Characterisation of a Clay Deposit at Malti, Purulia District, West Bengal

Haile Michael Fentaw; C. N. Rao; D. K. Sengupta

Characterisation of a Clay Deposit at Malti, Purulia District, West Bengal

Haile Michael Fentaw ¹, C. N. Rao ², D. K. Sengupta ²

Affiliations
1 Ethiopian Institute of Geological Survey, Addis Ababa, Ethiopia
2 Department of Geology and Geophysics, I.I.T., Khargpur, W. B, India

The clay deposits at Malti in Purulia District, West Bengal have formed on phyllites of probable Precambrian age.

X-ray diffraction, differential thermal and Infra-red spectral studies suggest that these clay deposits contain kaolinite as the predominant clay mineral. The kaolinite shows two distinct varieties of crystal perfection-one the highly crystalline with Hinckley Indices of well over 0.8 (8 samples) and the other of comparatively low crystallinity with Hinckley Indices of less than 0.8.

The poorly crystalline samples show strong low temperature endothermic peaks at 200°C in DTA curves suggesting the presence of some inter-layer water. The presence of hydrated halloysite has, however, not been conclusively established.