Journal of Applied Geochemistry

UGC CARE (Group 1)
  • Year: 2013
  • Volume: 15
  • Issue: 2

A note on the occurrence of S-type granite in Manai-Pyrda sector along north - Western margin of Shillong Basin, West Khasi hills district, Meghalaya.

  • Author:
  • H. S. Rajaraman, P. Sahoo1, Pradeep Pandey2,, K. Umamaheswar
  • Total Page Count: 7
  • DOI:
  • Page Number: 163 to 169

Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, Begumpet, Hyderabad

1Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, Bangalore

2Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, New Delhi

Abstract

An elongated body of pink, hypidiomorphic granitoid is exposed within the gneissic complex in northwest margin of Shillong Basin in Meghalaya. These granites are high in silica (70.9–77.1%), while K2O (4.41 to 5.51%) Na2O (3.45 to 4.96%), Al2O3 (12.36 and 16.11%) and CaO (0.33 to 0.66%) show restricted variation. Further, they are characterized by low content of Rb (119–239 ppm), Ba (10–945 ppm) and Sr (<10–29 ppm). These granites belong to graniteademellite series and are S- type, peraluminous in nature, which is corroborated by the presence of normative corundum. These granites show strongly differentiated character, which is further supported by high differentiation index.

Keywords

S-type granite, Manai-Pyrda area, Meghalaya