustained warmth of the 'Middle Miocene Climate Optimum' prevailed prior to the second step of the descent into the ice-house - with the major expansion of Antarctic ice sheet and global cooling at the middle Miocene Climate Transition. Coincident with these major changes in global temperatures and the cryosphere were substantial perturbations of the carbon cycle, as documented by the large fluctuations in oceanic carbonate ?13C values during the 'Monterey Excursion' as well as the various 'CM' events superimposed upon it. Critical to our understanding of Miocene climate and carbon cycle dynamics is a full understanding of atmospheric pCO2 during this fascinating time. A number of Miocene atmospheric pCO2 estimates are now available (Kürschner, Kva?ek and Dilcher, 2008; Foster, Lear and Rae, 2012; Badger et al., 2013) that help to better understand this relationship but differences between these new records and older published records (ie Pagani et al., 1999; Pearson and Palmer, 2000) raise interesting questions as to the drivers of Miocene climate and carbon cycling. Here we will discuss the implications of our records for the Monterey Excursion and the CM events, as well as presenting a novel probabilistic re-assessment of new and existing atmospheric pCO2 records. The combination of a larger dataset and more quantitative approach allows us to answer some of the outstanding questions about the operation of the Miocene climate system, and help to explain the apparent disparity between atmospheric pCO2 records and proxy temperature estimates.

Badger, M. P.; Foster, G. L.; Lear, C. H.; Pancost, R. D.; Bailey, T. R.; Leng, M. J.; Abels, H. A.

2013-12-01

293

Provenance of the lower Miocene of the Gulf of Mexico from detrital zircon double dating  

NASA Astrophysics Data System (ADS)

The lower Miocene interval of the Gulf of Mexico (GOM) has recently gained increasing attention from oil and gas industry due to its hydrocarbon potential below the salt canopy. However, it has been less well studied than both the underlying Oligocene and overlying middle Miocene strata. The lower Miocene worldwide is a transitional period of tectonic, climatic, and oceanographic change. In particular, it is a period of major tectonic reorganization in the western interior of North America (Rocky Mountains), involving a shift from the Oligocene thermal phase, with abundant volcanic activity recorded in the thick Frio/Vicksburg succession of the GOM, to the Miocene Basin-Range extensional phase. Climatic conditions also changed from a relatively arid Oligocene to wetter Miocene, resulting in increased sediment yields from exhumed tectonic structures. Previous provenance studies used proportions of quartz, feldspar and lithic fragments and consideration of likely river courses through known paleogeomorphological elements. Only limited detrital zircon (DZ) U-Pb studies on Paleocene strata have been undertaken and there has been no previous U-Pb and (U-Th)/He double dating in the GOM. In this study we apply the latest analytical approaches, such as DZ U-Pb dating to gain robust source terranes ages and more fully elucidate the complex sediment provenance and dispersal history of GOM. We also employ DZ (U-Th)/He (ZHe) dating, combined with DZ U-Pb, to not only define sedimentary provenance but also the exhumation histories of detrital source regions. Samples of lower Miocene outcrop exposures in Texas and Louisiana have been collected to discriminate the varied tectonic and drainage system changes across the basin in lateral. In addition, samples from the Eocene, Oligocene and middle Miocene have been obtained to reveal vertical shift of source terranes contributions. Our initial age data show detrital zircons of lower Miocene sediments come from a wide range of source terranes including a large populations from the western interior of North America (Rocky Mountains), Grenville, Mid-Continent, and Yavapai-Mazatzal provinces, with smaller populations from the Appalachian-Ouachita, Wyoming or Superior regions. Based on U-Pb dating results, we will carry out (U-Th)/He dating on selected zircons to reveal the detailed exhumation histories of the sediment source regions. Using the dual criteria of DZ crystallization age (U-Pb) and cooling age (U-Th/He) to constrain provenance will enable us to generate rigorous reconstructions of the lower Miocene depositional systems from source terrane to deep-water sink for this key transitional period in geologic history.

xu, J.

2013-12-01

294

The late Miocene 'paradox' of the CO2 climate sensitivity (Invited)  

NASA Astrophysics Data System (ADS)

Ancient climates provide opportunities for studying the impact of CO2 change on global temperatures. While advances in CO2-reconstruction techniques are yielding a clearer picture of the Cenozoic history of CO2 (Beerling and Royer, 2011), the late Miocene (~12-5 Ma) remains enigmatic. For example, recent sea-surface temperature reconstructions from 12-5 Ma have shown that mid-latitude and equatorial regions of the Pacific cooled 6°C (LaRiviere et al., 2012) and 2°C (Zhang et al., 2013), respectively. This cooling trend was probably initiated at the mid-Miocene climate transition (14 Ma), and continued into the Plio-Pleistocene. However, existing compilation of late Miocene - Pliocene CO2 records show little variability, with some indicating a rise in CO2 concurrent with global cooling. Here we present four continuous alkenone-based CO2 records using Pacific sediment samples (ODP Sites 769, 806, 850 and 1143), from late Miocene to Pliocene. Compound-specific carbon isotope measurements show a broad decrease in alkenone ?13C values in all four sites, suggesting increasing pCO2 levels in the late Miocene. Decreasing ocean temperature and increasing pCO2 in the late Miocene appears to challenge a leading climatic role for CO2 during this time. Alternatively, alkenone-CO2 estimates are flawed in the late Miocene because factors other than CO2, such as algal growth rate, cell geometry, and carbon-fixation pathways, can influence carbon isotopic fractionation during algae growth. We explore the uncertainty of the alkenone-CO2 methodology and assess the potential influence that non-CO2 variables have in producing spurious CO2 estimates and trends. Beerling, D.J., Royer, D.L., 2011. Convergent Cenozoic CO2 history. Nat. Geosci. 4, 418-420. LaRiviere, J.P., Ravelo, A.C., Crimmins, A., Dekens, P.S., Ford, H.L., Lyle, M., Wara, M.W., 2012. Late Miocene decoupling of oceanic warmth and atmospheric carbon dioxide forcing. Nature 486, 97-100. Zhang, Y.G., Pagani, M., Liu, Z., 2013. Temperature evolution of the equatorial Pacific since late Miocene and the ancient El Nino. In Preperation.

Zhang, Y.; Pagani, M.

2013-12-01

295

Global cooling in the late Miocene- a precursor to northern hemisphere glaciation  

NASA Astrophysics Data System (ADS)

Very large changes in terrestrial environments, floras, and faunas occurred in late Miocene (10-6 Ma) time. However, marine stable isotopes (?18O, ?13C) do not register signs of accelerated global change. We present here alkenone-based evidence that ocean temperatures from 10 mid-latitude and high latitude locations show coherent and large cooling in late Miocene time. Cooling probably began at ~14 Ma, coincident with the final 'refrigeration' of Antarctica, was clearly well underway by 10 Ma and intensified between ~8 to 6 Ma. The cooling can be reconciled with marine oxygen isotopic data if it involved large sea surface changes but did not reach the threshold of significant continental ice buildup in the northern hemisphere. In magnitude and intensity, the global late Miocene ocean temperature drop, however, dwarfs the better-known latest Pliocene-Pleistocene evolution of climate over the Northern Hemisphere ice ages. It was accompanied by aridification on land and the appearance of ephemeral Arctic sea ice and/or small scale glaciations of the northern hemisphere in latest Miocene and early Pliocene time. It is hard to find a mechanism other than a strong late Miocene reduction in atmospheric CO2 levels as originally suggested by Cerling and colleagues (1993) to explain the ensemble of marine and terrestrial data.

Herbert, T.; Tzanova, A.; Lawrence, K. T.; Kelly, C.; Peterson, L.

2013-12-01

296

Molluscan evidence for early middle Miocene marine glaciation in southern Alaska  

USGS Publications Warehouse

Profound cooling of Miocene marine climates in southern Alaska culminated in early middle Miocene coastal marine glaciation in the northeastern Gulf of Alaska. This climatic change resulted from interaction of the Yakutat terrane with southern Alaska beginning in late Oligocene time. The ensuing extreme uplift of the coastal Chugach and St. Elias Mountains resulted in progressive regional cooling that culminated in coastal marine glaciation beginning in the early middle Miocene (15-16 Ma) and continuing to the present. The counterclockwise flow of surface water from the frigid northeastern Gulf of Alaska resulted in a cold-temperate shallow-marine environment in the western Gulf of Alaska, as it does today. Ironically, dating of Gulf of Alaska marine glaciation as early middle Miocene is strongly reinforced by the presence of a few tropical and subtropical mollusks in western Gulf of Alaska faunas. Shallow-marine waters throughout the Gulf of Alaska were cold-temperate to cold in the early middle Miocene, when the world ocean was undergoing peak Neogene warming. -Author

Marincovich, L., Jr.

1990-01-01

297

A fish assemblage from an early Miocene horizon from Jabal Zaltan, Libya  

NASA Astrophysics Data System (ADS)

Recent excavations and prospecting in the early to middle Miocene deposits of the Maradah Formation in Jabal Zaltan, Libya, yielded a diverse fish assemblage coming from an early Miocene locality. The material described here includes more than 18 marine and freshwater taxa most of which were previously unreported from the area. Jabal Zaltan is one of the very few early Miocene Afroarabian fossil sites that produced such a diverse fish sample. Therefore, the fossils described here provide a unique insight into the composition of the early Miocene fish faunas from the northern African coast; a critical time period for faunas of the continent, as contact with Eurasia ended 100 million years of African isolation. In addition, the Jabal Zaltan fossils help consolidate the validity of Galeocerdo mayumbensis and extend its geographic range to include the Tethys. The Maradah deposits also host the first occurrences of two genera (Pteromylaeus, Distichodus) in the fossil record. The fish finds support the presumed depositional environment that of tropical shallow estuarine to deltaic conditions, and the freshwater fishes document the presence of a modern-type Nilosudanian fauna containing elements with both African and Asian affinities. The Jabal Zaltan ichthyofauna, with its diversity of taxa, has the potential to become a key reference fauna for future studies of early Miocene African fishes.

Argyriou, Thodoris; Cook, Todd D.; Muftah, Ahmed M.; Pavlakis, Paris; Boaz, Noel T.; Murray, Alison M.

2015-02-01

298

Strong winter monsoon wind causes surface cooling over India and China in the Late Miocene  

NASA Astrophysics Data System (ADS)

Modern Asian winter monsoon characterised by the strong northwesterly wind in East Asia and northeasterly wind in South Asia, has a great impact on the surface temperature of the Asian continent. Its outbreak can result in significant cooling of the monsoon region. However, it is still unclear whether such an impact existed and is detectable in the deep past. In this study, we use temperature reconstructions from plant and mammal fossil data together with climate model results to examine the co-evolution of surface temperature and winter monsoon in the Late Miocene (11-5 Ma), when a significant change of the Asian monsoon system occurred. We find that a stronger-than-present winter monsoon wind might have existed in the Late Miocene due to the lower Asian orography, particularly the northern Tibetan Plateau and the mountains north of it. This can lead to a pronounced cooling in southern China and northern India, which counteracts the generally warmer conditions in the Late Miocene compared to present. The Late Miocene strong winter monsoon was characterised by a marked westerly component and primarily caused by a pressure anomaly between the Tibetan Plateau and Northern Eurasia, rather than by the gradient between the Siberian High and the Aleutian Low. As a result, the close association of surface temperature with winter monsoon strength on inter-annual scale as observed at present may not have established in the Late Miocene.

Tang, H.; Eronen, J. T.; Kaakinen, A.; Utescher, T.; Ahrens, B.; Fortelius, M.

2015-01-01

299

Miocene-Pliocene transition in the southern Cyprus basins: The sedimentary expression of regional tectonic events  

SciTech Connect

In the southern part of Cyprus, a Maastrichtian-Pleistocene sedimentary area fringes Troodos Mountain, a fragment of an ancient crust. During the Neogene, three basins formed in this area: Polemi, Pissouri, and Psematismenos. A deep marine condition has prevailed since the Maastrichtian. During the Paleocene and early Miocene, the sea gradually become shallower until the Messinian, where the most spectacular sedimentary event concerns the deposition of evaporites contemporaneous with other Mediterranean evaporites. Some sedimentary phenomena express the tectonic instability during the upper Miocene. A well-known tectonic event affecting the east Mediterranean region generally referred to as the Miocene-Pliocene phase occurs at the Miocene-Pliocene limit. Recent sedimentological studies indicate this event is in fact complex. The Tortonian-lower Pliocene period is marked by a constraint involving an N20 distension in the Polemi and Pissouri basins and an N100 distension in the Psematismenos basin. Sedimentologic studies have demonstrated three tectonic pulsations during the Messinian prior to the Pliocene transgression. These are expressed by two episodes of seismic brecciation and a paleoemersion indicated by paleosols and detrital discharges. These phenomena suggest brief tectonic instability during the Messinian. Microtectonic studies reveal that the main change in tectonic constraint does not coincide with the Miocene-Pliocene contact but occurs at the top of the lower Pliocene.

Orzag-Sperber, F.; Rouchy, J.M. (Universite Paris XI, Orsay (France))

1988-08-01

300

Early Miocene Antarctic glacial history: new insights from heavy mineral analysis from ANDRILL AND-2A drill core sediments  

NASA Astrophysics Data System (ADS)

The present study deals with heavy mineral analysis of late Early Miocene marine sediments recovered in the McMurdo Sound region (Ross Sea, Antarctica) during the ANDRILL—SMS Project in 2007. The main objective is to investigate how heavy mineral assemblages reflect different source rocks and hence different provenance areas. These data contribute to a better understanding of East Antarctica ice dynamics in the Ross Sea sector during the Early Miocene (17.6-20.2 Ma), a time of long-term global warming and sea level rise. The AND-2A drill core recovered several stratigraphic intervals that span from Early Miocene to Pleistocene and it collected a variety of terrigenous lithologies. The heavy mineral assemblages of the lower 650-m-thick sedimentary succession were analyzed through SEM observations and SEM-EDS microanalyses on heavy mineral grains. The heavy mineral analysis shows that the sediments are a mix of detritus dominated by McMurdo Volcanic Group sources most likely located in the present-day Mount Morning area (Proto-Mount Morning) with minor contribution from Transantarctic Mountains source rocks located west of the drill site. The heavy mineral assemblages in Interval 1 indicate that between 20.2 and 20.1 Ma, the grounding line of the ice sheet advanced to a position near the present-day Mount Morning volcanic center. During deposition of Interval 2 (20.1-19.3 Ma), the ice sheet most likely experienced a dynamic behavior with interval of ice advance alternating with periods of ice retreat, while Interval 3 (19.3-18.7 Ma) records further retreat to open water conditions. A dynamic behavior is noted in Interval 4 (18.7-17.6 Ma) with a decreasing contribution of materials derived from the basalts of the Mount Morning volcanic center located to the south of the drill site and a consequent increasing contribution of materials derived from the Transantarctic Mountains to the west of the drill site.

Iacoviello, Francesco; Giorgetti, Giovanna; Turbanti Memmi, Isabella; Passchier, Sandra

2014-12-01

301

A new species of Shaanxispira (Bovidae, Artiodactyla) from the upper Miocene of China.  

PubMed

A new species of the bovid Shaanxispira, from the upper Miocene deposits of the Linxia Basin, Gansu Province, China, is described here. Shaanxispira is endemic to Northern China and was previously known only from the Lantian area, Shaanxi Province, by two species, S. chowi and S. baheensis. The new species, S. linxiaensis nov. sp., is of early Bahean in age, slightly older than the species from the Lantian area. The horn-cores of the new species are more derived, with large wing-shaped antero-medial keels, suggesting the occurrence of a different lineage of Shaanxispira in the Linxia Basin. Although Shaanxispira has homonymously twisted horn-cores, it is not closely related to other late Miocene bovids with homonymously twisted horn-cores, like Oioceros and Samotragus. Its phylogenetic status is still in debate, but might be more closely related to the late Miocene "ovibovines."  PMID:24870338

Shi, Qinqin; He, Wen; Chen, Shanqin

2014-01-01

302

Late Miocene Mediterranean desiccation: topography and significance of the `Salinity Crisis' erosion surface on-land in  

E-print Network

Discussion Late Miocene Mediterranean desiccation: topography and significance of the `Salinity in well-exposed on-land sections at Sorbas, Almeri´a, near the western end of the Mediterranean, 1991), is of deep-desicca- tion and reflooding of the Mediterranean near the close of the Miocene

Utrecht, Universiteit

303

Paleobiogeography of Miocene Equinae of North America: A phylogenetic biogeographic analysis of the relative roles of climate, vicariance, and dispersal  

E-print Network

Paleobiogeography of Miocene Equinae of North America: A phylogenetic biogeographic analysis underwent a major radiation during the Miocene in North America, diversifying from one species, Parahippus in North America during this time. However, the relationship between climate change and speciation has

Barnosky, Anthony D.

304

A SKULL OF ANCYLOTHERIUM (CHALICOTHERIIDAE, MAMMALIA) FROM THE LATE MIOCENE OF THERMOPIGI (SERRES, N.GREECE), AND THE RELATIONSHIPS  

E-print Network

1 A SKULL OF ANCYLOTHERIUM (CHALICOTHERIIDAE, MAMMALIA) FROM THE LATE MIOCENE OF THERMOPIGI (SERRES has yielded a well- preserved skull of Ancylotherium pentelicum, among a rich collection of late Miocene mammals. It is the most complete Ancylotherium skull ever reported, and lack of crushing makes

Paris-Sud XI, Université de

305

A new early species of the aquatic sloth Thalassocnus (Mammalia, Xenarthra) from the Late Miocene of Peru  

Microsoft Academic Search

Thalassocnus antiquus, sp. nov., is a marine nothrothere from the late Miocene Aguada de Lomas vertebrate horizon (ca. 7 to 8 Ma) of the Pisco Formation in the Sacaco area of the southern coast of Peru. It is similar to the slightly younger latest Miocene Thalassocnus natans, but smaller and distinctly more gracile. The sloping morphology of the lateral border

Christian De Muizon; H. Gregory Mcdonald; Rodolfo Salas; Mario Urbina

2003-01-01

306

Partial record of a Miocene geomagnetic field excursion: Paleomagnetic data from the Paiute Ridge volcanic center, southern Nevada  

SciTech Connect

In the Palute Ridge area, northern Halfpint Range, a complex system of late Miocene (about 8.5 Ma) intrusive and extrusive alkaline mafic rocks crops out over an area of about 25km[sup 2]. Post-magmatic faulting and erosion have resulted in excellent exposure of this sub-volcanic center, allowing for a detailed study of mechanisms and timing of magma emplacement. Paleomagnetic data have been obtained from over 50 sites in mafic rocks, and host ash-flow tuffs and carbonate strata, to better understand the duration of magmatic activity. Magnetizations, isolated in progressive alternating field and thermal demagnetization, for most of the sites at Palute Ridge deviate significantly from expected directions for a time-averaged late Miocene field. Demagnetization data show that there are two types of sample behavior. First, samples with close to expected reverse polarity directions (e.g., the chilled margin of a sill, D=209.2, l=[minus]36.4, [alpha]95=13.2, N=5, k=34.8). Second, and far more common, are samples giving magnetizations of southwest to northwest declination, with both shallow to moderate positive and negative inclination. Within this second grouping are several sites, including syenite pods which differentiated in situ from a large lopolith, having mean declinations that are due west and of shallow inclination. Contact tests performed at several sites are positive and show a clear correlation between sample position and isolated remanence direction. The authors preferred interpretation of the anomalously directed magnetization is that these rocks acquired a TRM during either a high amplitude excursion, or the transitional portion of a field reversal. Thermal models based on larger intrusions [+-] 10m thick at Paiute Ridge indicate that the magmas could cool through estimated magnetization blocking temperatures within weeks or months of emplacement.

Ratcliff, C.D.; Geissman, J.W.; Perry, F.V. (Univ. of New Mexico, Albuquerque, NM (United States)); Crowe, B.M. (Los Alamos National Lab., Las Vegas, NV (United States))

1993-04-01

307

Miocene and Pliocene dominated diversification of the lichen-forming fungal genus Melanohalea (Parmeliaceae, Ascomycota) and Pleistocene population expansions  

PubMed Central

Background Factors promoting diversification in lichen symbioses remain largely unexplored. While Pleistocene events have been important for driving diversification and affecting distributions in many groups, recent estimates suggest that major radiations within some genera in the largest clade of macrolichens (Parmeliaceae, Ascomycota) vastly predate the Pleistocene. To better understand the temporal placement and sequence of diversification events in lichens, we estimated divergence times in a common lichen-forming fungal genus, Melanohalea, in the Northern Hemisphere. Divergence times were estimated using both concatenated gene tree and coalescent-based multilocus species tree approaches to assess the temporal context of major radiation events within Melanohalea. In order to complement our understanding of processes impacting genetic differentiation, we also evaluated the effects of Pleistocene glacial cycles on population demographics of distinct Melanohalea lineages, differing in reproductive strategies. Results We found that divergence estimates, from both concatenated gene tree and coalescent-based multilocus species tree approaches, suggest that diversification within Melanohalea occurred predominantly during the Miocene and Pliocene, although estimated of divergence times differed by up to 8.3 million years between the two methods. These results indicate that, in some cases, taxonomically diagnostic characters may be maintained among divergent lineages for millions of years. In other cases, similar phenotypic characters among non-sister taxa, including reproductive strategies, suggest the potential for convergent evolution due to similar selective pressures among distinct lineages. Our analyses provide evidence of population expansions predating the last glacial maximum in the sampled lineages. These results suggest that Pleistocene glaciations were not inherently unfavorable or restrictive for some Melanohalea species, albeit with apparently different demographic histories between sexually and vegetatively reproducing lineages. Conclusions Our results contribute to the understanding of how major changes during the Miocene and Pliocene have been important in promoting diversification within common lichen-forming fungi in the northern Hemisphere. Additionally, we provide evidence that glacial oscillations have influenced current population structure of broadly distributed lichenized fungal species throughout the Holarctic. PMID:22963132

2012-01-01

308

A giant termite from the Late Miocene of Styria, Austria (Isoptera)  

NASA Astrophysics Data System (ADS)

A giant termite is described and figured from the Late Miocene of the Styrian Basin in southeastern Austria. Gyatermes styriensis gen. n. et sp. n. is represented by a relatively complete forewing, with basal scale. The fossil approximates in size the largest of all termites today and is the largest fossil termite on record. The presence of this species in the Late Miocene fauna of Europe indicates that climatic conditions were appropriate for the persistence of species and colonies requiring relatively stable, warm conditions. The genus is primitive in overall features but shares some similarity with the dampwood termites.

