Sunday, March 22, 2009

Geology

I just went for a hike at the Sedgwick Reserve. I got to learn about geology there. There are three main groups of rocks. These groups are called igneous, metamorphic, and sedimentary. All of these rocks are made in different ways. Igneous rocks are made by volcanoes. So in that group you can find rocks like granite and pumice. Metamorphic rocks are made by being compressed and heated over and over underground. The sedimentary rocks I find kind of boring because they are made by stuff like sand washing up on top of itself over and over again over millions of years. It includes rocks like sandstone and limestone.

One really interesting type of sedimentary rock is called radiolarion chert. Radiolarion chert starts out as an amoeboid protozoa called radiolarion or in latin radiolaria. They are made out of silica, and when they die they turn into a nasty oozey stuff. After millions of years they harden and turn into radiolarion chert.

Rocks are made of elements and minerals. An element is a type of atom such as magnesium. Atom means unbreakable so they are the smallest pieces of matter. But even atoms are made up of other things such as protons, neutrons and electrons. Some rocks can be made of pure elements like gold or silver. A mineral though, can be made up of more than one type of element like serpentine. A rock is a giant mess of minerals and elements. A few of the main elements in rocks are silica, magnesium, carbon, oxygen, and calcium. So elements make minerals and minerals make rocks.

I got to interview a geologist. Her name is Susie Bartz. Susie Bartz wanted to learn about rocks because she didn't know what she was walking on. She looked at rocks, walked on rocks, and then went to Santa Barbara City College. Her favorite rock is monterey shale (sedimentary). She told me a very rare type of rock is called an eclogite. Eclogites are metamorphic and form in the Earth's mantle. They are very dense. Geology is very interesting.

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