extrusive igneous rock sentence in Hindi

Examples

1. If crystallization occurs at the Earth�s surface, extrusive igneous rocks are formed; if crystallization occurs within the Earth�s lithosphere, intrusive igneous rocks are formed which can then be brought to Earth�s surface by denudation.
2. "' Phonolite "'is an uncommon extrusive igneous rock, volcanic rock, of intermediate chemical composition between felsic and mafic, with texture ranging from aphanitic ( fine-grain ) to porphyritic ( mixed fine-and coarse-grain ).
3. Because igneous rocks occur at specific intervals in time and are essentially instantaneous on a geologic time scale, and because they contain mineral assemblages which may be dated more accurately and precisely by isotopic methods, the construction of a chronostratigraphic column relies heavily upon intrusive and extrusive igneous rocks.
4. Additional metamorphic rock names exist : greenstone ( metamorphosed basalt and other extrusive igneous rock ) is a classification based on composition and being located Precambrian terranes, while quartzite is based only on composition, as quartz is too stable and homogeneous to change phase at typical metamorphic temperatures and pressures.