Field Trip March 13, 2009

We went up little cottonwood to look at a pluton and some metamorphic contacts. It was a beautiful day.

This is a picture of the first outcrop that we went to. If you see the layers, it isn't sedimentary. This is just how the pluton (magma chamber) settled. It is a beautiful granodiorite.
Here is a sample of a rock within the usual rock. It has a lot less blacker materials than the usual rock. And it has no quartz.


This shows the whole rock where there are the square inclusions.

Here is an up close look at the differences between the whole rock and the inclusion.

Here is another inclusion of more of the black minerals.

Granite weathers pretty cool. The black minerals weather much faster than the silica minerals. This causes the whole rock face to turn into granules. It was rough to hike in.

This shows some of the metamorphosed rocks I understand the concepts, but it is really hard to explain. It shows compression stress. You see it with the Schist that is present.

This is a dike of Quartz that goes through the metamorphosed sandstone. It shows rapid cooling as the molten magma goes through the "country rock" or the rock that was there first.

This shows folding. If you see the dark wavy thing in the center of the picture, that is the country rock right next to the granite.

This also shows the country rock right next to the granite. If you look closely you can see dikes of granite going through the quartzite.

Here is a close up of the quartz dike. If you notice it doesn't have any black minerals. This is because the time that the dike was formed, all of the black minerals had solidified and only SiO2 was left in the solution. This creates quartz.


I hope that you enjoy the pictures. It was an awesome field trip. I like metamorphic and igneous rocks better.