ORE DEP (CLASTIC SEDS) Flashcards
Deposits realted to Clastic Sediments
?Sanstone type Uranium
?Placer Deposits
?Qtz-Pebble Conglo Au-U - Witswatersrand deposit, SA
?Stratabound in Arkosic (Felds-Rich) Sed Rocks
?Devonian-Tertiary Age
?Enriched by “LATERAL SECRETION” - deposition of Uranium minerals from circulating Groundwater
Sandstone-Type Uranium
How much of the worlds resources is represented by Sed Uranium?
40%
Common Ore Minerals
Uraninite and Coffinite
Types of Sandstone Type Uranium
?Roll Front Type-U
?Salt Wash Type-U
?Humate Type-U
A deposit created by EROSION and/or SEDIMENTATION containing paticle of some valuable minerals
Placer Deposits
Most exploited deposits of this type?
Cenozoic
Two Types of Placer Accdng to Age
1) Modern - Actively Forming
2) Fossil - Buried by Younger Rocks
Types of Placer Concentrations
1) Eluvial - Hill Slopes
2) Alluvial - Fans
3) Fluvial - Streams
4) Marine - beach sands
5) Lacustrine - Lakes
6) Glacial - Tills
Type of placer-forming minerals which are more resistant to chemical and mechanical erosion
Resistate
Type of placer-forming minerals with high specific Gravities
Heavy minerals
Types of Resistates Mienrasl
1) Non Reactive - Inert
2) Maleable - Bend rather than break
3) High Hardness
Inert Oxide Mienrals
Cassiterite
Chromite
Rutile
Magnetie
Ilmenite
Inert Silicates
Zircon
Inert Tunsgates
Wolframite
Maleable Minerals
Gold
Platinum
Bismuth
Hard Minerals
Diamond
Corundum
Garnet
Most valuable placer commodity
Sg = 19.3
Chemically stable
Usually alloyed with Ag (Electrum)
Purer in Smaller Grains
Free Au
