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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
341

Controls on the development of clastic wedges and growth strata in foreland basins : examples from Cretaceous Cordilleran foreland basin strata, USA

Aschoff, Jennifer L., 1978- 19 January 2011 (has links)
Tectonic signatures such as growth strata, clastic progradation, detrital composition, thickness trends, paleoflow shifts, lithofacies distribution, and vertical stratigraphic stacking patterns provide the basis for a range of tectonic/structural interpretations. Complete understanding of the application and limitations of tectonic signatures is important to maintain consistency and reduce uncertainty of interpretations that use them. This study provides insight into the external controls on two frequently used tectonic signatures in foreland basins: (1) growth strata, and (2) clastic wedge progradation. First, two syntectonic unconformity types are recognized in non-marine, Cenomanian growth strata adjacent to the Sevier thrust-belt in southeastern Nevada, USA. Unconformities with larger angular discordance (>10°, “Traditional Type”) developed when uplift outpaced sediment accumulation. More subtle unconformities with less discordance (2-10°, “Subtle Type”) developed when sediment accumulation nearly kept pace with uplift. Increasing sediment supply with positive net accommodation, allows syntectonic deposits to aggrade above a growing structure, with no change in uplift rate. Hence, sediment supply and regional accommodation impart an important control over growth strata geometries that are often interpreted on the basis of tectonics alone. Identification of unconformity types in growth strata can therefore document additional phases of uplift, particularly for intervals where sediments aggraded above an active structure due to higher sediment supply during regional subsidence, or sea level rise. Second, an anomalous, Campanian clastic wedge is identified in Cordilleran Foreland basin fill, Utah and Colorado. The complex internal architecture, tide-dominated facies and characteristic flat-to-falling shoreline stacking patterns of the wedge reflect rapid progradation of wide (60-80 km), embayed, tide-influenced shorelines; these characteristics distinguish the anomalous wedge from the underlying and overlying clastic wedges in the basin. A high-resolution regional correlation and isopach maps for the anomalous wedge provide evidence that extensive clastic progradation was coeval with both Sevier- and Laramide-style deformation. Stratigraphic relations suggest that development of the anomalous character of Wedge B was due to uplift of a Laramide structure within the foredeep, and possibly enhanced by reduced dynamic subsidence. / text
342

Facies characterization and stratigraphic architecture of organic-rich mudrocks, Upper Cretaceous Eagle Ford Formation, South Texas

Harbor, Ryan Lee 04 October 2011 (has links)
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. / text
343

The sedimentology and stratigraphy of the Arab D Reservoir, Qatif Field

Al-Nazghah, Mahmoud Hasan 04 October 2011 (has links)
The Late Jurassic Arab D Formation in Saudi Arabia hosts the some of the world’s largest hydrocarbon reservoirs including Ghawar, the world’s largest oil field, and Khurais, the world’s largest supergiant to come into production in the last 5 years. Despite the vast oil reserves within the Arab D, and the central role of this reservoir at Ghawar in making up short-falls in global production, our understanding of the much fundamental characterization work both in terms of modern sequence stratigraphic reservoir frameworks and linked structural/fracture characterization. This study of Arab D reservoir at Qatif, immediately to the north of Ghawar, provides one of the first looks at a modern sequence analysis of this producing interval and illustrates that porosity zonations, and ultimately flow unit architecture may be substantially different than currently in use. The Arab D of the Arabian Plate is a carbonate ramp system of exceedingly low angle (<1o) developed during a low-eustatic-amplitude greenhouse Milankovitch setting. Combined macroscopic and petrographic data analysis allowed recognition of nine depositional facies: 1) spiculitic wackestone, 2) Planolites-burrowed wackestone, 3) bioturbated skeletal-peloidal packstone, 4) pelletal packstone, 5) peloidal-skeletal grain dominated packstone, 6) peloidal-skeletal grainstone, 7) skeletal-ooids grainstone, 8) cryptalgal laminites and 9) anhydrite. The depositional facies defined are used to interpret three facies tracts from deep to shallow across the ramp profile: 1) low energy sub-storm wave base (SWB) dominated facies that may illustrate disaerobic tendencies, 2) high energy within-fair-weather-wave-base ramp-crest or mid-ramp facies including foreshore and upper shoreface oolitic and skeletal grainstones that define one of the key reservoir pay zones and 3) back-barrier tidal flats consisting of cryptalgal laminites, sabkha-type anhydrites, and salina-type anhydrites. Three high frequency sequences are defined: QSEQ 1 is asymmetrical, dominated by subtidal lithofacies; and QSEQ 2 and QSEQ 3 are symmetrical and record a complex history of the fill on an intrashelf basin. Detailed cycle-scale correlations using core-based cycles and wireline log patterns allowed a cycle-scale correlation framework to be established that illustrates a north to south progradation of the Arab D reservoir strata, building landward from the Rimthan Arch. Diagenetic features observed in the Arab D reservoir include fitted fabric (chemical compaction), dolomitization, and cementation. These features play a major role altering reservoir quality properties as they essentially control fluid flow pathways which ultimately alter primary porosity and permeability. / text
344

