Extrusive Rocks


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Extrusive Rocks

 

(or effusive rocks), igneous rocks which, like modern lavas, poured out onto the surface of the earth through volcanic vents or cracks in the earth’s crust and solidified in the form of flows, sheets, and domes.

References in periodicals archive ?
It is worth mentioning that, according to the geophysical data, extrusive rocks forming the Deecan Plateau of India (famous for zeolites and associated minerals) are related to another hotspot active in the same region (but genetically younger at ~67 million years)--the Reunion Hotspot.
The oldest extrusive rocks are capped by a Quaternary basalt flow several hundred feet thick.
The property covers a sequence of intrusive and extrusive rocks that are host to a number of known occurrences of nickel, copper, PGM's and gold.
There was abundant disseminated and stringer sulfphid mineralizatiuon in the extrusive rocks and associated quartz veining.
Moreover, the presence of a complex variety of intrusive and extrusive rocks suggest that an extinct volcanic crater may in part underlie a large swamp in the main Dagobert zone.