Engel, Michael S.; Gross, Martin

2009-02-01

309

Stratigraphical investigations on a new Miocene fossil-bearing sequence in Central Inner Mongolia, China  

NASA Astrophysics Data System (ADS)

Central Inner Mongolia has been an area of great paleontological interest since the beginning of the 20th century. Although the area has produced numerous diverse collections of Miocene faunas, fossil records from the early Miocene of Inner Mongolia are relatively rare. The localities occur mainly as scattered faunal horizons and their stratigraphy is challenging owing to lack of continuous vertical exposures. Consequently, most age estimations of these Miocene sites are based on paleontological evidence alone, with very few sites having been dated independently based on paleomagnetics. The Damiao site in Siziwang Qi, Inner Mongolia, was discovered in 2006, and during the following four years extensive field activities were undertaken. The focus was on paleontological studies and on the stratigraphy of the Neogene sediments. The field survey led to the recovery of approximately 30 new fossiliferous localities, which have produced a rich mammalian fauna, including pliopithecid remains. The bulk of the vertebrate fossils and localities have been recovered from three main fossil horizons. We have interpreted the Damiao sequence as the remains of a fluvio-lacustrine system comprising channels, subaerially exposed floodplains and ephemeral/marginal lacustrine environments. This study presents the litho- and magnetostratigraphy of the Damiao area and provides age estimations for the important fossil-bearing localities. The two local stratigraphic sections measured and sampled for paleomagnetic analysis coincide with important vertebrate fossil localities. The western section is about 30 m thick and includes fossil locality DM16 while the eastern section spans up 40 m and comprises localities DM01 and DM02. The paleomagnetic results and faunal evidence suggest a correlation in the magnetozones C6Ar through C5r with an age range of ca 21 to 11 Ma. The interval of reversed polarity at the base of the section (C6Ar) coincides with fossil locality DM16. The pliopithecid locality DM01 represents late middle Miocene and has an age estimate of about 12 Ma while the locality DM02 represents earliest late Miocene with an age estimate of about 11.6- 11.7 Ma. Our magnetostratigraphic results confirm that the Damiao strata constitute one of the most continuous sequences in Inner Mongolia with early, middle and late Miocene fossil faunas in stratigraphic superposition. The results also provide constraints on the paleoenvironmenal evolution and bioevents of the area. The occurrence of pliopithecid primates in the middle Miocene of Inner Mongolia suggests relatively humid habitats and challenges the scenarios suggesting arid and highly seasonal conditions for Central Asia since Early Miocene.

Kaakinen, Anu; Aziz, Hayfaa Abdul; Passey, Benjamin H.; Zhang, Zhaoqun; Liu, Liping; Krijgsman, Wout; Fortelius, Mikael

2014-05-01

310

Equatorius: a new hominoid genus from the Middle Miocene of Kenya.  

PubMed

A partial hominoid skeleton just older than 15 million years from sediments in the Tugen Hills of north central Kenya mandates a revision of the hominoid genus Kenyapithecus, a possible early member of the great ape-human clade. The Tugen Hills specimen represents a new genus, which also incorporates all material previously referable to Kenyapithecus africanus. The new taxon is derived with respect to earlier Miocene hominoids but is primitive with respect to the younger species Kenyapithecus wickeri and therefore is a late member of the stem hominoid radiation in the East African Miocene. PMID:10464093

Ward, S; Brown, B; Hill, A; Kelley, J; Downs, W

1999-08-27

311

Diagenetic gypsum related to sulfur deposits in evaporites (Libros Gypsum, Miocene, NE Spain)  

NASA Astrophysics Data System (ADS)

The Libros Gypsum is the thickest evaporite unit of the Miocene infill of the Teruel Basin in NE Spain. During the deposition of this unit, intense bacterial sulfate-reducing (BSR) activity in the lake depocenter generated a native sulfur deposit. Diagenetic gypsum resulted from subsequent sulfur oxidation. The different processes involved in these transformations were first investigated by Anadón et al. (1992). The present paper is concerned with this diagenetic gypsum from the stratigraphic, petrographic, isotopic and genetic points of view. Diagenetic gypsum occurs mainly as continuous or discontinuous layers, individual levels or lenses, irregular masses, nodules and micronodules, and veins. Its main textures are coarse-crystalline anhedral and fine-grained (alabastrine), both of which can replace any former lithology (carbonate, gypsum, and sulfur). The following sequence of processes and mineral/textural transformations is deduced: primary gypsum deposition — BSR and biodiagenetic carbonate/H 2S production — growth of native sulfur — growth of diagenetic gypsum — partial recrystallization of the diagenetic gypsum textures. The gypsification of the native sulfur generated two types of banded structures in the diagenetic gypsum: (1) concentric structures of centripetal growth, and (2) expansive, roughly concentric structures. In the first type, the gypsification operated from the outer boundaries towards the inner parts. In the second type, part of the carbonate hosting the sulfur was also gypsified (replaced/cemented). In the diagenetic gypsum, the ?34S values are in agreement with a native sulfur and H 2S provenance. The ?18O sulfate values, however, enable us to differentiate two main groups of values: one with positive values and the other with negative values. In the group of positive values, interstitial (evaporated) solutions participated in the sulfur oxidation; this process presumably occurred in a first oxidation stage during shallow-to-deeper burial of the Libros Gypsum unit. In the group of negative values, however, only meteoric waters participated in the oxidation, which presumably occurred in a second oxidation stage during the final exhumation of the unit. A third group of values is characterized by very high sulfur and oxygen values, suggesting that BSR residual solutions also participated in the oxidation processes locally. During the two oxidation stages, both the textural characteristics and the isotopic composition of the diagenetic gypsum indicate that gypsification operated as a multistadic process.

Ortí, Federico; Rosell, Laura; Anadón, Pere

2010-07-01

312

The Miocene Sommières basin, SE France: Bioclastic carbonates in a tide-dominated depositional system  

NASA Astrophysics Data System (ADS)

The Miocene Sommières Basin in SE France is a semi-enclosed depression that was connected to the Mediterranean Sea by a flooded paleo-incised valley and then filled by a suite of sediments comprising carbonate grains coming from temperate factories that were largely deposited in tidal-dominated paleoenvironments. The strata are partitioned into two sequences that reflect repeated flooding of the incised valley system, one of several similar situations in this region of France. The carbonate grains are mostly bioclasts, namely from barnacles, bryozoans, coralline algae (encrusting, branching, and rhodoliths), echinoids, and benthic foraminifers (large and small) with ostracods, sponge spicules and planktic foraminifers prominent in muddy facies. Particles were produced by shallow water carbonate factories on hard substrates (valley walls in particular), associated with subaqueous dunes, and in deeper water basinal settings. Each depositional sequence is underlain by an eroded and bored hard surface that is progressively overlain by TST subaqueous tidal dunes or storm deposits that grade up, in one case, into HST marls (the HST of the upper sequence has been removed by erosion). The lower sequence is ebb tide dominated whereas the upper sequence is flood tide dominated. The succession is interpreted to represent a TST whose tidal currents were focused by the narrow valley and a HST that reflected flooding of the overbanks. This stratigraphic and depositional motif is comparable to that in other spatially separated Neogene paleovalleys that are filled with tide-dominated clastic carbonates in the region. Together with other recently documented similar systems, these limestones constitute an important new group of carbonate sand bodies in the carbonate depositional realm.

Reynaud, Jean-Yves; James, Noël P.

2012-12-01

313

High-resolution record of Early to Middle Miocene climate variability from Site 1195, Marion Plateau, NE Queensland margin  

NASA Astrophysics Data System (ADS)

Constraining and quantifying eustatic variations has been a priority for stratigraphers since the publication of the first global sea level curves by the Exxon research group in the late 1970s. Quantifying the glacio-eustatic component of sea level signals has become a greater focus as more recent work has demonstrated that far-field effects like ice-sheet gravitation and isostasy imprint on the "true" eustatic signal of waxing and waning ice sheets so that coeval signals from disparate sites may show significantly different local sea level variations. To this end, the Miocene sediments on the Marion Plateau, a drowned carbonate platform on the Queensland margin of Australia, were drilled by ODP Leg 194 to provide an independent, southern hemisphere test of the sea level record of the New Jersey Margin of North America, the most complete and oft-cited record of Cenozoic sea level variability. A high-resolution record is critical to compare sea level variations across hemispheres. Natural Gamma Ray (NGR) logs of core holes can provide a complete, high-resolution record independent of any problems with core recovery or sampling interval. We here present a NGR record of ODP Site 1195 tied to recently completed nannofossil assemblage data, planktic/benthic foraminiferal ratios, sedimentary particle counts, and benthic foraminifera stable isotopes. Peaks in glauconite and clay content correspond to peaks in NGR. The largest of these peaks correspond to sequence boundaries (lowstands), as glauconite accumulates during periods of low sedimentation along this carbonate-dominated margin. These sequence boundaries, in turn, are each associated with marine oxygen isotope events ("Mi Events") and correlate to sequences on the New Jersey margin, the Gulf of Papua, Great Australian Bight, and McMurdo Sound, indicating that these sequences are eustatically controlled. Although sedimentary particle counts only show strong peaks of glauconite at sequence boundaries, the NGR record shows long-period, low-amplitude variations in NGR between 20 and 18 Ma, a time corresponding to a pre-platform muddy ramp, short-period, high-amplitude variations between 18 and 14.8 Ma, a period of higher sea levels during the Miocene Climatic Optimum (MCO) and a dramatic spike corresponding to Mi3a at 14.8 Ma during the Middle Miocene Climate Transition (MMCT) followed by a slow decrease in the amplitude and frequency of variation during subsequent Antarctic ice growth and the drowning of the Marion Plateau. The variations in the NGR profile correspond directly (at a higher resolution) to variations in the oxygen isotope record, allowing us to create a cyclostratigraphic record that reflects fluctuations in oxygen isotopes. Calcareous nannofossil populations respond to variations in surface water nutrient availability and temperature; these changes coincide with climatic events of the early Miocene, including the MCO, the MMCT and the stepwise formation of ice sheets on Antarctica (<13.6 Ma). Calcareous nannofossil data show evidence for significantly cooler surface water at the Marion Plateau coinciding with the end of the MCO.

Lowery, C.; Browning, E.; Leckie, R. M.; John, C. M.

2012-12-01

314

Dispersals of Hyoscyameae and Mandragoreae (Solanaceae) from the New World to Eurasia in the early Miocene and their biogeographic diversification within Eurasia.  

PubMed

The cosmopolitan Solanaceae contains 21 tribes and has the greatest diversity in South America. Hyoscyameae and Mandragoreae are the only tribes of this family distributed exclusively in Eurasia with two centers of diversity: the Mediterranean-Turanian (MT) region and the Tibetan Plateau (TP). In this study, we examined the origins and biogeographical diversifications of the two tribes based on the phylogenetic framework and chronogram inferred from a combined data set of six plastid DNA regions (the atpB gene, the ndhF gene, the rps16-trnK intergenic spacer, the rbcL gene, the trnC-psbM region and the psbA-trnH intergenic spacer) with two fossil calibration points. Our data suggest that Hyoscyameae and Mandragoreae each forms a monophyletic group independently derived from different New World lineages in the early Miocene. Phylogenetic relationships within both tribes are generally well resolved. All genera of Hyoscyameae are found to be monophyletic and they diversified in middle to late Miocene. At nearly the same time, Mandragoreae split into two clades, corresponding to the MT region and the TP region, respectively. Both the phylogenetic relationships and the estimated ages of Hyoscyameae and Mandragoreae support two independent dispersal events of their ancestors from the New World into Eurasia. After their arrivals in Eurasia, the two tribes diversified primarily in the MT region and in the TP region via multiple biogeographic processes including vicariance, dispersal, recolonization or being preserved as relicts, from the mid Miocene to the late Quaternary. PMID:20858548

Tu, Tieyao; Volis, Sergei; Dillon, Michael O; Sun, Hang; Wen, Jun

2010-12-01

315

A diverse ichnofauna from Eocene?Miocene rocks of the Makran Range (S.E. Iran)  

Microsoft Academic Search

A diverse assemblage of trace fossils has been collected from Lower Eocene to Upper Miocene strata during regional geological mapping of 75,000 km of the Makran Range of southeastern Iran. Almost all are excellently preserved and this allows detailed descriptions, which in some cases can be used as a basis for taxonomic revisions of much used but inadequately analysed ichnogenera.27

T. P. Crimes; G. J. H. McCall

1995-01-01

316

The giant bite of a new raptorial sperm whale from the Miocene epoch of Peru  

Microsoft Academic Search

The modern giant sperm whale Physeter macrocephalus, one of the largest known predators, preys upon cephalopods at great depths. Lacking a functional upper dentition, it relies on suction for catching its prey; in contrast, several smaller Miocene sperm whales (Physeteroidea) have been interpreted as raptorial (versus suction) feeders, analogous to the modern killer whale Orcinus orca. Whereas very large physeteroid

Olivier Lambert; Giovanni Bianucci; Klaas Post; Christian de Muizon; Rodolfo Salas-Gismondi; Mario Urbina; Jelle Reumer

2010-01-01

317

Pliocene and latest Miocene anisotropy of magnetic susceptibility (AMS) from the Wilkes Land margin (Invited)  

NASA Astrophysics Data System (ADS)

During IODP Expedition 318, Sites U1359 and U1361 were drilled on the continental rise offshore the Wilkes Subglacial Basin to reconstruct the stability of the East Antarctic Ice Sheet (EAIS) during Neogene warm periods, such as the late Miocene and the early Pliocene. As the drilled core contains a complex history of compaction, erosion (thus hiatuses), and likely artificial disturbances, identifying these is important for reconstructing paleoenvironments. Anisotropy of magnetic susceptibility (AMS) is sensitive to lithological changes and differential compaction. At both sites, highly anisotropic layers correspond with turbidite units, lithologic boundaries and hiatuses. In places, it appears that low anisotropy is controlled by the bioturbated units and high productivity layers. Here we present a detailed study of the relationships between sediment compaction, based on AMS fabric variations in sedimentary records, and magnetic mineralogy. A clear correlation can be found between the degree of anisotropy and moisture content and diatom abundance during the Pliocene, but this pattern breaks down in the late Miocene. There are also strong rock magnetic indications for changes in the sources of the magnetic minerals throughout the Miocene to Pliocene. Furthermore, a significant difference exists between magnetic minerals at Sites U1359 and U1361. We will use our AMS and rock magnetic study to 1) characterize sediment compaction with biological productivity, and 2) detect the source of magnetic mineralogy throughout the late Miocene to Pliocene at both sites.

Sugisaki, S.; Tauxe, L.; Iwai, M.; van de Flierdt, T.; Cook, C.; Jimenez, F. J.; Khim, B.; Patterson, M. 0; Mckay, R. M.; Passchier, S.; Roehl, U.; González, J. J.; Escutia, C.

2013-12-01

318

Revised Miocene and Pliocene diatom biostratigraphy of Upper Newport Bay, Newport Beach, California  

USGS Publications Warehouse

North Pacific diatom zones XXIII through IX of Schrader are recognizable in the middle Miocene to lower Pliocene stratigraphic section exposed around Upper Newport Bay in Newport Beach, California. Correlation with DSDP Site 173 and other stratigraphic sections in California allows the selection of diatom datums that are the most reliable for long-distance correlation. Individual diatom datums are proposed as markers for North Pacific diatom zones XXIII through IX. Correlations with DSDP Site 173 reveal a hiatus in the lower part of Core 15 that corresponds with a distinct lithologic and floral change in the core. Preliminary silicoflagellate data for the Upper Newport Bay stratigraphic section supports the diatom correlations. Correlation with calcareous nannofossil, radiolarian, and silicoflagellate zones at Upper Newport Bay and at DSDP Site 173 suggests that the boundary between North Pacific diatom zones XVII and XVI approximates the middle Miocene/upper Miocene boundary. The Miocene/Pliocene boundary is estimated to be in North Pacific diatom zone X. One new stratigraphically useful diatom species is described, Lithodesmium reynoldsii. ?? 1976.

Barron, J.A.

1976-01-01

319

Large Mammals from the late Miocene of orakyerler, ankiri, Turkey DENIS GERAADS  

E-print Network

Large Mammals from the late Miocene of Ã?orakyerler, Ã?ankiri, Turkey DENIS GERAADS UPR 2147 CNRS, 44 account of the large mammal fauna from the hominid-bearing locality of Ã?orakyerler near Ã?ankiri, Turkey assigned it to the Vallesian on the basis of its large mammal fauna, which included, according

Boyer, Edmond

320

Mid-Miocene cooling and the extinction of tundra in continental Antarctica  

E-print Network

Mid-Miocene cooling and the extinction of tundra in continental Antarctica Adam R. Lewisa of a tundra community that inhabited the mountains before stepped cooling that first brought a full polar of this global climate transition. climate change tundra biota Dry Valleys diatoms ostracods The Earth's climate

Marchant, David R.

321

Iron oxide mineralogy in late Miocene red beds from La Gloria, Spain: rock-magnetic,  

E-print Network

Iron oxide mineralogy in late Miocene red beds from La Gloria, Spain: rock-magnetic, voltammetric March 2002; accepted 20 January 2003 Abstract Free ferric oxides of a red bed series were analyzed constituents. Free Fe oxides occurred at a concentration of 0.3­2.1%, i.e. in the majority of the samples below

Utrecht, Universiteit

322

A remarkable new pygmy grasshopper (Orthoptera, Tetrigidae) in Miocene amber from the Dominican Republic  

PubMed Central

Abstract A new genus and species of pygmy grasshopper (Orthoptera: Tetrigidae) is described from Early Miocene (Burdigalian) Dominican amber. Electrotettix attenboroughi Heads & Thomas, gen. et sp. n. is assigned to the subfamily Cladonotinae based on the deeply forked frontal costa, but is remarkable for the presence of tegmina and hind wings, hitherto unknown in this subfamily. PMID:25147472

Heads, Sam W.; Thomas, M. Jared; Wang, Yinan

2014-01-01

323

Lower Miocene Stratigraphy along the Panama Canal and Its Bearing on the Central American Peninsula  

Microsoft Academic Search

Before the formation of the Central American Isthmus, there was a Central American Peninsula. Here we show that southern Central America existed as a peninsula as early as 19 Ma, based on new lithostratigraphic, biostratigraphic and strontium chemostratigraphic analyses of the formations exposed along the Gaillard Cut of the Panama Canal. Land mammals found in the Miocene Cucaracha Formation have

Michael Xavier Kirby; Douglas S. Jones; Bruce J. MacFadden

2008-01-01

324

Evidence for sediment fan deposition on outer Texas shelf during Miocene eustatic sea level highstands  

SciTech Connect

Four types of data were reviewed in an attempt to clearly define the environments of deposition for reservoir sands in the Matagorda 668 field: well log curve shapes, seismic amplitude responses, micropaleontology, and thin section sedimentary petrology. All four lines of evidence support the interpretation that these lower Miocene sands were deposited as fan complexes.

Riese, W.C.; Olsen, R.S.; Rosen, R.N.

