DELINEATION OF HEAVY MINERAL PROVINCES IN THE BEACH PLACER AND INLAND TERI SANDS OF TAMIL NADU
S.Krishnan 1, S. Chandrasekharan 1, V. Anil Kumar 1, N. Rajgopal 1 and S.Q.Hoda 2
Atomic Minerals Division, Department of Atomic Energy.
1 Thiruvananthapuram-695012, 2 Hyderabad - 500 016.
Abstract
The beach placers and inland 'Teri' sands of Tamil Nadu containing, principally, ilmenite, rutile, leucoxene, zircon, monazite, garnet, sillimanite, amphibole, pyroxene and magnetite are classified into three distinct mineralogical provinces based on the predominance of : (i) ilmenite, (ii) garnet, and (iii) mixed ilmenite - garnet. The ilmenite province is represented by the beach placers in the southernmost coastal tract extending for 78 km from Kollamkode near Tamil Nadu-Kerala border in the west to Kutupuli on the east and inland 'Teri' sands occurring in the coastal plains. The garnet province is illustrated by the beach placers on the east coast over 68 km from Perumanal Panjal to Tiruchendur and the mixed ilmenite-garnet province with pyroxenes and amphiboles is observed in the beach placers over 262 km tract between Tiruchendur and Tondi. Mineral assemblages in 'Teri' sands directly reflect composition of the bed rocks. The three mineralogical provinces in the beach placers indicate differing provinces when looked at in a broader frame work for the entire transportation agencies are suggested for a comprehensive understanding of the provinces identified as they also control the distribution of heavy minerals in the beaches.