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Many explanations have been proposed for honeycomb and other cavernous weathering. These explanations include marine abrasion; wind corrosion; mechanical weathering resulting from short-term temperature variations; chemical weathering of the interior of the rock (core-softening) under a protective crust (case-hardening) followed by mechanical removal of the softened material; biogeochemical ...
A COLE value of 0.06 means that 100 inches of soil will expand by 6 inches when wet. [2] Soils with this shrink-swell capacity fall under the soil order of Vertisols. [6] As these soils dry, deep cracks can form on the surface, which then allows water to penetrate to deeper levels of the soil. [7]
The inorganic cycle begins with the production of carbonic acid (H 2 CO 3) from rainwater and gaseous carbon dioxide. [6] Due to this process, normal rain has a pH of around 5.6. [7] Carbonic acid is a weak acid, but over long timescales, it can dissolve silicate rocks
A scenario is a set of related concepts pertinent to the origin of life (abiogenesis), such as the iron-sulfur world.Many alternative abiogenesis scenarios have been proposed by scientists in a variety of fields from the 1950s onwards in an attempt to explain how the complex mechanisms of life could have come into existence.
Cyclic sediments (also called rhythmic sediments [1]) are sequences of sedimentary rocks that are characterised by repetitive patterns of different rock types or facies within the sequence. Processes that generate sedimentary cyclicity can be either autocyclic or allocyclic, and can result in piles of sedimentary cycles hundreds or even ...
An essential feature for the formation of laterite is the repetition of wet and dry seasons. [15] Rocks are leached by percolating rain water during the wet season; the resulting solution containing the leached ions is brought to the surface by capillary action during the dry season. [15]
1. "Down to Earth" – Beginning by comparing surface conditions on the planets Venus and Mars with the living landscapes of the Earth to highlight how unique the Earth is, the episode describes the goal of the study of geology and introduces major topics the series addresses, including the Earth's heat engines, plate tectonics, volcanism, earthquakes and seismology, erosion, and natural ...
Researched published in Nature Geoscience in October 2019 described how Gale crater underwent many wet and dry cycles as its lake waters disappeared. [174] Sulfate salts from evaporated water showed that pools of salty water once existed in Gale Crater. These ponds could have supported organisms.