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Systematics, Diversity, And Origins Of Upper Cretaceous Continental Molluscan Fauna In The Infra- And Intertrappean Strata Of The Deccan Plateau, Central India, Marron J. Bingle-Davis Jan 2012

Systematics, Diversity, And Origins Of Upper Cretaceous Continental Molluscan Fauna In The Infra- And Intertrappean Strata Of The Deccan Plateau, Central India, Marron J. Bingle-Davis

Theses and Dissertations

The Deccan Plateau in western and central India has been a major area of interest for researchers since the 1800s. In 1840, James Sowerby described the molluscan collection sent to him by John Malcolmson. In 1860, Stephen Hislop identified new molluscan species and redescribed based on better preserved material. Although this seminal work was comprehensive, interpretations have changed since the mid 1800s. Species need to be reassigned to current and/or accurate taxa, as well as revalidated statistically. Seventeen character traits were measured on over 600 specimens from five eastern Deccan Plateau localities representing a stratigraphic and temporal sequence. Cluster analysis …


An Integrated Geophysical And Geologic Study Of The Paleogene-Age Volcanic Body And Possible Landslide Deposit On The South Slope Of The Traverse Mountains, Utah, John C. Hoopes Dec 2011

An Integrated Geophysical And Geologic Study Of The Paleogene-Age Volcanic Body And Possible Landslide Deposit On The South Slope Of The Traverse Mountains, Utah, John C. Hoopes

Theses and Dissertations

Development of homes, roads, and commercial buildings in northern Utah has grown significantly during the last several decades. Construction has expanded from the valley floor to higher elevations of benches, foothills, and other elevated regions of the Wasatch Mountain Front. Construction in the higher elevation areas are a concern due to potential for landslides, both new and reactivated. Landslides have been identified in this region and are dated as Pleistocene to historical in age. A possible landslide of about 0.5 km2 on the south slope of Traverse Mountain has been mapped by the Utah Geological Survey in 2005. Its surface …


The Impact Of Modern Weathering On The Geochemistry Of A Marine Permo-Triassic Boundary Section, Jeremy Christopher Williams Jun 2011

The Impact Of Modern Weathering On The Geochemistry Of A Marine Permo-Triassic Boundary Section, Jeremy Christopher Williams

Graduate Masters Theses

The Permian-Triassic Boundary (PTB) marks the end-Permian extinction, the greatest mass extinction recorded in Earth's history. The Attargoo PTB section located in Spiti Valley, Himachal Pradesh, India was situated along the north continental margin of Gondwana-land in the Neo-Tethys Ocean during the end-Permian extinction. In Spiti Valley, PTB sections such as Attargoo are exposed by a thin (~ 2cm) ferruginous layer separating the Permian black shale from Triassic Limestone. Studies that have presented geochemical data to support a theory of the end-Permian extinction lack any interpretation of post-depositional effects on Spiti Valley PTB sections. In order to accurately present a …


Memorial To Charles Alexander Baskerville (1928–2009), Allen W. Hatheway, Ajitkumar Shah, Joseph J. Lifrieri, Nazrul I. Khandaker, Stanley Schleifer May 2011

Memorial To Charles Alexander Baskerville (1928–2009), Allen W. Hatheway, Ajitkumar Shah, Joseph J. Lifrieri, Nazrul I. Khandaker, Stanley Schleifer

Publications and Research

Charles Alexander Baskerville captured our imagination, as a senior colleague in the practice of engineering geology in New York City. “Charlie” held the seat of master Big Apple Geologist during his matured career. He was the source, he knew the possibilities, he was aware of the pitfalls of this most geologically complex of American cities. His final work was his greatest reach—the four bedrock geologic quadrangles of the city. Baskerville mapped New York City for more than fifty years. He was sought and given access to sites of bedrock and bedrock/ overburden interface on the various capitol construction projects undertaken …


Taxonomy, Nomenclature, And Evolution Of The Early Schubertellid Fusulinids, Vladimir I. Davydov Mar 2011

