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Gurmeet Singh posted an Question

September 17, 2020 • 05:04 am

30 points

IIT JAM
Geology (GG)

Sir how pegmatite forms and why he is relating gangue mineral to skarn

sir how pegmatite forms and why he is relating gangue mineral to skarn.

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Susmita nayak

sequence crystallization is similar to fractional crystallization?
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Rahul kumar

You are welcome Gurmeet. Please mark the comment as answered. In response to your query: Skarn deposits are associated with high temperature conditions. The assemblage of high temperature metamorphic minerals in skarn is considered as gangue because they are not economic.
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Rahul kumar Best Answer

Pegmatites are formed as part of the cooling and crystallization process of intrusive rocks. As the parent body begins to cool, a sequential crystallization process occurs that concentrates many volatile constituents such as H2O, boron, fluorine, chlorine, and phosphorous in a residual magma. Pegmatites form from these fluids (enriched in volatile constituents and rare elements) that separate from a magma in the late stages of crystallization; this activity often occurs in small pockets along the margins of a batholith. Pegmatite can also form in fractures that develop on the margins of the batholith. Most skarns form when carbonate rocks such as limestone, dolostone or marble are intruded by a magma body and altered by contact metamorphism and metasomatism. When the hot fluids related to pegmatitic deposits passes through rocks like limestone, dolostone or marble; skarn rock forms. The Pegmatite fluid enriched in rare elements and volatites also crystallizes along with skarn deposits. This is the way pegmatites and skarns are related to each other.
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thank you sir. also tell me sir what is the meaning of line that i bracketed ...." gangue mineral.....skarn".
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