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Environments in which subsurface life has been found [1]. The deep biosphere is the part of the biosphere that resides below the first few meters of the ocean's surface. It extends down below 10 kilometers below the continental surface and 21 kilometers below the sea surface, at temperatures that may reach beyond 120 °C (248 °F) [2] which is comparable to the maximum temperature where a ...
The lowest part of the mantle next to the core-mantle boundary is known as the D″ (D-double-prime) layer. [23] The pressure at the bottom of the mantle is ≈140 G Pa (1.4 M atm ). [ 24 ] The mantle is composed of silicate rocks richer in iron and magnesium than the overlying crust. [ 25 ]
The internal structure of Earth. Earth's mantle is a layer of silicate rock between the crust and the outer core. It has a mass of 4.01 × 10 24 kg (8.84 × 10 24 lb) and makes up 67% of the mass of Earth. [1] It has a thickness of 2,900 kilometers (1,800 mi) [1] making up about 46% of Earth's radius and 84% of Earth's volume.
The Ediacaran (/ ˌiːdiˈækərən /; formerly Vendian) biota is a taxonomic period classification that consists of all life forms that were present on Earth during the Ediacaran Period (c. 635–538.8 Mya). These were enigmatic tubular and frond-shaped, mostly sessile, organisms. [1][2] Trace fossils of these organisms have been found ...
Earth's crust is its thick outer shell of rock, referring to less than one percent of the planet's radius and volume. It is the top component of the lithosphere, a solidified division of Earth 's layers that includes the crust and the upper part of the mantle. [1] The lithosphere is broken into tectonic plates whose motion allows heat to escape ...
A pebble is a clast of rock with a particle size of 4–64 mm (0.16–2.52 in) based on the Udden-Wentworth scale of sedimentology. Pebbles are generally considered larger than granules (2–4 mm (0.079–0.157 in) in diameter) and smaller than cobbles (64–256 mm (2.5–10.1 in) in diameter). A rock made predominantly of pebbles is termed a ...
An endolith or endolithic is an organism (archaeon, bacterium, fungus, lichen, algae or amoeba) that is able to acquire the necessary resources for growth in the inner part of a rock, [1] mineral, coral, animal shells, or in the pores between mineral grains of a rock. Many are extremophiles, living in places long considered inhospitable to life.
Sedimentation results in the formation of depositional landforms and the rocks that constitute the sedimentary record. [6] The building up of land surfaces by sedimentation, particularly in river valleys, is called aggradation. [7] The rate of sedimentation is the thickness of sediment accumulated per unit time. [8]