Taxonomy, Nomenclature, And Evolution Of The Early Schubertellid Fusulinids, Vladimir I. Davydov

Geosciences Faculty Publications and Presentations

The types of the species belonging to the fusulinid genera Schubertella and Eoschubertella were examined from publications and type collections. Eoschubertella in general possesses all the features of Schubertella and therefore is a junior synonym of the latter. However, the concept of Eoschubertella best describes the genus Schubertina with its type species Schubertina curculi. Schubertina is closely related to the newly established genus Grovesella the concept of which is emended in this paper. Besides Schubertella, Schubertina, and Grovesella, the genera Mesoschubertella, Biwaella are reviewed and three new species, Grovesella nevadensis, Biwaella zhikalyaki, and Biwaella poletaevi, are described. The phylogenetic relationships …


New Data On The Upper Jurassic–Lower Cretaceous Limestones From Bihor Mountains: Case Study Of Gârda Seacă-Hodobana Region, Romania, Valentin Turi, Emanoil Sasaran, Ioan I. Bucur Jan 2011

New Data On The Upper Jurassic–Lower Cretaceous Limestones From Bihor Mountains: Case Study Of Gârda Seacă-Hodobana Region, Romania, Valentin Turi, Emanoil Sasaran, Ioan I. Bucur

Studia UBB Geologia

This study refers to some problems regarding the lithological succession, facies and carbonate microfacies, and to biostratigraphic markers of the Upper Jurassic-Lower Cretaceous carbonates from Bihor Mountains. Three types of facies (external marginal facies, subtidal and peritidal facies) were separated for the Upper Jurassic, and two (coastal-peritidal and open shelf facies) for the Lower Cretaceous carbonates. The micropaleontological assemblages identified contain species that allow the separation of the two formations of different age: Labyrinthina mirabilis, Kurnubia palastiniensis, Neokilianina rahonensis, Clypeina sulcata (Kimmeridgian-Lower Tithonian) and Parakoskinolina? jourdanensis, Montseciella arabica, Palorbitolina lenticularis, Falsolikanella danilovae (Barremian – Lower Aptian). Field observations and data …


Profiles In Science For Science Librarians: "What Lives Where, And Why": Alfred Russel Wallace, And The Field Of Biogeography, Charles H. Smith Jan 2011

Profiles In Science For Science Librarians: "What Lives Where, And Why": Alfred Russel Wallace, And The Field Of Biogeography, Charles H. Smith

DLPS Faculty Publications

Biogeography, the study of animal and plant distribution, has a history extending back to at least the eighteenth century. But it was not until the work of Charles Darwin and Alfred Russel Wallace in the mid-nineteenth century that it really came into its own as a science. Darwin’s importance notwithstanding, it was really Wallace who put the field on the map, and many of today’s research threads can be traced back to his influence. This article provides a summary review of Wallace’s life and work and biogeography as a field of study, including Wallace’s role in its development.


Hydrostratigraphic Interpretation Of Test-Hole And Geophysical Data, Upper Loup River Basin, Nebraska, 2008-10, Christopher M. Hobza, Theodore H. Asch, Paul A. Bedrosian Jan 2011

Hydrostratigraphic Interpretation Of Test-Hole And Geophysical Data, Upper Loup River Basin, Nebraska, 2008-10, Christopher M. Hobza, Theodore H. Asch, Paul A. Bedrosian

United States Geological Survey: Water Reports and Publications

Nebraska's Upper Loup Natural Resources District is currently (2011) participating in the Elkhorn-Loup Model to understand the effect of various groundwater-management scenarios on surface-water resources. During Phase 1 of the Elkhorn-Loup Model, a lack of subsurface geological information in the Upper Loup Natural Resources District, hereafter referred to as the upper Loup study area, was identified as a gap in current knowledge that needed to be addressed. To improve the understanding of the hydrogeology of the upper Loup study area, the United States Geological Survey, in cooperation with the Upper Loup Natural Resources District and the University of Nebraska Conservation …


Apparent Weekly And Daily Earthquake Periodicities In The Western United States, And Evolution Of Wadi Kubbania In Egypt, Ali Hadi Atef Jan 2011

