Submarine volcanic facies and its implication as possible tracker of sulphide mineralization -- a study from Jilharidev area, Betul belt, central India.

Felsic volcaniclastic rock forms part of host rock sequences in many of the base metal prospects in the Betul belt. However, the volcanic facies, fragmentation processes and depositional environments in mineralized areas are poorly understood because of the effects of synvolcanic hydrothermal alteration and subsequent regional metamorphism. A section in the Kanhan river valley, which exposes volcanics with relatively well preserved primary textures was mapped in detail to understand the disposition of the felsic volcanics namely rhyolite and to identify the various volcanic facies present within them (viz. massive, flow-banded, autobreccia and hyaloclastite). Four different facies types were distinguished based on phenocryst type, size and abundance. Presence of hyaloclastite autoclastic rocks and pillow lava and absence of pyroclastic deposits suggest a deep, submarine, passive, effusive-type volcanic setting. Autobreccia and hyaloclastite in the felsic volcanic sequence of the present study area lying within Betul Belt has similarities with well-known volcanic-hosted massive sulphide (VHMS) bearing areas in other parts of the world. Proper identification of the volcanic facies within highly altered host rocks near the deposits can help in building up facies models that would establish the genetic relationship between sulphide mineralization and the host-rock facies which in turn will have important implications for base metal exploration in the area. [ABSTRACT FROM AUTHOR]