1988-02-01

325

Correlating Miocene sequences in onshore New Jersey boreholes (ODP Leg 150X) with global 18  

E-print Network

Correlating Miocene sequences in onshore New Jersey boreholes (ODP Leg 150X) with global 18 O Jersey 08855 and Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York 10964 Peter J. Sugarman New Jersey Geological Survey, CN 427, Trenton, New Jersey 08625 ABSTRACT Recent onshore

326

Correlation of offshore seismic profiles with onshore New Jersey Miocene sediments  

E-print Network

Correlation of offshore seismic profiles with onshore New Jersey Miocene sediments D.H. Monteverdea,b,*, K.G. Millerb,c , G.S. Mountainc a New Jersey Geological Survey, P.O. Box 427, Trenton, NJ 08625, USA-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA Abstract The New Jersey passive

327

Regional climate model experiments to investigate the Asian monsoon in the Late Miocene  

Microsoft Academic Search

The Late Miocene (11.6-5.3 Ma) is a crucial period in the history of the Asian monsoon. Significant changes in the Asian climate regime have been documented for this period, which saw the formation of the modern Asian monsoon system. However, the spatiotemporal structure of these changes is still ambiguous, and the associated mechanisms are debated. Here, we present a simulation

H. Tang; A. Micheels; J. Eronen; M. Fortelius

2011-01-01

328

Testing Miocene Remagnetization of Bey Dalari: Timing and Amount of Neogene Rotations in SW Turkey  

E-print Network

Testing Miocene Remagnetization of Bey Dalari: Timing and Amount of Neogene Rotations in SW Turkey Engineering, TR-06531 Ankara, Turkey Received 07 December 2009; revised typescript receipt 07 December 2009 of the Aegean orocline, located in SW Turkey. The current model for this orocline involves a 25

Utrecht, Universiteit

329

Mosaic of environments recorded by bryozoan faunas from the Middle Miocene of Hungary  

Microsoft Academic Search

The marine sediments of the Badenian (Middle Miocene) of Hungary (Pannonian Basin, Central Paratethys) are composed of abundant bryozoan skeletal grains. Seventy-one bulk samples collected at 18 localities (outcrops and boreholes) yielded a total number of 238 bryozoan species.In order to reconstruct the Badenian palaeoenvironments, the present study investigates the composition of this very diverse fauna using a combination of

Pierre Moissette; Alfréd Dulai; Gilles Escarguel; Miklós Kázmér; Pál Müller; Jean-Paul Saint Martin

2007-01-01

330

Recognition and correlation of the Kapitean Stage (Upper Miocene, New Zealand)  

Microsoft Academic Search

The salient features of New Zealand Upper Miocene and Lower Pliocene microfaunas are outlined, and criteria for recognising the Kapitean Stage are summarised. Paleoecological evidence suggests that the Kapitean Age was a time when seas were relatively shallow, that the shallowing took place in the latest part of the Tongaporutuan Age, and that deepening took place in the earliest part

J. P. Kennett

1967-01-01

331

Tsunami-induced conglomerates in Miocene upper bathyal deposits, Chita Peninsula, central Japan  

Microsoft Academic Search

The Tsubutegaura conglomeratic tsunamiites occur in the middle section of the Miocene storm-related sand-silt alternation system in the Chita Peninsula, central Japan. Deposition of the system in the upper bathyal environment in a bay and synsedimentary seismic activity has been elucidated by palaeontological, palaeogeographical and sedimentological studies. Two coupled units, each built up by a conglomerate layer with an overlying

Tsunemasa Shiki; Teiji Yamazaki

1996-01-01

332

Carbonate depositional environments and reservoir properties of the Miocene rocks, east Gulf of Suez, Egypt  

SciTech Connect

Miocene carbonate rocks in six surface sections on the eastern side of the Gulf of Suez were carefully studied in the field, petrographically examined, and mineralogically analyzed using SEM and x-ray microanalysis for all elements. In general, reservoir quality of the Miocene carbonates was poor because of original composition and texture. Three different types of porosity were distinguished in the studied Miocene carbonates: primary (intergranular and moldic), secondary (leached), and fracture. Much of the porosity in the Miocene reservoirs is secondary; however, sometimes this secondary porosity may be reduced by compaction and/or precipitation of evaporites in fractures and pores. The authors conclude that the primary porosity of the carbonate rocks in the reef complex was eliminated by lithification and cementation; only secondary porosity remained. This secondary porosity developed in all environments (supratidal, intertidal, and subtidal), but the best porosity developed in the subtidal facies. This high porosity occurs because the dolomites in the subtidal facies are coarser and free from anhydrite cement, whereas in supratidal and intertidal facies the dolomites are finer and their porosity is plugged by secondary anhydrite cement.

Bakarat, M.A.K.; Kholief, M.M.

1988-08-01

333

Fauna from a new lower Miocene locality west of Lake Turkana, Kenya  

Microsoft Academic Search

A new Lower Miocene locality at Locherangan in northwestern Kenya has yielded over 300 specimens representing at least 13 mammalian species. The faunal assemblage includes at least two hominoid species and an array of ungulate taxa that suggest the existence of a mixed habitat. The strata at Locherangan are 49.1 m of lacustrine clays and mudstones. Two tuffaceous units near

William Anyonge

1991-01-01

334

The Biomarker Properties and Comparisons of ?ahinali, Beypazari and Karapinar (Turkey) Coaly Plio-Miocene Depositions  

NASA Astrophysics Data System (ADS)

The distribution values of m/z 191 triterpane and m/z 217 sterane of coaly Plio-Miocene units determined by GC-MS were used to compare biomarker properties of ?ahinali, Beypazar? and Karap?nar areas located in Ayd?n, Ankara and Konya (Turkey) regions within this study. In the ?ahinali (Ayd?n) region the Miocene units consist of conglomerate, coal, clayey coal, sandstone, siltstone, claystone, clayey limestone and silicified limestone. Middle-Upper Miocene units of the Beypazar? (Ankara) Basin are represented by conglomerate, agglomerate, sandstone, siltstone, claystone, coal, bituminous shale, limestone, and tuff. The Pliocene Karap?nar (Konya) area of interest, which is characterized by sandstone, siltstone, claystone, mudstone, lake and river bed coal deposits. When all the biomarker values are considered, it can be concluded that the organic matter is not mature. In two areas - except ?ahinali - gammacerane is present indicating salinity. According to the C27, C28 ve C29 sterane distribution, it can be observed that the dominant organic matter is terrestrial based and accompanied by simple herbaceous and alg. The deposition conditions are seen to be anoxic even though some oxic depositions are found in areas. All the areas had oleananes indicating angiosperm presence. C29/C30 hophane ratio and decrease in C31-C35 peak height indicated detrial facies in all the areas. Key Words: Plio-Miocene, Coal, Biomarker, Turkey

Unal, Neslihan; Hokerek, Selin; Altunsoy, Mehmet; Ozcelik, Orhan; Yalcin Erik, Nazan

2014-05-01

335

Rifting, recurrent landsliding and Miocene structural reorganization on NW-Tenerife (Canary Islands)  

Microsoft Academic Search

We studied mechanisms of structural destabilization of ocean island flanks by considering the linkage between volcano construction and volcano destruction, exemplified by the composite Teno shield volcano on Tenerife (Canary Islands). During growth, Tenerife episodically experienced giant landslides, genetically associated with rifting and preferentially located between two arms of a three-armed rift system. The deeply eroded late Miocene Teno massif

T. Walter; H.-U. Schmincke

2002-01-01

336

Tectono-stratigraphic evolution of the continental Miocene basins in southern Anatolia  

NASA Astrophysics Data System (ADS)

The exposed portion of the Tauride fold-thrust belt in southern Turkey is flanked and overlain by Neogene sedimentary basins. To the south and on top of the high ranges, these basins are mainly marine, whereas previously poorly studied intra-montane basins dominated by continental deposits are exposed to the north. We have studied the stratigraphy and structure of these continental basins - the Alt?napa, Yalvaç and Ilg?n Basins. Their stratigraphy displays overall fining upward sequences of fluvio-lacustrine sediments, deposition of which interrupted by basin-wide unconformities; similar hiatuses seems to exist in each basin. The most prominent unconformity surface occurred during the Middle Miocene and corresponds to the timing of volcanic activity in the region. 40Ar/39Ar dating of the volcaniclastic samples from the Alt?napa and Ilg?n basins yielded 11.8-11.6 Ma ages. The main basin forming regional deformation phase was extensional and occurred during the Middle Miocene. The extension directions obtained from paleostress inversion techniques indicate multidirectional extension under vertical uniaxial stress which are compatible with the recent seismic activity and available focal mechanism solutions. The main basin-bounding faults, however, are constrained mainly N-S to NW-SE implying that they are reactivated structures. The Middle Miocene and onwards extensional history of these basins occurs behind and atop a thrust front along the Cyprus arc, extending towards the Antalya nappes and Aksu thrust in the heart of the Isparta angle. The synchrounous, curved pairs of thrust fronts associated with subduction and overriding plate extension suggests that the Cyprus subduction zone has been retreating relative to central Anatolia since, at least, the Middle Miocene time. In addition to extensional history of the region, these continental basins contain evidence for the post-Late Miocene differential uplift of the Taurides in southern Anatolia. All of these continental basins were above sea level during the Middle and Late Miocene and are now found at an elevation of 1 km. On the other hand, the upper Miocene marine deposits just south of the study area currently are at an elevation of ~2 km, and have therefore been uplifted at least 1 km more than the continental basins to the north. We conclude that the current high elevation of the Taurides is synchronous with, and at least in part related to late Neogene extension and vertical differential uplift, likely related to the dynamics of the Cyprian subduction zone.

Koç, Ayten; Kaymakci, Nuretdin; van Hinsbergen, Douwe J. J.; Kuiper, Klaudia F.; Vissers, Reinoud L. M.

2014-05-01

337

Correlation and zonation of miocene strata along the atlantic margin of North America using diatoms and silicoflagellates  

USGS Publications Warehouse

Six Atlantic Miocene siliceous microfossil zones are proposed based on onshore and offshore samples from the United States Atlantic Margin. Diatoms and silicoflagellates are used to establish the zones. These zones are from oldest to youngest: 1. Zone I Actinoptychus heliopelta Concurrent Range Zone - Early Miocene 2. Zone II Delphineis ovata Partial Range Zone - late Early to early Middle Miocene 3. Zone III Delphineis ovata/Delphineis penelliptica Concurrent Range Zone - early Middle Miocene 4. Zone IV Delphineis penelliptica Partial Range Zone - Middle Miocene 5. Zone V Delphineis penelliptica/Coscinodiscus plicatus Concurrent Range Zone - Middle Miocene 6. Zone VI Coscinodiscus plicatus Partial Range Zone - Middle Miocene. The six zones are easily traced along the Southern and Middle Atlantic Seaboard, but the older three are found for the most part between Cape Hatteras and New Jersey. There is some suggestion of sea-level change during Zone IV. Using rare planktonic diatoms that are index species from other regions and the zonal markers established in this study, correlation can be made with the Standard Foraminiferal Zones, the North Pacific Diatom Zones and with DSDP core 391A in the Blake-Bahama Basin. ?? 1978.

Abbott, W.H.

1978-01-01

338

Oligo-Miocene onset of exhumation of the Tien Shan: the role of the Talas-Fergana strike-slip fault  

NASA Astrophysics Data System (ADS)

The Talas-Fergana dextral strike-slip fault (TFF) in Central Asia is one of the world's most prominent strike-slip faults. Separating the Western and Central Tien Shan, the TFF forms a prominent feature in the mountainous topography. Geological knowledge about the Western Tien Shan is substantially less developed than the surrounding areas and it is an area where the Pamir indentation should play an important role in its geodynamic evolution. In this contribution we present new thermochronological data from the Kyrgyz Western Tien Shan and relate them to the evolution of the mountain belt. Apatite fission track samples from the northern Western Tien Shan (Talas and Shandalash ranges) show clustered reset Oligo-Miocene (22-29 Ma) ages. This first group of samples was collected less than 15 km away from TFF and shows the maximum amount of Cenozoic exhumation. In contrast, a vertical profile located in the Shandalash range but ~60 km away from the TFF exhibit partially reset, Eocene (30-43 Ma) ages, implying a smaller amount of exhumation along strike moving further away from the main strike-slip fault. The northernmost samples (Ugam range) also showed partially reset ages (37-51 Ma), showing that exhumation also decrease moving towards the Kazakh platform. In addition, the Oligo-Miocene episode is also recorded in the stratigraphic section of the adjacent Fergana basin by a change in the source area, detected using detrital zircon age populations. Several studies in the northern Central Tien Shan show a regional increase in the exhumation rate by the late Miocene (~10 Ma). Although our data come from similar latitudes within the Tien Shan we have little evidence to extrapolate this event to the Western Tien Shan. However, our results can be compared with the onset of exhumation of the southernmost basement involved thrusts in the Chinese South Tien Shan. Studies north of the Kashgar area determined the initiation of exhumation there to be around 25 Ma. Paleomagnetic studies along the TFF show opposite sense of rotation on either side of the strike-slip fault in the Cenozoic, but the timing of that motion is not well constrained. Both the Northern Tien Shan west of the TFF and the Southern Tien Shan east of the TFF show onset of exhumation at around the Oligo-Miocene boundary, despite being separated from each other by ~400 km. We explain this behavior by interpreting both set of ranges as horse-tails, kinematically-linked to the main strike-slip fault. Furthermore, we can conclude that the onset of Cenozoic slip along the TFF was at around the same time frame.

Bande, A.; Sobel, E. R.; Mikolaichuk, A.; Auxietre, J.; Munsch, H.

2012-12-01

339

Style and age of late Oligocene-early Miocene deformation in the southern Stillwater Range, west central Nevada: Paleomagnetism, geochronology, and field relations  

USGS Publications Warehouse

Paleomagnetic and geochronologic data combined with geologic mapping tightly restrict the timing and character of a late Oligocene to early Miocene episode of large magnitude extension in the southern Stillwater Range and adjacent regions of west central Nevada. The southern Stillwater Range was the site of an Oligocene to early Miocene volcanic center comprising (1) 28.3 to 24.3 Ma intracaldera ash flow tuffs, lava flows, and subjacent plutons associated with three calderas, (2) 24.8 to 20.7 Ma postcaldera silicic dikes and domes, and (3) unconformably overlying 15.3 to 13.0 Ma dacite to basalt lava flows, plugs, and dikes. The caldera-related tuffs, lava flows, and plutons were tilted 60°-70° either west or east during the initial period of Cenozoic deformation that accommodated over 100% extension. Directions of remanent magnetization obtained from these extrusive and intrusive, caldera-related rocks are strongly deflected from an expected Miocene direction in senses appropriate for their tilt. A mean direction for these rocks after tilt correction, however, suggests that they were also affected by a moderate (33.4° ± 11.8°) component of counterclockwise vertical axis rotation. Paleomagnetic data indicate that the episode of large tilting occurred during emplacement of 24.8 to 20.7 Ma postcaldera dikes and domes. In detail, an apparent decrease in rotation with decreasing age of individual, isotopically dated bodies of the postcaldera group indicates that most tilting occurred between 24.4 and 24.2 Ma. The onset of tilting immediately following after the final caldera eruptions suggests that the magmatism and deformation were linked. Deformation was not driven by magma buoyancy, however, because tilting equally affected the caldera systems of different ages, including their plutonic roots. It is more likely that regional extension was focused in the southern Stillwater Range due to magmatic warming and reduction of tensile strength of the brittle crust. Faults that accommodated deformation in the southern Stillwater Range initially dipped steeply and cut deeply to expose more than 9 km of crustal section. The exposed crustal sections are probably rotated blocks above an unexposed basal detachment that lay near the early Miocene brittle-ductile transition.

Hudson, Mark R.; John, David A.; Conrad, James E.; McKee, Edwin H.

2000-01-01

340

Style and age of late Oligocene-early Miocene deformation in the southern Stillwater Range, west central Nevada: Paleomagnetism, geochronology, and field relations  

NASA Astrophysics Data System (ADS)

Paleomagnetic and geochronologic data combined with geologic mapping tightly restrict the timing and character of a late Oligocene to early Miocene episode of large magnitude extension in the southern Stillwater Range and adjacent regions of west central Nevada. The southern Stillwater Range was the site of an Oligocene to early Miocene volcanic center comprising (1) 28.3 to 24.3 Ma intracaldera ash flow tuffs, lava flows, and subjacent plutons associated with three calderas, (2) 24.8 to 20.7 Ma postcaldera silicic dikes and domes, and (3) unconformably overlying 15.3 to 13.0 Ma dacite to basalt lava flows, plugs, and dikes. The caldera-related tuffs, lava flows, and plutons were tilted 60°-70° either west or east during the initial period of Cenozoic deformation that accommodated over 100% extension. Directions of remanent magnetization obtained from these extrusive and intrusive, caldera-related rocks are strongly deflected from an expected Miocene direction in senses appropriate for their tilt. A mean direction for these rocks after tilt correction, however, suggests that they were also affected by a moderate (33.4° ±11.8°) component of counterclockwise vertical axis rotation. Paleomagnetic data indicate that the episode of large tilting occurred during emplacement of 24.8 to 20.7 Ma postcaldera dikes and domes. In detail, an apparent decrease in rotation with decreasing age of individual, isotopically dated bodies of the postcaldera group indicates that most tilting occurred between 24.4 and 24.2 Ma. The onset of tilting immediately following after the final caldera eruptions suggests that the magmatism and deformation were linked. Deformation was not driven by magma buoyancy, however, because tilting equally affected the caldera systems of different ages, including their plutonic roots. It is more likely that regional extension was focused in the southern Stillwater Range due to magmatic warming and reduction of tensile strength of the brittle crust. Faults that accommodated deformation in the southern Stillwater Range initially dipped steeply and cut deeply to expose more than 9 km of crustal section. The exposed crustal sections are probably rotated blocks above an unexposed basal detachment that lay near the early Miocene brittle-ductile transition.

Hudson, Mark R.; John, David A.; Conrad, James E.; McKee, Edwin H.

2000-01-01

341

The giant bite of a new raptorial sperm whale from the Miocene epoch of Peru.  

PubMed

The modern giant sperm whale Physeter macrocephalus, one of the largest known predators, preys upon cephalopods at great depths. Lacking a functional upper dentition, it relies on suction for catching its prey; in contrast, several smaller Miocene sperm whales (Physeteroidea) have been interpreted as raptorial (versus suction) feeders, analogous to the modern killer whale Orcinus orca. Whereas very large physeteroid teeth have been discovered in various Miocene localities, associated diagnostic cranial remains have not been found so far. Here we report the discovery of a new giant sperm whale from the Middle Miocene of Peru (approximately 12-13 million years ago), Leviathan melvillei, described on the basis of a skull with teeth and mandible. With a 3-m-long head, very large upper and lower teeth (maximum diameter and length of 12 cm and greater than 36 cm, respectively), robust jaws and a temporal fossa considerably larger than in Physeter, this stem physeteroid represents one of the largest raptorial predators and, to our knowledge, the biggest tetrapod bite ever found. The appearance of gigantic raptorial sperm whales in the fossil record coincides with a phase of diversification and size-range increase of the baleen-bearing mysticetes in the Miocene. We propose that Leviathan fed mostly on high-energy content medium-size baleen whales. As a top predator, together with the contemporaneous giant shark Carcharocles megalodon, it probably had a profound impact on the structuring of Miocene marine communities. The development of a vast supracranial basin in Leviathan, extending on the rostrum as in Physeter, might indicate the presence of an enlarged spermaceti organ in the former that is not associated with deep diving or obligatory suction feeding. PMID:20596020

Lambert, Olivier; Bianucci, Giovanni; Post, Klaas; de Muizon, Christian; Salas-Gismondi, Rodolfo; Urbina, Mario; Reumer, Jelle

2010-07-01

342

A zircon study on Miocene silicic pyroclasts in the Bukkalja, Hungary  

NASA Astrophysics Data System (ADS)

During the Miocene, reapeted explosive eruptions of silicic magmas occurred in the Pannonian Basin,simultaneously with the main period of basin formation. The majority of the volcanic products are covered by post-Miocene sediments, the best study area in Hungary is the Bukkalja. Traditionally, the Miocene silicic piroklastic rocks of the Pannonian Basin have been devided into three horizonts (Lower-Middle-Upper Riolithe Complex) based on primary stratigraphic observations. Other studies point out that there are three horisonts based on the paleomagnetic data but several volcanic events based on radiometric ages (Marton &Pecskay, 1998.) Morphology of zircon mineral depends upon the temperatur and type of the magma (calc-alcaline, alcaline or peralcaline) it is crystallised from. This lead Pupin (1980) to introduce a methode to distinguish different granitic magmas, based on the morphology of their zicon population. We applied this method for silicic volcanic rocks in the Bukkalja area with an attempt to see similarities and/or differences among the previously distinguish Miocene pyroclastic horisonts. We applied our resultes taking into account recent resultes of Vavra and Klotzli. We focused on the bimodal samples wich has been already studied by cathodluminescence image. As a results of our study we can conclude the followings about Miocen silicic piroclasts in the Bükkalja: 1., The source of magma is the mantel with different magnitude crustal contamination. 2., Generally the samples from the "same horison" have different chemical characteristics, so we cannot say: there are three well defined complexes. 3., In some cases zircon morphology seems to be a good method to follow piroclast levels. 4., There are some samples with bimodal zircon population, wich means that the magma it is crystallised from has a higher alcaline component. 5., Using the Pupin method we can see examples for the solution of local stratigraphic problems. The preliminary results of zircon morphological study are supported by geochemical data.

Szabo, Zs.; Harangi, Sz.

