Week 5 – Converging Plates
Beginning of the Appalachian trail Cohutta National Forest, Helen, GA 30545, USA (SkyScanner)
This week I travel to an ancient example of Convergent Plates called the Appalachian Mountain Range. I joined the likes of 2 million people a year by hiking a part of the Appalachian Trail (2000 Milers). A trail that runs along this beautiful Appalachian Mountain Range in eastern North America. It stretches almost the entire length north to south of the eastern United States. The Appalachian Mountain Range is still a formidable challenge to hikers due to dramatic ridgelines and valleys stretching for 2,181 miles north to south.
Generalized east-to-west cross section through the central Hudson Valley region. USGS Image
It is said this system of mountains formed 480 million years ago and once reached to the height similar of the Alps and the Rocky Mountains but has since eroded greatly over these millions of years. The rocks exposed today are long belts of folded and thrust faulted marine sedimentary rocks, a little bit of ocean floor, and volcanic rocks. This is strong evidence that these rocks were deformed by plate collision due to the compression seen. The coolest thing about the Appalachian Mountain Range is that this could be one of the first plate collisions that were caused by the plate movement creating the supercontinent Pangaea!
Paleogeographic reconstruction showing the Appalachian Basin area during the Middle Devonian period. Read more: http://www.geologypage.com/2013/02/appalachian-mountain-range.html#ixzz5N9pZBqs1
This looks like a continental plate colliding and pushing beneath it an oceanic plate since I can see some of the thinner basalt type rock far under layers of the thicker granite. This is an old subduction zone. You can see thrust faulting that created up-folds and downfolds deforming sedimentary rock that now defines the area. In these up-folded mountains, I can see deposits of anthracite coal and in the far distance bituminous coal. The ridges I am standing on are made up of erosion resistant sandstone, while the valley’s I look down on are made up of limestone that erodes easier over time. You can see the limestone that has been deposited in the lower lying areas.
Thank you,
Will
Resources:
Appalachian Mountain Range. (2013)
Read more : http://www.geologypage.com/2013/02/appalachian-mountain-range.html#ixzz5N9bo4L5c
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Beginning of the Appalachian trail. Cohutta National Forest, Helen, GA 30545, USA (SkyScanner) https://www.skyscanner.com/trip/sautee-nacoochee-ga/things-to-do/appalachian-trail-georgia
Geologic Provinces of the United States: Appalachian Highlands Province: https://geomaps.wr.usgs.gov/parks/province/appalach.html
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