Laurentia or the North American Craton is a large continental craton that forms the ancient geological core of North America.Many times in its past, Laurentia has been a separate continent, as it is now in the form of North America, although originally it also included the cratonic areas of Greenland and also the northwestern part of Scotland, known as the Hebridean Terrane.

Ur is a hypothetical supercontinent that formed in the Archean (3.1 billion).. In a reconstruction by Rodgers, Ur is half a billion years older than Arctica and, in the early period of its existence, it was probably the only continent on Earth, and as such can be considered a supercontinent, though it was probably smaller than present-day Australia.In more recent works geologists often refer ...

North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the west and south by the Pacific Ocean.Because it is on the North American Tectonic Plate, Greenland is included as a part of …

Dec 06, 2022 · Browse the archive of articles on Nature Geoscience. Anthropogenic nitrogen deposition is known to affect forest soil respiration, but it remains unclear how soil respiration responds to nitrogen ...

About the Journal. Geology has been the Web of Science's #1 ranked "geology" journal for 15 years in a row.. The journal Geology publishes timely, innovative, and provocative articles relevant to its international audience, representing research from all fields of the geosciences. Full-text available for all issues. Submit Author Information

Laurentia, which makes up the North American craton. During the Paleozoic Era, sea-levels rose and fell four times. With each sea-level rise, the majority of North America was covered by a shallow tropical ocean. Evidence of these submersions are the abundant marine sedimentary rocks such as limestone with fossils corals and ooids.

Dating of the geologic record. The geologic record is the strata (layers) of rock in the planet's crust and the science of geology is much concerned with the age and origin of all rocks to determine the history and formation of Earth and to understand the forces that have acted upon it. Geologic time is the timescale used to calculate dates in the planet's geologic history from its origin ...

subduction zone, oceanic trench area marginal to a continent in which, according to the theory of plate tectonics, older and denser seafloor underthrusts the continental mass, dragging downward into the Earth’s upper mantle the accumulated trench sediments. The subduction zone, accordingly, is the antithesis of the mid-oceanic ridge. New seafloor is generated from the …

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Great Falls orogeny, also known as the Big Sky orogeny – Proterozoic collision between the Hearne craton and the Wyoming craton in southwest Montana, (1770 Ma) Ivanpah orogeny – Mojave region, south western U.S. Yavapai orogeny – Mountain building event 1.7 billion years ago in the southwestern United States, (1710–1700 Ma)