Apparent Weekly And Daily Earthquake Periodicities In The Western United States, And Evolution Of Wadi Kubbania In Egypt, Ali Hadi Atef

Doctoral Dissertations

"The dissertation consists of two separate sections. The first section is on apparent daily and weekly periodicities in earthquake occurrence in the western United State [sic]. Analysis of Apparent Seismicity Rate (ASR) in the western United States confirmed the existence of prominent spectral peaks with a period of 1 and 7 days. The number of recorded earthquakes on Sundays for the duration of 1963-2008 is about 5% higher than that on weekdays, and, more significantly, there is a 9% increase of ASR in the early morning compared with that in the middle of the days. Significant similarities between the spatial …


Stratigraphy, Sedimentology And Palynology Of The Neogene-Pleistocene(?) Rocks Around Akçaşehir- Tire-İzmir (Küçük Menderes Graben, Western Anatolia), Tahi̇r Emre, Meti̇n Tavlan, Mehmet Serkan Akki̇raz, İsmai̇l İşi̇ntek Jan 2011

Stratigraphy, Sedimentology And Palynology Of The Neogene-Pleistocene(?) Rocks Around Akçaşehir- Tire-İzmir (Küçük Menderes Graben, Western Anatolia), Tahi̇r Emre, Meti̇n Tavlan, Mehmet Serkan Akki̇raz, İsmai̇l İşi̇ntek

Turkish Journal of Earth Sciences

The basement rocks located in the central part of the southern edge of the Küçük Menderes Graben, around Akçaşehir-Tire are composed of marbles, schists, gneisses and metagabbros of the Ödemiş-Kiraz submassif of the Menderes Massif, and schists, marbles and meta-olistostromes of the Cycladic Complex. The basement is unconformably overlain by Neogene-Quaternary continental sediments. These continental basin fills are comprised of the Ayaklıkırı Formation, the Aydoğdu Formation and alluvium that unconformably overlies them. The Lower-Upper Miocene Ayaklıkırı Formation consists of lacustrine and fluvial deposits. The Plio-Pleistocene (?) Aydoğdu Formation is made up of alluvial fan deposits. Vast plains of alluvium cover …


Lithology And Internal Structure Of The San Andreas Fault At Depth Based On Characterization Of Phase 3 Whole-Rock Core In The San Andreas Fault Observatory At Depth (Safod) Borehole, Kelly Keighley Bradbury, James P. Evans, J. S. Chester, F. M. Chester, D. L. Kirshner Jan 2011

Lithology And Internal Structure Of The San Andreas Fault At Depth Based On Characterization Of Phase 3 Whole-Rock Core In The San Andreas Fault Observatory At Depth (Safod) Borehole, Kelly Keighley Bradbury, James P. Evans, J. S. Chester, F. M. Chester, D. L. Kirshner

Geosciences Faculty Publications

We characterize the lithology and structure of the spot core obtained in 2007 during Phase 3 drilling of the San Andreas Fault Observatory at Depth (SAFOD) in order to determine the composition, structure, and deformation processes of the fault zone at 3 km depth where creep and microseismicity occur. A total of approximately 41 m of spot core was taken from three separate sections of the borehole; the core samples consist of fractured arkosic sandstones and shale west of the SAF zone (Pacific Plate) and sheared fine-grained sedimentary rocks, ultrafine black fault-related rocks, and phyllosilicate-rich fault gouge within the fault …


Provenance Signature Of A Forearc Basin Modified By Spreading Ridge Subduction: Detrital Zircon Geochronology And Detrital Modes From The Paleogene Arkose Ridge Formation, Southern Alaska, Cullen Kortyna Jan 2011

Provenance Signature Of A Forearc Basin Modified By Spreading Ridge Subduction: Detrital Zircon Geochronology And Detrital Modes From The Paleogene Arkose Ridge Formation, Southern Alaska, Cullen Kortyna