Λεπτομερής ιζηματολογική ανάλυση του ολισθημένου τεμάχους ολιγοκαινικής ηλικίας μέσα στην μειοκαινική ακολουθία στο δυτικότερο περιθώριο της λεκάνης προχώρας της Πίνδου, στην περιοχή της Ζακύνθου, και η συμβολή του ολιγόκαινου στο πετρελαϊκό δυναμικό της περιοχής

Κυπαρίσση, Χριστίνα-Αγγέλα 13 January 2015 (has links)
Η παρούσα διπλωματική διατριβή εκπονήθηκε στα πλαίσια πτυχιακής εργασίας του τμήματος Γεωλογίας της σχολής Θετικών Επιστημών του Πανεπιστημίου Πατρών. Σε αυτό το σημείο θα ήθελα να ευχαριστήσω όλους όσους συνέλαβαν και με βοήθησαν στην συγγραφή και την ολοκλήρωση της παρούσας εργασίας. Καταρχήν θα ήθελα να ευχαριστήσω: Τον επιβλέποντα της διπλωματικής εργασίας κ. Ζεληλίδη Αβραάμ, καθηγητή του Πανεπιστημίου Πατρών, για την βοήθεια που μου παρείχε τόσο στο θεωρητικό όσο και στο ερευνητικό μέρος της εργασίας μου καθώς και για την άψογη συνεργασία που είχαμε κατά την εκπόνηση της. Επίσης, θα ήθελα να ευχαριστήσω θερμά τους υποψήφιους διδάκτορες Τσερόλα Παναγιώτη και Θωμαή Αναγνωστούδη για την βοήθεια που μου παρείχαν τόσο κατά την δαδικασία της δειγματοληψίας, όσο και κατά το εργαστηριακό κομμάτι αλλά και την συγγραφή, αλλά και τους μεταπτυχιακούς φοιτητές Μπελιβάνη Δήμητρα, Μποτζιολή Χρύσανθο και Πετράκο Γεώργιο που συνέβαλαν καθοριστικά στην ολοκλήρωση της διπλωματικής. Επιπλέον, πέρα από την οικογένειά μου, για την στήριξή της αυτά τα τέσσερα χρόνια της φοίτησης μου στο τμήμα Γεωλογίας του Πανεπιστημίου Πατρών, θα ήθελα να ευχριστήσω και τους φίλους Κολοκύθα Δημήτριο, Κουρουπάκη Ασημίνα, Τριανταφύλλου Μαλαματένια και Γκάτζο Ιωάννη για την ηθική τους στήριξη και την πολύτιμη βοήθεια τους. Τέλος, θα ήταν σκόπιμο να αναφερθεί ότι η παρούσα διπλωματική εργασία, αποτελεί την ερευνητική συνέχεια της διπλωματικής του Μποτζιολή Χρύσανθου με τίτλο «Περιβάλλοντα ιζηματογένεσης, παλαιογεωγραφική εξέλιξη και δυνατότητα γένεσης υδρογονανθράκων των Μειοκαινικών αποθέσεων του νησιού της Ζακύνθου» όσον αφορά την ΤΟΜΗ 3, όμως συμπληρωματικά και για συγκριτικούς λόγους, λήφθηκαν δείγματα και από τις υπόλοιπες 3 τομές. / This dissertation was prepared for the Department of Geology-University of Patras. At this point I would like to thank all those who conceived and helped in the writing and completion of this work.Firstly, I would like to thank the supervisor of my thesis Mr. Zelilidis Abraham, Professor of the University of Patras, for the help he gave me both in the theoretical research and for the excellent cooperation during the preparation of this dissertation. I would also like to thank the PhD students Tserolas Panagiotis and Thomai Anagnostoudi for the help they have given me during the procedure of the samples, and in the laboratory part and writing, but also the graduate students Belivani Dimitra and Botziolis Chrysanthos, as well as Petrakos George, who contributed to the completion of the thesis. Moreover, apart from my family for the support of these four years of my studies, I would also like to thank my friends Kolokythas Dimitrios, Triantafyllou Malamatenia and Gkatzos Ioannis, not only for their moral support, but also for their valuable help. Finally, it should be noted that the present work is the continuation of the thesis of Botziolis Chrysanthos, entitled "Sedimentary Environments, paleogeographic evolution and hydrocarbon potential of the Miocene deposits of the island of Zakynthos" for the section number 3, but for additional and comparative purposes, I also examined samples from the other three sections.
345

