The late Paleozoic uplifts of the Rocky Mountain region; they eroded away long before the present Rocky Mountains formed.
Basin and Range Province
A broad, Cenozoic continental rift that has affected a portion of the western United States in Nevada, Utah, and Arizona; in this province, tilted fault blocks form ranges, and alluvium-filled valleys are basins.
The remarkable diversification of life, indicated by the fossil record, that occurred at the beginning of the Cambrian Period.
A province in the interior of a continent in which Phanerozoic strata bury most of the underlying Precambrian rock.
In the context of planet formation, the process by which a planet separates into a metallic core and a rocky mantle very early in its history.
The oldest of the Precambrian eons; the time between Earth's origin and the formation of the first rocks that have been preserved.
The mountain-building event that lasted from about 80 Ma to 40 Ma, in western North America; in the United States, it formed the Rocky Mountains as a result of basement uplift and the warping of the younger overlying strata into large monoclines.
Pleistocene ice age
The period of time from about 2 Ma to 14,000 years ago, during which the Earth experienced an ice age.
Our planet during periods in the Precambrian when its entire surface was ice covered.
An interval of strata deposited during periods of relatively high sea level, and bounded above and below by regional unconformities.
Layered mounds of sediment formed by cyanobacteria; cyanobacteria secrete a mucuous-like substance to which sediment sticks, and as each layer of cyanobacteria gets buried by sediment, it colonizes the surface of the sediment, building a mound upward.