I was looking up some information on the topography of Florida today and came across this blog. I have copied the interesting part below:
https://jacquithurlowlippisch.com/2016/01/22/mount-pisgah-and-the-hills-of-marin-county-former-frances-langford-estateslrirl/Today I will transcribe a piece of “Martin County’s 1982 Coastal Management Zone” shared with me years ago by Mr. Mark Perry. It talks about high places, ancient sand dunes, through out our county.
The 1982 Coastal Zone Management Study of Hutchinson Island, Martin County, Florida, 1982, was written by Florida Oceanographic Society and the Martin County Development Department.
Part II is entitled “Natural Geologic History.” It reads: “Just before the most recent Ice Age, the Wisconsin, which lasted from 100,000 to 11,000 years before present, the sea level was approximately 25-35 feet above the present mean seal level…At that time the sea was covering most of Martin County except for the Orlando Ridge, which was a narrow peninsula or series of islands and shoals, and the Green Ridge which was an offshore bar with the crest at sea level…The sea beating against the much smaller Florida coast formed, by erosion and deposition, a broad terrace of Pamlico sands.
