Marine regression
A marine regression is a geological process occurring when areas of submerged
Description
According to one hypothesis, regressions may be linked to a "slowdown in sea-floor spreading, leading to a generalized drop in sea level (as the mid-ocean ridges would take up less space)...."
Evidence of marine regressions and transgressions occurs throughout the fossil record, and the fluctuations are thought to have caused or contributed to several
A major regression could cause marine organisms in shallow seas to go extinct, but mass extinctions tend to involve both terrestrial and aquatic species, and it is harder to see how a marine regression could cause widespread extinctions of land animals. Regressions are, therefore, seen as correlates or symptoms of major extinctions, rather than primary causes. The Permian regression might have been related to the formation of Pangaea. The accumulation of all major landmasses into one body could have facilitated a regression by providing "a slight enlargement of the ocean basins as the great continents coalesced."[4] However, that cause could not have applied in all or even many of the other cases.
Ice ages
During the
See also
- 8.2-kiloyear event – Rapid global cooling around 8,200 years ago
- Marine terrace – Emergent coastal landform
References
- ^ Monroe, James Stewart, and Reed Wicander. Physical Geology: Exploring the Earth. Fifth edition; Thomson Brooks/Cole, 2005; p. 162.
- ^ Courtillot, p. 141.
- ^ Courtillot, Vincent. Evolutionary Catastrophes: The Science of Mass Extinction. Cambridge, Cambridge University Press, 1999; p. 89.
- ^ Ward, Peter D. Rivers in Time: The Search for Clues to Earth's Mass Extinctions. New York, Columbia University Press, 2000; p. 77.