Honors Theses

Upper Paleocene–Eocene boulder conglomerate, cross-stratified sandstone, and laminated carbonaceous mudstone of the Arkose Ridge Formation exposed in the southern Talkeetna Mountains record fluvial-lacustrine deposition proximal to the volcanic arc in a forearc basin modified by Paleogene spreading ridge subduction beneath southern Alaska. U-Pb ages of detrital zircon grains and modal analyses were obtained from stratigraphic sections spanning the 2,000 m thick Arkose Ridge Formation in order to constrain the lithology, age, and location of sediment sources that provided detritus. Detrital modes from 24 conglomerate beds and 54 sandstone thin sections aredominated by plutonic and volcanic clasts and plagioclase feldspar with …


Crustal Structure Across The Central Alaska Range: Anatomy Of A Mesozoic Collisional Zone, P.R.K. Brennan, H. Gilbert, K. D. Ridgway Jan 2011

Crustal Structure Across The Central Alaska Range: Anatomy Of A Mesozoic Collisional Zone, P.R.K. Brennan, H. Gilbert, K. D. Ridgway

Department of Earth, Atmospheric, and Planetary Sciences Faculty Publications

A first-order process in the growth of continents is the collision and accretion of terranes against continental margins. Collision leads to the formation of a suture zone between the accreted terrane and the former continental margin. New insights on the suturing process are observed from two receiver function transects across the Mesozoic Alaska Range suture zone. Three distinct crustal sections are identified from observations of crustal thickness, intracrustal discontinuities, and Vp/Vs: a northern section with ∼27 km thick crust of felsic to intermediate composition, a central section that is ∼37 km thick that exhibits intracrustal discontinuities and has felsic to …


Designing And Using Virtual Field Environments To Enhance And Extend Field Experience In Professional Development Programs In Geology For K-12 Teachers, Frank Douglas Granshaw Jan 2011

Designing And Using Virtual Field Environments To Enhance And Extend Field Experience In Professional Development Programs In Geology For K-12 Teachers, Frank Douglas Granshaw

Dissertations and Theses

Virtual reality (VR) is increasingly used to acquaint geoscience novices with some of the observation, data gathering, and problem solving done in actual field situations by geoscientists. VR environments in a variety of forms are used to prepare students for doing geologic fieldwork, as well as to provide proxies for such experience when venturing into the field is not possible. However, despite increased use of VR for these purposes, there is little research on how students learn using these environments, how using them impacts student field experience, or what constitutes effective design in light of emerging theories of geocognition.

To …


On Constrained Optimization Schemes For Joint Inversion Of Geophysical Datasets, Uram Anibal Sosa Aguirre Jan 2011

On Constrained Optimization Schemes For Joint Inversion Of Geophysical Datasets, Uram Anibal Sosa Aguirre

Open Access Theses & Dissertations

In the area of geological sciences, there exist several experimental techniques used to advance in the understanding of the Earth. We implement a joint inversion least-squares (LSQ) algorithm to characterize one dimensional Earth's structure by using seismic shear wave velocities as a model parameter. We use two geophysical datasets sensitive to shear velocities, namely Receiver Function and Surface Wave dispersion velocity observations, with a choice of an optimization method: Truncated Singular Value Decomposition (TSVD) or Primal-Dual Interior-Point (PDIP). The TSVD and the PDIP methods solve a regularized unconstrained and a constrained minimization problem, respectively. Both techniques include bounds into the …


Volcanic Stratigraphy And A Kinematic Analysis Of Ne-Trending Faults Of Allens Ranch 7.5' Quadrangle, Utah County, Utah, Adam Paul Mckean Dec 2010

Volcanic Stratigraphy And A Kinematic Analysis Of Ne-Trending Faults Of Allens Ranch 7.5' Quadrangle, Utah County, Utah, Adam Paul Mckean

Theses and Dissertations

The mineral resources of the Tintic Mining District are influenced by three major events in its geologic history; the Mesozoic Sevier Orogeny, Paleogene volcanism and Late Neogene Basin and Range extension. In this paper a detailed analysis of each these geologic events is presented to help us understand the structural host, mineralization and exhumation of the Tintic Mining District ore. A kinematic analysis of the faults was completed to determine the origin of NE-trending faults, Sevier Orogeny or Basin and Range extension, in the northern part of the East Tintic Mountains in Allens Ranch 7.5' quadrangle, near the eastern margin …


