Click here to view fulltext PDF

Permanent link:
https://www.ias.ac.in/article/fulltext/jess/129/0152

Europium anomaly; thorium; charnockite; khondalite; chemical index of alteration (CIA); Odisha.

This study presents major element, radioactive element and rare earth element (REE) concentrations of the Garampeta to Markandi beach along the southern coast of Odisha, India to delineate the source signature and resource potential of the beach placer deposits. Average $\sum$REE concentration of the beach sand samples is about four times higher than the average crustal concentration. The LREE concentration is higher than HREE, with a pronounced negative europium anomaly. The study also discusses about the radioelement $^{238}$U, $^{232}$Th and $^{40}$K concentrations in the study area, and their relationship with REE. Weathering condition of the source rock, based on the major elements and Th$/$U ratio indicated a reasonably high degree of weathering. Major element and the REE composition along with the europium anomaly, relate the beach placers to mainly charnockite and khondalite source. An elevated level of thorium (>60 times than the average UCC values) as exhibited by the samples could be attributed due to the presence of monazites. The high concentration of REEs like Nd and Dy along with La and Ce indicates significant REE resource potential in the beach placers which is important for the resource potential in terms of the strategic mineral reserves of the country.

SHAYANTANI GHOSAL¹ SUDHA AGRAHARI¹ SANTANU BANERJEE² RAMANANDA CHAKRABARTI³ DEBASHISH SENGUPTA¹

1. Department of Geology and Geophysics, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721 302, India.
2. Department of Earth Sciences, Indian Institute of Technology Bombay, Mumbai 400 076, India.
3. Center for Earth Sciences, Indian Institute of Science, Bengaluru 560 012, India.

Published

15 July 2020

Manuscript received

30 January 2020

Manuscript revised

8 April 2020

Accepted

11 April 2020

Final version published online

3 July 2020