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Solidified lava flow in Hawaii Sedimentary layers in Badlands National Park, South Dakota Metamorphic rock, Nunavut, Canada. Geology (from Ancient Greek γῆ (gê) ' earth ' and λoγία () ' study of, discourse ') [1] [2] is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over ...
This is a list of Global Boundary Stratotype Sections and Points.Since 1977, Global Boundary Stratotype Sections and Points (abbreviated GSSPs) are internationally agreed upon reference points on stratigraphic sections of rock which define the lower boundaries of stages on the geologic time scale.
The following outline is provided as an overview of and topical guide to geology: . Geology – one of the Earth sciences – is the study of the Earth, with the general exclusion of present-day life, flow within the ocean, and the atmosphere.
Also called Indianite. A mineral from the lime-rich end of the plagioclase group of minerals. Anorthites are usually silicates of calcium and aluminium occurring in some basic igneous rocks, typically those produced by the contact metamorphism of impure calcareous sediments. anticline An arched fold in which the layers usually dip away from the fold axis. Contrast syncline. aphanic Having the ...
Map of isothermal lines across North America and Europe from Lyell's Principles of Geology (6th edition). Published in three volumes in 1830–1833 by John Murray, the book established Lyell's credentials as an important geological theorist and popularized the doctrine of uniformitarianism (first suggested by James Hutton in Theory of the Earth published in 1795). [3]
[7] [8] [9] Tectonic uplift during the creation of high mountainous regions can produce incredible surface elevations and therefore exposure of rocks to wind and water. High precipitation can drive enhanced erosion of the exposed rocks and lead to rapid denudation of sediment from the mountains.
The geographic cycle, or cycle of erosion, is an idealized model that explains the development of relief in landscapes. [1] The model starts with the erosion that follows uplift of land above a base level and ends, if conditions allow, in the formation of a peneplain. [1]
The internal structure of Earth. In geology, the crust is the outermost solid shell of a planet, dwarf planet, or natural satellite.It is usually distinguished from the underlying mantle by its chemical makeup; however, in the case of icy satellites, it may be defined based on its phase (solid crust vs. liquid mantle).