Testing Models Related To The Laramide Uplift Of The Uinta Mountains And Geologic Mapping Of The Jessen Butte 7.5 Minute Quadrangle, Dagget County, Utah And Sweetwater County, Wyoming, Coreen Hurst Mar 2010

Testing Models Related To The Laramide Uplift Of The Uinta Mountains And Geologic Mapping Of The Jessen Butte 7.5 Minute Quadrangle, Dagget County, Utah And Sweetwater County, Wyoming, Coreen Hurst

Theses and Dissertations

Geologic mapping of the Jessen Butte 7.5 minute quadrangle and the gathering of structural data throughout the quadrangle was used to determine the paleostress regime during the Laramide Orogeny along the north flank of the Uinta Mountains. The Henrys Fork thrust fault and the Uinta thrust fault are major north bounding faults and within the Jessen Butte quadrangle these faults transfer deformation from one to the other. The Jessen Butte thrust fault is a fault splay that splits off from the Henrys Fork thrust fault. Complex fold geometries were created by the interaction of the faults. Bedding plane orientation, mode …


Integrating Facies Analysis, Terrestrial Sequence Stratigraphy, And The First Detrital Zircon (U-Pb) Ages Of The Twist Gulch Formation, Utah, Usa: Constraining Paleogeography And Chronostratigraphy, Tyson L. Perkes Mar 2010

Integrating Facies Analysis, Terrestrial Sequence Stratigraphy, And The First Detrital Zircon (U-Pb) Ages Of The Twist Gulch Formation, Utah, Usa: Constraining Paleogeography And Chronostratigraphy, Tyson L. Perkes

Theses and Dissertations

The Jurassic Twist Gulch Formation of central Utah was deposited in the active Arapien sub-basin of the Western Cordillera foreland trough. We herein demonstrate the utility of integrating facies analysis, terrestrial sequence stratigraphy, and detrital zircon (U-Pb) ages to improve paleogeographic reconstructions as well as identify regional unconformities, locate fluvial depocenters, and infer sediment supply/accommodation space ratios. Strata of the Twist Gulch Formation in Pigeon Creek Canyon (PCC) near Levan, Utah consists primarily of alluvial deposits, while in Salina Canyon (SC) the Twist Gulch Formation is comprised of a mix of alluvial and marginal marine deposits associated with the Jurassic …


Slab Window Migration And Terrane Accretion Preserved By Low‐Temperature Thermochronology Of A Magmatic Arc, Northern Antarctic Peninsula, William R. Guenthner, David L. Barbeau Jr, Peter W. Reiners, Stuart N. Thomson Mar 2010

Slab Window Migration And Terrane Accretion Preserved By Low‐Temperature Thermochronology Of A Magmatic Arc, Northern Antarctic Peninsula, William R. Guenthner, David L. Barbeau Jr, Peter W. Reiners, Stuart N. Thomson

Faculty Publications

Existing paleogeographic reconstructions indicate that the northern Antarctic Peninsula was central to several Mesozoic and Cenozoic tectonic events that have implications for ocean circulation and continental margin evolution. To evaluate the exhumational record of these processes, we collected new samples and measured fission track and (U‐Th)/He cooling ages of apatite and zircon from 13 Jurassic and Cretaceous granitoids in western Graham Land between the northern tip of the peninsula and the Antarctic Circle. Apatite He data reveal distinct ages and systematic age patterns north and south of Anvers Island, near the midpoint of the study area: To the south, apatite …


Carbonates In Skeleton-Poor Seas: New Insights From Cambrian And Ordovician Strata Of Laurentia, Sara B. Pruss, Seth Finnegan, Woodward W. Fischer, Andrew H. Knoll Feb 2010

