Search results
Results From The WOW.Com Content Network
The geology of South Dakota began to form more than 2.5 billion years ago in the Archean eon of the Precambrian. Igneous crystalline basement rock continued to emplace through the Proterozoic, interspersed with sediments and volcanic materials. Large limestone and shale deposits formed during the Paleozoic, during prevalent shallow marine ...
Coteau des Prairies. Coordinates: 44.0000°N 96.3167°W. The Coteau des Prairies: blue arrows indicate paths of the two lobes of the glacier around either side of the formation. This excerpt from the Lewis and Clark map of 1814 shows the rivers of western Iowa and eastern South Dakota. The Coteau des Prairies is seen near the upper center of ...
Lake Agassiz (/ ˈæɡəsi / AG-ə-see) was a large proglacial lake that existed in central North America during the late Pleistocene, fed by meltwater from the retreating Laurentide Ice Sheet at the end of the last glacial period. At its peak, the lake's area was larger than all of the modern Great Lakes combined. [2]
Laurentide ice sheet. The maximum extent of glacial ice in the north polar area during the Pleistocene period included the vast Laurentide ice sheet in eastern North America. The Laurentide ice sheet was a massive sheet of ice that covered millions of square miles, including most of Canada and a large portion of the Northern United States ...
Manitoba. Centered on the Kivalliq Region, Nunavut, Canada (known as the Keewatin Region, Northwest Territories, until 1999) (ca 102 W, 63 N) the ice sheet covered up to 2,500,000 km 2 (970,000 sq mi) the Last Glacial Maximum. At its greatest reach, (14*146=2044 N-S by 12*146=1752 E-W) the northern edge abutted the Greenland ice sheet in Baffin ...
Geography of South Dakota. South Dakota is a state located in the north-central United States. It is usually considered to be in the Midwestern region of the country. The state can generally be divided into three geographic regions: eastern South Dakota, western South Dakota, and the Black Hills.
Aftonian (interglacial) Nebraskan (glacial) As developed between 1894 and 1909, the Kansan Stage was based on a model that assumed that the Pleistocene deposits contained only two glacial tills and one volcanic ash bed within Nebraska and Kansas. Of these two proposed glacial tills, the Kansan till, which defined the Kansan Stage, was the upper ...
The southern glacial maximums extended south to Washington state near Olympia in the west and to Spokane, the Idaho Panhandle, and much of Western Montana at the eastern glacial edge. At its eastern end the Cordilleran ice sheet merged with the Laurentide Ice Sheet at the Continental Divide , forming an area of ice that contained one and a half ...