Voodoo science . Sounds like my opinions on aerospace technology. ;-)The black sand attracts more sunlight and thus reflects more heat. Similar to why the asphalt is always hotter than the concrete sidewalk. ;-)
This "ilmenite" is also what I occasionally see large, fist sized chunks of I imagine?Not closet geologist, but close enough. I actually get paid.
Mica's are typically much softer and lighter, and are "sheet-like" so they don't survive the beach energy that well.
It's a mineral called ilmenite. The reason you see it in layers is because it is heavier then quartz and as hard. It makes up about 2-3% of the sand on the beach. So, when storms come in and "re-work" all the sand on the beach, the lighter sand is pulled offshore (quartz) and typically a thin layer or crust forms on top of the remaining sand. Then as the quartz makes its way back on shore, it covers up that crust forming the layers. You can actually get an idea of storm history and smaller erosional and accretional events based on those layers.
As for peat, it does underly our beaches and is also dark/black. The reason is just what was posted earlier, there use to be a marsh where our beaches are now. The difference is that the peat is oily to the touch and typically requires mineral spirits to remove. In many areas the peat is only a few feet (less than 3) under the white sandy beaches. So, if you are seeing it in layers and it feels like sand, it is likely ilmenite. If it is in clumps and is oily, it is likely peat.
If you want to see the peat, go look in the dunes in Seacrest in front of Tranquility by the Sea, or the beach in the Seacrest area after a hurricane or tropical storm.
This "ilmenite" is also what I occasionally see large, fist sized chunks of I imagine?
Long ago I would dive the pass between St. Andrews and Shell island. toward the St. Andrews side, remnants of an ancient Pine forest were visible. I don't know wheter the trees were logged or swamped when the pass opened. , But, the dark sand was evident all around the ancient trees. Divers that liked to venture further out than me, told me that pockets of the dark sand were evident all along the beaches wherever wood decay was kept in the sand. They also told me the trunks of the ancient trees were fossalized...but then they also told me there were no sharks in the Pass and that I should eat chili before going out on the dive boats. But, gosh, I loved those days and those guys!!!!
I guess it wasn't pine but cypress or cedar. I just saw that the trees must have been huge....
Not all that ancient, try a badly loaded barge from the 90's carrying left over logs from the old St. Joe papermill to the one over in Parker. A strap broke and about half of the logs fell off.
But what I saw in the pass was stumps not logs. They may be there, I judt didn't got very far down. After seeing the sharks swimming in the pass, my interest declined dramatically and I went to look for shells. The stumps looked to be about 4 to 5 feet tall and straight up like stumps would be on land. It just fascinated me how it looked. Weird and eerie....
Long ago I would dive the pass between St. Andrews and Shell island. toward the St. Andrews side, remnants of an ancient Pine forest were visible. I don't know wheter the trees were logged or swamped when the pass opened. , But, the dark sand was evident all around the ancient trees. Divers that liked to venture further out than me, told me that pockets of the dark sand were evident all along the beaches wherever wood decay was kept in the sand. They also told me the trunks of the ancient trees were fossalized...but then they also told me there were no sharks in the Pass and that I should eat chili before going out on the dive boats. But, gosh, I loved those days and those guys!!!!
Did those same divers say they never pee in there wet suit also!