person standing on narrow mountain ridge with peaks extending into the distance
diagram of the upper layers of the earth in the arctic 100 mya
diagram of oceanic crust being subducted under continental crust
diagram of ancient ocean basin
diagram of upper layers of the earth 120 million years ago northern alaska
snow covered mountain peaks
diagram 280 mya soft continental collision
diagram of 200 million year ago closing of an ancient ocean
diagram of upper layers of the earth 150 million years ago northern alaska
diagram of oceanic crust being subducted under continental crust
diagram of upper layers of the earth showing arctic ocean opening
diagram of atlantic basin
diagram iapetus ocean completely closes
diagram of upper layer of the earth showing gulf of mexico opens
diagram of continent rift
geologic cross-section of the southern appalachian mountains
illustration of the upper layers of the earth showing subduction zone
illustration of the upper layers of the earth showing subduction zone and narrowing ocean basin
illustration of the upper layers of the earth showing subduction zone and collisional mountins
person standing on a rocky mountain ridge with peaks extending into the distance
map of the southern and eastern united states showing major mountain ranges and national park system units
close up view of hot spring pool with small waterfall
Shaded relief map of United States, highlighting National Park Service sites in Colisional Mountain Ranges.
mountain ranges and misty valleys
shaded relief map of alaska showing nps units
river flowing through rocky cascades
three people standing in front of rock cliff with folded rock layers
view looking up at rock cap on mountains
mountain stream with waterfalls
ancient north america
map of the world showing location of continents today
map of the world showing location of continents 250 million years ago
map of the world showing location of continents 500 million years ago
Geologic Resources Division

Tectonic Evolution of the Southern Appalachian Mountains—750 Million Years Ago

750 Million Years Ago—Old Continent Rips Apart. The long mountain ranges and rift valleys were similar to those forming today in East Africa and the Basin and Range Province.

illustrations above modified from “Parks and Plates: The Geology of our National Parks, Monuments and Seashores,” by Robert J. Lillie, New York, W. W. Norton and Company, 298 pp., 2005, www.amazon.com/dp/0134905172.
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*Images credited to NPS without any copyright symbol are public domain. Images credited with a copyright symbol (indicating that the creator may maintain rights to the work) or credited to any entity other than NPS must not be presumed to be public domain; contact the host park or program to ascertain who owns the material.

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plate tectonicsgeology

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