U.S. Department of the Interior U.S. Geological Survey Physical Stratigraphy, Paleontology, and Magnetostratigraphy of the USGS - Santee Coastal Reserve Core (CHN-803), Charleston County, South Carolina by Lucy E. Edwards1, Gregory S. Gohn1, Jean M. Self-Trail1, David C. Prowell2, Laurel M. Bybell1, Leon P. Bardot3, John V. Firth4, Brian T. Huber5, Norman O. Frederiksen1, and Kenneth G. MacLeod6 __________________________________________________________________ Open-File Report 99-308 Prepared in cooperation with the South Carolina Department of Natural Resources This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or with the North American Stratigraphic Code. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. 1Reston, Virginia 2Atlanta, Georgia 3Oxford, United Kingdom 4College Station, Texas 5Washington, D.C. 6Columbia, Missouri 1999 CONTENTS Abstract ........................................................................................................................................4 Introduction ........................................................................................................................................4 Acknowledgments...........................................................................................................................6 Unit conversions.............................................................................................................................6 Methods ........................................................................................................................................6 Physical stratigraphy and lithology.....................................................................................................6 Paleontology..................................................................................................................................6 Calcareous nannofossils..............................................................................................................6 Palynology..............................................................................................................................6 Foraminifera.............................................................................................................................7 Strontium-isotope measurements........................................................................................................7 Paleomagnetic measurements.............................................................................................................7 Results and stratigraphic discussions.........................................................................................................7 Stratigraphy...................................................................................................................................7 Paleontology................................................................................................................................11 Strontium-isotope results................................................................................................................14 Paleomagnetic results.....................................................................................................................14 Donoho Creek Formation (Black Creek Group)...................................................................................14 Physical stratigraphy and lithology.............................................................................................14 Paleontology..........................................................................................................................15 Magnetostratigraphy................................................................................................................15 Peedee Formation..........................................................................................................................15 Physical stratigraphy and lithology.............................................................................................15 Paleontology..........................................................................................................................17 Strontium-isotope stratigraphy...................................................................................................21 Magnetostratigraphy................................................................................................................21 Rhems Formation (Black Mingo Group) sensu stricto.......................................................................... 21 Physical stratigraphy and lithology.............................................................................................21 Paleontology..........................................................................................................................23 Magnetostratigraphy................................................................................................................23 Upper part of the Rhems Formation (Black Mingo Group) sensu Bybell and others (1998)..........................23 Physical stratigraphy and lithology.............................................................................................23 Paleontology..........................................................................................................................24 Magnetostratigraphy................................................................................................................26 Lower Bridge Member of the Williamsburg Formation (Black Mingo Group)...........................................26 Physical stratigraphy and lithology.............................................................................................26 Lower beds.......................................................................................................................26 Upper beds.......................................................................................................................27 Paleontology..........................................................................................................................27 Magnetostratigraphy................................................................................................................27 Chicora Member of the Williamsburg Formation (Black Mingo Group)...................................................27 Physical stratigraphy and lithology.............................................................................................27 Paleontology..........................................................................................................................28 Magnetostratigraphy................................................................................................................28 Mollusk-bryozoan limestone...........................................................................................................28 Physical stratigraphy and lithology.............................................................................................28 Paleontology..........................................................................................................................29 Magnetostratigraphy................................................................................................................29 Wando Formation..........................................................................................................................29 Physical stratigraphy and lithology.............................................................................................29 Paleontology..........................................................................................................................30 2 Magnetostratigraphy................................................................................................................30 Silver Bluff beds (informal).............................................................................................................30 Physical stratigraphy and lithology.............................................................................................30 Paleontology..........................................................................................................................30 Magnetostratigraphy................................................................................................................30 Implications and Conclusions................................................................................................................30 References ......................................................................................................................................33 TABLES Table 1. Summary of samples from the Santee Coastal Reserve corehole examined for pollen......................24 2. Distribution of Early Tertiary pollen taxa in the Santee Coastal Reserve core................................25 3. Distribution of Late Tertiary to Quaternary pollen taxa in the Santee Coastal Reserve core..............25 4. Magnetic-polarity ratings for discrete samples.........................................................................26 5. Values used in the calculation of sediment accumulation rates for the Santee Coastal Reserve core....32 ILLUSTRATIONS Figure 1. Map of South Carolina showing location of coreholes discussed in text.........................................5 2. Stratigraphy and