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Paleogeographic and Tectonic Implications of The University of Kentucky UKnowledge University of Kentucky Doctoral Dissertations Graduate School 2005 PALEOGEOGRAPHIC AND TECTONIC IMPLICATIONS OF THE LATE PALEOZOIC ALLEGHANIAN OROGEN DEVELOPED FROM ISOTOPIC SEDIMENTARY PROVENANCE PROXIES FROM THE APPALACHIAN FORELAND BASIN Thomas Patrick Becker University of Kentucky, [email protected] Right click to open a feedback form in a new tab to let us know how this document benefits ou.y Recommended Citation Becker, Thomas Patrick, "PALEOGEOGRAPHIC AND TECTONIC IMPLICATIONS OF THE LATE PALEOZOIC ALLEGHANIAN OROGEN DEVELOPED FROM ISOTOPIC SEDIMENTARY PROVENANCE PROXIES FROM THE APPALACHIAN FORELAND BASIN" (2005). University of Kentucky Doctoral Dissertations. 367. https://uknowledge.uky.edu/gradschool_diss/367 This Dissertation is brought to you for free and open access by the Graduate School at UKnowledge. It has been accepted for inclusion in University of Kentucky Doctoral Dissertations by an authorized administrator of UKnowledge. For more information, please contact [email protected]. ABSTRACT OF DISSERTATION Thomas Patrick Becker The Graduate School University of Kentucky 2005 PALEOGEOGRAPHIC AND TECTONIC IMPLICATIONS OF THE LATE PALEOZOIC ALLEGHANIAN OROGEN DEVELOPED FROM ISOTOPIC SEDIMENTARY PROVENANCE PROXIES FROM THE APPALACHIAN FORELAND BASIN ABSTRACT OF DISSERTATION A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the College of Arts and Sciences at the University of Kentucky By Thomas Patrick Becker Lexington, Kentucky Director: Dr. William A. Thomas, Hudnall Professor of Geological Sciences Lexington, Kentucky 2005 Copyright (c) Thomas Patrick Becker 2005 ABSTRACT OF DISSERTATION PALEOGEOGRAPHIC AND TECTONIC IMPLICATIONS OF THE LATE PALEOZOIC ALLEGHANIAN OROGEN DEVELOPED FROM ISOTOPIC SEDIMENTARY PROVENANCE PROXIES FROM THE APPALACHIAN FORELAND BASIN The Alleghanian orogeny was a collision between the Gondwanan and Laurentian continents that produced the Pangean supercontinent. Mechanical and kinematic models of collisional orogens are believed to follow a critical taper geometry, where the tectonic imbrication of continental crust begins nearest to the edge of continental plate and advances toward the craton in a break-forward sequence. Studies of shear zones within the Alleghanian collisional orogen, however, suggest that most of the early deformation was translational. Propagation of craton-directed thrusts into the foreland did not occur until the latest Pennsylvanian in the southern Appalachians, and the middle-late Permian in the central Appalachians. Radiometric sedimentary provenance proxies have been applied to the late Mississippian-early Permian strata within the Appalachian foreland basin to determine the crustal composition and structural evolution of the orogen during the continental collision. U-Pb ages of detrital zircons from the early to middle Pennsylvanian sandstones suggest that most of the detritus within the Appalachian basin was recycled from Mesoproterozoic basement and Paleozoic strata of the Laurentian margin. The presence of Archean and late Paleoproterozoic age detrital zircons is cited as evidence of recycling of the Laurentian syn-rift and passive-margin sandstones. Detrital zircon ages from early-middle Permian-age sandstones of the Dunkard Group do not contain any Archean or Paleoproterozoic detrital-zircon ages, implying a source of sediment with a much more restricted age population, possibly the igneous and metamorphic internides or middle Paleozoic sandstones from the Appalachian basin. The persistance of 360-400 Ma K/Ar ages of detrital white mica suggest that the sediment was supplied from a source that was exhumed during the Devonian Acadian orogeny. Detrital-zircon and detrital-white-mica ages from Pennsylvanian-age sandstones indicate that the late Paleozoic orogen did not incorporate any significant synorogenic juvenile crust. The 87Sr/86Sr ratios of middle Pennsylvanian-early Permian lacustrine limestones within the Appalachian basin show a slight enrichment through time, suggesting that labile 87Sr-rich minerals in the Alleghanian hinterland are being exposed. Stable isotopic data from the lacustrine limestones also corroborates that the Appalachian basin became much more arid through time. KEYWORDS: Appalachian, Detrital Zircon, Provenance, Pennsylvanian, Permian _______Thomas P. Becker________ _______December 16, 2004_______ PALEOGEOGRAPHIC AND TECTONIC IMPLICATIONS OF THE LATE PALEOZOIC ALLEGHANIAN OROGEN DEVELOPED FROM ISOTOPIC SEDIMENTARY PROVENANCE PROXIES FROM THE APPALACHIAN FORELAND BASIN by Thomas Patrick Becker William A. Thomas, Ph.D. Director of Dissertation Alan E. Fryar, Ph.D. Director of Graduate Studies December 16, 2004 RULES FOR THE USE