The Rock Springs Uplift is an area of uplifted
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...
to
Eocene
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...
rocks in
Wyoming
Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the s ...
surrounded and once covered by sediments of the
Green River Formation
The Green River Formation is an Eocene geologic formation that records the sedimentation in a group of intermountain lakes in three basins along the present-day Green River in Colorado, Wyoming, and Utah. The sediments are deposited in very fine ...
which were deposited in the Eocene Lake Gosiute.
[Surdam, Ronald C. and K. O. Stanley, ''Lacustrine sedimentation during the culminating phase of Eocene Lake Gosiute, Wyoming (Green River Formation),'' Geological Society of America Bulletin, 1979, 90, no. 1, pp. 93-110] The Rock Springs Uplift formed in the Late Cretaceous through the Eocene and is related to the
Laramide orogeny
The Laramide orogeny was a time period of mountain building in western North America, which started in the Late Cretaceous, 70 to 80 million years ago, and ended 35 to 55 million years ago. The exact duration and ages of beginning and end of the ...
. The structure is a north–south trending
anticline
In structural geology, an anticline is a type of fold that is an arch-like shape and has its oldest beds at its core, whereas a syncline is the inverse of an anticline. A typical anticline is convex up in which the hinge or crest is the ...
[''Rock Springs Uplift,'' Wyoming Geological Survey]
/ref> with a surface expression of approximately by . The community of Rock Springs is located on the western margin of the uplift.
A recently discovered lithium
Lithium (from el, λίθος, lithos, lit=stone) is a chemical element with the symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard conditions, it is the least dense metal and the least dense solid ...
deposit is estimated at 228,000 tons. Additional deposits in the same formation were extrapolated to be as much as 18 million tons.
Features
* White Mountain
* Aspen Mountain
* Wilkins Peak
References
Landforms of Wyoming
{{Wyoming-geo-stub