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South Atlantic Water Science Center (SAWSC)

Georgia Geologic Survey Bulletin 131

GEOLOGY OF OLIGOCENE, MIOCENE, AND YOUNGER DEPOSITS IN THE COASTALAREA OF GEORGIA

Georgia Department of Natural Resources, Environmental Protection Division, Georgia Geologic Survey

Robert E. Weems and Lucy E. Edwards

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Analysis of cores and geophysical logs for ten coreholes and wells in the coastal area of Georgia has allowed a detailed synthesis and correlation of the Oligocene and Miocene strata across this area. A total of eighteen unconformity-bounded Oligocene and Miocene stratigraphic units can be recognized in the area. Erosion during the times represented by the intervening unconformities has produced cut and fill patterns that greatly complicate the stratigraphic and hydrologic patterns across the region. The Tiger Leap Member of the Parachucla Formation of Huddlestun and the Ebenezer Member of the Coosawhatchie Formation of Huddlestun are raised to formational rank. With these changes, the eighteen unconformity-hounded stratigraphic units can be clustered into seven lithologically distinctive formations. At the same time, however, these stratigraphic units also compose three hydrologic aquifers and their conforming units. By integrating and clarifying the relations between stratigraphic units and hydrologic units, a more useful framework for both stratigraphers and hydrologists can be achieved than by basing the stratigraphic system on only one of these two concepts.


For additional information contact:
Director, South Atlantic Water Science Center - Georgia

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Contents

Abstract

Introduction

Geologic units

Lower Oligocene stratigraphic units

Upper Oligocene and Miocene stratigraphic units

Pliocene stratigraphic units

PIeistocene strati.graphic units

Depositional environments and lithofacies

Influence of lithofacies on water availability

Summary

Selected references

Appendices