2008 Volume 67 Issue 1 Pages 3-17
The present research work mainly deals with the qualitative and quantitative analysis of heavy minerals of the Neogene sandstones (Plio-Miocene) and beach sands of the Inani-Dakhin Nhila area and also deals with preliminary approach on chemical composition of garnets and ilmenites to infer the provenance. The Neogene sandstones of the Inani-Dakhin Nhila hill ranges contain about 2% heavy minerals whereas the beach sands of the Inani-Dakhin Nhila area contain about 8% heavy minerals.
The heavy mineral assemblages of the sands/sandstones of the Inani-Dakhin Nhila area are characterized by clear predominance of opaque minerals (with abundant ilmenite), epidote, garnet, staurolite followed by hornblende and tourmaline, lesser amounts of zircon, rutile and kyanite and by minor to trace amounts of apatite, sillimanite, monazite and sphene. The heavy mineral data suggest a wide range of metamorphic as well as granitoid source areas. The heavy mineral suites reflect that the probable sources of the clastics which have contributed to the study area of interest is located in the north, northwest and east-northeastern part of Bangladesh. These detrital grains could have been derived from crystalline and sedimentary deposits of the Himalayas, Rajmahal hills, Shillong Plateau and Indo-Burman ranges.
