1. Field Assignment Part 1 Lenai Munch Geology Judy Horn Due May 15, 2011
3. DescriptionObsidian is an extrusive igneous rock alsoknown as volcanic glass.This rock is similar in look to a glass. It is ablack color with the glossy look to it. Theparticular piece that I found had once been usedby a Native American most likely, because ithas been changed in original shape to make theappearance of an arrowhead. The texture issmooth but can be sharp around the edges.
4. Background InformationBishop CaliforniaBishop is where I was born and raised and growing up there we alwayslooked for pieces of obsidian that had been made into arrowheads. Themain areas we find them are in the desert area when we are horseback.The desert in which they are found usually consist of the sand,sagebrush and other rcoks. There are obsidian domes in the area thatwere formed by volcanic eruptions 550 to 600 years ago. The stickylava reached the surface and cooled quickly without allowing crystalsto form which then forms the glass like obsidian. As time has passed,obsidian pieces have spread and can be found around Bishop. In thepast Native Americans used obsidian to form arrowheads which is mostinteresting to come across. From our backyard we have found manypieces. There are multiple volcanoes around Bishop includingMammoth Mountain and some others close by which could have atsome point been the reason for the obsidian around the area.
6. DescriptionGranite is an intrusive felsic igneous rock.
7. The granite rock is gray in color withspecks of black. Granite is formed byintruding into another rock. Thisigneous rock is formed by magma. Therocks are intruded into the Earth’s crust.
8. Background Information This piece of granite that I found was in Raymond California. Nearby Raymond is Yosemite National Park which contains the half dome. The half dome is a granite rock formation. There is also a huge granite area in Raymond that you can see from driving by on the road.
10. DescriptionThese rocks are actually a silicate mineral calledstaurolite crystals. They are more commonlyknown as “cross rocks”This was harder to identify and research. The rockI found is prismatic in shape with four sides.When the rock is rinsed off it is a red color inappearance with a blackish colored cross in themiddle hence the name cross rock. Thepicture shows the cross up close.
11. BackgroundI found these rocks in ChowchillaCalifornia in the horse arena. They aresmall but abundant in this area.Through research I found that they arenot commonly found in very manyplaces in the world.
12. Cross RocksThese rocks through time have becomesymbols of myths, tales andsuperstitions. Many religions believethese rocks have good faith and luck.
13. Sedimentary Rock
14. This rock that I found is gray withsmaller rocks embedded within it as wellas a pink or red color throughout therock. I identified this rock as asedimentary rock because multiple otherrocks inside. The texture seemed to beclastic. I found this rock in ChowchillaCalifornia.
15. Metamorphic Rocks
16. DescriptionThis rock was a lighter tone of black with whitestreaks running through it and some hints ofa reddish color throughout the rock. I was notpositive on my identification of this rock butthe reason it made me believe that it wasmetamorphic was because of the streaks of colorlike layers in the rock. It seemed as though thecolors got there through some chemical change. Ifound this rock near a slough in ChowchillaCalifornia where water is often running.