Process of deposition of ore/minerals
Minerals are naturally formed chemical compound having a definite chemical composition ,an ordered internal arrangement of atoms and characteristic crystal form and physical properties .The ore is occurring materials from which a mineral or minerals of economic value can be excracted a profits .A continues well defined mass of minerals of sufficient ore content to make extraction economically feasible.
There are several process of minerals /ore deposits
1.Magmatic concentration :
Magma is a molten rock together with a suspanded minerals grain and dissolve gases tgat forms when temperature rise and melting occurs in mentle and crust.Magnatic ore deposit are characteristic by their close relationship with intermediate or deep seated,intrusive igneous rock.Actually,they themselves are igneous rock whose composition happen to be of particular value to man.They constituent either whole igneous mass or a part of it ,or form offset bodies .They are magmatic products crystallize from magma.They are also termed as magmatic segregation ,magmatic injection,igneous syngenetic deposit .
The magmatic deposits are classified into two major groups ie late magmatic deposits and eraly magmatic deposits.The early magmatic deposit are believed to been formed simultaneously with the bed whereas the late magmatic deposit are formed towards the close of the magmatic deposit .The early magmatic deposit are formed by
I.simple crystallization without concentration .
ii.segregation of early form crystal
iii.injection of material concentration elsewhere by differentation.
A.Dissemination:
It involves simple crystillazation where by early formed crystal are found desseminated(spread )throughout the host rock.Eg diamond pipes of south africa ,the uranium minerals in the singhbhum,granites of bihar.
B.Segregation:
The term segregation often being loosly used to designate nagmatic deposit as contrast with those formed by solution or other magma.In other words it is the process of separation of different minerals constituent from each others .
C.Injection:
In this case the metalic concentratesinstead of remaining at the pkace at their original accumulation,get injected into a adjcent solid rock masses .It occur at thr resudial magmatic stage Eg magmatic deposit of kiruna(sweden ).
2.Sublimation:
It is the conversion of solid matter directly into vapour.This process is applies only to compound that are volatilized and subsequently redeposits from vapour at lower temperature or pressure .It doesn't include minerals formed by reaction of gases and vapour.Many compound cannot be sublimed in the presence of oxygen .This process is associated with Volcanism and fumaroles.Fumaroles meab the vent that emits hot gases usually associate with past or current magmatic activity below .
3.Contact metasomatism:
The metamorphic process that occurs as a result of the passage of chemically active fluid through a rock,adding to or removing constituent during metamorphism.
4.Hydrothermal process :
The term hydrothermal means hot water.and hot water may originate by other than magmatic process .The may be a mingling of waters as already mentioned or they may be meteoric (very fast or sudden ),or connate(analogous )or the water constituent of minerals released during metamorphism that have become heated within the earth and thus become hydrothermal solution .Rescent isotopic studies of hydrothermal solution indicate that connate and meteoric water play more prominent role then hitherto recognized .
As Roedder who had made extensive studies of tge character and temperate formation of fluid inclusion in ore deposit minerals ,suggested that the mississippi valley type of deposit have been formed from the modefied deep circulating heated connet brine solution carrying trace amount of lead,zinc
This process also involve in
I.Cavity filling
ii.Replacement
...to be continue in next blog
There are several process of minerals /ore deposits
Magma is a molten rock together with a suspanded minerals grain and dissolve gases tgat forms when temperature rise and melting occurs in mentle and crust.Magnatic ore deposit are characteristic by their close relationship with intermediate or deep seated,intrusive igneous rock.Actually,they themselves are igneous rock whose composition happen to be of particular value to man.They constituent either whole igneous mass or a part of it ,or form offset bodies .They are magmatic products crystallize from magma.They are also termed as magmatic segregation ,magmatic injection,igneous syngenetic deposit .
The magmatic deposits are classified into two major groups ie late magmatic deposits and eraly magmatic deposits.The early magmatic deposit are believed to been formed simultaneously with the bed whereas the late magmatic deposit are formed towards the close of the magmatic deposit .The early magmatic deposit are formed by
I.simple crystallization without concentration .
ii.segregation of early form crystal
iii.injection of material concentration elsewhere by differentation.
A.Dissemination:
It involves simple crystillazation where by early formed crystal are found desseminated(spread )throughout the host rock.Eg diamond pipes of south africa ,the uranium minerals in the singhbhum,granites of bihar.
B.Segregation:
The term segregation often being loosly used to designate nagmatic deposit as contrast with those formed by solution or other magma.In other words it is the process of separation of different minerals constituent from each others .
C.Injection:
In this case the metalic concentratesinstead of remaining at the pkace at their original accumulation,get injected into a adjcent solid rock masses .It occur at thr resudial magmatic stage Eg magmatic deposit of kiruna(sweden ).
2.Sublimation:
It is the conversion of solid matter directly into vapour.This process is applies only to compound that are volatilized and subsequently redeposits from vapour at lower temperature or pressure .It doesn't include minerals formed by reaction of gases and vapour.Many compound cannot be sublimed in the presence of oxygen .This process is associated with Volcanism and fumaroles.Fumaroles meab the vent that emits hot gases usually associate with past or current magmatic activity below .
3.Contact metasomatism:
The metamorphic process that occurs as a result of the passage of chemically active fluid through a rock,adding to or removing constituent during metamorphism.
4.Hydrothermal process :
The term hydrothermal means hot water.and hot water may originate by other than magmatic process .The may be a mingling of waters as already mentioned or they may be meteoric (very fast or sudden ),or connate(analogous )or the water constituent of minerals released during metamorphism that have become heated within the earth and thus become hydrothermal solution .Rescent isotopic studies of hydrothermal solution indicate that connate and meteoric water play more prominent role then hitherto recognized .
As Roedder who had made extensive studies of tge character and temperate formation of fluid inclusion in ore deposit minerals ,suggested that the mississippi valley type of deposit have been formed from the modefied deep circulating heated connet brine solution carrying trace amount of lead,zinc
This process also involve in
I.Cavity filling
ii.Replacement
...to be continue in next blog
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