Please enable JavaScript.
Coggle requires JavaScript to display documents.
ORE-LECTURE 6 - Coggle Diagram
ORE-LECTURE 6
Banded iron formations
-
Sedimentary rocks, interlayered Fe oxides and chert
Algoma type: sedimentary units in submarine volcanics, Archean
Superior type: laterally and vertically extensive, Archean. Majority of Fe
-
-
-
-
Chemical sedimentation induced by oxidation of Fe2+ to Fe3+ (insoluble), either by photooxidation or photosynthesis (GOE link)
Placer deposits
Sedimentary ores resulting from physical erosion, transport and deposition
-
-
-
-
-
Surficial processes
-
-
Laterite formation
-
-
-
Frim intense weathering in warm, humid intertropical regions
Thin organic poor soil over leached Fe and AL oxide rich zone, overlying bedrock
Clay rich, Fe Al oxides. Al ore-bauxite. Can contain Ni, Mn, Au, Cu and PGE
-
Leaching of silicate elements and enrichment of oxide phases (insoluble). Transport of materials away from the site of ore formation is the main process of concentration
Bauxite: AL favoured over Fe when rainfall/humidity higher and lower T. Si and Fe mobility enhanced over Al (higher pH)
Supergene process
-
In situ enrichment of Cu, Zn, Ag and Au
-