cerium, thorium and zirconium bearing minerals from charnockites of the eastern ghats granulites belt, andhrapradesh southern india

Research Article
*K. Ravikumar, B. Veera Narayana and T. Ramesh
DOI: 
xxx-xxxx-xxx
Subject: 
science
KeyWords: 
Allanite, Monazite, Zircon, Charnockite and Eastern Ghats Granulite Belt.
Abstract: 

Radioactive minerals allanite, monazite and zircon are observed in the charnockites, from Eleswaram and Visakhapatnam in the Eastern Ghats Granulite Belt (EGGB). Intrusive charnockites (garnetiferrous hypersthene gneisses) in the host khondalites (garnetiferrous sillimanite gneisses) are occasionally allanite bearing and rich with ubiquitous accessory minerals, monazite and zircon. These radioactive minerals are found to be more Ce, Th, and Zr rich. It is observed that Ce is more than Y in allanite and monazite. Similarly Th and U are more significant in monazite than allanite. Zr is more in zircon, while REE, U and Th are less. Further allanite is highly altered and different stages of metamictisation characterized by loss of major elements, REE and enrichment of Th rendering the altered allanites to be highly radioactive. The wide spread charnockite occurrences in the EGGB are favorable for the mineralization of radioactive minerals and detailed investigation may through light in locating new findings. In addition to the allanite, monazite and zircon, an unknown Y rich mineral (Ca, Y, Ti silicate) was found with unusual composition in the REE (Predomination of HREE). A significant amount of Bao is also found in Ca, Y and Ti silicate mineral.