Carbonates In Skeleton-Poor Seas: New Insights From Cambrian And Ordovician Strata Of Laurentia, Sara B. Pruss, Seth Finnegan, Woodward W. Fischer, Andrew H. Knoll

Geosciences: Faculty Publications

Calcareous skeletons evolved as part of the greater EdiacaranCambrian diversification of marine animals. Skeletons did not become permanent, globally important sources of carbonate sediment, however, until the Ordovician radiation. Representative carbonate facies in a Series 3 (510501 Ma) Cambrian to Tremadocian succession from western Newfoundland, Canada, and Ordovician successions from the Ibex area, Utah, USA, show that, on average, Cambrian and Tremadocian carbonates contain much less skeletal material than do post-Tremadocian sediments. Petrographic point counts of skeletal abundance within facies and proportional facies abundance in measured sections suggest that later Cambrian successions contain on average volume, whereas the skeletal content …


Epidiceras (Bivalvia, Hippuritoidea) From The Tithonian–Berriasian Torinosu-Type Limestones Of The Sakawa Area, Southwest Japan, Shin-Ichi Sano, Peter W. Skelton Jan 2010

Epidiceras (Bivalvia, Hippuritoidea) From The Tithonian–Berriasian Torinosu-Type Limestones Of The Sakawa Area, Southwest Japan, Shin-Ichi Sano, Peter W. Skelton

Turkish Journal of Earth Sciences

Excavated specimens of two primitive rudists, Epidiceras speciosum (Goldfuss) and Epidiceras guirandi (de Loriol), are systematically described for the first time from the Tithonian-Berriasian Torinosu-type limestones of the Torinosu Group in the Sakawa area, Central Shikoku, Southwest Japan. E. guirandi was previously known only from the Late Kimmeridgian Mediterranean Tethys, so this occurrence in Southwest Japan significantly extends the recorded biogeographical and stratigraphical distribution of the species. Moreover, the documentation of E. speciosum from the Torinosu-type limestones in Japan and the Bau Limestone in Sarawak, Borneo, indicate that this species was already widespread throughout the Tethyan Realm at that time. …


Basement Types, Lower Eocene Series, Upper Eocene Olistostromes And The Initiation Of The Southern Thrace Basin, Nw Turkey, Aral İ. Okay, Ercan Özcan, William Cavazza, Ni̇lgün Okay, György Less Jan 2010

Basement Types, Lower Eocene Series, Upper Eocene Olistostromes And The Initiation Of The Southern Thrace Basin, Nw Turkey, Aral İ. Okay, Ercan Özcan, William Cavazza, Ni̇lgün Okay, György Less

Turkish Journal of Earth Sciences

The Eocene sequence of the southern Thrace Basin unconformably overlies two types of basement: (1) Slate, limestone and phyllite crop out in small inliers under the Upper Eocene conglomerates and limestones in the Mecidiye region, north of Saros Bay. These low-grade metamorphic rocks form the eastern extension of the Circum-Rhodope Belt of Greece. (2) In the Şarköy region south of the Ganos Fault, tectonically elevated basement consisting of serpentinite, metadiabase and Upper Cretaceous blueschists is unconformably overlain by the upper Bartonian to lower Priabonian shallow marine limestones of the Soğucak Formation. In some places erosional remnants of an upper Ypresian …


Surface And Subsurface Characteristics Of The Çankırı Basin (Central Anatolia, Turkey): Integration Of Remote Sensing, Seismic Interpretation And Gravity, Nuretdi̇n Kaymakçi, Şenol Özmutlu, Paul M. Van Van Dijk, Yakup Özçeli̇k Jan 2010

Surface And Subsurface Characteristics Of The Çankırı Basin (Central Anatolia, Turkey): Integration Of Remote Sensing, Seismic Interpretation And Gravity, Nuretdi̇n Kaymakçi, Şenol Özmutlu, Paul M. Van Van Dijk, Yakup Özçeli̇k

