Creek cuts or road cuts are often an open history book not of recent times but of times long gone. Perhaps millions of years can be read in one spot. This is knowledge I hunger for and spend endless time trying to "read" the geological happenings that created this place, this time.
Above is a creek cut with layers of clay alternating with layers of lime. This could be read as a long time of drought followed by a body of water which caused the lime build up. The time of water was long because of the sediment and the fact water with lime began seeping into the clay or silt stone. Both are considering sedimentary rocks.
Then, Boom! There's a nice shelf of igneous rock bubbling out of the creek floor. Now this is where it gets confusing to me. This could be metamorphic rock because "Metamorphism is the result of solidification of material under high temperature and pressure. There are two types of metamorphism, contact and regional. The difference between the two is simple. Contact will occur in a small area usually as a result of an igneous intrusion. Regional occur in a large area due to intense heat and pressure within the earth." So could it be an igneous intrusion cooling as it is reaching the surface which then makes it a metamorphic stone? Metamorphic stone is made by squashing or heating.
Are you confused yet? I am.
At this point I know I don't know enough unless all I need to know about rocks is the pleasure of collecting and just listening to what they have to say.
I know barely enough to know if it's sedimentary, igneous or metamorphic...sometimes but I surely have fun trying to figure it out because under these main divisions are many, many more.
...and that is your geology lesson for the day.
Knowing there is no simple stone keeps me looking.
a tale of tails, tenacity, and tedium, as told by me, usually barefoot and bellowing
Showing posts with label sedimentary rock. Show all posts
Showing posts with label sedimentary rock. Show all posts
Thursday, October 22, 2015
Wednesday, September 10, 2014
I Know You're Wondering About The Rocks
Those who know me well also know what a rock hound I am. Instead of postcards I collect rocks and know where each one was gathered.
Fossils in limestone too large to carry
Quarried limestone along the boat ramp full of quartz
Limestone ledges shelters fish under water
and whatever needs shelter above it.
Most of our rocks are different forms of sedimentary.
Note the snail fossil here.
I could not catch the sparkle with the camera
but sunshine and the eyes can find the quartz.
I love rocks where the hole goes completely through it.
We call them fairy rocks as in door ways for the little folks.
Others call them Crone Stones
and believe that the wearer can see the future.
All are sedimentary rocks of varying types.
Silt stone
These I carried home. I had my handy canvas bag just for this reason. I had to be selective because it was a long way back to the boat.
Double prize here with a hole that is also a fossil.
I found some thin flat rocks to paint and others I will incorporate around my water gardens.
We've found metamorphic rocks and some volcanic rocks along with lots of sedimentary rocks At The Farm. I enjoy reading the history in each stone. Millions of years can be seen in a rock cliff and I get lost in time.
And that is Geology One for preschool...I try to learn more with every rock I touch but I have a long way to go.
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