Petrography and Petrochemistry of the Kimberlite and Associated Volcanic Rocks of the Jungel Valley, District Mirzapur, U.P., India

The kimberlite plugs and the associated volcanics of the Jungel valley occur within the Bijawar Group. The Jungel ultramafics occur in the form of plugs. Serpentinization and calcitization are common. The rock has 53% serpentine, 17% calcite, 14% opaque minerals, 5% pseudomorphs of olivine and pyroxene, 6% tremolite-actinolite and 5% chlorite and glass. The rock is porphyritic in texture and agglomeratic in nature.

Percentage of oxides and oxide ratios of the Jungel samples are comparable to those of the known kimberlites of the world. The normative composition of 17 samples analysed has brought out the special feature of the kimberlite, viz., its unusually high apatite and ilmenite and the general lack of clinopyroxene in the rock. The oxide relationship in the form of ternary plots falls within the kimberlite field and the electron microprobe analyses confirm the kimberlitic nature of the plug rock.