OF DISSERTATIONS Unpublished dissertations submitted for the Doctor’s degree and deposited in the University of Kentucky Library are as a rule open for inspection, but are to be used only with due regard to the rights of the authors. Bibliographical references may be noted, but quotations or summaries of parts may be published only with the permission of the author, and with the usual scholarly acknowledgements. Extensive copying or publication of the dissertation in whole or in part also requires the consent of the Dean of the Graduate School of the University of Kentucky. DISSERTATION Thomas Patrick Becker The Graduate School University of Kentucky 2005 PALEOGEOGRAPHIC AND TECTONIC IMPLICATIONS OF THE LATE PALEOZOIC ALLEGHANIAN OROGEN DEVELOPED FROM RADIOMETRIC SEDIMENTARY PROVENANCE PROXIES FROM THE APPALACHIAN FORELAND BASIN DISSERTATION A dissertation submitted in partial fulfillment of the Requirements for the degree of Doctor of Philosophy in the College of Arts and Sciences At the University of Kentucky By Thomas Patrick Becker Lexington, Kentucky Director: Dr. William A. Thomas, Hudnall Professor of Geological Sciences Lexington, Kentucky 2005 Copyright (c) Thomas Patrick Becker, 2005 This dissertation is dedicated to My parents, James Arthur and Donna Deanna Becker, My parents in-law, Bahadur Sarkari, M.D. and Shirin Sarkari, Ph.D., and lastly My incredible wife, Natasha Sarkari Becker, M.D. ACKNOWLEDGEMENTS Nothing is more rewarding to me than learning something new. In this sense, I have been rewarded richly during my collegiate career. There are too many people to thank for all of those opportunities, but I’ll try to list some below. Several faculty members in the Department of Geological Sciences at Case Western Reserve University deserve to be acknowledged at this point in my life. Dr. James Aronson instilled a passion for learning while I was an undergraduate at Case Western Reserve University. In several classes taught by Dr. Philip Banks, he reinforced a logical approach to problem solving. Dr. Peter Whiting gave me the opportunity to participate in fieldwork in beautiful central Idaho for two consecutive summers. I also absorbed ideas and lessons from Drs. Sam Savin, Ralph Harvey, Gerald Matisoff, Peter McCall, John Stamm, Chris Bonniwell, and Million Hailemicheal. I finished my B.S. at Case Western Reserve with the vigor to learn more about the world, and the skills necessary to do it. My two years at Lehigh University were also personally and intellectually rewarding. Drs. Frank Pazzaglia, David Anastasio, Gray Bebout, Ed Evenson, Carl Moses, Bobb Carson, and Peter Zeitler were all great teachers and mentors. Perhaps the greatest opportunities to learn grew out of my interaction with fellow graduate students, including Bangyeon Kim, David Schneider, Chris Osburn, Diana Latta, Jane Casteline Osburn, Joy Ramstack, Brent Zaprowski, and Chris Shade. At the University of Kentucky, I had several great minds and great people with whom I interacted. Several faculty provided insight and support during my time in the department. I couldn’t ask for a better advisor than Dr. William Thomas. He has a wealth of knowledge about tectonics on a local, regional, and global scale and the ability to contextualize it into a simple framework. He also possesses an insatiable drive to learn more, and is unafraid to challenge “conventional” thinking about tectonic problems. He has mastered the knack of supervising graduate students by staying engaged, having an infinite reservoir of patience, and the using his ability to be unassumingly critical. His editorial prowess is remarkable. He has made me a much better geologist and scientist. I iii have been enlightened by the brilliance of many other faculty members as well. Dr. Harry Rowe was always willing to teach me more about geochemistry, gave me unhindered access to analyzing samples in the ERTL laboratory, and always lent some encouraging words. Dr. David Moecher spent a lot of time with me discussing problems surrounding Appalachian tectonic paradigms and teaching me about New England geology. Dr. Shelley Kenner taught me a lot about global tectonics and their underlying mechanisms, and was always willing to spend time patiently explaining concepts to me. Similarly, Dr. Ana Carmo taught me the basics of compound specific isotope geochemistry and its potential utility in solving geological problems. In addition, she provided lots of encouragement in my search for employment in the petroleum industry. Drs. Paul Howell, Sue Rimmer, Kieran O’Hara, and Alan Fryar have also been tremendous in their support and willingness to teach me about a variety of concepts. Robert King II and Tricia Coakley of the Environmental Research and Training Laboratory (ERTL) helped
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