2003-04-01

343

Paleogeographic and structural setting of Miocene strata in central western Nevada  

SciTech Connect

Late Cenozoic sedimentary rocks as old as 19 Ma are widely distributed in central western Nevada. They are greatly more abundant than older Cenozoic strata and are commonly interpreted to have formed in fault-bounded basins that mark the onset of widespread extension in the Basin and Range Province. Miocene strata are largely coeval with a magmatic arc that extended south southeast near the boundary of the Basin and Range and Sierra Nevada Provinces. This arc produced voluminous andesitic flows and lahars that locally interfinger with the Miocene strata. Miocene depositional basins apparently varied greatly in size. The largest that can be defined clearly is the Esmeralda Basin that was at least 65 km long and 45 km wide. Other basins may have been larger but are difficult to reconstruct; still other basins may be small and isolated, particularly within the magmatic arc. Lacustrine deposits and minor interfingering deltaic and distal fluvial units predominate; near-source, coarse alluvial-fan and megabreccia landslide deposits are locally conspicuous. coarse near-source deposits, particularly landslide deposits, are interpreted to be adjacent to basin-bounding normal faults. The Esmeralda, Coal Valley, and Gabbs Valley-Stewart Valley-Tonopah Basins are interpreted to be related to large-scale Miocene extension. Other basins may be (1) pull-apart structures related to strike-slip faults, (2) downdropped blocks in areas of cross-cutting normal and/or strike-slip faults related to changes in the extension direction or (3) grabens or half-grabens related to uniform extension. Younger Cenozoic basins, including present-day basins, overprint and cut across the Miocene basins.

Stewart, J.H. (Geological Survey, Menlo Park, CA (United States))

1993-04-01

344

Cementation in Oligo-Miocene non-tropical shelf limestones, Otway Basin, Australia  

NASA Astrophysics Data System (ADS)

The Oligocene to Miocene Heytesbury Group of the Otway Basin, southeastern Australia, is a non-tropical carbonate shelf succession. This subsurface stratigraphic succession consists of bioclastic grainstones to mudstones containing bryozoa, benthonic and planktonic foraminifera, echinoderms, brachiopods, and molluscs. The basal bryozoa-dominated Clifton Formation was deposited in relatively shallow waters. The overlying Gellibrand Marl, rich in planktonic foraminifera and bryozoa, formed under deep waters. The uppermost unit, benthonic foraminifera-dominated Port Campbell Limestone, was deposited in a moderately deep, middle shelf environment. Cementation is limited and includes: (1) scalenohedral calcite (non-luminescent to bright, Mn- and Fe-poor, in inter- and intraparticle porosity); (2) blocky equant calcite (dull, Mn- and Fe-rich, in interparticle porosity); (3) syntaxial calcite overgrowths on echinoderm particles (non/bright/dull-zoned); (4) euhedral dolomite (in the interparticle pore space of the Port Campbell Limestone); (5) bladed-prismatic calcite (ferroan, in planktonic foraminifera); (6) fibrous calcite (non-luminescent, in intraparticle porosity); and (7) glauconite and iron-oxides (only in intraparticle porosity). All CaCO 3 cements are low-Mg calcites (< 4 mol% MgCO 3). The cements observed in the Heytesbury Group appear to have formed in three successive diagenetic environments: (1) early shallow burial (early Fe- and Mn-poor, non-luminescent syntaxial overgrowths and non-luminescent scalenohedral calcite, under oxidising conditions); (2) late shallow burial (bright, more Mn-rich syntaxial overgrowth zone, i.e., more than the initial non-luminescent one, and bright scalenohedral calcite, under moderately reducing pore water conditions); and (3) moderate burial (ferroan, dull blocky calcite and dull syntaxial overgrowth zone, under reducing conditions). Pressure solution was the main cement-producing mechanism, although seawater and aragonite dissolution could account for the precipitation of the early non-luminescent cements. Scarcity of early interparticle cements may have been caused by the calcite-rich character of the original sediments. The ferroan dully luminescent blocky equant calcite and syntaxial overgrowths, typically interpreted to represent products of deep burial in ancient carbonate successions, are observed in the shallow-buried Port Campbell Limestone.

Nicolaides, Stelios

1995-02-01

345

Highly extended terrains, lateral segmentation of the substratum, and basin development: The middle-late Miocene Radicondoli Basin (inner northern Apennines, Italy)  

NASA Astrophysics Data System (ADS)

This paper deals with the evolution of sedimentary basins not delimited by normal faults, with a substratum characterized by an upward concave shape and with infilling sediments synclinally deformed. We describe the middle-late Miocene Radicondoli Basin, representing an example of such bowl-shaped basins. Its tectonic origin is controversial, being related both to compression and extension; these opposite interpretations bear significant consequences on the geodynamic context in which the inner northern Apennines developed during the middle-late Miocene. The results of our structural studies, carried out in the substratum and infilling sediments, indicate that the Radicondoli Basin is an example of a hanging wall basin developed in an extensional setting. Extensional tectonics determined the lateral segmentation of the substratum competent levels (i.e., Tuscan Nappe and Verrucano Group) and the consequent collapse of overlying less competent levels (i.e., the Ligurian units) with the formation of a bowl-shaped tectonic depression. Here, the syntectonic sediments (Serravallian-late Messinian) are deformed in a large syncline, characterized by minor gravity-driven folds, with vergences toward the depocenter and traces of their axial planes parallel to the basin margins. This paper highlights the role of the competence contrast during the postcollisional tectonic evolution and the influence of substratum lateral segmentation for the accommodation of syntectonic sediments.

Brogi, Andrea; Liotta, Domenico

2008-09-01

346

The occurrence of an abdominal fauna in an articulated tapir (Tapirus polkensis) from the Late Miocene Gray Fossil Site, Northeastern Tennessee.  

PubMed

The analysis of samples recovered from the abdominal area of an articulated tapir (Tapirus polkensis) from the Late Miocene (4.5-7 million BP) Gray Fossil Site (GFS) revealed a rich palyno-fauna comprised of about 94% egg/oocyst-like structures and 6% pollen and other palynomorphs. In addition, a group of 6 hickory nuts (Carya) was recovered from the same area suggesting that the samples represent the abdominal contents. The analysis of a sample from immediately outside the tapir produced a sample with 98% pollen and less than 0.5% egg/oocyst-like structures. The size, shape, and general morphology of egg/oocyst-like structures were analyzed with light and scanning electron microscopy and were compared to a variety of intestinal parasites found in extant ungulates, and the Perissodactyla in particular. We also compared fossil structures to the numbers and kind of intestinal parasites recovered from fecal samples from the Baird's tapir (T. bairdii) in Costa Rica and from samples collected from the lowland tapir (T. terrestris) from Ecuador to assess their similarity to our fossil sample. Based on these data, we discuss what role parasites may have played in the biology of T. polkensis during the Late Miocene-Early Pliocene. PMID:23586562

McConnell, Shannon M; Zavada, Michael S

2013-03-01

347

The antiquity of riverine adaptations in Iniidae (Cetacea, Odontoceti) documented by a humerus from the late Miocene of the Ituzaingó Formation, Argentina.  

PubMed

"River dolphins" are a paraphyletic group of toothed whales (Odontoceti) that represent independent secondary invasions of freshwater habitats. Different "river dolphin" lineages display suites of convergent morphological specializations that commonly reflect adaptations to riverine and freshwater environments, such as longirostry, reduced orbits, and wide, paddle-like flippers. One lineage, the Iniidae, is presently endemic to South America, and includes several extinct Neogene taxa along with their sole extant genus, Inia (the Amazon River dolphin). We report here a humerus recovered from the late Miocene deposits of the Ituzaingó Formation in the Paraná Basin of Argentina. The specimen exhibits diagnostic features of the family Iniidae, including a scapular-sternal joint of the humerus, which is a unique anatomical connection among mammals. This joint permits enhanced parasagittal adduction of the flipper as a control surface, relative to other odontocetes, providing Inia with a high degree of maneuverability in its structurally complex and heterogenous riverine habitat. This unique anatomical connection, here documented from the late Miocene (?9 million years-6.5 million years old), not only provides the oldest diagnostic record for Iniidae, but it also indicates a similar habitat use for this lineage, a finding coincident with the current paleoenvironmental interpretation for the Ituzaingó Formation. PMID:24585575

Gutstein, Carolina Simon; Cozzuol, Mario Alberto; Pyenson, Nicholas D

2014-06-01

348

Petrofacies and provenance of the Puente Formation (middle to upper Miocene), Los Angeles basin, southern California: Implications for rapid uplift and accumulation rates  

SciTech Connect

The Peunte Formation is a Middle-Upper Miocene clastic unit lying unconformably on the Lower-Middle Miocene El Modeno Volcanics and Topanga Group, in the Los Angeles basin. The Puente Formation, about 3900 m thick, is composed of conglomerate, sandstone, and mudrock deposit;ed as a submarine fan at bathyal depths. Several intrabasinal discordances suggest tectonic activity during deposition. The succession consists of two main upward-thickening and -coarsening megacycles, reflecting submarine-fan progradation. The Puente Formation is characterized up-section by: (1) thin-bedded sandstone and shale (La Vida member) grading to thick-bedded sandstone and conglomerate (Soquel Member); and (2) thin-bedded mudrock and sandstone (Yorba Member) grading to thick- to very thick-bedded sandstone and conglomerate (Sycamore Canyon Member). There is consistent provenance signal in spite of complex transportation tectonics, responsible for opening of the Los Angeles Basin, and later transpressional processes, which are still active. Detailed provenance study of the Puente Formation and related units provides important constraints on paleogeographic and paleotectonic reconstructions of southern California basins and uplifts.

Critelli, S. [Consiglio Nazionale delle Ricerche, Roges di Rende (Italy). Istituto di Ricerca per la Protezione Idrogeologica nell`Italia Meridionale ed Insulare; Rumelhart, P.E.; Ingersoll, R.V. [Univ. of California, Los Angeles, CA (United States). Dept. of Earth and Space Sciences

1995-10-02

349

A new species of long-necked turtle (Pleurodira: Chelidae: Chelodina) from the late Miocene Alcoota Local Fauna, Northern Territory, Australia  

PubMed Central

The new species Chelodina (Chelodina) murrayi is described from the late Miocene Alcoota Local Fauna of central Australia, in the Northern Territory. The new species is based on shell fragments and can be diagnosed by a ventrally reflexed anterior margin of the plastron, a ventrally narrowed cervical scute and strongly dorsally curved margins of the carapace extending from approximately peripheral two to peripheral nine or ten as well as by a unique combination of characters. Within Chelodina the new species is part of the nominal subgenus and within that subgenus it is most closely related to the Chelodina (Chelodina) novaeguineae species group. This is not only the oldest record but also the most southerly occurrence of this species group. PMID:24133635

2013-01-01

350

The role of CO2 in modulating Miocene climate and ice volume (Invited)  

NASA Astrophysics Data System (ADS)

The Neogene period is characterised by long term cooling interrupted by a number of prominent warming events, for example the Middle Miocene climate optimum (MCO), an interval of global warmth, that was followed by the Mid-Miocene climate transition (MMCT), a step cooling superimposed on the long-term climate trend. Several Antarctic climate records suggest that the East Antarctic ice sheet was dynamic during the early Miocene (Lewis et al., 2006, Passchier et al., 2011). However, the output from ice sheet modeling experiments suggest that once large ice sheets have grown on East Antarctica they are inherently stable and consequently relatively high levels of CO2 are needed in order to initiate a deglaciation (~1000 ppm; Pollard and DeConto 2005). Over the past 5 years or so an increasing number of studies have illustrated that atmospheric CO2 was much more variable during the Miocene than previously thought, although the magnitude of CO2 change remains much smaller than anticipated by the ice sheet models (Foster et al., 2012, Kurshner et al., 2008, Zhang et al., 2013). Here we will draw together ?11B-pCO2 records, both new published, to evaluate the role of CO2 in modulating Miocene climate. Calculated ?11B-CO2 spanning 5-23 Ma from ODP Sites 926 and 872 are in broad agreement with the other recently published alkenone CO2 records despite the limitations of ?11B based CO2 reconstruction over these long timescales (e.g. variable ?11B of seawater) (Sosdian et al. 2013). We will also present high-temporal resolution boron isotope records from ODP Site 761 across the MCO and ODP Site 926 across the Oligocene-Miocene boundary. We examine the role of CO2 in controlling the stability of the East Antarctic ice sheet during these short time intervals thought to be characterised by substantial retreat of the AIS (Feakins et al. 2012, Passchier et al. 2011, Warny et al. 2009). References: Feakins et al. (2012) Nat. Geoscience 5(8) 557-560, Foster et al., (2012) ESPL 341 243-254, Lewis et al., (2006) Geology 34(7) 513-516, Kurshner et al., (2008) PNAS 105(2) 449-453, Passchier et al., (2011) Geol Soc Am Bull, 123(11-12), 2352-2365, Pollard & DeConto (2005) Global and Planetary Change 45(1-3) 9-21, Sosdian et al. (2013) ICP11 abstract no. 161, Warny et al. (2009) Geology 37(10) 955-958, Zhang et al., (2013) in press, Phil. Trans. R. Soc. A

Greenop, R.; Sosdian, S. M.; Lear, C. H.; Foster, G. L.; Wilson, P.

2013-12-01

351

Constraining the Late Miocene paleo-CO2 estimates through GCM model-data comparisons  

NASA Astrophysics Data System (ADS)

The period following the Mid-Miocene Climatic Optimum experienced a continued downward trend in the ?18O record - a record acknowledged as a proxy indicator of both ice volume and temperature (Zachos et al., 2001). Given the link between atmospheric CO2 and temperature (IPCC, 2007), it could be thought that the timeline throughout the Late Miocene would show a general decline in CO2 in accordance with the ?18O record. However, examination of the palaeo-CO2 record shows a relatively flat profile across this time, or perhaps even a slight increase, but there is a wide variation in the palaeo-CO2 estimate for the differing approximation methods. We use the fully coupled atmosphere-ocean-vegetation model of the Hadley Centre, HadCM3L, which has a low resolution ocean (Hadley Centre Coupled Model, Version 3 - low resolution ocean) with TRIFFID (Top-down Representation of Interactive Foliage and Flora Including Dynamics: Cox, 2001) to generate CO2 sensitivity scenarios for the Late Miocene: 180ppmv, 280ppmv and 400ppmv, as well as a preindustrial control simulation: 280 ppmv. We also run the BIOME4 model offline to produce predicted biome distributions for each of our scenarios. We compare both marine and terrestrial modelled temperatures, and the predicted vegetation distributions for these scenarios against available palaeodata As we simulate with a coupled dynamic ocean model, we use planktonic and benthic foraminiferal-based proxy palaeotemperature estimates to compare to the modelled marine temperatures at the depths consistent with the reconstructed palaeoecology of the foraminifera. We compare our modelled terrestrial temperatures to vegetation-based proxy palaeotemperatures, and we use a newly compiled vegetation reconstruction for the Late Miocene to compare to our modelled vegetation distributions. The new Late Miocene vegetation reconstruction is based on a 200+ point database of palaeobotanical sites. Each location is classified into a biome consistent with the BIOME4 model, to allow for easy data - model comparison. We use all these data - model comparisons to constrain the best-fit scenario and the overall most likely Late Miocene CO2 estimate according to the model simulations. Preliminary results suggest that the 400ppmv simulation provides the best fit to the proxy data.

Bradshaw, Catherine; Pound, Matthew; Lunt, Daniel; Flecker, Rachel; Salzmann, Ulrich; Haywood, Alan; Riding, James; Francis, Jane

2010-05-01

352

Equatorial Pacific climatic variations during the Miocene - Pliocene at IODP-Site U-1338  

NASA Astrophysics Data System (ADS)

The modern Equatorial Pacific setting has been established during the late Miocene-Pliocene. We provide here a new record of Equatorial Pacific sea surface conditions during the Miocene-Pliocene at IODP Site U1338 (2°30.469’N, 117°58.178’W), which contains a continuous and well-preserved sedimentary record. Our reconstruction is mainly based on stable isotopic measurements of oxygen and carbon on bulk carbonate, planktonic foraminifera and calcareous nannofossils 2-5 µm, as well as the alkenone unsaturation index (Uk’37) proxy. The data provide a new and detailed alkenone based SST reconstruction for mid-Miocene through Pliocene in the Eastern Equatorial Pacific and indicate a steady trend about 27 °C during mid-Miocene. Coccolith ?18O curve shows no resemblance to the benthic isotope curve established by Zachos et al. (2001) and shows an anti-correlation with alkenone based SST from 6.5 Ma, indicating that isotopic sea surface variations are mainly controlled by the temperature. Especially, these curves point jointly to a rapid cooling from 3.5 Ma. Moreover, sea surface temperatures variations fluctuate in parallel with cycles of environment fertility at about 2 Ma, supported by ?13C variations and modifications of nannofossil assemblages, and permit to hypothesize regular fluctuations of under current circulation. Combined these results with climatic and tectonic evolutions allow to demonstrate a series of paleoceanographic events, including: - High-productivity conditions characterized the mid-Miocene time interval. - The “carbonate crash”, around 11-9 Ma, during which deep oceanic conditions changes occurred, are assigned to the closing of the Panama gateway. - The late Miocene, in which the Indonesian and Central American seaways are gradually narrowing. The east-west Pacific circulations are then restricted and we hypothesize the gradual establishment of long-term El Niño-La Niña-like oceanic and climatic conditions, with the settlement of the Equatorial Under Current. - The late Pliocene global cooling is linked with the onset of the Northern hemisphere glaciation.

Rousselle, G.; Beltran, C.; Sicre, M.; de Rafélis, M.; Raffi, I.; Backman, J.; Iodp Expeditions 320/321 Shipboard Scientific Party

2010-12-01

353

Ozakia, a new genus of winged fruit shared between the Miocene of Japan and western North America.  

PubMed

A new genus is recognized based on winged fruits with a single species shared between the Miocene of southwestern Honshu, Japan, and the Miocene of Oregon and Idaho, USA. Calyces of Ozakia emryi gen. et sp. n. were formerly attributed to Heptacodium (Caprifoliaceae) and Amelanchier (Rosaceae); however, newly recovered specimens reveal additional characters that contradict these assignments. The pedicellate fruits are obovate, tapering basally and truncate apically, with about 10 longitudinal ribs, a prominent epigynous synsepalous calyx of five lobes, each with a midvein and a pair of weaker, ascending intramarginal primary veins. The single style has a capitate stigma. Ozakia is considered to represent an extinct eudicot genus, the familial affinities of which remain uncertain. The eastern Asian-western North American disjunction of Ozakia occurrences suggests that this plant traversed the Beringia land bridge during or prior to the Middle Miocene. Relatively few extinct angiosperm genera are known as late as the Miocene. PMID:24306324

Manchester, Steven R; Uemura, Kazuhiko

2014-03-01

354

The species richness of Miocene browsers, and implications for habitat type and primary productivity in the North American grassland biome  

Microsoft Academic Search

Abstract We have documented elsewhere, and briefly reviewed here, the anomalously high species richness of browsing ungulates (hoofed mammals),in the mid Miocene (f18–12 Ma) woodland,savanna habitats of North America. In the mid Miocene these habitats supported substantially more brachydont,(browsing) species than do any present-day savanna,habitats. We present some preliminary data to show,that such species-rich browser communities,are not observed after the

Christine M. Janis; John Damuthsupbsu; Jessica M. Theodor

2004-01-01

355

The species richness of Miocene browsers, and implications for habitat type and primary productivity in the North American grassland biome  

Microsoft Academic Search

We have documented elsewhere, and briefly reviewed here, the anomalously high species richness of browsing ungulates (hoofed mammals) in the mid Miocene (?18–12 Ma) woodland savanna habitats of North America. In the mid Miocene these habitats supported substantially more brachydont (browsing) species than do any present-day savanna habitats. We present some preliminary data to show that such species-rich browser communities

Christine M Janis; John Damuth; Jessica M Theodor

2004-01-01

356

Seismic facies and growth history of Miocene carbonate platforms, Wonocolo Formation, North Madura area, East Java Basin, Indonesia  

E-print Network

SEISMIC FACIES AND GROWTH HISTORY OF MIOCENE CARBONATE PLATFORMS, WONOCOLO FORMATION, NORTH MADURA AREA, EAST JAVA BASIN, INDONESIA A Thesis by RAHADIAN ADHYAKSAWAN Submitted to the Office of Graduate Studies of Texas A&M University... in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE December 2002 Major Subject: Geophysics SEISMIC FACIES AND GROWTH HISTORY OF MIOCENE CARBONATE PLATFORMS, WONOCOLO FORMATION, NORTH MADURA AREA, EAST JAVA BASIN, INDONESIA...

Adhyaksawan, Rahadian

2002-01-01

357

The first fossil leptofoenine wasp (Hymenoptera, Pteromalidae): A new species of Leptofoenus in Miocene amber from the Dominican Republic  

E-print Network

Th e fi rst fossil leptofoenine wasp (Hymenoptera, Pteromalidae): A new species of Leptofoenus 57 The first fossil leptofoenine wasp (Hymenoptera, Pteromalidae): A new species of Leptofoenus in Miocene amber from the Dominican Republic Michael S... fossil leptofoenine wasp (Hymenoptera, Pteromalidae): A new species of Leptofoenus in Miocene amber from the Dominican Republic. ZooKeys 13: 57-66. doi: 10.3897/zookeys.13.159 Abstract Th e fi rst fossil of the pteromalid subfamily Leptofoeninae...

Engel, Michael S.

