Download or read book High Resolution Stratigraphy and Facies Architecture of the Upper Cretaceous Cenomanian Turonian Eagle Ford Group Central Texas written by Michael Douglas Fairbanks and published by . This book was released on 2012 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heightened industry focus on the Upper Cretaceous (Cenomanian-Turonian) Eagle Ford has resulted from recent discoveries of producible unconventional petroleum resource in this emerging play. However, little has been published on the facies and facies variabilities within this mixed carbonate-clastic mudrock system. This rock-based study is fundamental to understanding the controls, types, and scales of inherent facies variabilities, which have implications for enhanced comprehension of the Eagle Ford and other mixed carbonate-clastic mudrock systems worldwide. This study utilizes 8 cores and 2 outcrops with a total interval equaling 480 feet and is enhanced by synthesis of thin section, XRD, XRF, isotope, rock eval/TOC, and wireline log data. Central Texas Eagle Ford facies include 1) massive argillaceous mudrock, 2) massive argillaceous foraminiferal mudrock, 3) laminated argillaceous foraminiferal mudrock, 4) laminated foraminiferal wackestone, 5) cross-laminated foraminiferal packstone/grainstone, 6) massive bentonitic claystone, and 7) nodular foraminiferal packstone/grainstone. High degrees of facies variability are observed even at small scales (50 ft) within the Eagle Ford system and are characterized by pinching and swelling of units, lateral facies changes, truncations, and locally restricted units. Facies variability is attributed to erosional scouring, productivity blooms, bottom current reworking, and bioturbation. At the 10-mile well spacing scale and greater, the data significantly overestimates intra-formational facies continuity but is successful in defining the following four-fold stratigraphy: The basal Pepper Shale is an argillaceous, moderate TOC, high CGR and GR mudrock. The Waller Member is a newly designated name used in this study for an argillaceous and foraminiferal, high TOC, massive mudrock with a generally moderate CGR and GR profile. The Bouldin Member is a high energy, carbonate-rich (foraminiferal), low TOC, low and variable CGR but high GR zone. Finally, the South Bosque Formation is an argillaceous and foraminiferal, moderate TOC, massive and laminated mudrock with a moderate CGR and GR signature. GR logs alone are inadequate for determination of facies, TOC content, depositional environment, and sequence stratigraphic implications. Using integrated lithologic, isotopic, and wireline log data, cored wells in the study area are correlated across the San Marcos Arch. Geochemical proxies (enrichment in Mo, Mn, U, and V/Cr) indicate that maximum basin restriction occurred during deposition of the Bouldin Member. Bottom current activity influenced depositional processes and carbonate sediment input was driven by water column productivity. These primary controls on Eagle Ford stratigraphy and character are independent from eustatic fluctuation, rendering classical sequence stratigraphy unreliable.

Download or read book Stratigraphic Architecture and Associated Sedimentological and Geochemical Variability in the Upper Cretaceous Eagle Ford Group South Texas written by Ahmed Wasel Alnahwi and published by . This book was released on 2018 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: A detailed, rock-based investigation of three Upper Cretaceous Eagle Ford Group cores situated behind (L1), at (L2), and downdip (L3) of the Lower Cretaceous Stuart City paleoreef-shelf margin in south Texas was conducted to understand stratigraphic, sedimentological, and geochemical relationships. An understanding of stratigraphic, sedimentological, and geochemical variability across the ancestral shelf margin is currently lacking. The Cenomanian–Turonian Eagle Ford Group is composed predominantly of calcareous mudstones that were deposited below storm-wave base on the drowned South Texas Shelf. The Lower to Upper Eagle Ford contact approximates the Cenomanian–Turonian boundary, at which the OAE-2 occurred and was identified in all three cores. The low-relief raised rim of the paleoshelf margin may have acted as a barrier, dividing the Eagle Ford Group into two sedimentological systems: (1) a restricted drowned shelf to the north and (2) an open-marine basinal setting to the south. Pre-OAE-2 Eagle Ford strata on the drowned shelf are cyclic and enriched in molybdenum, suggesting anoxic to euxinic water masses. Anoxic basinward strata are less cyclical and have a lower molybdenum content. The cores were investigated to quantify mineralogical composition and TOC. Machine learning of XRF dataset was conducted using neural-network analysis to predict mineralogies and TOC. Quantitative laboratory-measured XRD mineralogies and TOC were used to conduct the training and develop high-resolution quantitative models. Derived mineralogic and organic matter quantitative models represent continuous relative abundances. This method allows for the utilization of the relatively inexpensive and nondestructive XRF analysis that requires minimal sample preparation to construct high-resolution mineral abundances and TOC content. Hyperspectral imagery was used to generate mineral maps of the L1 core. The used hyperspectral imaging system uses the SWIR (shortwave infrared) and LWIR (longwave infrared) spectrometers. The introduction of the LWIR made it possible to identify minerals that were not detected by previous SWIR systems such as quartz and feldspars. Hyperspectral imaging facilitates the study of textural and fabric relationships. The diagnostic cyclicity of the Lower Eagle Ford is closely related to calcite compositional variations and coccolithophore productivity. Strontium-rich calcite indicates smaller allochem size dominance as well as lower sedimentation rates.

