Biostratigraphic and Lithostratigraphic Correlation of Sedimentary Strata in the Atlantic Coastal Plain J Bret Bennington J Bret Bennington

Correlation (lithostrat. and chronostrat.) Utility of fossils for dating strata Fossils as chronostratigraphic markers Transgressions and regressions Unconformities - angular, disconformity Subsidence rates Group problem solving / teamwork Discussion: sea level changes, changes in deposition, practical applications of stratigraphy, time trangressive nature of strata, subsidence of the continental margin Correlation (lithostrat. and chronostrat.) Utility of fossils for dating strata Fossils as chronostratigraphic markers Transgressions and regressions Unconformities - angular, disconformity Subsidence rates Group problem solving / teamwork Discussion: sea level changes, changes in deposition, practical applications of stratigraphy, time trangressive nature of strata, subsidence of the continental margin Learning Objectives

1. Assign ages to strata based on foraminifera index fossils.

2. Locate unconformity surfaces based on: a. biostratigraphic evidence (missing index fossils / time interval). b. lithologic evidence (paleosols). 2. Locate unconformity surfaces based on: a. biostratigraphic evidence (missing index fossils / time interval). b. lithologic evidence (paleosols).

3. Correlate unconformity surfaces that cut out the same time intervals. (Question for discussion: Why do unconformities merge landward and disappear seaward?) 3. Correlate unconformity surfaces that cut out the same time intervals. (Question for discussion: Why do unconformities merge landward and disappear seaward?)

4. Correlate invertebrate index fossils. (Question for discussion: Why are fossils useful for identifying unique time intervals?) 4. Correlate invertebrate index fossils. (Question for discussion: Why are fossils useful for identifying unique time intervals?)

5. Draw in lithostratigraphic correlations. Discuss rules for making correlations, pinching of sands landward and muds seaward, “dead ending” of correlations into unconformities. 5. Draw in lithostratigraphic correlations. Discuss rules for making correlations, pinching of sands landward and muds seaward, “dead ending” of correlations into unconformities.

6. Color lithologies to complete the fence diagram.

6. Color lithologies to complete the fence diagram. Identify disconformities and angular unconformities. 6. Color lithologies to complete the fence diagram. Identify disconformities and angular unconformities.

Subsidence Rates 85 my >90 my 135 my 140 my 150 my Downward flexure of the continental margin