2009-06-30

358

Post-Miocene stratigraphy and depositional environments of valley-fill sequences at the mouth of Tampa Bay, Florida  

Microsoft Academic Search

Post-Miocene sea-level low stands allowed rivers and karst processes to incise the exposed carbonate platform along the Gulf Coast of Florida. Few Miocene to mid-Pleistocene deposits survived erosion along the present coast except within incised valleys. Since their formation, these valleys have been filled and incised multiple times in response to sea-level changes. The thick sedimentary sequences underlying the mouth

Thomas W. Ferguson; Richard A. Davis

2003-01-01

359

High-resolution ice-volume estimates for the early Miocene: Evidence for a dynamic ice sheet in Antarctica  

Microsoft Academic Search

Ice-volume estimates for the early Miocene (23–16 Ma ATS) were determined by applying ?18O to sea-level calibrations to high-resolution ?18O records from ODP Sites 1090 and 1218. These calibrated records indicate that ice-volume ranged between 50% and 125% of the present day East Antarctic Ice Sheet (EAIS) during most of the early Miocene (23–17 Ma). Maximum ice-volume occurred at each

Stephen F. Pekar; Robert M. DeConto

2006-01-01

360

Faunal change in the Turkana Basin during the late Oligocene and Miocene.  

PubMed

Faunal evolution over the last 65 million years of earth's history was dominated by mammalian radiations, but much of this era is poorly represented in Africa. Mammals first appeared early in the Mesozoic, living alongside dinosaurs for millions of years, but it was not until the extinction of dinosaurs 65 myr ago that the first major explosion of mammalian taxa took place. The Cenozoic (65 Ma to Recent) witnessed repeated and dynamic events involving the radiation, evolution, and extinction of mammalian faunas. Two of these events, each marking the extinction of one diverse fauna and subsequent establishment of another equally diverse fauna, both involving advanced catarrhine primates, are recorded in sites in the Turkana Basin, despite the poorly represented record of Cenozoic faunas elsewhere in sub-Saharan Africa. The first of these events occurred at the Oligocene-Miocene transition and the other at the Miocene-Pliocene transition. PMID:22170693

Leakey, Meave; Grossman, Ari; Gutiérrez, Mercedes; Fleagle, John G

2011-01-01

361

Sensitivity of climate and Atlantic overturning circulation to uncertain ocean gateway configurations for the late Miocene  

NASA Astrophysics Data System (ADS)

The palaeorecord documents late Miocene (11.6-5.3 Ma) climate to be much warmer and wetter than today yet CO2 reconstructions are similar to modern levels. Given the apparent decoupling between CO2 and warmth for this period we investigate here the role of the oceans. The late Miocene experienced significant tectonic change including the restriction of some of the last ocean gateways to close (Panama Gateway and Indonesian Seaway) and open (Bering Strait and Barents/Kara Sea). However, the timing and configuration of these tectonic changes is uncertain. The final closure of the Panama Gateway is dated to the Pliocene, but continental mammal exchange suggests the existence of a Central American archipelago from the mid-late Miocene. The Bering Strait is typically assumed to have opened at the very end of the late Miocene/early Pliocene based on diatom exchange, but other marine and terrestrial evidence points to a much earlier, perhaps intermittent, opening. The timing of the restriction of the Indonesian Seaway is very poorly constrained at middle Miocene to Pliocene. The Barents Sea and Kara Sea shelves are documented as having being subject to extensive glacial erosion and post-glacial uplift since the Pliocene and throughout the Quaternary but records of uplift and erosion during the earlier Cenozoic are limited. However, the presence of significant preglacial sediments suggests that this region underwent tectonic uplift, volcanism and subsequent erosion during the Eocene-Miocene period although the age assignment of the data remains controversial. The Panama Gateway has been suggested to influence North Atlantic Deep Water (NADW) production through numerous modelling studies, the Bering Strait has been suggested to greatly impact NADW during the Quaternary, and the strength of Indonesian Throughflow is hypothesised to influence Agulhas Leakage, which, in turn, has been speculated to influence Atlantic meridional overturning and thus NADW production. Here, we investigate how the opening and closing of these gateways might influence ocean circulation, and hence climate, with late Miocene boundary conditions using the fully coupled atmosphere-ocean-vegetation GCM HadCM3L with TRIFFID. We show how the model suggests these gateways in different configurations might influence NADW production, with results from all possible combinations of these three gateways presented and compared to the available proxy data. The climatic implications of the presence of the Barents Shelf and Kara Shelf land masses prior to their final erosion has not been the subject of much research, either through modelling or data interpretation, and indeed many model simulations for the Miocene do not include these shelves as land masses at all. Here we also test our hypothesis that these land masses also impact NADW production through the restriction of the exchange of water between the Arctic Ocean and the Greenland-Iceland-Norwegian Sea. We hypothesize that their presence as land masses results in a saltier North Atlantic than occurs after their erosion; without the land masses there, the North Atlantic would experience more influence from the East Greenland Current (colder/fresher) and less influence of the Irminger Current (warmer/saltier).

Bradshaw, C.; Lunt, D. J.; Flecker, R.; Martinez-Mendez, G.

2013-12-01

362

Eocene to post-Miocene kinematic evolution of the central Cyclades (Greece)  

NASA Astrophysics Data System (ADS)

Due to the extraordinary geotectonic location of the Aegean above an active subduction zone and an exceptional high seismicity, this area and especially the Cyclades have been in the focus of structural investigations for several decades. The present deformation is the result of ongoing plate tectonic movements in this area since at least the Miocene. The ductile structures of the Miocene extension and related metamorphic core type deformation are quite well studied and understood. Equally well investigated are the active tectonic deformation and associated brittle structures through several decades of seismic records. However, due to the difficulties of dating brittle faults, the kinematic evolution from the early to middle Miocene ductile structures, to later Miocene brittle-ductile and brittle faults is much less understood. For these reasons detailed structural fieldwork, combined with Ar-Ar geochronology and P-T studies, have been carried out on the uninhabited island of Despotiko, SW of Antiparos, which is situated virtually in the center of the Cycladic islands. This island has been selected because the existence of metamorphic rocks penetrated by Messinian rhyolite pipes and Pleistocene eolianites provide exceptional age constraints for Eocene to post-Miocene deformation structures. Despotiko is part of lower structural levels of the polymetamorphic Blueschist Unit of the Attic-Cycladic Metamorphic Belt and correlated lithologically with the Parikia gneisses and Marathi unit of Paros. Foliation is shallowly dipping towards the SSW. The main lithologies of the island, from the footwall to the hanging wall, consist of dark to pale grey, strongly foliated, mylonitic granite gneiss with abundant pegmatite dikes. The gneiss is overlain by prominent white, strongly foliated, mylonitic gneiss. Above are medium-grained, white calcite marble followed by greenish-white, mylonitic gneiss and an alternation of mica schist, greenschist, thin marble layers and some small serpentinite lenses. The structurally highest levels, in the south and southwest of the island, comprise several tens of meters of dolomite marble. This metamorphic succession has been cut by six Messinian rhyolitic volcanic vents and all crystalline rocks have been covered by late Pleistocene eolianites. The kinematic evolution of the investigation area can be divided based on the deformation style and age. (1) The ductile deformation results in NE-SW trending stretching lineation and shear senses both top-to NE and top-to SW. Ar-Ar white mica cooling ages indicate an early Miocene age for this ductile deformation. (2) The brittle/ductile structures, which gradually advance from the previous ductile deformation, start with small but pervasive flanking folds, followed by larger shear bands and finally faults with tourmaline slickenlines. The shear sense is consistently top-to SW with middle to late Miocene age constrained by Ar-Ar white mica cooling ages and zircon fission-track data from Paros. (3a) Large, subvertical, sinistral strike-slip faults cross-cut the metamorphic rocks and show up to hundreds of meters displacement. Late Miocene age is constrained by apatite fission-track data from Paros and the observation that these faults are sealed by Messinian rhyolites. (3b) The Messinian volcanic rocks are almost exclusively deformed by E-W striking conjugate brittle normal faults, which started already during the formation of the volcanic rocks. No unequivocal tectonic deformation structures have been observed in the Pleistocene eolianites.

Draganits, E.; Huet, B.; Grasemann, B.; Schneider, D.; Ertl, A.

2012-04-01

363

Palynology of the Heath Formation (Miocene) from the Progreso Basin, Peru  

SciTech Connect

A diverse and well preserved assemblage of pollen, spores, dinoflagellates, and acritarchs were recovered from outcrop samples of the Heath Formation, exposed along Bocapan Creek near Tumbes, Peru. The pollen and spores include representatives of Arecipites, Bombacacidites, Caryapollenites, Cicatricosisporites, Couperipollis, Cyathidites, Diporisporites, Distaverrusporites, Dyadosporites, Echiperiporites, Faramea, Foveodiporites, Foveotriletes, Fusiformisporites, Gothanipollis, Granitricolpites, Hymenophyllum, Hexpollenties, Involutisporites, Laevigatosporites, Lygodiumsporites, Magniperiporites, Malvacearumpollis, Monocolpopollenites, Perissyncolporites, Peritheciumites, Phragmothyrites, Polyadadporites, Polypodiaceisporites, Polypodiisporites, Retibrevitricolpites, Striadisporites, Tetracolporites, Tricolporopollenties, and Verrucosisporites. Plankton are assignable to Lejeunecysta, Operculodinium, Pterospermella, Selenopemphix, Spiniferites, Sumatradinium, Tythodiscus, and Tuberculodinium. The palynomorph assemblage can be placed in the Early Miocene based on the co-occurrence of Cicatricosisporites dorogensis, Couperipollis rarispinosus, Echiperiporites estelae, Magniperiporites echinatus, Perisyncolporites porkornii, Polypodiaceoisporites minor, P. potoniei, Reticolporites guianesnsis, R. irregularis, Scabriporites asymetricus, Selenopemphix nephroides and Tuberculodinium vancampoae. This is an agreement with foraminiferal evidence which positions the Heath Formation in the Early Miocene Catapsydrax dissimilis, Catapsydrax stainforthi and oldest portion of the Globigerinatella insueta zones.

Engelhardt, D.W. (Univ. of South Carolina, Columbia (United States)); Wood, G.D. (Amoco Production Co., Houston, TX (United States))

1993-02-01

364

Basal Adare volcanics, Robertson Bay, North Victoria Land, Antarctica: Late Miocene intraplate basalts of subaqueous origin  

USGS Publications Warehouse

Late Cenozoic lavas and associated hyaloclastite breccias of the Adare volcanics (Hallett volcanic province) in Robertson Bay, North Victoria Land rest unconformably on Paleozoic greywackes. Abundant hyaloclastite breccias are confined to a paleovalley; their primary geological features, and the stable isotope ratios of secondary minerals, are consistent with eruption in a subaqueous environment with calcite formation probably involving seawater. In contrast, the lavas which stratigraphically overlie the hyaloclastites on Mayr Spur probably were erupted subaerially. K-Ar dating of eight samples from this basal sequence confirms the known older age limit (Late Miocene) of the Hallett volcanic province. Geochemical data reveal an ocean island basalt-like affinity, similar to other Cenozoic igneous rocks of the Hallett volcanic province. If a submarine eruptive paleoenvironment is accepted then there has been net tectonic or isostatic post-Late Miocene uplift of a few hundred metres in the Robertson Bay-Adare Peninsula area

Mortimer, N.; Dunlap, W.J.; Isaac, M.J.; Sutherland, R.P.; Faure, K.

2007-01-01

365

Depositional and structural evolution of the Middle Miocene depositional episode, east-central Gulf of Mexico  

NASA Astrophysics Data System (ADS)

Two widespread, transgressive deposits associated with the faunal top Amphistegina B (15.5 Ma) and Textularia W (12.1 Ma) define the Middle Miocene depositional episode. An extensive stratigraphic correlation framework established in this study allowed tracing of the middle Miocene sediment dispersal system from the shelf through the slope to the basin floor in the complex paleogeography of the east-central Gulf of Mexico. The Middle Miocene depositional episode is recorded in four genetic cycles (˜1 to 2 Ma), bounded by regional maximum flooding surfaces in the shelf and shelf margin setting, and three equivalent seismic sequences punctuated by condensed sections in the slope and basin floor. Two principal, long-lived extrabasinal fluvial/delta axes, the ancestral Mississippi and the Tennessee systems, provided the bulk of sediments that infilled the middle Miocene depocenters. Salt-related structural provinces controlled the configuration of the depocenters. Structural linked systems, dominated by gravity spreading, and a minibasin province, driven by differential subsidence, were established during the Middle Miocene depositional episode. Sediment supply coupled with wave energy flux, high-frequency sea-level changes, and salt tectonism determined the time and space distribution of progradation, aggradation, and retrogradation of system tracts. Middle Miocene shelf margins have prograded 20 to 40 miles from the relict lower Miocene shelf margin. Two depositional systems tracts characterize the constructional shelf margin: (1) a mixed-load fluvial-dominated platform delta/shelf-margin delta/delta-fed apron systems tract; and (2) a strandplain/shelf/muddy slope systems tract. However, the constructional, offlapping shelf margin systems were locally punctuated by a large-scale phase of retreat and erosion, named the Harang collapse system, in which a large volume of sediments bypassed the shelf margin to be deposited on the slope and basin floor. The Harang collapse system is a type of large-scale slope failure produced by massive salt-withdrawal, retreat of major delta systems, and high-frequency sea-level fluctuations. A large volume of sediment bypassed the confined minibasin province and the unconfined Florida slope at the flank of active deltaic depocenters, forming the long-lived MCAVLU submarine fan system (named for its location beneath the Mississippi Canyon, Atwater Valley, and Lund continental shelf (OCS areas) in the linked, primary minibasin corridor of the lower slope and basin floor. The MCAVLU submarine fan system evolved from a structurally-controlled, elongate sand-rich to mixed sand/mud fan to a large radial, mixed sand/mud fan. Significant untapped middle Miocene hydrocarbon resources remain in the confined channel fills and lobes of the Harang collapse system and sand-rich ponded facies assemblages of the MCAVLU submarine fan system.

Combellas Bigott, Ricardo Ignacio

366

Chemical composition and palaeobotanical origin of Miocene resins from Kerala-Konkan Coast, western India  

NASA Astrophysics Data System (ADS)

The terpenoid composition of resins from the Miocene lignite horizons from the Kerala-Konkan Coast, western India was analyzed by Curie-point pyrolysis-gas chromatography-mass spectrometry (Cupy-GC-MS). The major pyrolysates were cadalene-based bicyclic sesquiterpenoids including some C30-C31 bicadinenes and bicadinanes typical of dammar resin from angiosperm plants of Dipterocarpaceae family. These plants are typically supported by tropical climates which the western Indian region was known to have experienced during early Tertiary period. The present study suggests that these palaeoclimatic conditions persisted until at least the Miocene epoch. These sesquiterpenoids which are commonly detected in many SE Asian crude oils may be utilised as useful biomarkers for petroleum exploration in the western Indian region.

Dutta, Suryendu; Mallick, Monalisa; Mathews, Runcie Paul; Mann, Ulrich; Greenwood, Paul F.; Saxena, Rakesh

2010-10-01

367

A simple petrogenetic model for the formation of Miocene Low-?18O rhyolites of the Yellowstone Hotspot track, USA  

NASA Astrophysics Data System (ADS)

The inland northwest of the United States contains a large intraplate igneous province that was initiated at ~16.6 Ma and is still active at the present. Its products include the Miocene Columbia River Basalt Group (CRBG), Miocene to Quaternary basalts and rhyolites of the High Lava Plains and the Snake River Plain, and the Quaternary Yellowstone volcanic plateau. The total volume of magma produced is uncertain, but approximately 2.5 x 105 km3 of basalts were erupted during the first million years of activity; applying magma supply rates calculated for the Snake River Plain, the total volume of mantle-derived basalt represented by the entire province may be twice that figure. Snake River Plain rhyolites are notable for the abundance of 18O-depleted units (<6‰) compared to most volcanic rocks on Earth. Low-?18O rhyolitic magma requires a source component that has exchanged oxygen at high temperatures with surface derived meteoric fluids; the degree of 18O-depletion seen in Snake River Plain rhyolites therefore requires a dominant proportion of meteoric-hydrothermally altered shallow crust among their source materials. No previous modeling has attempted to simultaneously satisfy constraints from O, Nd, Pb, and Sr isotopes for both rhyolites and basalts of the Snake River Plain using unmodified end member compositions from real surface samples. Any model for low ?18O Snake River Plain rhyolites must first account for O isotopes, because oxygen is ~50% of any silicate rock. We avoid the assumption that the geochemical character of the Snake River Plain basalts is wholly inherited from the mantle. Instead, we choose crustal materials that are abundantly exposed in proximity to the province (i.e. Idaho Batholith granitoids) and basalts that are generally accepted as primitive mantle-derived compositions (i.e. Steens basalts). The influence of continental crust on the chemistry of hotspot eruptives has been well documented. We assume this as a starting point, and construct mass balance models in order to find the simplest possible explanation for the observed features of the Snake River Plain rhyolites. We show that, when the Yellowstone hotspot track including the Columbia River and Steens basalts is treated as a single province derived ultimately from a common mantle source, the isotope geochemistry of these lavas and tuffs can be explained to a first order by simple mixing of asthenosphere-derived basalt (10%-40%) and granitic crust of the Idaho batholith (60%-90%). This model is consistent with, but does not require, a stationary mantle plume as the origin of the province.

Boroughs, S.; Wolff, J. A.; Starkel, W. A.

2012-12-01

368

Genesis of siderite in the Upper Miocene, offshore Sarawak: Constraints on pore fluid chemistry and diagenetic history  

SciTech Connect

The cored sequence of the Upper Miocene reservoir of Baram field, offshore Sarawak, consists of cyclic deltaic-related quartz-rich sandstones and mudstones interpreted to have been deposited during storm events in shallow to midshelf water depths. The sequence is intercalated with minor tidal intervals. Authigenic siderite is common in sandstones throughout the sequence. Siderite cemented zones are up to 2 m thick. The cement is found in four different sandstone types: laminated sandstone, massive sandstone, bioturbated sandstone, and in association with shell fragments. Whole-rock XRD gives estimates of 20 to 40% siderite in bioturbated sandstones and 10 to 25% for the others. Petrographic analysis reveals that diagenetic siderite occurs in four different crystal morphologies: rhombic, [open quotes]bundles,[close quotes] acicular, and cylindrical. The rhombic siderite, which commonly occurs in bioturbated sandstone, has the most adverse effect on the poroperm characteristics of the sandstones, reducing porosity to 10% and permeability to 2 md. [sigma][sup 13]C and [sigma][sup 18]O plots show groupings based on morphology. Bundled and acicular siderite show ranges of [sigma][sup 13]C[sub PDB] of [minus]15 to [minus]25 and [sigma][sup 18]O[sub PDB] of 0 to [minus]1. The late Miocene seawater [sigma][sup 18]O estimate for the region is [minus]0.8 PDB. This would give the bundles/acicular siderite a temperature of formation range of 26[degrees] to 30[degrees]C. The [sigma][sup 18]O values are compatible with precipitation at shallow burial depth from unaltered seawater; [sigma][sup 13]C values are inherited from sulfate reduction horizons. Rhombic siderite has ranges of [sigma][sup 13]C[sub PDB] of [minus]5 to [minus]15 and [sigma][sup 18]O[sub PDB] of [minus]3 to [minus]4. The range of [sigma][sup 13]C indicates that siderite diagenesis occurred within both the shallow sulfate reduction zone and at deeper levels within the zone of decarboxylation.

Abdul Hadi, A.R.; Astin, T.R. (Univ. of Reading (United Kingdom))

1994-07-01

369

A new Late Miocene hominoid from Kenya: Samburupithecus kiptalami gen. et sp. nov.  

NASA Astrophysics Data System (ADS)

A new genus and species of hominoid, Samburupithecus kiptalami, is erected on the basis of a maxillary specimen with complete post canine dentition. Its age is established as upper Miocene (9.5 Ma) on the basis of radioisotopic dating and associated mammalian fauna. The new genus is more closely related to the African ape —human clade (AAH) than is any other known extinct hominoid and it may well be on the line leading to hominids.

Ishida, Hidemi; Pickford, Martin

1997-11-01

370

Coeval formation of cataclasite and pseudotachylyte in a Miocene forearc granodiorite, southern Kyushu, Japan  

Microsoft Academic Search

Cataclastic rocks and pseudotachylytes are exposed along the Uchinoura shear zone, a normal fault zone cutting the middle Miocene (14 Ma) Osumi granodiorite in southern Kyushu, Japan. Cataclastic rocks include non-foliated clast-supported to matrix-supported cataclasite and foliated clast-supported cataclastic granodiorite. In these rocks, fracturing and comminution played a major role, but dissolution and recrystallization of quartz, and plastic deformation of

Olivier Fabbri; Aiming Lin; Hirotaka Tokushige

2000-01-01

371

FOSSIL BLOOD DROPLETS IN MIOCENE DOMINICAN AMBER YIELD CLUES TO SPEED AND DIRECTION OF RESIN SECRETION  

Microsoft Academic Search

Two spiders (Filistatidae) in Miocene Dominican Republic amber, one newly identified and only the second known fossil of this family, have autospasized legs (detached at a predetermined locus of weakness when restrained by a non-self-induced source) at the patella-tibia joint. In both specimens, droplets of haemolymph (blood) are preserved exiting the patellae. The autospasized legs and the presence of haemolymph

DAVID PENNEY

2005-01-01

372

The interaction between Aegean back-arc extension and Anatolia escape since Middle Miocene  

NASA Astrophysics Data System (ADS)

The Aegean domain is a key area for understanding the processes of back-arc extension. Observed deformation pattern and present day kinematics result from the interaction between the southward retreat of the Hellenic trench and the westward escape of Anatolia. Lithosphere-scale analogue models were employed to display that the overall pattern of Aegean extension requires not only the combination of trench retreat and Anatolia escape since middle Miocene but also the presence of an inherited lithosphere-scale mechanical discontinuity: the Vardar Suture Zone (VSZ). The reactivation in dextral shear of the eastern branch of the VSZ accommodates both the trench retreat (NS stretching) and the westward escape of Anatolia (EW shortening) in the Cyclades area since middle Miocene. Additionally, our model shows that the North Anatolian Fault (NAF) is a late structure in the evolution of the Aegean, initiated around 10 Ma after the onset of Anatolia escape. The displacement field at the surface of the model allows the identification of sub-domains, which result from strain partitioning instead of being “rigid microplates”, directly comparable to the present-day displacement field (GPS) of the Aegean and western Anatolia. Our model provides a simple but powerful way to look at the dynamics of Aegean extension in two main stages. From middle Eocene to middle Miocene, extension was only driven by the southward retreat of the Hellenic trench at a rate lower than 1 cm·y- 1. Since middle Miocene, the combination of slab rollback with Anatolia westward escape resulted in a southwest direction of trench retreat, with an accelerating rate of up to 3 cm·y- 1.