Download or read book Chemostratigraphy of the Upper Cretaceous from Central and South Texas with Focus on the Eagle Ford Group written by Brett Huffman and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The fine-grained organic-rich rocks of the Eagle Ford (Cenomanian-Turonian) were deposited during the Upper Cretaceous in the shallow waters of the Western Interior Seaway. Five drill cores recovered from two counties, four from Travis County, Texas and one from Frio County, Texas, have been scanned from between two foot and half foot intervals with a hand-held energy-dispersive x-ray fluorescence (HH-ED-XRF) spectrometer to acquire major (e.g. Ca, Si, Al) and trace (e.g. Mo, V, Ni) element data for quantitative analysis. Additionally, gamma ray logs have been analyzed for two of the cores. Major element geochemistry indicates the Eagle Ford deposited in South Texas is different from the Eagle Ford deposited in Central Texas. South Texas Eagle Ford is much more Ca (carbonate) rich, with a noticeably lower Al (clay) content. South Texas and Central Texas Eagle Ford both have low Si (quartz) content relative to the Al and Ca content, indicating a negligible siliciclastic contribution during deposition. Trace element analysis reveals the redox conditions of the bottom waters during deposition. Mn -- an element which becomes mobile and may be removed from an open system in reducing conditions -- levels are much higher in the Austin Chalk and Buda with notably lower values in the Eagle Ford in both Central Texas and South Texas. Mo, an element which tends to bind with organic matter or sulfides during reducing conditions, is notably higher in the Eagle Ford of both South Texas and Central Texas. The correlation of decreased Mn levels and increased Mo levels suggests that the Eagle Ford was deposited in reducing conditions in an open system capable of removing mobilized Mn. Geochemical analysis of major and trace elements obtained from ED-XRF may be used in the petroleum industry in concert with XRD, electric logs, and standard core analysis to give a more complete picture of the depositional environment, clay type and volume, geophysical rock properties, and areal extent of a potential unconventional shale reservoir for hydrocarbon extraction. XRF data offers insight about the rocks, leading to improved understanding of the depositional environment and chemical makeup. Applying these technologies to the Eagle Ford helps unlock the potential of this significant hydrocarbon source and reservoir.

Download or read book Directory of Geoscience Departments 2015 written by Carolyn Wilson and published by American Geosciences Inst. This book was released on 2015-02-27 with total page 2140 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Directory of Geoscience Departments 50th Edition is the most comprehensive directory and source of information about geosciences departments and researchers available. It is an invaluable resource for individuals working in the geosciences or must identify or work with specialists on the issues of Earth, Environmental, and related sciences and engineering fields. The Directory of Geoscience Departments 50th Edition provides a state/country-sorted listing of nearly 2300 geoscience departments, research departments, institutes, and their faculty and staff. Information on contact information for departments and individuals is provided, as well as details on department enrollments, faculty specialties, and the date and source of faculty and staff's highest degree. New in the 50th edition: Listing of all US and Canadian geoscience theses and dissertations accepted in 2012 that have been reported to GeoRef Information Services, as well as a listing of faculty by their research specialty.

Download or read book Late Cretaceous to Quaternary Strata and Fossils of Texas written by Brian Butler Hunt and published by Geological Society of America. This book was released on 2013-04-01 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The four field trips in this volume focus on sedimentology and paleontology in Texas. All the trips can directly trace their roots to the work of early geologic explorers"--Provided by publisher.

