Igneous Protolith To Marble

Marbles have a variety of colors and are often complexly banded.

Igneous protolith to marble.

Mafic protoliths are mainly mafic igneous rocks basic to intermediate intrusive and extrusive rocks and to a much lesser extent marls of unusual composition similar to basalts. Ultramafic protoliths are mainly peridotites and related rocks from the earth s mantle and reflect a rather simple mgo rich silicate composition. They are commonly used as a decorative stone. The recrystallization usually obliterates all fossils.

Such marble is often used as decorative stone in buildings. Metamorphic rocks have protoliths and limestone or dolomite are the protoliths of marble. Your textbook incorrectly uses the term source rocks for the pre existing rock. Mylonite is a high grade metamorphic rock that is characteristic of a high shear zone and usually has an igneous protolith.

The most abundant metamorphic products are serpentinites. Metamorphic rock any rock that results from the alteration of preexisting rocks in response to changing conditions such as variations in temperature pressure and mechanical stress and the addition or subtraction of chemical components. All metamorphic rocks are derived by the action of heat and or pressure on pre existing igneous sedimentary or metamorphic rocks. The pre existing rock is called either the parent rock or the protolith.

Marble is metamorphosed limestone created by contact metamorphism meaning it is heated through contact by a large igneous intrusion. Marble marble is a metamorphic rock made up almost entirely of either calcite or dolomite for which the protolith was either limestone or dolostone respectively. Marble a limestone or dolostone made up only of calcite or dolomite will metamorphose to a marble which is made mostly recrystallized calcite or dolomite. The preexisting rocks may be igneous sedimentary or other metamorphic rocks.

It is composed primarily of the mineral calcite caco 3 and usually contains other minerals such as clay minerals micas quartz pyrite iron oxides and graphite under the conditions of metamorphism the calcite in the limestone recrystallizes to form a rock that is. Marbles may have bands of different colors which were deformed into convoluted folds while the rock was ductile. Metamorphic rocks and processes metamorphism comes from the greek words meta change morphe form metamorphic rocks form by solid state no melting transformation of preexisting rock by processes that take place beneath earth s surface. A protolith is the parent rock.

In many cases we can infer the lithology of the rock that was metamorphosed the protolith to produce the metamorphic one. Marble is made of calcite or some other carbonate and this mineral is common in only one possible protolith.