All of the uplifting of the rocks that you see on the mountain side is the direct result of orogenic or mountain building activity that uplifted these rocks as well as rocks in the Central Basin Platform, a major geological province in the region. Associated with the tilting of the rocks is erosion. Where rocks have been eroded away is called an unconformity.
There are four types of unconformities in nature: a disconformity, a nonconformity, a paraconfomity, and an angular unconformity. A disconformity is where sedimentary rock lays on top of sedimentary rock that has been eroded. A nonconformity is where sedimentary rock lays on top of either an igneous or metamorphic rock that has been eroded. An angular unconformity is where beds have been tilted, eroded, and flat-lying rocks have been deposited on top of it. A paraconformity is where flat lying beds are eroded and covered by flat-lying beds but can only be recognized by the gap in the rock record.
This area is very important because geologists are able to examine the rocks and folds and determine why they formed in the way they did and how this area has developed into what you see today. This area is also associated with a large amount of oil production and provides a snapshot image of many of the fields in the Permian Basin allowing geologists to predict better where the oil occurs. This is the only place where this occurs at the surface. The rocks you are looking at are known as the Hazel Formation and Van Horn Formation and were deposited 550-490 million years ago in the ocean.
Tasks:
Go to the posted coordinates and look due East and answer the following questions:
1. Are the rocks on the mountainside flat-lying or are they tilted? To determine this follow the linear features until they meet the rocks at the very top of the mountain. (It may help to have binoculars or a zooming in camera for this)
2. If they are tilted, what angle are they laying at?
To determine this either bring a protractor to estimate the angle or take a picture and use a protractor at home.
3. Referring to the descriptions of the above paragraphs and your answer to Question 1, what type of unconformity is present in these rocks?
4. Include a picture of yourself (or an object) with the slopes in the background.
References:
Wicander, R., and Monroe, J. S., 2000. Historical Geology: Evolution of Earth and Life Through Time 3rd Edition. Van Der Pluijm, B. A., and Marshak S., 2004. Earth Structure 2nd Edition. http://sepmstrata.org/terminology/unconformity.html
