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In geology, a terrane (/ t ə ˈ r eɪ n, ˈ t ɛr eɪ n /; [1] [2] in full, a tectonostratigraphic terrane) is a crust fragment formed on a tectonic plate (or broken off from it) and accreted or "sutured" to crust lying on another plate. The crustal block or fragment preserves its distinctive geologic history, which is different from the ...
The secant lines of isograds with the surface form lines on a geologic map. Changes in mineralogical composition in a terrane reflect differences in metamorphic grade of the rocks. Minerals that are characteristic for a certain metamorphic grade are called index minerals. The first or last appearance of an index mineral (the place where a ...
An example of using thermal modeling in P-T-t path reconstruction. The above diagram shows the calculated geothermal gradients upon crustal thickening at 0 million year (m.y.) followed by an immediate uplift event at a rate of 1 mm per year. The P-T-t evolution of a rock originally at 40 km below ground is marked as red dots on the diagram.
The Franciscan Complex or Franciscan Assemblage is a geologic term for a late Mesozoic terrane of heterogeneous rocks found throughout the California Coast Ranges, and particularly on the San Francisco Peninsula. It was named by geologist Andrew Lawson, who also named the San Andreas Fault that defines the western extent of the assemblage. [1]
This glossary of geology is a list of definitions of terms and concepts relevant to geology, its sub-disciplines, and related fields. For other terms related to the Earth sciences , see Glossary of geography terms (disambiguation) .
Triangular diagrams showing the aluminium (A), calcium (C) and iron (F) content of the main phases (dark dots) in metamorphic rocks in various facies. Thin grey lines are stable phase equilibria. Triangular diagrams showing the aluminium (A), iron (F) and magnesium (M) content of the main phases (dark dots and, when the composition can vary ...
The Yakutat Terrane is currently colliding with the continental margin below the central Gulf of Alaska. During the Neogene the terrane's western part was subducted after which a sediment wedge accreted along the northeast Aleutian Trench. This wedge incorporates sediment eroded from the continental margin and marine sediments carried into the ...
Plates in the crust of Earth. 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]