Download or read book Geochronologic and Chemostratigraphic Record of Cenomanian Turonian Eagle Ford South Texas written by Michael Anthony Nieto and published by . This book was released on 2016 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Eagle Ford Shale of South Texas is an organic-rich, calcareous mudrock succession which was deposited on the Comanche Platform during the earliest Late Cretaceous. Many academic and industry sponsored Eagle Ford studies over the past 10 years have concentrated their efforts on trying to understand the rock fabrics, facies architecture and heterogeneities present in the succession. However, despite heavy economic and academic interest in the system, few studies focus on trying to understand timing and source of the many bentonite ash beds present in the Eagle Ford; which serve as regional chronostratigraphic markers across South Texas. One of the primary goals of the study is the determination of U-Pb age dates in bentonite-rich ash beds from a group of subsurface cores that penetrate the Eagle Ford Formation in Atascosa County, Texas. Absolute age dates provide a chronostratigraphic framework that is used to estimate the depositional timing of variable Eagle Ford facies, as well as define the timing, duration and magnitude of isotopic events in the region. Secondly, age estimates are utilized to determine and calculate Eagle Ford accumulation rates across South Texas. Absolute age dates are incorporated with lithofacies definitions to better 1) understand the cyclic relationship between dominant Eagle Ford lithologies, 2) identify the controls responsible for the cyclic mode of deposition, and 3) determine the lateral continuity of key lithofacies and lithologic units. Lastly, elemental (XRF) data are utilized to describe the subtle paleoceanographic and sediment source conditions that persisted across the entire Eagle Ford section. These findings are integrated with stable carbon ([delta]13C) isotopic data, which allow for the accurate definition of Ocean Anoxic Event 2 (OAE 2) in the study area and provide a basis for regional correlation with previous studies. Recent studies have suggested that anoxic conditions experienced within the Western Interior Seaway during this time were asynchronous with the well-documented global OAE 2 event. The present study compares local U-Pb age dates, isotopic and elemental results with regional studies to better define the onset timing and paleoceanograpic conditions associated with Eagle Ford Shale deposition.

Download or read book Upper Cretaceous Stratigraphy of the Western Gulf Coast Area of M xico Texas and Arkansas written by Emile A. Pessagno and published by Geological Society of America. This book was released on 1969 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Stratigraphy of the Eagle Ford Group upper Cretaceous and Its Source rock Potential in the East Texas Basin written by Cleavy L. McKnight and published by . This book was released on 1982 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Stratigraphic Sequences and Facies Architecture of the Woodbine Eagle Ford Interval Upper Cretaceous North Central Texas written by Patrick Alexander Trudel and published by . This book was released on 1994 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Stratigraphy of the Eagle Ford Group upper Cretaceous and Its Source rock Potential in the East Texas Basin written by Milton A. Surles and published by . This book was released on 1987 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Facies Characterization and Stratigraphic Architecture of Organic rich Mudrocks Upper Cretaceous Eagle Ford Formation South Texas written by Ryan Lee Harbor and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Eagle Ford is a well-known source rock for both sandstone (Woodbine) and carbonate (Austin and Buda) hydrocarbon reservoirs in East and South Texas. Recent discoveries have demonstrated that source rocks, such as the Eagle Ford, are capable of producing significant volumes of gas and oil. At the same time, variations in well producibility indicate that these rocks, like conventional reservoirs, display considerable geological heterogeneity. Yet, only limited research has been published on the subsurface stratigraphy and character of Eagle Ford facies. Understanding the types, controls, and distribution of these heterogeneities requires in-depth rock-based studies. In order to characterize Eagle Ford facies, 27 cores from 13 counties were investigated for rock textures, fabrics, sedimentary structures, and fossil assemblages. These studies were supported by light and electron microscopy as well as analysis of elemental chemistry and mineralogy. Regional subsurface stratigraphic correlations and facies distributions were defined using wireline logs calibrated from core studies. In South Texas, the Eagle Ford Formation was deposited during a second-order transgressive/regressive cycle on the flooded, oxygen-restricted Comanche Shelf. Nine depositional facies consisting predominately of organic-rich, fine-grained (5.0 % TOC) to coarser-grained (3.05 % TOC) fabrics were identified. Facies developed in low-energy environments episodically interrupted by higher-energy, event sedimentation (current winnowing, cohesive and non-cohesive density flows, and turbidity flows). Locally, these rocks show evidence of early diagenetic recrystallization of calcite. Concurrent water anoxia and organic matter preservation persisted locally into later Austin deposition, resulting in formation of a three-fold division of the Cenomanian-Coniacian Eagle Ford Formation. Common facies of lower and upper Eagle Ford members include (1) unlaminated, fissile, clay- and silica-rich, organic-rich mudrocks, (2) laminated, calcareous, organic-rich mudrocks, and (3) laminated, foraminifera- and peloid-rich, organic-rich packstones. The transitional Eagle Ford member consists of highly-cyclic (1) ripple-laminated, organic-rich wackestone (cycle base) and (2) burrowed, organic-lean lime wackestones (cycle top). Transitional Eagle Ford facies developed in oxygen-restricted, basinal depositional environments as distal equivalents to burrowed, foraminiferal lime wackestones of the Austin Formation. Facies complexities in the Eagle Ford stem from complicated and interrelated processes of sediment production and distribution, diagenesis, and water column chemistry. Integrated core studies shed light on both controls of facies formation and their spatial distribution. These findings provide a framework for upscaling the fine-scale, heterogeneous character of shelfal Eagle Ford mudrocks; thus allowing development of predictive models into the distribution of key reservoir properties in the subsurface.

