Report of Investigations No. 201 Stratigraphic Analysis of the Upper Devonian Woodford Formation, Permian Basin, West Texas and Southeastern New Mexico John B. Comer* *Current address Indiana Geological Survey Bloomington, Indiana 47405 1991 Bureau of Economic Geology • W. L. Fisher, Director The University of Texas at Austin • Austin, Texas 78713-7508 Contents Abstract ..............................................................................................................................1 Introduction ..................................................................................................................... 1 Methods .............................................................................................................................3 Stratigraphy .....................................................................................................................5 Nomenclature ...................................................................................................................5 Age and Correlation ........................................................................................................6 Previous Work .................................................................................................................6 Western Outcrop Belt ......................................................................................................6 Central Texas ...................................................................................................................7 Northeastern Oklahoma and Northern Arkansas .................................................................8 Ouachita Fold Belt .......................................................................................................................8 Central and Southern Oklahoma ........................................................................................8 Permian Basin ..................................................................................................................9 Formation Boundaries ....................................................................................................9 Distribution ...................................................................................................................10 Northwestern Shelf and Matador Uplift ....................................................................10 Eastern Shelf ...................................................................................................................10 Central Basin Platform and Pecos Arch .....................................................................11 Delaware Basin ...............................................................................................................11 Midland Basin ................................................................................................................11 Val Verde Basin ..............................................................................................................11 Diablo Platform and Western Outcrop Belt ...............................................................12 Lithofacies .......................................................................................................................12 Black Shale ......................................................................................................................12 Characteristic Features ....................................................................................................12 Bedding and Sedimentary Structures ...............................................................................12 Texture ..........................................................................................................................13 Composition ...................................................................................................................13 Siltstone ...........................................................................................................................16 Characteristic Features ....................................................................................................16 Bedding and Sedimentary Structures ...............................................................................17 Texture ..........................................................................................................................17 Composition ................................................................................................................... 17 Formation-Boundary Lithologies ................................................................................20 Lower Contact ................................................................................................................20 Upper Contact ................................................................................................................20 Lithofacies Correlation ..................................................................................................22 Lithofacies Distribution ................................................................................................23 Depositional Processes ..................................................................................................25 Siltstone .........................................................................................................................25 Black Shale .....................................................................................................................26 Lithologic Patterns and Origin of Sediments ............................................................26 Depositional Setting ..................................................................................................30 Paleogeography .............................................................................................................30 Paleotectonics .................................................................................................................31 Paleoclimate ....................................................................................................................32 Paleoceanography ..........................................................................................................33 iii Depositional Mechanisms ............................................................................................34 Synopsis of Depositional History ................................................................................35 Petroleum Potential ....................................................................................................36 Summary .........................................................................................................................36 Acknowledgments ......................................................................................................38 References .......................................................................................................................39 Appendices A. Location of cores and measured sections ...........................................................................43 B. Description of cores and measured sections ......................................................................44 C. Point-count data for the Woodford Formation .................................................................60 D. Organic content of the Woodford Formation ....................................................................61 Figures 1. Index maps showing structural provinces in the Permian Basin ......................................................................2 2. Map showing lines of cross sections and locations of cores and measured sections ......................................4 3. Correlation chart for Devonian and Mississippian Systems in West Texas and southeastern New Mexico................................................................................................................................ 7 4. Photos of Woodford black shale ...........................................................................................................................14 5. Photos of Woodford Siltstone................................................................................................................................ 18 6. Photos of Woodford contacts ................................................................................................................................21 7. Log correlation of Woodford lithofacies..............................................................................................................23 8. Fence diagram of Upper Devonian units ............................................................................................................24 9. Regional lithologic variations in Upper Devonian rocks in West Texas and southeastern New Mexico .....................................................................................................................................26 10. Late Devonian paleogeography of West Texas and southeastern New Mexico ...........................................30 11. Late Devonian paleogeography of North America............................................................................................32 12. Model of Late Devonian circulation during eustatic highstand ......................................................................34 Plates (in pocket) 1. Structure map of Woodford Formation, Permian Basin. 2. Isopach map of Woodford Formation, Permian Basin.