INVESTIGATING TERTIARY-QUATERNARY STRATIGRAPHIC RELATIONSHIPS ACROSS NORTHERN FLORIDA: AN EXAMINATION OF SURFICIAL GEOLOGY AND STRATIGRAPHIC CORRELATION ISSUES.

The attempt to correlate surficial stratigraphic units across Florida has highlighted many of the spatial and temporal complications encountered when working with quartz sand-dominated units of a similar age. Workers continue to struggle with establishing a formal lithostratigraphic framework for these surficial units largely due to their litholologic similarity, surficial expression, reworking, and a paucity of dateable material. Although our interpretations continue to improve, issues with correlating and formalizing some units have persisted since they were first described and mapped. These siliciclastic units largely consist of unconsolidated to moderately indurated, variably sorted, very fine-grained to graveliferous, clean to clayey quartz sand. Recent geologic mapping efforts of surficial and near-surface units in north Florida have sparked renewed debate and the need for additional lithostratigraphic investigations to evaluate and interpret depositional environments, timing of deposition and reworking, characterization of accessory mineral assemblages, and reviewing stratigraphic relationships.

Ongoing Earth MRI efforts to establish and construct a statewide quartz sand coverage will shed more light on the lithostratigraphic relationships of these units. The surficial quartz sand units are significant in part due to their regional extent and environmental applications (mining and mineral commodities, construction and resource management, environmental and land-use planning, hazard mapping, and resiliency efforts). We present samples and a discussion of the informal Miocene coarse clastics and the formal Pliocene-Pleistocene Citronelle, Miccosukee, and Cypresshead Formations.