Philippon, Mélody; Brun, Jean-Pierre; Gueydan, Frédéric; Sokoutis, Dimitrios

2014-09-01

373

A new chronology for the middle to late Miocene continental record in Spain  

Microsoft Academic Search

The first detailed chronology for the middle to late Miocene continental record in Spain is presented, based on high-resolution magnetostratigraphic data of mammal-bearing sections which were studied in several basins (Calatayud-Daroca, Teruel, Vallès-Penedès, Duero and Júcar-Cabriel). Our results indicate that these sections compose an almost complete magnetostratigraphic succession from the lower Aragonian (MN4) to the middle Turolian (MN12). Seven successive

W. Krijgsman; M. Garcés; C. G. Langereis; R. Daams; J. van Dam; A. J. van der Meulen; J. Agustí; L. Cabrera

1996-01-01

374

Fossils reveal an early Miocene presence of the aberrant gruiform Aves: Aptornithidae in New Zealand  

Microsoft Academic Search

A member of the New Zealand endemic family (Aves: Aptornithidae) is described from the Early Miocene St Bathans Fauna of Central\\u000a Otago, South Island, New Zealand. The new species, based on two thoracic vertebrae, is provisionally referred to the highly\\u000a distinctive Late Pleistocene–Holocene extinct genus Aptornis Mantell, 1848 (in Quart J Geol Soc Lond 4:225–238, 1848). It differs from both

Trevor H. WorthyAlan; Alan J. D. Tennyson; R. Paul Scofield

2011-01-01

375

DNA Sequences from a Fossil Termite in Oligo-Miocene Amber and Their Phylogenetic Implications  

Microsoft Academic Search

DNA was extracted from the fossil termite Mastotermes electrodominicus preserved in Oligo-Miocene amber (25 million to 30 million years old). Fragments of mitochondrial [16S ribosomal DNA (rDNA)] and nuclear (18S rDNA) genes were amplified by polymerase chain reaction. Phylogenetic analysis of fossil and extant 18S rDNA confirmed morphological cladistic analyses of living dictyopterans (termites, cockroaches, and mantids). The fossil termite

Rob Desalle; John Gatesy; Ward Wheeler; David Grimaldi

1992-01-01

376

Confirmation of a late Oligocene-early Miocene age of the Deseadan Salla Beds of Bolivia.  

USGS Publications Warehouse

Three new fission-track (zircon) and four new K-Ar (biotite) dates corroborate a late Oligocene-early Miocene age (22-28 Ma) for the Salla Beds of Bolivia. These ages contrast markedly with the previously accepted age of about 35 Ma for these strata and their contained faunas, and recasts of order and chronology of interchange between New World and Old World mammals. -Authors

Naeser, C.W.; McKee, E.H.; Johnson, N.M.; Macfadden, B.J.

1987-01-01

377

Paleomagnetic evidence for Late Miocene counterclockwise rotation of north coast carbonate sequence, Puerto Rico  

SciTech Connect

A paleomagnetic study of the essentially undeformed middle Tertiary carbonate sequence along the north coast of Puerto Rico reveals statistically significant pre-Pliocene discordance of characteristic component directions against those expected from cratonic North America for much of the section. Despite generally weak to moderately weak magnetic intensities, confirmation of the magnetization as primary in origin comes from the presence of two distinct components of magnetization, intrasite bipolarity, and/or the reproducibility of measurements. The mean geographic direction for the upper Oligocene to middle Miocene strata is 335.2{degree}/32.9{degree} and the corrected mean paleomagnetic pole is 207.6{degree}/66.5{degree}, (N = 3, {alpha}95 = 4.3{degree}). This suggests a counter-clockwise (CCW) block rotation of Puerto Rico and its microplate of 24.5{degrees} ({plus minus} 5.8{degrees}) during the late Miocene. Using a width of 250 km for the Northern Caribbean Plate Boundary Zone (NCPBZ) between the North American Plate and Caribbean Plate, the mean left lateral displacement implied is 1.8 to 2.4 cm/yr, which agrees fairly well with published relative motion rates for the two plates. Average rotation rate for 50 Ma to 20 Ma was 0.7{degree}/my but perhaps as great as 4{degree}/my in the Miocene. Resolution of mean paleolatitude indicates northward motion of a degree or less during the period of rotation. Causes of this short-lived rotation may include (1) tectonic escape from the inhibiting presence of the Bahama Banks and Beata Ridge during eastward motion of Puerto Rico along the sinistral transpressive Puerto Rico Trench and Muertos Trough fault systems or (2) changes in relative plate motions of the Caribbean and North American Plate during the late Miocene.

Reid, J.A.; Plumley, P.W. (Syracuse Univ., NY (United States)); Schellekens, J.H. (Univ. of Puerto Rico, Mayaguez (Puerto Rico))

1991-03-01

378

First joint record of Mesopithecus and cf. Macaca in the Miocene of Europe.  

PubMed

Cercopithecid fossil remains from the post-evaporitic Messinian (5.40-5.33 Ma, MN13, latest Turolian, latest Miocene) locality of Moncucco Torinese (Tertiary Piedmont Basin, NW Italy) are described. A talus is assigned to the fossil colobine Mesopithecus pentelicus, while a proximal fragment of ulna and a male lower canine are attributed to cf. Me. pentelicus. An isolated I(2) and M3 are assigned to the papionin cf. Macaca sp., and two cercopithecid phalanges are left unassigned even to the subfamily level. The record of Mesopithecus at Moncucco Torinese agrees well with the previously-known range of this species in Italy and elsewhere in Europe, whereas that of cf. Macaca constitutes only the second occurrence of macaques in the Miocene of Eurasia. Although the co-occurrence of these two genera in a single locality had been previously reported in the Pliocene, this is the first instance in which macaques are associated with the Late Miocene M. pentelicus instead of Mesopithecus monspessulanus. The record of cf. Macaca and Mesopithecus-and especially the latter's talar morphology, similar to that of extant arboreal colobines-fits well with paleoenvironmental reconstructions of Moncucco Torinese based on the associated fauna, which indicate a humid and densely-forested environment, probably with more open and drier habitats nearby. From a paleobiogeographic viewpoint, the record of Macaca at Moncucco Torinese, together with the previously reported occurrence at Almenara-Casablanca M (Spain), supports the contention that macaques dispersed from Africa into Europe during the latest Miocene (ca. 5.9-5.3 Ma) at the same time as the sea level drop associated with the Messinian Salinity Crisis. PMID:24342451

Alba, David M; Delson, Eric; Carnevale, Giorgio; Colombero, Simone; Delfino, Massimo; Giuntelli, Piero; Pavia, Marco; Pavia, Giulio

2014-02-01

379

Miocene Bahean stratigraphy in the Longzhong Basin, northern central China and its implications in environmental change  

Microsoft Academic Search

Fossil mammal-riched Neogene strata are widely distributed in the southeast corner of the huge Longzhong Basin at Tianshui,\\u000a Gansu Province, northern central China. Hipparion weihoense, a typical member of late Middle Miocene Bahean stage, was recently excavated at Yaodian along a well-exposed outcrop. Owing\\u000a to the importance of the Bahean stage in the mammalian evolution and its potential for environmental

Jijun Li; Jun Zhang; Chunhui Song; Zhijun Zhao; Yong Zhang; Xiuxi Wang; Jianming Zhang; Qiaoyu Cui

2006-01-01

380

Functional anatomy of the limbs of erethizontidae (Rodentia, Caviomorpha): Indicators of locomotor behavior in Miocene porcupines.  

PubMed

Functional analysis of the limb bones of the erethizontid Steiromys duplicatus, one of the most abundant Miocene porcupines from Patagonia, provides evidence to infer their locomotor behavior. Remains of the giant Neosteiromys pattoni (Late Miocene of Northeast Argentina) are also analyzed. Osteological and myological features of extant porcupines were evaluated and used as a model to interpret the functional significance of Miocene species' limbs. Several features in erethizontids are compatible with the ability to climb: the low humeral tuberosities indicate a mobile gleno-humeral joint; the prominent and distally extended deltopectoral crest indicates a powerful pectoral muscle, which is particularly active when climbing; the humero-ulnar and humero-radial joints are indicative of pronation-supination movements; the well-developed lateral epicondylar ridge and the medially protruding entepicondyle are in agreement with an important development of the brachioradialis, supinator, flexor digitorum profundus, and pronator teres muscles, acting in climbing and grasping functions; the mechanical advantage of the biceps brachii would be emphasized because of its distal attachment on the bicipital tuberosity. As with extant porcupines, in Miocene species, the large femoral head would have permitted a broad range of abduction of the femur, and the medially protruding lesser trochanter would have emphasized the abduction and outward rotation of the femur by the action of the ilio-psoas complex. In S. duplicatus, the shape of the hip, knee, and cruro-astragalar, calcaneo-astragalar, and astragalo-navicular joints would have allowed lateral and rotational movements, although probably to a lesser degree than in extant porcupines. Foot features of S. duplicatus (e.g., great medial sesamoid bone, medial astragalar head, complete hallux) indicate that this species would have had grasping ability, but would not have achieved the high degree of specialization of Coendou. Steiromys duplicatus would have been a semiarboreal dweller, resembling Erethizon dorsatum. PMID:18157864

Candela, Adriana M; Picasso, Mariana B J

2008-05-01

381

Volcanic ash in the Makara Basin (Upper Miocene), Hawke's Bay, New Zealand  

Microsoft Academic Search

Volcanic ash products of intermediate composition were found, mixed with detrital sediment, in some samples of the Silver Range Sandstone. The Silver Range Sandstone is a prominent thick-bedded sandstone within the Upper Miocene thinner-bedded, flysch-like deposits in the Makara Basin, Central Hawke's Bay. The ash is probably derived from intermediate volcanism in the north-western part of the North Island. Tuff

G. J. van der Lingen

1968-01-01

382

A new Middle Miocene Niveria Jousseaume, 1884 (Mollusca: Gastropoda: Trivioidea) from Hungary  

NASA Astrophysics Data System (ADS)

A new species of Niveria from the Middle Miocene (Badenian) of the Paratethys of Borsodbóta, Hungary is described. This species is characterized by its callused dorsum and dorsal depression. Niveria jozefgregoi sp. nov. is discussed with comparative species from the Badenian of Hungary, the Pliocene of the Mediterranean region, Florida and Recent species from Madeira and the Islas Galápagos.

Fehse, Dirk

2011-02-01

383

Fossil whale preservation implies high diatom accumulation rate in the Miocene Pliocene Pisco Formation of Peru  

Microsoft Academic Search

Diatomaceous deposits in the Miocene Pliocene Pisco Formation contain abundant whales preserved in pristine condition (bones articulated or at least closely associated), in some cases including preserved baleen. The well-preserved whales indicate rapid burial. The 346 whales within ˜1.5 km2 of surveyed surface were not buried as an event, but were distributed uninterrupted through an 80-m-thick sedimentary section. The diatomaceous

Leonard R. Brand; Raúl Esperante; Arthur V. Chadwick; Orlando Poma Porras; Merling Alomía

2004-01-01

384

Climate Response to Orbital Forcing Across the Oligocene-Miocene Boundary  

Microsoft Academic Search

Spectral analyses of an uninterrupted 5.5-million-year (My)-long chronology of late Oligocene-early Miocene climate and ocean carbon chemistry from two deep-sea cores recovered in the western equatorial Atlantic reveal variance concentrated at all Milankovitch frequencies. Exceptional spectral power in climate is recorded at the 406-thousand-year (ky) period eccentricity band over a 3.4-million-year period [20 to 23.4 My ago (Ma)] as well

James C. Zachos; Nicholas J. Shackleton; Justin S. Revenaugh; Heiko Pälike; Benjamin P. Flower

2001-01-01

385

A new Old World vulture (Falconiformes: Accipitridae) from the Miocene of Gansu Province, northwest China  

Microsoft Academic Search

A large-sized and almost complete fossil vulture was discovered from the Late Miocene Liushu Formation of Linxia Basin in\\u000a northwestern China. It is the best-preserved and the most complete fossil vulture yet discovered. The new genus and species\\u000a Gansugyps linxiaensis is proposed and assigned to the family Accipitridae; morphology and limb proportions suggest it was chiefly an arboreal and\\u000a soaring

Zihui Zhang; Xiaoting Zheng; Guangmei Zheng; Lianhai Hou

2010-01-01

386

A Miocene termite nest from southern Argentina and its paleoclimatological implications  

USGS Publications Warehouse

A Miocene termitarium attributable to the extant termite Syntermes (Isoptera: Termitidae, Nasutitermitinae) is the first fossil termite nest reported from South America and possibly the oldest record of the Isoptera from that continent. A new ichnogenus and ichnospecies, Syntermesichnus fontanae, is proposed for this distinctive trace fossil. It differs from nests constructed by other members of the Nasutitermitinae in its architectural organization and its large size. -from Authors

Bown, T.M.; Laza, J.H.

1990-01-01

387

A Miocene Forest Assemblage in the Columbia River Basalts of Washington State, USA  

NSDL National Science Digital Library

This report describes a fossil locality in Washington State in which fossil trees are preserved standing upright in a Miocene basalt flow. Topics include the Columbia River Flood Basalts (one of which inundated the trees), a description of the fossil site, the ages of the basalt and the underlying clay, analyses of the fossil wood to determine tree species, and a discussion of the depositional environment in which the trees are preserved.

388

Middle Miocene ice sheet dynamics, deep-sea temperatures, and carbon cycling: A Southern Ocean perspective  

Microsoft Academic Search

Relative contributions of ice volume and temperature change to the global ?1‰ ?18O increase at ?14 Ma are required for understanding feedbacks involved in this major Cenozoic climate transition. A 3-ma benthic foraminifer Mg\\/Ca record of Southern Ocean temperatures across the middle Miocene climate transition reveals ?2 ± 2°C cooling (14.2–13.8 Ma), indicating that ?70% of the increase relates to

Amelia E. Shevenell; James P. Kennett; David W. Lea

2008-01-01

389

Relationship between surface-water temperature and ice-sheet expansion during the middle Miocene  

Microsoft Academic Search

A three-fold expansion of the Antarctic ice sheet at 13.60, 12.82, and 11.60 Ma has been inferred from ?18O maxima analyzed in planktonic and benthic foraminiferal tests, although accompanying changes in sea surface temperature have not been detailed. We present estimated changes in middle Miocene surface-water temperatures based on analysis of ?18O in planktonic foraminifera collected at mid-latitude Deep Sea

Satoshi Ohta; Kunio Kaiho; Tomohiro Takei

2003-01-01

390

Paleoenvironmental inferences from diatom assemblages of the middle Miocene Shanwang Formation, Shandong, China  

Microsoft Academic Search

Diatoms were analyzed in a laminated sediment sequence from the middle Miocene, lacustrine Shanwang Formation, Shandong Province,\\u000a eastern China, to reconstruct past conditions in the lake and evaluate relationships between inferred changes in the aquatic\\u000a and terrestrial environments. Changes in the diatom assemblages over the 22.9-m-long sediment sequence were used to assign\\u000a 19 lithologic layers to five zones. In Zone

Ya-Meng Li; David K. Ferguson; Yu-Fei Wang; Cheng-Sen Li

2010-01-01

391

Marine biological productivity, carbon cycling, and climate cooling during the Oligocene to Miocene transition  

NASA Astrophysics Data System (ADS)

The Oligocene to Miocene boundary (the so-called Mi1 event) marks one of the major Cenozoic cooling steps. A corresponding but slightly out of phase ?13C maximum has been attributed to increased organic matter burial associated with global climate cooling (e.g., Zachos et al., 2001). To test this idea we have constructed records of marine biological productivity (based on benthic foraminiferal accumulation rates, BFAR) to parallel the stable isotope records from 20-25 Ma at three sites from the Atlantic Ocean sampling different hydrographic regimes. Our data show that the ?18O and ?13C maximum that characterize the Oligocene/Miocene boundary is accompanied by a pronounced maximum in BFAR derived paleoproductivity at all sites. In the subtropical Atlantic (Site 1265) and the Southern Ocean (Site 1090), productivity increases about 500 kyr prior to Mi1 in tune with the beginning of enhanced amplitude variations in the benthic foraminiferal ?13C record. In the tropical Atlantic (Site 926), where we have appropriate sampling resolution (~10 kyr), eccentricity-scale variations in paleoproductivity are coherent with the stable isotope records and in-phase with the ?18O values. Paleoproductivity leads ?13C at the 400 kyr period in agreement with the lead of ?18O values with respect to ?13C values. These results illustrate that the link between Oligocene to Miocene climate transition and the carbon cycle is one of marine primary productivity both during the glacial event of Mi1 as well as on eccentricity time scales. The late Oligocene (24 Ma) increase of productivity suggests that a reduction of atmospheric CO2 levels mediated by increased biological productivity may have lead to climate cooling at the Oligocene to Miocene boundary.

Diester-Haass, Liselotte; Billups, Katharina; Emeis, Kay-Christian

2010-05-01

392

An Early Miocene anthropoid skull from the Chilean Andes  

Microsoft Academic Search

PARTLY because of their poor fossil record, the relationships of neotropical platyrrhine monkeys to other groups of primates and to each other remain perhaps the most poorly known for any major primate clade1. Here we report the discovery of a complete platyrrhine skull from the Andes of central Chile, by far the best preserved Tertiary primate cranium from South America.

John J. Flynn; André R. Wyss; Reynaldo Charrier; Carl C. Swisher

1995-01-01

393

Early evidence for complex social structure in Proboscidea from a late Miocene trackway site in the United Arab Emirates  

PubMed Central

Many living vertebrates exhibit complex social structures, evidence for the antiquity of which is limited to rare and exceptional fossil finds. Living elephants possess a characteristic social structure that is sex-segregated and multi-tiered, centred around a matriarchal family and solitary or loosely associated groups of adult males. Although the fossil record of Proboscidea is extensive, the origin and evolution of social structure in this clade is virtually unknown. Here, we present imagery and analyses of an extensive late Miocene fossil trackway site from the United Arab Emirates. The site of Mleisa 1 preserves exceptionally long trackways of a herd of at least 13 individuals of varying size transected by that of a single large individual, indicating the presence of both herding and solitary social modes. Trackway stride lengths and resulting body mass estimates indicate that the solitary individual was also the largest and therefore most likely a male. Sexual determination for the herd is equivocal, but the body size profile and number of individuals are commensurate with those of a modern elephant family unit. The Mleisa 1 trackways provide direct evidence for the antiquity of characteristic and complex social structure in Proboscidea. PMID:22357934

Bibi, Faysal; Kraatz, Brian; Craig, Nathan; Beech, Mark; Schuster, Mathieu; Hill, Andrew

2012-01-01

394

Multivariate statistical analyses of palynodebris from the Middle Miocene of the Niger Delta and their environmental significance  

SciTech Connect

Fourteen types of palynodebris have been identified in Middle Miocene reservoir sediments from the Niger Delta. They include palynomorphs, cuticle, parenchyma, resins, black debris, woody fragments and degraded components. The palynodebris types were interpreted by Principal Components Analysis and Average Linkage Cluster Analysis. Four assemblages of samples emerged and they have been grouped into two palynofacies associations, A/C and B/D, because of their correlation with mudstone and muddy heterolithic lithofacies and sandstone lithofacies, respectively. The significant palynodebris components are black debris, parenchyma, resins and amorphous organic matter. The size, shape and texture of all the components were integrated with sedimentological features, palynomorph and foraminiferal assemblages to recognize seven, possibly eight, deltaic sub-environments of deposition in the reservoir. Mudstones and muddy heteroliths from low energy depositional environments are characterized by small-sized, lath-shaped woody debris, and high concentration of buoyant components such as palynomorphs, cuticles and degraded bundles. The sandstones contain larger and more equidimensional woody fragments. These sediments are also richer in black debris which are believed to be a function of exposure to oxidizing conditions for a longer period of time. Parenchyma and resins, though rare, are characteristic of distributary channel-fill sandstones. 59 refs., 7 figs., 3 tabs.

