Thursday, November 15, 2012
Meteorites Part IV
Meteorites create other interesting artifacts on impact.
There are a lot of meteorite-created artifacts on earth. Tektites are the most common and are sometimes called impact glass. Tektites are glass blebs created when a meteorite impacts certain types of soils. Even though they are common they are all named by where they are found and some are more valuable than others.
Moldavite is a yellow-emerald green glass from the Czech republic .
Libyan Glass is a light yellow glass from the Great Sand Sea in Egypt .
Dark green tektites are common in Thailand , China , Ivory Coast , Ghana , and other places around the planet.
In the U.S. , Georgia and Texas have tektite that range in color from root beer-brown to dark olive green. They are usually smaller than a nickel.
Besides tektites, meteorites create craters in the ground. These are wonderful curiosities to visit. It is estimated that 40,000 to 60,000 tons of meteorite falls to earth each year. By far the majority of this is in the form of dust. (Which, I suppose you could collect off of the roof of your house with a shop vac). Larger meteorites, say over 200+, are much more rare with only about 40 per year falling. To make a crater on earth, it takes a meteorite weighing in excess of 50,000kg (110,220 pounds).
Impacts also cause Shatter Cones. These are found along the outer rims of impact craters. It is where the soil has been “shocked” into what looks like a stack of ice cream cones and can form miles away from the actual impact. They ALWAYS point to the center of the impact.