metamorphic rock


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metamorphic rock

[¦med·ə¦mȯr·fik ′räk]
(petrology)
A rock formed from preexisting solid rocks by mineralogical, structural, and chemical changes, in response to extreme changes in temperature, pressure, and shearing stress.

metamorphic rock

Rock which has been altered in appearance, density, and crystalline structure (and in some cases mineral composition) by high temperature and/or high pressure; e.g., slate is a metamorphic rock derived from shale.
References in periodicals archive ?
IGNEOUS ROCK: Formed when metamorphic rocks melt to form magma (melted rock), which then cools underground or erupts and cools on Earth's surface.
These grains with constituent minerals showing straight to sutured contacts resembling "stretched quartz", indicate derivation from metamorphic rocks (Blatt, 1967).
A Tropeptic Haplorthox formed on metamorphic rock, with high Depreciation Index, was incubated for 3 months in the laboratory at field moisture content, with powdered basalt rock at a rate of 50 t/ha.
Sedimentary rock with heat and pressure forms metamorphic rock.
It was another seven miles to Phantom Ranch, but a good bit of that would be spent in the Box, a narrow gorge of black metamorphic rock that radiates afternoon heat like a pancake griddle.
The gravel can be characterized as common rock and mineral compositions from the southern shore of Lake Erie, including limestone, dolomite, quartzite, shale, sandstone, siltstone, chert, flint, quartz, coal, and a variety of igneous and metamorphic rock and mineral types.
The main concentration occurs on a large, metamorphic rock outcrop measuring approximately 60x25 m at its widest points.
We do not know whether it resides primarily in the flooded fractures of the park's metamorphic rock or only in the saturated overburden above the bedrock, or both.
They expected abalone aragonite to resemble the aragonite found in metamorphic rock in Aragon, Spain.
The occurrence of some clasts of high-grade metamorphic rock stratigraphically below this interval may record the progressive emergence of the new source, prior to its effective blockage of former drainage.
There is also a very subdued circular feature in the soil gridded area of the main river that is about 1,000 meters in diameter; it consists of poorly-sorted boulders (up to 2m wide) and cobble sized metamorphic rock fragments.
The researchers turned to eclogite, a metamorphic rock that forms from ocean floor basalt in the subduction channel.