Oboh, F.E. (Univ. of Missouri, Rolla (United States))

1992-12-01

395

Chewing through the Miocene: an examination of the feeding musculature in the ground sloth Hapalops from South America (Mammalia: Pilosa)  

PubMed Central

Hapalops, a smaller-sized and early sloth of the Megatheroidea, appeared in the middle Miocene Santa Cruz formation of Argentina. This genus is part of the group from which later, larger megatheroids arose, i.e., Nothrotheriops and Megatherium. Many cranial characters support this idea; however Hapalops is not merely a smaller antecedent of the later forms. Specifically, Hapalops retains short anterior caniniform teeth, and a temporomandibular joint elevated above the cheek tooth row; a combination distinct among sloths. An elevated temporomandibular joint occurs in Bradypus, a tree sloth with anterior chisel-shaped teeth instead of caniniforms, and the tree sloth Choloepus, which is aligned with the megalonychids, has anterior caniniforms. Hapalops has an elongated zygomatic ascending process that is reminiscent of that in Bradypus; however, the Bradypus skull is extremely foreshortened while that of Hapalops is elongated, as in nothrotheres, but not deepened as in megatheres. Previous work identified many sloth cranial character complexes, and functional limitations on skull feature combinations. The unique Hapalops character patterns indicate a selective feeder with a mediolaterally oriented grinding stroke during mastication. PMID:25075299

Naples, Virginia L.; McAfee, Robert K.

2014-01-01

396

Chewing through the Miocene: an examination of the feeding musculature in the ground sloth Hapalops from South America (Mammalia: Pilosa).  

PubMed

Hapalops, a smaller-sized and early sloth of the Megatheroidea, appeared in the middle Miocene Santa Cruz formation of Argentina. This genus is part of the group from which later, larger megatheroids arose, i.e., Nothrotheriops and Megatherium. Many cranial characters support this idea; however Hapalops is not merely a smaller antecedent of the later forms. Specifically, Hapalops retains short anterior caniniform teeth, and a temporomandibular joint elevated above the cheek tooth row; a combination distinct among sloths. An elevated temporomandibular joint occurs in Bradypus, a tree sloth with anterior chisel-shaped teeth instead of caniniforms, and the tree sloth Choloepus, which is aligned with the megalonychids, has anterior caniniforms. Hapalops has an elongated zygomatic ascending process that is reminiscent of that in Bradypus; however, the Bradypus skull is extremely foreshortened while that of Hapalops is elongated, as in nothrotheres, but not deepened as in megatheres. Previous work identified many sloth cranial character complexes, and functional limitations on skull feature combinations. The unique Hapalops character patterns indicate a selective feeder with a mediolaterally oriented grinding stroke during mastication. PMID:25075299

Naples, Virginia L; McAfee, Robert K

2014-01-01

397

Fossil wood from the Miocene and Oligocene epoch: chemistry and morphology.  

PubMed

Fossil wood is the naturally preserved remain of the secondary xylem of plants that lived before the Holocene epoch. Typically, fossil wood is preserved as coalified or petrified and rarely as mummified tissue. The process of fossilization is very complex and it is still unknown why in the same fossil record, wood can be found in different fossilisation forms. In 2007, a fossil forest was found in the Bükkábrány open-pit coal mine in Hungary. The non-petrified forest is estimated to be 7 million years old (Miocene epoch) and its trees were found standing in an upright position. This fossil assemblage is exceptionally rare because wood has been preserved as soft waterlogged tissue. This study aimed to investigate this remarkable way of fossil wood preservation, by examining its chemistry with (13) C CPMAS NMR and its morphology with light and electron microscopy. For comparison reasons, a petrified wood trunk from the Oligocene epoch (30 Myr) found in 2001 at Porrentruy region in Switzerland and two fresh wood samples of the modern equivalents of the Miocene sample were also examined. The results obtained showed that the outstanding preservation state of the Miocene fossil is not owed to petrification or coalification. Mummification is a potential mechanism that could explain Bükkábrány trunks' condition, however this fossilisation process is not well studied and therefore this hypothesis needs to be further investigated. Copyright © 2014 John Wiley & Sons, Ltd. PMID:25294390

Bardet, Michel; Pournou, Anastasia

2015-01-01

398

First Occurrence of Platycladus from the Upper Miocene of Southwest China and Its Phytogeographic Implications  

PubMed Central

Platycladus Spach is native to Central China, but its natural occurrences are very difficult to establish. According to molecular phylogenetic data, this genus might have originated since the Oligocene, but no fossil record has been reported. Here, we describe eight foliage branches from the upper Miocene in western Yunnan, Southwest China as a new species, P. yunnanensis sp. nov., which is characterized by foliage branches spread in flattened sprays, and leaves decussate, imbricate, scale-like and dimorphic. The leaves are amphistomatic, and the stomata are elliptical or oblong, haplocheilic, and monocyclic type. Based on a detailed comparison with the extant genera of Cupressaceae sensu lato, our fossils are classified into the genus Platycladus. The occurrence of P. yunnanensis sp. nov. indicates that this genus had a more southernly natural distribution in the late Miocene than at present. Molecular phylogeny and fossil records support a pre-Oligocene common ancestor for the genera Platycladus, Microbiota and Calocedrus. The separation of the three taxa was most likely caused by the arid belt across Central China during the Oligocene. In addition, the cooling down of the global temperature and the strengthening of Asian monsoon since the Miocene will further promote the migration of these genera. PMID:25517767

Li, Qi-Jia; Zhao, Zhen-Rui; Sun, Bai-Nian

2014-01-01

399

Middle Miocene environmental and climatic evolution at the Wilkes Land margin, East Antarctica  

NASA Astrophysics Data System (ADS)

Integrated Ocean Drilling Program (IODP) Expedition 318 successfully drilled a Middle Miocene (~ 17 - 12.5 Ma) record from the Wilkes Land Margin at Site U1356A (63°18.6138'S, 135°59.9376'E), located at the transition between the continental rise and the abyssal plain at 4003 mbsl. We present a multiproxy palynological (dinoflagellate cyst, pollen and spores), sedimentological and organic geochemical (TEX86, MBT/CBT) study, which unravels the environmental and climate variability across the Miocene Climatic Optimum (MCO, ~17-15 Ma) and the Mid Miocene Climate Transition (MMCT). Several independent lines of evidence indeed suggest a relatively warm climate during the MCO. Dinocyst and pollen assemblage diversity at the MCO is unprecedented for a Neogene Antarctic record and indicates a temperate, sea ice-free marine environment, with woody sub-antarctic vegetation with elements of forest/shrub tundra and peat lands along the coast. These results are further confirmed by relatively warm TEX86-derived Sea Surface Temperatures and mild MBT-derived continental temperatures, and by the absence of glacially derived deposits and very few ice-rafted clasts. A generally colder but highly dynamic environment is suggested for the interval 15-12.5 Ma.

Sangiorgi, F.; Passchier, S.; Salzmann, U.; Schouten, S.; Pross, J.; Bijl, P.; Tauxe, L.; Bendle, J. A.; Escutia, C.; Brinkhuis, H.

2012-12-01

400

Terpenoid Compositions and Botanical Origins of Late Cretaceous and Miocene Amber from China  

PubMed Central

The terpenoid compositions of the Late Cretaceous Xixia amber from Central China and the middle Miocene Zhangpu amber from Southeast China were analyzed by gas chromatography-mass spectrometry (GC-MS) to elucidate their botanical origins. The Xixia amber is characterized by sesquiterpenoids, abietane and phyllocladane type diterpenoids, but lacks phenolic abietanes and labdane derivatives. The molecular compositions indicate that the Xixia amber is most likely contributed by the conifer family Araucariaceae, which is today distributed primarily in the Southern Hemisphere, but widely occurred in the Northern Hemisphere during the Mesozoic according to paleobotanical evidence. The middle Miocene Zhangpu amber is characterized by amyrin and amyrone-based triterpenoids and cadalene-based sesquiterpenoids. It is considered derived from the tropical angiosperm family Dipterocarpaceae based on these compounds and the co-occurring fossil winged fruits of the family in Zhangpu. This provides new evidence for the occurrence of a dipterocarp forest in the middle Miocene of Southeast China. It is the first detailed biomarker study for amber from East Asia. PMID:25354364

Shi, Gongle; Dutta, Suryendu; Paul, Swagata; Wang, Bo; Jacques, Frédéric M. B.

2014-01-01

401

Nuciruptor rubricae, a new pitheciin seed predator from the Miocene of Colombia.  

PubMed

A new genus and species of platyrrhine primate, Nuciruptor rubricae, are added to the increasingly diverse primate fauna from the middle Miocene of La Venta, Columbia. This species displays a number of dental and gnathic features indicating that it is related to living and extinct Pitheciinae (extant Callicebus, Pithecia, Chiropotes, Cacajao, and the Colombian middle Miocene Cebupithecia sarmientoi). Nuciruptor is markedly more derived than Callicebus but possesses a less derived mandibular form and incisor-canine complex than extant and extinct pitheciins (Cebupithecia, Pithecia, Chiropotes, and Cacajao), suggesting that it is a primitive member of the tribe Pitheciini within the larger monophyletic Pitheciinae. Nuciruptor has procumbent and moderately elongate lower incisors and low-crowned molars, suggesting that is was a seed predator, as are living pitheciins. Its estimated body size of approximately 2.0 kg places it within the size range of extant pitheciines. The dental and gnathic morphology of Nuciruptor clarifies several aspects of dental character evolution in Pitheciinae and makes it less likely that the enigmatic Mohanamico hershkovitzi (m. Miocene, Columbia) is a pitheciin. PMID:9098507

Meldrum, D J; Kay, R F

1997-03-01

402

Dental microwear profilometry of African non-cercopithecoid catarrhines of the Early Miocene.  

PubMed

The Early Miocene of Kenya has yielded the remains of many important stem catarrhine species that provide a glimpse of the East African primate radiation at a time of major faunal turnover. These taxa have been subject to innumerable studies, yet there is still no consensus on their dietary niches. Here we report results of an analysis of dental microwear textures of non-cercopithecoid catarrhines from the Early Miocene of Kenya. Scanning confocal profilometry of all available molar specimens with undamaged occlusal surfaces revealed 82 individuals with unobscured antemortem microwear, representing Dendropithecus, Micropithecus, Limnopithecus, Proconsul, and Rangwapithecus. Scale-sensitive fractal analysis was used to generate microwear texture attributes for each individual, and the fossil taxa were compared with each other using conservative non-parametric statistical tests. This study revealed no discernible variation in microwear texture among the fossil taxa, which is consistent with results from a previous feature-based microwear study using smaller samples. Our results suggest that, despite their morphological differences, these taxa likely often consumed foods with similar abrasive and fracture properties. However, statistical analyses of microwear texture data indicate differences between the Miocene fossil sample and several extant anthropoid primate genera. This suggests that the African non-cercopithecoid catarrhines included in our study, despite variations in tooth form, had generalist diets that were not yet specialized to the degree of many modern taxa. PMID:25282274

Shearer, Brian M; Ungar, Peter S; McNulty, Kieran P; Harcourt-Smith, William E H; Dunsworth, Holly M; Teaford, Mark F

2015-01-01

403

Marine biological productivity and carbon cycling during the Oligocene to Miocene climate transition  

NASA Astrophysics Data System (ADS)

The Oligocene to Miocene boundary marks one of the major Cenozoic cooling steps. A corresponding but slightly out of phase ?13C maximum has been attributed to increased organic matter burial associated with global climate cooling (e.g., Zachos et al., 2001). To test this idea we have constructed records of marine biological productivity (based on benthic foraminiferal accumulation rates, BFAR) and sequestration of total organic carbon (TOC) in pelagic sediments to parallel the stable isotope records from 20-25 Ma. Here we present first results from Ceara Rise Site 926 located in the tropical northwestern Atlantic. Our data show that the ?18O/?13C maximum that characterized the Oligocene/Miocene boundary is accompanied by a pronounced maximum in BFAR derived paleoproductivity. In addition, there are longer term variations in paleoproductivity that follow the well established eccentricity-scale variations in the ?18O and ?13C record. Cross-spectral analysis focusing on the Oligocene/Miocene boundary interval (22-24 Ma), for which we have an average sampling resolution of about 10 kyr, verifies that paleoproductivity is coherent with the stable isotope records above the 80% level. These results support the hypothesis that there is a relationship between global climate cooling and the carbon cycle via marine primary productivity.

Billups, K.; Diester-Haass, L.; Emeis, K.

2009-12-01

404

First occurrence of platycladus from the upper miocene of southwest china and its phytogeographic implications.  

PubMed

Platycladus Spach is native to Central China, but its natural occurrences are very difficult to establish. According to molecular phylogenetic data, this genus might have originated since the Oligocene, but no fossil record has been reported. Here, we describe eight foliage branches from the upper Miocene in western Yunnan, Southwest China as a new species, P. yunnanensis sp. nov., which is characterized by foliage branches spread in flattened sprays, and leaves decussate, imbricate, scale-like and dimorphic. The leaves are amphistomatic, and the stomata are elliptical or oblong, haplocheilic, and monocyclic type. Based on a detailed comparison with the extant genera of Cupressaceae sensu lato, our fossils are classified into the genus Platycladus. The occurrence of P. yunnanensis sp. nov. indicates that this genus had a more southernly natural distribution in the late Miocene than at present. Molecular phylogeny and fossil records support a pre-Oligocene common ancestor for the genera Platycladus, Microbiota and Calocedrus. The separation of the three taxa was most likely caused by the arid belt across Central China during the Oligocene. In addition, the cooling down of the global temperature and the strengthening of Asian monsoon since the Miocene will further promote the migration of these genera. PMID:25517767

Wu, Jing-Yu; Ding, Su-Ting; Li, Qi-Jia; Zhao, Zhen-Rui; Sun, Bai-Nian

2014-01-01

405

The palaeoclimatic significance of Eurasian Giant Salamanders (Cryptobranchidae: Zaissanurus, Andrias) - indications for elevated humidity in Central Asia during global warm periods (Eocene, late Oligocene warming, Miocene Climate Optimum)  

NASA Astrophysics Data System (ADS)

Cryptobranchids represent a group of large sized (up to 1.8 m) tailed amphibians known since the Middle Jurassic (Gao & Shubin 2003). Two species are living today in eastern Eurasia: Andrias davidianus (China) and A. japonicus (Japan). Cenozoic Eurasian fossil giant salamanders are known with two genera and two or three species from over 30 localities, ranging from the Late Eocene to the Early Pliocene (Böhme & Ilg 2003). The Late Eocene species Zaissanurus beliajevae is restricted to the Central Asian Zaissan Basin (SE-Kazakhstan, 50°N, 85°E), whereas the Late Oligocene to Early Pliocene species Andrias scheuchzeri is distributed from Central Europe to the Zaissan Basin. In the latter basin the species occur during two periods; the latest Oligocene and the late Early to early Middle Miocene (Chkhikvadse 1982). Andrias scheuchzeri is osteological indistinguishable from both recent species, indicating a similar ecology (Westfahl 1958). To investigate the palaeoclimatic significance of giant salamanders we analyzed the climate within the present-day distribution area and at selected fossil localities with independent palaeoclimate record. Our results indicate that fossil and recent Andrias species occur in humid areas where the mean annual precipitation reach over 900 mm (900 - 1.300 mm). As a working hypothesis (assuming a similar ecology of Andrias and Zaissanurus) we interpret occurrences of both fossil Eurasian giant salamanders as indicative for humid palaeoclimatic conditions. Based on this assumption the Late Eocene, the latest Oligocene (late Oligocene warming) and the late Early to early Middle Miocene (Miocene Climatic Optimum) of Central Asia (Zaissan Basin) are periods of elevated humidity, suggesting a direct (positive) relationship between global climate and Central Asian humidity evolution. Böhme M., Ilg A. 2003: fosFARbase, www.wahre-staerke.com/ Chkhikvadze V.M. 1982. On the finding of fossil Cryptobranchidae in the USSR and Mongolia. Vertebrata Hungarica, 21: 63-67. Gao K.-Q., Shubin N.H. 2003. Earliest known crown-group Salamanders. Nature, 422: 424-428. Westphal F. 1958. Die Tertiären und rezenten Eurasiatischen Riesensalamander. Palaeontolographica Abt. A, 110: 20-92.

Vasilyan, Davit; Böhme, Madelaine; Winklhofer, Michael

2010-05-01

406

Palinspastic reconstruction of southeastern California and southwestern Arizona for the middle Miocene  

NASA Technical Reports Server (NTRS)

A paleogeographic reconstruction of southeastern California and southwestern Arizona at 10 Ma was made based on available geologic and geophysical data. Clockwise rotation of 39 deg was reconstructed in the eastern Transverse Ranges, consistent with paleomagnetic data from late Miocene volcanic rocks, and with slip estimates for left-lateral faults within the eastern Transverse Ranges and NW-trending right lateral faults in the Mojave Desert. This domain of rotated rocks is bounded by the Pinto Mountain fault on the north. In the absence of evidence for rotation of the San Bernardino Mountains or for significant right slip faults within the San Bernardino Mountains, the model requires that the late Miocene Pinto Mountain fault become a thrust fault gaining displacement to the west. The Squaw Peak thrust system of Meisling and Weldon may be a western continuation of this fault system. The Sheep Hole fault bounds the rotating domain on the east. East of this fault an array of NW-trending right slip faults and south-trending extensional transfer zones has produced a basin and range physiography while accumulating up to 14 km of right slip. This maximum is significantly less than the 37.5 km of right slip required in this region by a recent reconstruction of the central Mojave Desert. Geologic relations along the southern boundary of the rotating domain are poorly known, but this boundary is interpreted to involve a series of curved strike slip faults and non-coaxial extension, bounded on the southeast by the Mammoth Wash and related faults in the eastern Chocolate Mountains. Available constraints on timing suggest that Quaternary movement on the Pinto Mountain and nearby faults is unrelated to the rotation of the eastern Transverse Ranges, and was preceded by a hiatus during part of Pliocene time which followed the deformation producing the rotation. The reconstructed Clemens Well fault in the Orocopia Mountains, proposed as a major early Miocene strand of the San Andreas fault, projects eastward towards Arizona, where early Miocene rocks and structures are continuous across its trace. The model predicts a 14 deg clockwise rotation and 55 km extension along the present trace of the San Andreas fault during late Miocene and early Pliocene time. Palinspastic reconstructions of the San Andreas system based on this proposed reconstruction may be significantly modified from current models.

Richard, Stephen M.

1992-01-01

407

Palynology, paleoclimatology and correlation of middle Miocene beds from Porcupine River (locality 90-1), Alaska  

USGS Publications Warehouse

Beds in the Upper Ramparts Canyon of the Porcupine River, Alaska (67?? 20' N, 141?? 20' W), yielded a flora rich in pollen of hardwood genera now found in the temperate climates of North America and Asia. The beds are overlain or enclosed by two basalt flows which were dated to 15.2 ?? 0.1 Ma by the 40Ar 39Ar method, fixing the period of the greatest abundance of warm-loving genera to the early part of the middle Miocene. The assemblage is the most northern middle Miocene flora known in Alaska. Organic bed 1 underlies the basalt and is older than 15.2 Ma, but is of early to middle Miocene age. The pollen assemblage from organic bed 1 is dominated by conifer pollen from the pine and redwood-cypress-yew families with rare occurrences of temperate hardwoods. Organic bed 2 is a forest floor containing redwood trees in life position, engulfed by the lowest basalt flow. A pine log has growth rings up to 1 cm thick. Organic beds 3 and 4 comprise lacustrine sediment and peat between the two basalt flows. Their palynoflora contain conifers and hardwood genera, of which about 40% have modern temperate climatic affinities. Hickory, katsura, walnut, sweet gum, wingnut, basswood and elm pollen are consistently present, and beech and oak alone make up about 20% of the pollen assemblage. A warm high latitude climate is indicated for all of the organic beds, but organic bed 3 was deposited under a time of peak warmth. Climate data derived by comparison with modern east Asian vegetation suggest that, at the time of deposition of organic bed 3, the Mean Annual Temperature (MAT) was ca. 9??C, the Warm Month Mean Temperature (WMMT) was ??? 20??C and the Cold Month Mean Temperature (CMMT) was ca. -2??C. In contrast, the modern MAT for the region is -8.6??C, WMMT is 12.6??C and CMMT is -28??C. Organic beds 3 and 4 correlate to rocks of the middle Miocene-late Seldovian Stage of Cook Inlet and also probably correlate to, and more precisely date, the lower third of the Suntrana Formation in the Alaska Range, beds at Unalaklect, part of the upper Mackenzie Bay sequence in the Beaufort-Mackenzie basin, and the Mary Sachs gravel of Banks Island. This suggests that forests with significant percentages of temperate deciduous angiosperms existed between latitudes 60?? and 72??N during the early middle Miocene. ?? 1994.

White, J.M.; Ager, T.A.

