A High-Resolution Study of Depositional Facies and Architecture of Fords Branch Outcrop: A Middle Pennsylvanian Sedimentary Sequence Near Pikeville, Kentucky, U.S.A.
Sumanta K. Chatterjee, Arthur D. Cohen, Christopher G. St. C. Kendall, 2011. "A High-Resolution Study of Depositional Facies and Architecture of Fords Branch Outcrop: A Middle Pennsylvanian Sedimentary Sequence Near Pikeville, Kentucky, U.S.A.", Outcrops Revitalized: Tools, Techniques and Applications, Ole J. Martinsen, Andrew J. Pulham, Peter D.W. Haughton, Morgan D. Sullivan
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A Middle Pennsylvanian deltaic succession is exposed in the Fords Branch road cut located on US Highway 23, south of Pikeville, Kentucky, USA. The outcrop is 1.5 km long and 20 m in thickness and is oriented in an oblique strike orientation with respect to local paleoflow indicators and regional fluvio-deltaic drainage directed broadly to the west in a late Paleozoic Appalachian foreland basin.
Sedimentological analysis of the outcrop and interpretation of a panoramic photo montage establishes that the succession in the road cut accumulated in three depositional episodes bounded by sequence stratigraphic surfaces. A basal complex of distributary- mouth bars, channels and levees is cut by and overlain by an incised-valley fill. A capping unit of bay-fill and distributary-mouth-bars sediments completes the exposed succession.
Both the basal and capping depositional episodes are interpreted as lower-delta-plain settings. The incised valley is dominated by fluvial channel deposits and exhibits an upward increase in fluvial channel amalgamation.
The focus of the study presented here is twofold: (1) the nature of delta-front settings and how best analogs might be chosen, and (2) the evolution of fluvial channels in the outcrop panel, the architecture of which suggests a changing balance of sedimentation rate versus avulsion frequency over time.
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Outcrops are fundamental to everything we hope to achieve in geological understanding. They are gateways to geological processes, earth history and they help ground-truth remote sensing applications. With increasing resolution of subsurface tools and techniques, one could be forgiven in believing that outcrops have had their day and their utility is less than in the past great eras of field mapping and the development of facies models. This premise is far from the truth and this new SEPM volume illustrates how new analytical techniques are revitalizing outcrops and in the process creating a wealth of new data and fresh geological understandings. In this book you will find a compilation of the growing arsenal of outcrop tools and techniques and a consideration of future developments. This collection of papers, delivered at a SEPM Research Conference on the West coast of Ireland in the summer of 2008, is a smorgasbord of case studies, workflows, modeling, and applications which spans clastic and carbonate settings. Whatever your interest in outcrop geology and its application there is something in this volume for you. If you are seeking guidance for using new outcrop tools, looking for efficiencies in data collection or desiring new insights for old and favorite outcrops, this volume is a must have. This volume also makes an excellent reference or textbook for any group of professionals or students working or studying the new technologies that have allowed new insights from outcrops. We also consider this a superbly timed publication because many new outcrop tools are now becoming mainstream via reduced purchase and operating costs. Once you read this volume, and there are reduced prices for SEPM members and students, please share your new experiences with the authors and editors and help continue the revitalization of our shared and continually surprising outcrop library of the earth.