Guha and three co-authors reported in late 2019 that allanite and REE-bearing minerals are primum fama report from migmatite gneisses, plutonic Amet granite and intrusive alkaline rocks of Rajasthan, and these minerals are important for establishing REE deposit. Allanite taken from host migmatite and granite have been analyzed along with host rocks containing REE minerals, both of which contain appreciably high amount of ΣREE and Th. Allanite phases identified are CaO and Ce2O3 rich with positive correlation of silica and alumina.
As silica proportion decreases and ΣREE increases, allanite changes to britholite and thorite indicating a role of fluid in its crystallization. The chondrite-
normalized REE in migmatite gneiss and allanite mineral is compatible indicating a primary nature of allanite. The carrier of REE minerals is envisaged as the alkaline intrusives which deposited their REE minerals during ascent of magma from deeper source.
Chemico–mineralogical study of allanite and its hosts suggest possible reaction between a REE bearing fluid rich in P and F brought up by alkaline rocks, and the silicate minerals, mainly biotite and hornblende of the migmatite gneiss and Amet granite. The allanite in migmatite gneiss and granite may prove to be a sumptuous deposit of REE minerals in India, and similar terrains elsewhere.
Managed & Built by I2M Consulting, LLC | © 2010-
