Main      Site Guide    
Message Forum
sand
Posted By: Howard, on host 205.184.139.60
Date: Thursday, May 4, 2000, at 08:50:09

Sand makes me think of beaches. That's reason enough to like sand. But the more I look at it the more I like it for itself. Sand is not a single uniform substance. It varies in chemical make-up, color, and texture. The sand on Cape Cod is not like the sand in Florida. Years ago out of the tip of Cape Cod, I took a closeup look at the sand. It was composed of red, brown, black, white and clear crystals. Some of the darker crystals even had a greenish cast. Partical size was much larger than most sand. It was clearly granite and other hard rocks ground up by ice-age glaciers and further refined by a few thousand years of surf. Well, it was clear to me. I had just taught an earth science unit on glaciation. You learn a lot teaching something to somebody else.

On the beaches of southern states, that is Virginia to Florida, the partical size is much smaller. The sand contains silicates and carbonates. The silicon compounds have been coming down rivers from the mountains for a couple of hundred million years. Much of it is quartz ground very fine by surf. The calcium carbonate is mostly from shell and choral. The further south you go the less quartz sand you will find in it. By the time you get to the tip of Florida, it's almost all calcium carbonate.
Beaches in California and Hawaii are ground up volcanic materials. That's why Hawaii has black sand beaches, red sand beaches, green sand beaches and even white sand beaches. On Kauai, the oldest major island in the chain, the beaches tend to be a golden color that is a mixture of red lava and coral sands.
Next time you go to the beach, don't just sit and look at the ocean.
Howard

Replies To This Message