Rocks

Obsidian was a rock that we learned about and it is a volcanic rock and therefore classified as a ingenious rock formed by the lava cooling down.  It is mainly found in the western US and is prized for its reflectiveness and sharpness.  This was a common material to use as arrow heads for Indians or the end of spears because of the durability and sharpness of it. The chemical composition is 70-75% SiO2 and contains MgO and Fe3O4.



Another rock we learned about was sandstone.  This is formed by an immense pressure on different layers of sand that  will then come together and form a solid form.  Since sand is required for this rock, it is mainly found in dry, sandy areas mainly deserts.  It has some components of it such as felspar and quartz which are common to be found in the ground. 

Another one is called slate and this is a metamorphic rock which means it was formed with a massive amount of pressure and low heat.  This is popular and has many uses such as flooring, writing aids and decoration.  Most of the common slate is grey with some varying from purple to green varaitaions. 




Lastly, the rock we learned about was actually a mineral called zoisite.  It is classified as a metamorphic or pegamitic mineral. It has a well known pink color called thulite.  It was named in 1805 after an Austrian scientist Sigmund Baron Zois. 

Soil

We learned about soil and the 12 soil orders of the road.  The soils are classified by a chart called a soil diagram chart.  This allows the soil found to be classified to either clay, loam or sand and any variation in between.  This is a very basic chart to read as you simply match the numbers up and move inwards from the particular variation. 











We then learned abut the Munsell Soil Chart which can can determine the soil type based on its color or more specifically the hue and chroma.  This was developed by a professor and is used by the USDA.





Lastly, the 12 soil orders of the world were talked about and the list is shown below.  The common soil type for Georgia is utisol.  The 12 soil orders of the world are alfisol, andisol, ardisol, entisol, gelisol, histisol, inceptisol, mollisol, oxisol, spodosol, ultisol and vertisol.

Olcmulgee National Monument

For lab this week, we went to the Olcmulgee National Monument and went into the park and looked at the different soils in different areas.  We then measured the soil against a Munsell Color book.  Then we went to an old Indian mound and went inside a small tunnel to the opening.  It was a place of dwelling for Indians and was one of many mounds in the area.  The mounds were discovered by workers digging up the area to lay down track for the railroad and ended up pulling out bones.  They then realized it was a burial ground and it has been protected ever since.  This area has been occupied by many different civilizations and was a source of trade as it was very easy to access from the river.  Later on it was more modernized when a doctor paid for a highway to be built close by in order to see his family.