Abstract
Chemical analysis of 62 rock samples representing 24 flows of the Panjal Traps on Mount Kayol in Lidder Valley area do not show any systematic variation of the various oxides from the base to the top. The plots on MgO-Al/Si diagram of Murata, and Fe
2O
3/FeO ratio indicate that the rocks are of tholeiitic lineage. However, the points fall within the fields of alkali-olivine basalt and high-alumina basalt on the alkali-silica diagram of Kuno. This is interpreted to be due to alkali metasomatism. The addition of alkali is probably responsible for the shift of the points to the alkali-olivine basalt field on the alkali-silica diagram.
The Solidification Index (MgO × 100/MgO+Fe2O3+FeO+Na2O+K2O) lies within the range of basalt and basaltic andesite of 'pigeonite rock series'.