Turkish Journal of Earth Sciences

The geology of the Çankırı Basin has been studied using multi-source data including satellite images, aerial photos, gravimetric data and seismic sections, which are subsequently used to generate maps and a 3D model of that part of the basin covered by the seismic sections. From the compilation, three different phases of deformation are recognized. The earliest phase is characterized by thrusting during the Early Tertiary. The second deformation phase is characterized by extensional deformation associated with normal faulting in the latest Early Miocene to Middle Miocene. The third, and the last, phase is characterized by compressional deformation manifested by inversion …


Application Of The Normalized Full Gradient (Nfg) Method To Resistivity Data, Ali̇ Aydin Jan 2010

Application Of The Normalized Full Gradient (Nfg) Method To Resistivity Data, Ali̇ Aydin

Turkish Journal of Earth Sciences

This paper proposes the application of the normalized full gradient (NFG) method to resistivity studies and illustrates that the method can greatly reduce the time and work load needed in detecting buried bodies using resistivity measurement. The NFG method calculates resistivity values at desired electrode offsets by extrapolation of a function of resistivity measurements (i.e. the gradient) to other depth levels using resistivity measurements done at one electrode offset only. The performance and reliability of the NFG method is tested on laboratory and field resistivity data from two sites by comparing the trend of the resistivity values at six or …


Ontogeny And Funtional Morphology Of A Lower Cretaceous Carpinid Rudist (Bivalvia, Hippuritoida), Robert W. Scott, Meghan Weaver Jan 2010

Ontogeny And Funtional Morphology Of A Lower Cretaceous Carpinid Rudist (Bivalvia, Hippuritoida), Robert W. Scott, Meghan Weaver

Turkish Journal of Earth Sciences

Caprinuloidea rudists are locally abundant and widespread in Lower Cretaceous (Albian Stage) Edwards Formation in Texas. Landward of the shelf margin on the shallow marine Comanche Shelf rudists built circular and elongate bioherms with coarse-grained flank deposits. Two caprinid morphotypes suggest that some lived as elevators above the substrate and others were recumbent upon mobile grain flats. Elevators have elongated attached valves and weakly coiled free valves and recumbents have arcuate attached valves and strongly coiled free valves. Detailed morphologic studies are not possible on the many molds and casts, but a few specimens are silicified. Their internal structures can …


Geophysical Properties Within The San Andreas Fault Zone At The San Andreas Fault Observatory At Depth (Safod) And Their Relationships To Rock Properties And Fault Zone Structure, Tamara N. Jeppson, Kelly Keighley Bradbury, James P. Evans Jan 2010

Geophysical Properties Within The San Andreas Fault Zone At The San Andreas Fault Observatory At Depth (Safod) And Their Relationships To Rock Properties And Fault Zone Structure, Tamara N. Jeppson, Kelly Keighley Bradbury, James P. Evans

Geosciences Faculty Publications

We examine the relationships between borehole geophysical data and physical properties of fault‐related rocks within the San Andreas Fault as determined from data from the San Andreas Fault Observatory at Depth borehole. Geophysical logs, cuttings data, and drilling data from the region 3‐ to 4‐km measured depth of the borehole encompass the active part of the San Andreas Fault. The fault zone lies in a sequence of deformed sandstones, siltstone, shale, serpentinite‐bearing block‐in‐matrix rocks, and sheared phyllitic siltstone. The borehole geophysical logs reveal the presence of a low‐velocity zone from 3190 to 3410 m measured depth with Vp and …


Oligocene History Of The Çardak - Dazkırı Subbasin (Denizli, Sw Turkey): Integrated Molluscan And Planktonic Foraminiferal Biostratigraphy, Yeşi̇m İslamoğlu, Aynur Hakyemez Jan 2010

Oligocene History Of The Çardak - Dazkırı Subbasin (Denizli, Sw Turkey): Integrated Molluscan And Planktonic Foraminiferal Biostratigraphy, Yeşi̇m İslamoğlu, Aynur Hakyemez

