Where are phosphate nodules found?
Phosphatic nodules are commonly found within the black and dark gray shales of the Midcontinent Pennsylvanian outcrop belt. These shales form part of a cyclic sequence of alternating shales and limestones representing eustatic fluctuations in the epicontinental sea (Heckel 1986, 1991).
What are phosphate nodules?
Phosphate nodules: These are spherical concentrations that are randomly distributed along the floor of continental shelves. Most phosphorite grains are sand size although particles greater than 2 mm may be present. These larger grains, referred to as nodules, can range up to several tens of centimeters in size.
Which deposits occur mainly on the continental shelf?
Deposits of several types of minerals on the continental shelves of the world are characteristic of the environment in which they are found, such as the phosphorite, glauconite, and calcareous shell deposits.
Where is phosphorite found?
Significant deposits of phosphorite are found in the Xisha Islands (Ritterbush, 1978). Phosphorite is also formed in regions of oceanic upwelling where large volumes of phosphate-rich cold water rise from great depths to the surface.
Where is phosphate found in India?
Phosphorus in India Phosphate rocks are majorly produced only from two States in India, namely Rajasthan and Madhya Pradesh. Currently, there exists 30 lakh MT of phosphorite deposits in the country, for which important steps are being taken by the Government to ramp up its production.
Where is rock phosphate found in Rajasthan?
Huddled in the Aravali range in the southern part of Rajasthan about 26 km from Udaipur, is the largest reserve of phosphate in India. Also known as the Jhamarkotra mines, it is the only commercially exploitable rock phosphate deposit in the country.
How are phosphate nodules formed?
A sequence of events consisting of 1) upwelling, 2) development of a prolific pelagic biota, 3) decay of dead pelagic organisms and fecal material that released P to the interstitial waters of the black muds, and 4) cementation by apatite, pyrite, quartz, and calcite is proposed to have formed the phosphate nodules …
What are sedimentary phosphate deposits?
Sedimentary phosphate deposits are a type of bioelemental sediment, a class of chemical sedimentary rock composed of precipitates of the nutrient elements P, Fe, or Si (Pufahl, 2010).
Where is a continental shelf usually found?
The term “continental shelf” is used by geologists generally to mean that part of the continental margin which is between the shoreline and the shelf break or, where there is no noticeable slope, between the shoreline and the point where the depth of the superjacent water is approximately between 100 and 200 metres.
Is the continental a shelf?
A continental shelf is the edge of a continent that lies under the ocean. Continents are the seven main divisions of land on Earth. A continental shelf extends from the coastline of a continent to a drop-off point called the shelf break.
What is the luster of apatite?
Vitreous
Apatite
| Apatite group | |
|---|---|
| Mohs scale hardness | 5 (defining mineral) |
| Luster | Vitreous to subresinous |
| Streak | White |
| Diaphaneity | Transparent to translucent |
Is phosphorus found in India?