3. • California is an ideal place to observe many
different types or rocks and offers a wide range of
geological specimens.
• I was a little hesitant at first to try and determine
where I could find these different types of rocks.
Once I observed some geological maps of California
online and researched my surrounding area, it
didn’t take me long to discover that these rocks can
be found in a number of different places and we
don’t even know it.
• It takes a good understanding on California’s
geological history to complete this field
observation.
• The process I used in order to figure out rock types
I collected was similar to that of a scientist.
Question, research, hypothesize, test, analyze and
conclude. With this formula I was able to accurately
determine what type the collected rocks were.
4. What is an Igneous Rock?
Igneous rocks are formed from the solidification and cooling of
molten rock material. There are two basic types: 1)intrusive
igneous rocks such as diorite, gabbro, granite and pegmatite
that solidify below Earth's surface; and 2) extrusive igneous
rocks such as andesite, basalt, obsidian, pumice, rhyolite and
scoria that solidify on or above
Type of Rocks
The first rock to the left is Granite an example of intrusive
igneous rock and the one to the right is Andesite and example of
extrusive igneous rocks.
6. Information
I got both of my igneous rocks at the famous Yosemite National Park. I
found both of them in different parts of the park but it wasn’t till later I
realized that only one of them was granite and the other was andesite.
Most of Yosemite park is full of different rock types but mainly granite. I
knew right away that both were igneous rocks from previous research
and knowledge so it was an easy observation. After careful review and at
home I figured out my hypothesis were correct. Below is a picture of the
famous park where I located both these magnificent finds.
8. What is a Metamorphic
Rock?by heat, pressure and chemical
Metamorphic rocks have been modified
process usually while buried deep below Earth's surface. Exposure to
these extreme conditions has altered the mineralogy, texture and
chemical composition of the rocks. There are two basic types of
metamorphic rocks: 1) foliated metamorphic rocks such as gneiss,
phyllite, schist and slate which have a layered or banded appearance
that is produced by exposure to heat and directed pressure; and, 2) non-
foliated metamorphic rocks such as marble and quartzite which do not
have a layered or banded appearance.
Type of Rocks
These rocks that I collected were all examples of foliated
metamorphic rocks. I believe the one on the right is Phyllite and
the other two on the left are Gneiss.
9. Information
I found this type of metamorphic rock at a random place along the
highway. When I was driving down south to visit my daughter. I
happened to see a small boulder on the side of the road at the
bottom of a mountain and had to take a look. I had a feeling that the
rock I had came across was Gneiss. It was rough, and was layered
with different but similar colors. I took a picture of the boulder but
also found a small piece next to it. Out of all the rocks I enjoyed
observing this one the most because of its appearance and
appealing color change. I found the other metamorphic rock outside
my parents house in the country where there is a lot of dirt and
rocks. I came across this type of rock and of course it caught my
eye because of its color and texture. After further investigation I
concluded that it was indeed Phyllite.
11. What is a Sedimentary
Rock?
Sedimentary rocks are formed by the accumulation of sediments. There
are three basic types of sedimentary rocks: 1) clastic sedimentary
rocks such as breccia, conglomerate, sandstone and shale, that are
formed from mechanical weathering debris; 2) chemical sedimentary
rocks such as rock salt and some limestones, that form when dissolved
materials precipitate from solution; and, 3)organic sedimentary
rocks such as coal and some limestones which form from the
accumulation of plant or animal debris.
Type of Rocks
The rocks that I collected are examples of classic sedimentary
rock. The rock on the right is conglomerate and the rock on the
left is siltstone.
12. Information
The second to last rock I came across or I should say came across
me is an example of sedimentary rock. I found this rock when I was
visiting my daughter down south over Thanksgiving break and
happened to see this interesting rock on a construction job site near
her house. It was very eye catching as I saw the many different
clasts formed into one solid rock. I only realized then it was some
type of sedimentary rock which later accurately discovered it to be
conglomerate. Finally the last rock I collected was up near Millerton
Lake, familiar ground to where my children take their boat. I had a
prediction that this type of rock was siltstone because of its smooth
appearance with some indentations. After careful observation and
research back at the house I concluded it was indeed siltstone.
13. Reference Page
http://geology.com/rocks/igneous-rocks.shtml
http://geology.com/rocks/sedimentary-rocks.shtml
http://geology.com/rocks/metamorphic-rocks.shtml
http://www.wikipedia.org/
This was a tough, challenging yet exciting experience that I enjoyed very much. I
hope after all the research and knowledge obtained throughout this class I was able
to determine what rocks were correct.