1994-01-01

408

The strontium isotope seawater curve during the early Middle Miocene and its relation to paleoceanographic events  

SciTech Connect

Breaks in slope of the strontium isotope seawater curve signal fundamental changes in either rates of continental weathering, seafloor spreading (i.e., tectonic reorganizations), or submarine dissolution of marine carbonates. The authors conducted a detailed study of the change in slope of the strontium isotopic seawater curve that occurred during the early middle Miocene in three Pacific DSDP sites (289, 574, and 588). The change in slope from the rapid rise in Sr-87/Sr-86 of the early Miocene (60 ppm/Ma) to the less rapid increase of the mid- and late Miocene (22 ppm/Ma) occurred between two periods of maximum [delta]C-13 values dated between 15.5 and 15.2 Ma. This internal was followed by relatively constant Sr-87/Sr-86 values (averaging 0.70878) between 15.2 and 14.2 Ma. Sr-87/Sr-86 ratios began to increase again after 14.2 Ma, but at a reduced rate compared to the early Miocene. The break in slope in Sr-87/Sr-86 preceded the mid-Miocene increase in [delta]O-18 that represents ice growth on Antarctica, which began at 14.9 Ma and increased rapidly after 14.2 Ma. In 2 out of 3 of the sites, the break in Sr-slope between 15.5 and 15.2 Ma is accompanied by a small, but significant, decrease in Sr-87/Sr-86 values. They speculate, that this decrease in Sr-87/Sr-86 may have been related to massive dissolution of older carbonate on the sea floor associated with NH2B (Neogene Hiatus 2 of Keller and Barron, 1983). This event may have important implications for changes in carbonate chemistry of the oceans. Numerical modeling of the strontium isotope budget will be used to test the feasibility of this mechanism and to estimate the volume and age of dissolved carbonate needed to produce the observed decrease in Sr-87/Sr-86.

Hodell, D.A. (Univ. of Florida, Gainesville, FL (United States). Dept. of Geology); Woodruff, F. (Univ. of Southern California, Los Angeles, CA (United States). Dept. Geological Sciences)

1992-01-01

409

The Late Miocene paleogeography of the Amazon Basin and the evolution of the Amazon River system  

NASA Astrophysics Data System (ADS)

On the basis of paleontological content (vertebrates and palynology) and facies analysis from river banks, road cuts, and three wells, we have assigned the uppermost levels of the Solimões Formation in western Amazonia, Brazil, to the Late Miocene. The vertebrate fossil record from outcropping sediments is assigned to the Huayquerian-Mesopotamian mammalian biozones, spanning 9-6.5 Ma. Additionally, we present results that demonstrate that deposits in Peruvian Amazonia attributed to Miocene tidal environments are actually fluvial sediments that have been misinterpreted (both environmentally and chronologically) by several authors. The entire Late Miocene sequence was deposited in a continental environment within a subsiding basin. The facies analysis, fossil fauna content, and palynological record indicate that the environment of deposition was dominated by avulsive rivers associated with megafan systems, and avulsive rivers in flood basins (swamps, lakes, internal deltas, and splays). Soils developed on the flatter, drier areas, which were dominated by grasslands and gallery forest in a tropical to subtropical climate. These Late Miocene sediments were deposited from westward of the Purus arch up to the border of Brazil with Peru (Divisor Ranges) and Bolivia (Pando block). Eastward of the Iquitos structural high, however, more detailed studies, including vertebrate paleontology, need to be performed to calibrate with more precision the ages of the uppermost levels of the Solimões Formation. The evolution of the basin during the late Miocene is mainly related to the tectonic behavior of the Central Andes (˜ 3°-15°S). At approximately 5 Ma, a segment of low angle of subduction was well developed in the Nazca Plate, and the deformation in the Subandean foreland produced the inland reactivation of the Divisor/Contamana Ranges and tectonic arrangements in the Eastern Andes. During the Pliocene southwestern Brazilian Amazonia ceased to be an effective sedimentary basin, and became instead an erosional area that contributed sediments to the Amazon fluvial system. At that time, the lowland fluvial systems of southwestern Amazonia (the Purus, Jurua and Javarí basins) become isolated from the Andes by the newly formed north-flowing Ucayali system and south-east flowing Madre de Dios System. It was during the early Pliocene that the Amazon fluvial system integrated regionally and acquired its present appearance, and also when it started to drain water and sediments on a large scale to the Atlantic Ocean.

Latrubesse, Edgardo M.; Cozzuol, Mario; da Silva-Caminha, Silane A. F.; Rigsby, Catherine A.; Absy, Maria Lucia; Jaramillo, Carlos

2010-05-01

410

The Cenozoic Diversity of Agglutinated Foraminifera - Evidence for a late Oligocene to early Miocene diversification event  

NASA Astrophysics Data System (ADS)

The agglutinated foraminifera are among the most abundant micro-organisms in the deep marine environment and have a diversity record extending back to the late Precambrian. We present an updated diversity curve for agglutinated foraminiferal genera based on the stratigraphic ranges of all the agglutinated genera recognized as valid in the classification of Kaminski (2014). The data set for this analysis is based on the stratigraphic ranges of agglutinated genera published in Foraminiferal Genera and their Classification, which has been subsequently updated based on published studies and our new observations. The mean standing diversity of agglutinated foraminiferal genera was compiled by counting the number of boundary crossers rather than the number of genera in each stage. In this study, we report the stratigraphic and geographical occurrence of a benthic foraminiferal diversification event that has previously received little attention. In the latest Oligocene to earliest Miocene a number of trochospiral agglutinated genera with alveolar or canaliculate walls first appeared in the fossil record. Our studies of late Oligocene of the Congo fan, offshore Angola (Kender et al., 2008; Cetean and Kaminski, 2011) have revealed a diverse assemblage that includes new taxa of deep-water agglutinated foraminifera. In a biostratigraphic study of the Miocene foraminiferal assemblages Kender et al. (2008) noted steadily increasing diversity and proportions of infaunal agglutinated foraminiferal morphotypes over the lower Miocene interval. The proportion of infaunal agglutinated foraminifera assigned to the order Textularida increased dramatically in the lower mid-Miocene, suggesting expansion of the oxygen minimum zone into deeper waters. In addition to the trochospiral alveolar genera, several species of Reticulophragmium and Cyclammina display rapid diversification into numerous separate lineages that are at present not reflected in our generic diversity record owing to their poorly established taxonomy. Genera such as Alveovalvulina, Guppyella, Goesella, and Alveovalvulinella, are typical of assemblages found in subtropical oxygen minimum zones, especially in West Africa and the Caribbean. These agglutinated genera are not found in coeval assemblages from the northern high latitudes (Kaminski et al. 2005), suggesting they are restricted to the low-latitude OMZ. It is likely that the global warming of the latest Oligocene to Early Miocene contributed to intensification of dysoxic conditions in low-latitude upwelling regions, possibly from enhanced productivity and reduced deep-sea ventilation, creating an expanded niche for these organisms that flourished in low-oxygen conditions with high particulate organic matter input. We believe a more detailed phylogenetic approach to these agglutinated genera would result in the description of new genera for individual lineages and refinement of the foraminiferal diversity record.

Kaminski, Michael; Setoyama, Eiichi; Kender, Sev; Cetean, Claudia

2014-05-01

411

Paleo-environment in the upper amazon basin during early to middle Miocene times  

NASA Astrophysics Data System (ADS)

The Amazon River has the largest catchment in the world and is responsible for the largest water discharge from land to the ocean. The river system that flows from the Andes to the Atlantic Equatorial Margin exists since the late Miocene, and results from Andean uplift which strongly affected erosion/deposition and major flow patterns in northern South-America. Two outcrop sites from the Solimões basin, Mariñame (17.7-16.1 Ma) and Los Chorros (14.2-12.7 Ma), may shed light on the inland paleo-environmental conditions during a period of active Andean uplift in the early to middle Miocene. Earlier works revealed the Mariñame outcrops to represent a river born in Amazonia. Instead the Los Chorros outcrops are relics of the Amazon River system, characterized by extensive wetlands consisting of swamps, shallow lakes, crevasse splays channels and crevasse-delta lakes (e.g. Hoorn et al., 2010). The freshwater ecosystems alternate with some intervals that are rich in marine palynomorphs (such as dinocysts), mangrove pollen, brackish tolerant molluscs and ostracods, which indicate brackish conditions and a marine influence. It is thought that these marine incursion are related to phases of global sea-level rise and rapid subsidence in the Andean foreland (Marshall & Lundberg, 1996). Still, much remains unknown about the Miocene river systems, like the extent and diversity of the wetland system and the nature of the marine incursions. To get a better understanding of the sources of the (in)organic material, geochemical methods were used. Strontium (Sr) and Neodymium (Nd) isotopes were analyzed on bulk sediments, and used for a paleo-provenance study. The Sr and Nd isotopic signature in the older section (Mariñame) is in general more radiogenic compared to the Los Chorros section. The most radiogenic values are comparable to those found nowadays in the the Precambrian Guyana shield. A Guyana sediment source would suggest a distinctly different flow direction of the major rivers during early-middle Miocene. The younger Los Chorros sediments show Sr and Nd values comparable to those nowadays found in the Solimões region, indicating an Andean source existed already during early-middle Miocene times. Lipid biomarkers were identified and quantified and carbon isotopic compositions of organic matter for whole samples were determined to identify the sources of organic matter. Ratio's between typically terrestrial and aquatic GDGTs indicate shifts between more terrestrial settings and more aquatic settings. Intervals which suggest a more aquatic setting often contain marine palynomorphs and thus could result from a marine incursion at the time. Changes in the overall composition of biomarker lipids at each site reflects the diversity and dynamic features of the wetland. Differences in both provenance and biomarker composition between the two sites demonstrate the diversity within the basin. This diversity could either be geographical diversity since the two sites are located about 380 km from each other. Or, considering the differences in age between the two sites of 2-5 Myrs, it could also reflect the fast changing environmental conditions as a result of Andean uplift. Hoorn, C. et al (2010). The Development of the Amazonian Mega-Wetland (Miocene; Brazil, Colombia, Peru, Bolivia). In: C. Hoorn and F. Wesselingh (eds) Amazonia: Landscape and Species Evolution: A look into the past. Wiley-Blackwell Publishing Ltd., pp. 123- 142. Marshall, L.G., Lundberg, J.G. (1996) Miocene deposits in the Amazonian Foreland Basin. Science 273, 123-124.

van Soelen, Els; Hoorn, Carina; Santos, Roberto V.; Dantas, Elton L.; Sinninghe Damsté, Jaap S.; Kim, Jung-Hyun

2014-05-01

412

Assessment of East Antarctic ice flow directions, ice grounding events, and glacial thermal regime across the middle Miocene climate transition from the ANDRILL-SMS and CRP drill holes  

NASA Astrophysics Data System (ADS)

Here we present a synthesis of early and middle Miocene ice sheet development based on facies analyses and multiple compositional studies on the AND-2A and CRP drillcores from the Ross Sea, ca. 10 km off the coast of East Antarctica. The middle Miocene is characterized by one of the three largest shifts in deep-sea oxygen isotope records. During this time the East Antarctic ice sheet became dry-based at high elevation in the Transantarctic Mountains and advanced across the Ross Sea continental shelf to create widespread glacial unconformities. However, detailed proxy records also indicate that ice development was complex and may have occurred in a stepwise fashion, instead of one major episode. Our analyses of “grounded ice” diamictites from both the CRP and AND-2A cores show a significant change in composition across the middle Miocene transition. More detailed analyses of the stratigraphic distribution of facies, heavy mineral provenance, particle size, and major and trace element geochemistry in AND-2A show that relatively large polythermal ice-sheets similar in size to the modern were already present between 17.6 and 17.1 Ma. These results are in agreement with proxy records suggesting that Antarctic ice volumes were larger than today’s volume during the Mi-1b glaciation. Between 17.1 and 15.6-14.9 Ma, a predominance of iceberg debris sourced from the Ferrar Group in the Transantarctic Mountains suggests vigorous glacial erosion and fjord incision by East Antarctic outlet glaciers. The facies characteristics and comparison with compositional data from Neogene tills in the Transantarctic Mountains further suggest that the East Antarctic ice sheet may have been smaller than today during the Miocene climatic optimum (~17-15 Ma) with ice possibly reaching sea level only near the central Transantarctic Mountains. Advance of the grounding line and the development of glacial flow patterns compatible with a larger ice sheet than the modern commenced between 15.6 and 14.7 Ma and was established prior to 14.2 Ma. These results suggest an earlier onset of Antarctic ice growth across the middle Miocene climate transition than is generally inferred from geochemical proxy records.

Passchier, S.; Hauptvogel, D.; Hansen, M.; Falk, C.; Martin, L.

2010-12-01

413

S concentrations and its speciation in Miocene basaltic magmas north and south of Gran Canaria (Canary Islands): constraints from glass inclusions in olivine and clinopyroxene  

NASA Astrophysics Data System (ADS)

We report S concentrations and relative proportions of SO 42- and S 2- in OL- and CPX-hosted glass inclusions and in host glassy lapilli from Miocene basaltic hyaloclastites drilled north and south of Gran Canaria during ODP Leg 157. Compositions of glass inclusions and lapilli resemble those of subaerial Miocene shield basalts on Gran Canaria and comprise mafic to more evolved tholeiitic to alkali basalt and basanite (10.3-3.7 wt.% MgO, 44.5-56.9 wt.% SiO 2). Glass inclusions fall into three groups based on their S concentrations: a high-sulfur group (1050 to 5810 ppm S), an intermediate-sulfur group (510 to 1740 ppm S), and a low-sulfur group (<500 ppm S). The most S-rich inclusions have the highest and nearly constant proportion of sulfur dissolved as sulfate determined by electron microprobe measurements of S K? peak shift. Their average S 6+/S total value is 0.75 ± 0.09, unusually high for ocean island basalt magmas. The low-sulfur group inclusions have low S 6+/S total ratios (0.08 ± 0.05), whereas intermediate sulfur group inclusions show a wide range of S 6+/S total (0.05-0.83). Glassy lapilli and their crystal-hosted glass inclusions with S concentrations of 50 to 1140 ppm S have very similar S 6+/S total ratios of 0.36 ± 0.06 implying that sulfur degassing does not affect the proportion of SO 42- and S 2- in the magma. The oxygen fugacities estimated from S 6+/S total ratios and from Fe 3+/Fe 2+ ratios in spinel inclusions range from NNO-1.1 to NNO+1.8. The origin of S-rich magmas is unclear. We discuss (1) partial melting of a mantle source at relatively oxidized fO 2 conditions, and (2) magma contamination by seawater either directly or through magma interaction with seawater-altered Jurassic oceanic crust. The intermediate sulfur group inclusions represent undegassed or slightly degassed magmas similar to submarine OIB glasses, whereas the low-sulfur group inclusions are likely to have formed from magmas significantly degassed in near-surface reservoirs. Mixing of these degassed magmas with stored volatile-rich ones or volatile-rich magma replenishing the chamber filled by partially degassed magmas may produce hybrid melts with strongly varying S concentrations and S 6+/S total ratios.

Gurenko, Andrey A.; Schmincke, Hans-Ulrich

2000-07-01

414

Dated molecular phylogenies indicate a Miocene origin for Arabidopsis thaliana.  

PubMed

Dated molecular phylogenies are the basis for understanding species diversity and for linking changes in rates of diversification with historical events such as restructuring in developmental pathways, genome doubling, or dispersal onto a new continent. Valid fossil calibration points are essential to the accurate estimation of divergence dates, but for many groups of flowering plants fossil evidence is unavailable or limited. Arabidopsis thaliana, the primary genetic model in plant biology and the first plant to have its entire genome sequenced, belongs to one such group, the plant family Brassicaceae. Thus, the timing of A. thaliana evolution and the history of its genome have been controversial. We bring previously overlooked fossil evidence to bear on these questions and find the split between A. thaliana and Arabidopsis lyrata occurred about 13 Mya, and that the split between Arabidopsis and the Brassica complex (broccoli, cabbage, canola) occurred about 43 Mya. These estimates, which are two- to threefold older than previous estimates, indicate that gene, genomic, and developmental evolution occurred much more slowly than previously hypothesized and that Arabidopsis evolved during a period of warming rather than of cooling. We detected a 2- to 10-fold shift in species diversification rates on the branch uniting Brassicaceae with its sister families. The timing of this shift suggests a possible impact of the Cretaceous-Paleogene mass extinction on their radiation and that Brassicales codiversified with pierid butterflies that specialize on mustard-oil-producing plants. PMID:20921408

Beilstein, Mark A; Nagalingum, Nathalie S; Clements, Mark D; Manchester, Steven R; Mathews, Sarah

2010-10-26

415

The Owen Ridge uplift in the Arabian Sea: implications for the sedimentary record of Indian monsoon in Late Miocene  

NASA Astrophysics Data System (ADS)

The pelagic cover of the Owen Ridge in the Arabian Sea recorded the evolution of the Indian monsoon since the Middle Miocene. The uplift of the Owen Ridge resulted from tectonic processes along the unidentified fossil Miocene India-Arabia plate boundary. Based on seismic reflection data tied with deep-sea drillings to track the Miocene India-Arabia plate boundary, we propose a new timing for the uplift of the Owen Ridge and highlight its impact on the record of climate changes in pelagic sediments. The new dataset reveals a fracture zone east of the Owen Ridge corresponding to the fossil plate boundary, and documents that the main uplift of the Owen Ridge occurred close to ~8.5 Ma, and is coeval with a major uplift of the east Oman margin. Late Miocene deformation at the India-Arabia plate boundary is also coeval with the onset of intra-plate deformation in the Central Indian Ocean, suggesting a kinematic change of India and surrounding plates in the Late Miocene. The uplift of the Owen Ridge above the lysocline at ~8.5 Ma accounts for a better preservation of Globigerina bulloides in the pelagic cover, previously misinterpreted as the result of a monsoon intensification event.

Rodriguez, Mathieu; Chamot Rooke, Nicolas; Huchon, Philippe; Fournier, Marc; Delescluse, Matthias

2014-05-01

416

The Owen Ridge uplift in the Arabian Sea: Implications for the sedimentary record of Indian monsoon in Late Miocene  

NASA Astrophysics Data System (ADS)

The pelagic cover of the Owen Ridge in the Arabian Sea recorded the evolution of the Indian monsoon since the Middle Miocene. The uplift of the Owen Ridge resulted from tectonic processes along the previously unidentified Miocene India-Arabia plate boundary. Based on seismic reflection data tied with deep-sea drilling to track the Miocene India-Arabia plate boundary, we propose a new timing for the uplift of the Owen Ridge and highlight its impact on the record of climate changes in pelagic sediments. The new dataset reveals a fracture zone east of the Owen Ridge corresponding to the fossil plate boundary, and documents that the main uplift of the Owen Ridge occurred close to ˜8.5 Ma, and is coeval with a major uplift of the east Oman margin. Late Miocene deformation at the India-Arabia plate boundary is also coeval with the onset of intra-plate deformation in the Central Indian Ocean, suggesting a kinematic change of India and surrounding plates in the Late Miocene. The uplift of the Owen Ridge above the lysocline at ˜8.5 Ma accounts for a better preservation of Globigerina bulloides in the pelagic cover, previously misinterpreted as the result of a monsoon intensification event.

Rodriguez, Mathieu; Chamot-Rooke, Nicolas; Huchon, Philippe; Fournier, Marc; Delescluse, Matthias

2014-05-01

417

Paleogeographic and geodynamic Miocene evolution of the Tunisian Tell (Numidian and Post-Numidian Successions): bearing with the Maghrebian Chain  

NASA Astrophysics Data System (ADS)

The Numidian and Post-Numidian stratigraphy of the Tunisian Tell has been updated based on 16 stratigraphic sections belonging to the Massylian sub-domain of the Maghrebian Flysch Basin and to the External Domain. The new data concern detailed litho- and biostratigraphy, gaps, synchronous marker levels, lateral correlations, tectonic contacts, etc. The successions studied show many diachronous and unconformity boundaries delimiting sedimentary depositional sequences related to some tectonic/sedimentary processes. Two main Miocene sedimentary successions (Numidian and Post-Numidian) are recognized overlying the Sub-Numidian Succession (pre-Early Aquitanian) by new integrated (planktonic foraminifera and calcareous nannoplankton) chronostratigraphic analyses, allowing an update of the formations studied. The Miocene tectonic/sedimentary relationships and the timing of the deformation are summarized as follows: (1) the activation of a foredeep stage and a tectogenesis phase gives rise to an accretionary orogenic wedge during mainly the Early Miocene; (2) a late-orogenic phase is checked in the Late Burdigalian-Early Langhian characterized by a marine glauconitic terrigenous sedimentation; (3) a post-orogenic generalized phase is confirmed from the Middle Miocene on in shallow marine or continental sedimentation. These results show good correlation along the Maghrebian Chain and Betic Cordillera. Finally, a paleogeographic and geodynamic evolutionary model concerning the Miocene African Tunisian Margin is postulated.

Belayouni, Habib; Guerrera, Francesco; Martín-Martín, Manuel; Serrano, Francisco

2013-04-01

418

A drastic lower Miocene regolith evolution triggered by post obduction slab break-off and uplift in New Caledonia  

NASA Astrophysics Data System (ADS)

lower Miocene coarse conglomerate that crops out in the Népoui Peninsula does not represent the base of the marine transgression that followed obduction in New Caledonia. Instead, the conglomeratic alluvial fan that contains peridotite cobbles and reworked weathering products records a short-lived episode of terrestrial erosion intercalated between two intervals of subsidence marked by marine carbonate deposition. Considering the Miocene sea level evolution reported in the literature, it is concluded that neither lower Miocene transgression nor erosion were driven by sea level variation. In contrast, a southeastward propagating slab tear that initiated at the latitude of the high pressure/low temperature metamorphic complex of northern New Caledonia likely generated east to west tilting of New Caledon