The Gulf Trough, also known as the Suwanee Straits,[1] is an ancient geologic feature of Florida present during the Paleogene period (65.5—23.03 Ma). The trough hosted a strong marine current, similar to the Gulf Stream.
What would be Florida during the Paleogene, was the submerged Florida Platform, a feature not unlike the Bahama Banks composed of carbonate sediments containing foraminifera, corals, bryozoa, and mollusks. Due to the current running through the Gulf Trough, materials needed for sedimentation were instead carried away toward the northeast.
During the Eocene through Oligocene (55.8—23 Ma), a period of roughly 32.8 million years, erosion born material began building up more rapidly in the Gulf Trough due to the uplifting of the Appalachian Mountains to the north, the primary source of siliciclastic material transported via rivers and streams. By the Early Miocene, the trough was filled and materials continued to move southward covering and replacing the carbonate-depositing environment with sands, silts, and clays creating the peninsula and making way for flora and fauna to become established.[2]