Mineralogical Composition of Sand Deposits of an Estuarine Sequence, Bangladesh

Author(s) Name:

Sudip Saha, Syed Samsuddin Ahmed & Mrinal Kanti Roy

Abstract:

The present study deals with the mineralogical composition of the sand deposits of the Jayanti estuary. The sands are composed of quartz (42.09%), feldspar (16.08%), rock fragments (0.79%), mica (4.75%), chlorite (0.75%), heavy minerals (8.45%), matrix (22.17%) and organic matter (4.48%) on an average. The relative abundance of the major minerals and lithic grains can be expressed as quartz>feldspars>lithic grains. The heavy minerals include hornblende, pyroxene, garnet, zircon, epidote, tourmaline, rutile, magnetite etc. The average matrix content of the sands is 22.17% that reflects the sands are wackes/dirty in nature. The presence of feldspar and clay particles in the sands are indicative of immaturity of the deposits. The sands might have derived from less resistant subcrustal plutonic rocks as the amount of total feldspars is higher than the lithic grains/rock fragments. The heavy mineral garnet indicates a high-grade metamorphic source while zircon, tourmaline and rutile suggestive of both igneous and metamorphic origin. The ZTR index varies from 27.69% to 50.08% with an average value of 37.58% which suggest that the sands are mineralogically immature.

 Keywords:

Quartz, feldspar, rock fragments, heavy minerals and ZTR index.

Please cite this article as:

Sudip Saha, Syed Samsuddin Ahmed & Mrinal Kanti Roy (2020). Mineralogical composition of sand deposits of an estuarine sequence, Bangladesh. International Journal of Recent Research and Applied Studies, 7, 5(4), 29-35.