Download or read book Shorter Contributions to the Stratigraphy and Geochronology of Upper Cretaceous Rocks in the Western Interior of the United States written by Geological Survey (U.S.) and published by . This book was released on 1995 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Shelf Sedimentation and Depositional Sequence Stratigraphy of the Upper Cretaceous Woodbine Eagle Ford Groups East Texas written by Sandra Phillips and published by . This book was released on 1987 with total page 650 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book U Pb Geochronology of the Late Cretaceous Eagle Ford Shale Texas written by John Donald Pierce and published by . This book was released on 2014 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Eagle Ford Shale and equivalent Boquillas Formation (Late Cretaceous) contain abundant volcanic ash beds of varying thickness. These ash beds represent a unique facies that displays a range of sedimentary structures, bed continuity, and diagenetic alteration. They are prominent not only in West Texas outcrops, but also in the subsurface of South Texas where hydrocarbon production is actively occurring. The ash beds have the potential to be used for stratigraphic correlation for understanding early diagenesis and -- most importantly -- for obtaining high-resolution geochronology, which can then be used for defining depositional rates and chronostratigraphy. Study of the ash beds was conducted at outcrops along U.S. 90, west of Comstock, Texas, the subsurface in Atascosa and Karnes County, and at a construction site in South Austin. Bed thicknesses range from 0.1-33 cm and were collected throughout the entirety of the Eagle Ford succession. Mineral separation yielded abundant non-detrital zircons for U-Pb dating. Dating was conducted using LA-ICP-MS at The University of Texas at Austin, to attain a base level understanding of the age range for the Eagle Ford. High-resolution ages for the base and top of the Eagle Ford were obtained, in addition to radioisotopically defining the Cenomanian-Turonian boundary within the section. U-Pb ages for the Eagle Ford Shale range from Early Cenomanian to Late-Coniacian near Comstock, Mid-Cenomanian to the Turonian-Coniacian boundary in the subsurface, and Early Cenomanian to Late Turonian in Austin area. These findings contrast with many of the regional biostratigraphic studies across the Eagle Ford and indicate a more prolonged period of Eagle Ford deposition than previously observed.

Download or read book Mass Extinctions Volcanism and Impacts written by Thierry Adatte and published by Geological Society of America. This book was released on 2020-04-13 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This volume covers new developments and research on mass extinctions, volcanism, and impacts. It addresses the following topics: the Central Iapetus magmatic province; thermogenic degassing in large igneous provinces; global mercury enrichment in Valanginian sediments; Guerrero-Morelos carbonate platform response to the Caribbean-Colombian Cretaceous large igneous province; implications for the Cretaceous-Paleocene boundary event in shallow platform environments and correlation to the deep sea; environmental effects of Deccan volcanism on biotic transformations and attendant Cretaceous/Paleogene boundary mass extinction in the Indian subcontinent; Deccan red boles; and factors leading to the collapse of producers during the Chicxulub impact and Deccan Traps eruptions"--

Download or read book Stratigraphic Paleontologic and Paleoenvironmental Analysis of the Upper Cretaceous Rocks of Cimarron County Northwestern Oklahoma written by Erle Galen Kauffman and published by . This book was released on 1977 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Upper Cretaceous Stratigraphy in Miller County Arkansas written by John Harding Dolloff and published by . This book was released on 1951 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: