black in sand

This area used to be a bog/marsh. The black sand and layer of dirt under the sand are a remnant of that.

I heard that millions of years ago the beach used to be a cypress forest and the black is "peat" from that forest. I don't know if this is true, though. I don't know why the sand would be hotter in parts, but I'll see for myself in August (can't wait, no matter if the sand is hot or cool on the feet!).

I heard that millions of years ago the beach used to be a cypress forest and the black is "peat" from that forest. I don't know if this is true, though. I don't know why the sand would be hotter in parts, but I'll see for myself in August (can't wait, no matter if the sand is hot or cool on the feet!).

this is exactly what I've always heard. But don't know how true this is.

I heard that millions of years ago the beach used to be a cypress forest and the black is "peat" from that forest. I don't know if this is true, though. I don't know why the sand would be hotter in parts, but I'll see for myself in August (can't wait, no matter if the sand is hot or cool on the feet!).

The black sand attracts more sunlight and thus reflects more heat. Similar to why the asphalt is always hotter than the concrete sidewalk. ;-)

I had this same discussion a while back on the board with somebody who claimed to be a closet geologist. He explained what it was, but I can't find the threads. He said it was some mineral. Personally, I don't know what it is other than hot on the feet!

Mica maybe? It's also got a little bit of a sheen to it.

I had this same discussion a while back on the board with somebody who claimed to be a closet geologist. He explained what it was, but I can't find the threads. He said it was some mineral. Personally, I don't know what it is other than hot on the feet!

Not closet geologist, but close enough. I actually get paid.

Mica maybe? It's also got a little bit of a sheen to it.

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.

Not closet geologist, but close enough. I actually get paid.

Yup...It was you. I remember, now. Thanks for chiming in. I don't know why I couldn't find our thread...

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....

The black sand attracts more sunlight and thus reflects more heat. Similar to why the asphalt is always hotter than the concrete sidewalk. ;-)

Voodoo science . Sounds like my opinions on aerospace technology. ;-)

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?

This "ilmenite" is also what I occasionally see large, fist sized chunks of I imagine?

No, that is more likely the consolidated peat deposits. The ilmenite will be the tiny specks that are the same size as the quartz sand grains.

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.

You can go see some exposed peat right now at Inlet Beach-it looks like black rocks in the surf.

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....

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....

Oh okay, I just remember the great spill and the furor that insued. Didn't realize it was stumps down there, the current and sharks have always kept me away.

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!

Did those same divers say they never pee in there wet suit also!

Might not be pee if you spot a big enough shark.

I don't know anything about ancient pine forests or geology, but I do agree the sand was definitely hotter this year on the feet......ouch!!!!

Depending on where you are walking, the "new" sand used for restoration or to cover seawalls isn't as nice to walk on as the stuff Ma Nature put there.

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....

It kind of sounds like the stump hole part of Cape San Blas right where you turn to get onto the peninsula. There's a huge broken concrete wall on the seaward side to keep the road from going under during storms. On the other side of the rip rap, it used to be a small beach area where forest came almost right up to the water line. Then a series of storms from George in 1998 onward took out a ton of the sand in the area south of the seawall. What had been forest was now under water, and the trees died from salt water intrusion in the roots.

Give it a couple more storms where the top of the dead trees snapped off, and more water washed away more of the sand at the tree trunks, and that area now probably has a pretty similar underwater dead tree structure as the pass/ Shell Island area does.

There are a lot of areas in between the pass and Apalachee Bay that get flagged as 'highly and frequeently erroding- we're not even going to try to put a shoreline line down' on official marine charts.

It kind of sounds like the stump hole part of Cape San Blas right where you turn to get onto the peninsula. There's a huge broken concrete wall on the seaward side to keep the road from going under during storms. On the other side of the rip rap, it used to be a small beach area where forest came almost right up to the water line. Then a series of storms from George in 1998 onward took out a ton of the sand in the area south of the seawall. What had been forest was now under water, and the trees died from salt water intrusion in the roots.

Give it a couple more storms where the top of the dead trees snapped off, and more water washed away more of the sand at the tree trunks, and that area now probably has a pretty similar underwater dead tree structure as the pass/ Shell Island area does.

There are a lot of areas in between the pass and Apalachee Bay that get flagged as 'highly and frequeently erroding- we're not even going to try to put a shoreline line down' on official marine charts.

Luckily there are plenty of idiots that have decided there is a water line and that regardless of what Ma Nature says it will remain there.

Black sand bedevils Crystal Beach homeowners (PHOTOS) | beach, pat, crystal - Top Story - TheDestinLog.com

If only they checked sowal.com, they would know what the black sand is and where it comes from instead of asking people what they "think" in a poll. The sad part is that 98% of them appear to be wrong out of over 100 people as of my vote.

They could, I don't know, call a real live geologist? Any geologist. :roll: