Rocky Mountains
https://en.wikipedia.org/wiki/Rocky_Mountains#/media/File:Jackson_Glacier_terminus.jpg
This week I went to Colorado to take a look at the Rocky mountains. However, the Rocky mountains stretch much further than just the expanse of Colorado. The Rocky mountains seem to be made up primarily of metamorphic and sedimentary rocks. There are large deposits of limestone and dolomite.
This mountain range is particularly interesting because when two continental plates collide, the resulting mountain range is typically 200 to 400 miles inland from a subduction zone; however, this particular range is hundreds of miles further inland. Geologists are still unsure of why this is the case, but they believe the most likely cause is an unusual subducting slab. The two plates in question here are the Farallon plate and the North American plate.
Looking at the rocks here, it seems that rather than breaking, the rocks have been deformed in a ductile fashion. There are clear wrinkles that are visible which look like overturned folds due to their strong tilt. Seeing these folds makes me believe that the stresses are compressive as they are pushing the rocks together and the rocks are folding and thickening vertically. This would also lead to the fact that the Rocky mountains are a reverse or thrust fault rather than normal, since they are pushing together rather than pulling apart.
Sources:
https://geomaps.wr.usgs.gov/parks/province/rockymtn.html
https://en.wikipedia.org/wiki/Rocky_Mountains
https://www.livescience.com/37052-types-of-faults.html
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