Adkins

Although the red and pink markers are very pretty, you will find that most of the markers in Parsons are grey, like this one here. The key difference is the absence of the pink feldspar minerals. This rock is made exclusively of white, grey and black minerals. This rock would be classified as felsic. (Image 2)

Most of the “igneous” markers in Parsons are one of the six types of igneous rock shown above. The terms geologists use to classify different types of igneous rocks are based on the relative proportion of the different minerals they contain. For example, granite or granodiorite will have a large amount of quartz, syenite or monzonite will have very little quartz, and diorite or gabbro will have no quartz at all. (Image 3)

The marker at Stop 1 would be classified as a granite, the marker at Stop 2 would be classified as a syenite, and the marker at Stop 3 is a granodiorite.