Ore Genesis
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Metallogeny: The rationale behind space (WHERE?) – time (WHEN?): distribution of ore deposits
Whether there is any globally discernible unifying pattern about the space-time distribution pattern
The exclusivity in spatial-temporal distribution of ore deposits is a tangible proposition
Such distribution patterns are REAL and not apparent (not artifacts due to inadequate sampling)
Such patterns can be explained in the light of the known/emerging facts about the evolution of the planet Earth (⇒solid + fluid + living)
Salient Features of the global distribution pattern of ore Deposits
A critical look at the spatial – temporal distributions of ore deposits on a global scale reveals the following salient features:
1. Chemical heterogeneity in the lithosphere – three distribution patterns:
a) Occurrence of metallogenic provinces characterized by specific metal(s) e.g. Arizona Cu (Archaean to Tertiary), Colorado plateau U-V ores (Triassic to Tertiary) b) Occurrence of barren tracts between regions of phenomenally rich mineralization (eg. Ecuador and New England states) c) S. African greenstone belt represents mantle heterogeneity of the extreme type as nearly 67% of the world’s chromite have been formed during 1.8 Ga
2 d) Extensive VMS mineralization (Cu-Zn-Au-Ag) throughout the Canadian Archaean shield e) Greater amount of Archaean Au in S. Africa compared to that in Canada, Western Australia and India.
2. Ore-lineament Association (eg. Rocky Mountain trench; Mother Lode, CA; Owen Rift, Tasmania, Singhbhum Shear Zone?) ⇒ received a new meaning with the advent of plate tectonics, leading to two interpretations: they were (i) paleo- subduction zones now represented by mega-
lineaments and (ii) transform faults which were either genetically related to oblique subduction zone of the ocean floor or extension of the transform fault related to the beginning of ocean floor spreading beneath the intracontinental rift (metal- rich brine in the
Metallogeny: The rationale behind space (WHERE?) – time (WHEN?): distribution of ore deposits
Whether there is any globally discernible unifying pattern about the space-time distribution pattern
The exclusivity in spatial-temporal distribution of ore deposits is a tangible proposition
Such distribution patterns are REAL and not apparent (not artifacts due to inadequate sampling)
Such patterns can be explained in the light of the known/emerging facts about the evolution of the planet Earth (⇒solid + fluid + living)
Salient Features of the global distribution pattern of ore Deposits
A critical look at the spatial – temporal distributions of ore deposits on a global scale reveals the following salient features:
1. Chemical heterogeneity in the lithosphere – three distribution patterns:
a) Occurrence of metallogenic provinces characterized by specific metal(s) e.g. Arizona Cu (Archaean to Tertiary), Colorado plateau U-V ores (Triassic to Tertiary) b) Occurrence of barren tracts between regions of phenomenally rich mineralization (eg. Ecuador and New England states) c) S. African greenstone belt represents mantle heterogeneity of the extreme type as nearly 67% of the world’s chromite have been formed during 1.8 Ga
2 d) Extensive VMS mineralization (Cu-Zn-Au-Ag) throughout the Canadian Archaean shield e) Greater amount of Archaean Au in S. Africa compared to that in Canada, Western Australia and India.
2. Ore-lineament Association (eg. Rocky Mountain trench; Mother Lode, CA; Owen Rift, Tasmania, Singhbhum Shear Zone?) ⇒ received a new meaning with the advent of plate tectonics, leading to two interpretations: they were (i) paleo- subduction zones now represented by mega-
lineaments and (ii) transform faults which were either genetically related to oblique subduction zone of the ocean floor or extension of the transform fault related to the beginning of ocean floor spreading beneath the intracontinental rift (metal- rich brine in the