How are cobalt deposits formed?
How are cobalt deposits formed?
Cobalt Geology This element is found in highest concentrations when incorporated into minerals (pentlandite and linnaeite) as magma or lava cools to form igneous rocks such as dunite, serpentinite, and basalt. These are known as magmatic Nickel-Cobalt sulfide deposits.
What type of rock is cobalt found in?
Cobalt is present in several carbonate- hosted lead-zinc and copper districts. It is also variably present in Besshi-type volcanogenic massive sulfide and siliciclastic sedimentary rock-hosted deposits in back arc and rift environments associated with mafic-ultramafic rocks.
Where are VMS deposits found?
VMS deposits consist of massive or semi-massive accumulations of sulphide minerals which form in lens-like or tabular bodies parallel to stratigraphy or bedding. VMS deposits form on, or below, the ocean floor and are typically associated with volcanic and/or sedimentary rocks.
Why are volcanogenic massive sulfide deposits not commonly the target of major mining companies?
The biggest negative for VMS deposits as exploration targets is that they are typically small and therefore often of little economic value. There are some very good, large VMS deposits but they are rare and the chance of discovery is low.
What are cobalt deposits?
Cobalt is a chemical element with the symbol Co and atomic number 27. Like nickel, cobalt is found in the Earth’s crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron….Cobalt.
Where are cobalt deposits?
With the exception of production in Morocco and artisanally mined cobalt in Congo (Kinshasa), most cobalt is mined as a byproduct of copper or nickel. China was the world’s leading producer of refined cobalt, most of which it produced from partially refined cobalt imported from Congo (Kinshasa).
What ore is cobalt found in?
Nearly all cobalt is found associated with ores of copper, nickel, or copper-nickel.
What geologic setting is the likely source of volcanogenic massive sulfide deposits?
Volcanogenic massive sulfide deposits are forming today on the seafloor around undersea volcanoes along many mid ocean ridges, and within back-arc basins and forearc rifts.
How do Sedex deposits form?
The term Sedex, or “sedimentary exhalative,” is a generic name that reflects the current understanding of the genesis of these deposits as having formed by the precipitation of sulfides from hydrothermal fluids vented or “exhaled” on to the seafloor.
What is Kuroko type deposits?
Synopsis. The Kuroko deposits of Japan are predominantly massive, stratiform sulphide ores with associated underlying stockwork ores of Miocene age in the Green Tuff volcanic sequences. The zoning of minerals may have resulted from changes in density of the ore solution-sea water mixtures as precipitation proceeded.
Which of the following are key components of a volcanogenic massive sulfide VMS deposit?
The mineralogy of VMS massive sulfide consists of over 90% iron sulfide, mainly in the form of pyrite, with chalcopyrite, sphalerite and galena also being major constituents. Magnetite is present in minor amounts; as magnetite content increases, the ores grade into massive oxide deposits.
Where is the biggest cobalt deposit in the world?
The six largest cobalt reserves in the world by country
- Democratic Republic of Congo – 3.6 million tonnes.
- Australia – 1.4 million tonnes.
- Cuba – 500,000 tonnes.
- Philippines – 260,000 tonnes.
- Russia – 250,000 tonnes.
- Canada – 220,000 tonnes.
Where are cobalt deposits found in the United States?
In the United States, exploration for cobalt deposits may focus on magmatic nickel-copper deposits in the Archean and Proterozoic rocks of the Midwest and the east coast (Pennsylvania) and younger mafic rocks in southeastern and southern Alaska; also, possibly basement rocks in southeastern Missouri. Other potential exploration targets include—
How are massive sulfide and VMS deposits related?
VMS deposits are commonly associated with regionally developed iron- and (or) manganese-rich metalliferous sediment and chert developed at the same time-stratigraphic horizon as the massive sulfide deposits. Some Archean VMS deposits may be transitional to volcanic-associated iron formation.
What kind of minerals are in massive sulfide deposits?
Massive sulfide deposits, by definition, contain zones or lenses of massive sulfide minerals, many with sulfide. mineral contents exceeding 90 volume percent. Most deposits also contain extensive zones of semi-massive sulfide. rock (25 to 50 volume percent) that contain economically exploitable ore.
What kind of rock are Kuroko deposits made of?
Kuroko deposits (Model 28a; Singer, 1986b) are typically developed in intermediate to felsic volcanic rock and are generally interpreted to have formed in extensional environments associated with arc volcanism. They are commonly high grade and can be very large.