Provenance and Depositional History of Late Pleistocene New Jersey Shelf Sediments

Turner, Roxie Jessica 12 May 2005 (has links)
Pleistocene New Jersey shelf sedimentology is strongly influenced by glacially driven sea level changes. A combination of regressive shoreline processes, subaerial exposure, fluvial downcutting, and deposition and reworking during transgression has influenced the NJ shelf sediment composition. Sediment provenance and transport history may be determined on a shelf environment through analysis of grain size distribution, heavy mineral content, magnetic mineral concentrations, and isotopic dating methods. A combination of surface grab and stratigraphic samples were analyzed within the study area. Relatively high percentages of heavy minerals were found in the 2 phi and 3 phi size fractions and hornblende grains provided K-Ar age values indicating two groups of sediment sources. The first source is Grenville with apparent ages above 900 Ma deposited during marine OIS 1. The second source is a mixed assemblage of Grenvillian and Paleozoic sources deposited during marine OIS 3, with apparent ages of approximately 850 ± 20 Ma.
346

A SEDIMENTOLOGICAL AND GEOMORPHICAL INVESTIGATION OF THE PARIS MORAINE IN THE GUELPH AREA, ONTARIO, CANADA

McGill, Michael 21 August 2012 (has links)
A sedimentological and geomorphologic investigation southeast of the City of Guelph, Ontario was undertaken to determine the nature, trends in distribution, and origin of subsurface sediments in the Paris moraine. Sediments were investigated by drilling five cored-holes, mapping geomorphic elements, and creating a database of existing data. Nine broadly encompassing and reoccurring lithofacies were identified, ranging from gravel to clayey silt. The general transverse trend of geomorphic elements across the moraine consists of a frontslope, hummocky, and backslope element. Sediment-landform associations were identified from the synthesis of cored-hole, geomorphic element mapping, and lithologic cross-section data. Based on these results, the Paris Moraine is thought to be the remnants of an ice-cored controlled moraine. The relief inversion process responsible for the formation of the controlled moraine creates a horizontally and vertically variable distribution of lithofacies. Hydrogeologic properties of the moraine sediments will likely be similarly spatially variable and difficult to predict. / Ontario Research Fund, NSERC, OMAFRA
347

Sedimentological and ichnological characteristics of modern and ancient channel-fills, Willapa Bay, Washington

Schoengut, Jesse Unknown Date
No description available.
348

Sedimentology, diagenesis, and dolomitization of the Brac Formation (Lower Oligocene), Cayman Brac, British West Indies

Uzelman, Breanna C. Unknown Date
No description available.
349

Bioturbation and Resource Quality: A Case Study from the Upper Cretaceous Lysing and Nise Formations, Ellida and Midnatsoll Fields, Norwegian Sea

Polo, Camilo Unknown Date
No description available.
350

Some applications of digital image processing for automation in palynology

Langford, Mitchel January 1988 (has links)
No description available.

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