Turkish Journal of Earth Sciences

The detailed analysis of molluscan and planktonic foraminiferal fauna in the Oligocene Çardak-Dazkırı sub-basin, in northeastern Denizli provin ce (western Turkey) allowed accurate dating of the deposits, together with interpretation of their depositional environments. Gastropod, bivalve, scaphopod and planktonic foraminiferal assemblages identified in ten sections reveal a succession which was deposited between the Late Rupelian and Early Chattian. Planktonic foraminifera, documented for the first time in the basin, indicate the P19 Zone (Turborotalia ampliapertura Zone) of the Late Rupelian at the base of the succession whereas Molluscan fauna, determined for the first time in this study, assign the whole succession, …


Cretaceous/Paleogene Boundary Biostratigraphy And Palynofacies Of The Alo-1 Well, Southeastern Nigeria, Janet Diane Raymer Jan 2010

Cretaceous/Paleogene Boundary Biostratigraphy And Palynofacies Of The Alo-1 Well, Southeastern Nigeria, Janet Diane Raymer

Masters Theses

"The Cretaceous/Paleogene boundary (K/Pg) has been studied in great detail because of the fascination most people have with the extinction of the dinosaurs. The response of the vegetation to this extinction event has been studied in detail in mid to high latitudes, but little is known about what happened in the tropics. Sixty-seven samples from the Nsukka and Imo formations in the Alo-1 well in the Anambra Basin, southeastern Nigeria have been studied for their palynological contents. The aims of the study was to use spores, pollen and dispersed organic matter components to interpret biostratigraphy, and evaluate depositional conditions across …


High Geologic Slip Rates Since Early Pleistocene Initiation Of The San Jacinto And San Felipe Fault Zones In The San Andreas Fault System, Southern California, Usa, Susanne U. Janecke, R. J. Dorsey, D. Forand, A. N. Steely, S. M. Kirby, A. T. Lutz, B. A. Housen, B. Belgarde, V. E. Langenheim, T. M. Rittenour Jan 2010

High Geologic Slip Rates Since Early Pleistocene Initiation Of The San Jacinto And San Felipe Fault Zones In The San Andreas Fault System, Southern California, Usa, Susanne U. Janecke, R. J. Dorsey, D. Forand, A. N. Steely, S. M. Kirby, A. T. Lutz, B. A. Housen, B. Belgarde, V. E. Langenheim, T. M. Rittenour

Geosciences Faculty Publications

The San Jacinto right-lateral strike-slip fault zone is crucial for understanding plate-boundary dynamics, regional slip partitioning, and seismic hazards within the San Andreas fault system of southern California, yet its age of initiation and long-term average slip rate are controversial. This synthesis of prior and new detailed studies in the western Salton Trough documents initiation of structural segments of the San Jacinto fault zone at or slightly before the 1.07-Ma base of the Jaramillo subchron. The dextral faults changed again after ca. 0.5–0.6 Ma with creation of new fault segments and folds. There were major and widespread basinal changes in …


Results Of New Petrologic And Remote Sensing Studies In The Big Bend Region, Stevan Christian Benker Jan 2010

Results Of New Petrologic And Remote Sensing Studies In The Big Bend Region, Stevan Christian Benker

Open Access Theses & Dissertations

The initial section of this manuscript involves the South Rim Formation, a series of 32.2-32 Ma comenditic quartz trachytic-rhyolitic volcanics and associated intrusives, erupted and was emplaced in Big Bend National Park, Texas. Magmatic parameters have only been interpreted for one of the two diverse petrogenetic suites comprising this formation. Here, new mineralogic data for the South Rim Formation rocks are presented. Magmatic parameters interpreted from these data assist in deciphering lithospheric characteristics during the mid-Tertiary.

Results indicate low temperatures (< 750 °C), reduced conditions (generally below the FMQ buffer), and low pressures (≤ 100 MPa) associated with South Rim Formation magmatism with slight conditional differences between the two suites. Newly discovered fayalite microphenocrysts allowed determination of oxygen fugacity values (between -0.14 and -0.25 ΔFMQ over temperature ranges of 680-700 °C), via mineral equilibria based QUILF95 calculations, for Emory Peak Suite.

Petrologic information is correlated with structural evidence from Trans-Pecos Texas and adjacent regions to evaluate debated timing of tectonic …