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Elsewhere in North America, as in Illinois, the Yarmouth Soil also has developed over a variable number of multiple glacial - interglacial cycles. [4] [8] Thus, the presumption that the Yarmouth Soil, by which the Yarmouthian (Yarmouth) Interglacial was later defined, represents a single interglacial stage or period has been completely discredited.
After the Cretaceous, a new era of geologic time began; the Cenozoic era, which means the era of "recent life". Traditionally, the first period of the Cenozoic was called the Tertiary , [ 131 ] however recent recommendations of the International Commission on Stratigraphy discourage its use, with the correspondent time span divided between the ...
Ancient history – Aggregate of past events from the beginning of recorded human history and extending as far as the Early Middle Ages or the Postclassical Era. The span of recorded history is roughly five thousand years, beginning with the earliest linguistic records in the third millennium BC in Mesopotamia and Egypt .
1743 – Dr Christopher Packe produces a geological map of south-east England 1746 – Jean-Étienne Guettard presents the first mineralogical map of France to the French Academy of Sciences . 1760 – John Michell suggests earthquakes are caused by one layer of rocks rubbing against another
The North American land-mammal-age system was formalized in 1941 as a series of provincial land-mammal ages. [2] The system was the standard for correlations in the terrestrial Cenozoic record of North America and was the source for similar time scales dealing with other continents.
During much of the Mesozoic Era, the North American continental interior was mostly well above sea level, with two notable exceptions. During part of the Jurassic (208-144 million years ago), rising seas flooded the low-lying areas of the continent. Much of the Interior Plains eventually lay submerged beneath the shallow Sundance Sea. [16]
The Great Valley Sequence of California is a 40,000-foot (12 km)-thick group of related geologic formations that are Late Jurassic through Cretaceous in age (150–65 Ma) on the geologic time scale. These sedimentary rocks were deposited during the late Mesozoic Era in an ancient seaway that corresponds roughly to the outline of the modern ...
In North America, the time encompasses the Paleo-Indian period, which subsequently is divided into more specific time terms, such as Early Lithic stage or Early Paleo-Indians, and Middle Paleo-Indians or Middle Lithic stage. [6] Examples include the Clovis culture and Folsom tradition groups. The Lithic stage was followed by the Archaic stage.