What's Done This?

[got4boyz]

Thanks, that was very interesting.

 

[armyscuba]

Fecal Pile-The Oceans bottom is made up of it..Sand is full of it..Fish and Sea Life Make it everyday..

 

[The Chairman]

So what DID make those beautiful beaches???

 

[fgray1]

Fred

 

[Rick Murchison]

So what DID make those beautiful beaches???

Well, there's sand, and then there's sand... the calcium based sands typical of coral reef areas are largely fish poop. But the snow white sands of Lower Alabama are quartz, ground up not by parrotfish but by geologic forces. Yellow/orange sands are likewise usually quartz grains broken off by grinding of rocks together through the ages. Black sands are ususally ground up volcanic rock but can be other stuff too. In my travels one of the things that surprised me was the variety of texture and materials that ended up as beach sand. Figuring out how it got there and where it came from is fun.
Rick

 

[The Chairman]

Rick, I used to think that ALL sand was geoogically produced... a parrot fish destroyed my theory with one single poop. But Archaman said

Many of the older texts still tout parrotfishes as the "creator" of those sparkling carbonate beaches found in the tropics. Eventually the phycologists knocked this notion over the head... though it keeps popping up on semi-science sources.

and it is THIS statement that has me puzzled, and I would love to hear his elucidation before the "sparkling carbonate" material hits the sea fan.

 

[Stone]

Here's a parrot fish making a contribution to the sandy bottom.

 

[H2Andy]

i think archman is referring to the fact that while parrotfish contribute to the sand
that ends up at the beach, geological action (wave, wind, etc.) is really the main
producer of sand by breaking rocks up into tiny grains of the stuff we love to track
into our cars and hotel rooms and wash out of our ... hair.

 

[got4boyz]

Pretty funny that you caught him in the act Stone!

Well this has been educational, learning how we get different kinds of sand. So where did the sand on SE Texas come from? Too bad it makes the water so brown.

 

[MSP Rescue Diver]

So where did the sand on SE Texas come from? Too bad it makes the water so brown.

Dogfish?

Marc