What is secondary enrichment in geology?
▪ Secondary enrichment: is an ore concentrating process that occurs when metals are leached from surface. rocks and precipitated just below the water table. ▪ Leaching: is where elements are dissolved from rocks and carried downwards in solution. ▪ A Gossan: is an impermeable cap of iron oxides at the surface.
What is hypogene and supergene?
Supergene is a term used to describe near-surface processes and their products, formed at low temperature and pressure by the activity of descending water and gas. The opposite term is hypogene, formed by ascending water and gas at high temperature and pressure.
What is supergene alteration?
Supergene alteration typically involves low-temperature alteration of primary gold-bearing mineralised rocks and causes liberation of the gold, with some gold dissolution and reprecipitation.
How many zones have been recognized in the supergene enrichment deposits?
Such a process is known as supergene enrichment. The primary, subeco- nomic material underlying the enriched zone is known as protore. Ideally then, there are three fundamental zones in a near-surface ore deposit: The oxidized zone, the supergene enriched zone, and the primary or prot- ore zone.
What is supergene gold?
Gold in the supergene zones is commonly crystalline with octahedral shapes and nuggety forms which fill cavities and coat prismatic quartz crystals. This gold retains some or all of the Ag (typically 2–8 wt%) from the primary source gold.
What are the steps in secondary enrichment?
tems (4 items) Drag and drop into the appropriate area) Items in order First activity ceases after ore-bearing 1 flows through deposit and leaches out New ore minerals are tated in a new location. 2 ore-bearing deposit cools 3 4 Last.
What causes supergene enrichment?
Supergene sulfide enrichment, also called Secondary Enrichment, in geology, natural upgrading of buried sulfide deposits by the secondary or subsequent deposition of metals that are dissolved as sulfates in waters percolating through the oxidized mineral zone near the surface.
Is hypo an ore?
Hypogene also often refers to primary, unaltered ore that formed directly from thermal aqueous solutions that derived from great depths (e.g., Ague and Brimhall 1989; Webb and Rowston 1995; Rakovan 2003).
How do supergene deposits form?
Supergene processes include the predominance of meteoric water circulation with concomitant oxidation and chemical weathering. The descending meteoric waters oxidize the primary (hypogene) sulfide ore minerals and redistribute the metallic ore elements.
Where the supergene sulphide enrichment zone is found?
What is oxidation zone?
The portion of an orebody near the surface that: (1) has been leached by percolating water carrying oxygen, carbon dioxide, or other gases; or (2) in which sulfide minerals have been partially dissolved and redeposited at depth, the residual portion changing to oxides, carbonates, and sulfates.
