Well-cuttings based, sequence stratigraphic framework of the mixed siliciclastic-carbonate Lower Cretaceous sediments of the North Carolina coastal plain

A lithology-based, sequence stratigraphic framework and depositional model for mixed siliciclastic-carbonate Lower Cretaceous sediments of the North Carolina coastal plain (southeastern U.S.) is proposed. Twenty-five lithofacies are recognized. Ten recurring facies associations are defined, and are merged into siliciclastic - and carbonate-dominated depositional profiles, comprising coastal plain to deep shelf depositional environments. Parasequences are recognized from the well data, and are grouped into parasequence sets indicating progressive progradational or retrogradational (highstand and transgressive systems tracts, respectively) stacking patterns. Lowstand deposits are not recognized, although they probably occur in more basinward positions lying to the east. Seismic reflectors guided correlations between wells, and typically coincided with key sequence stratigraphic surfaces. Three third-order sequences are defined, which are dominated by siliciclastic depositional processes. The late highstand deposits of Sequence 1, however, are carbonate rich. The low relative sea-level conditions during late highstand likely favoured climatic aridity, facilitating carbonate-dominated sedimentation.