Mid-oceanic ridges are the primary site of volcanic activity and the site of creation of new crust on the planet.
Exert a major influence on the evolution
of the solid earth, affect the composition of the ocean waters and support unique forms of life.
It is estimated that about 25% of the
Earth's total heat flux is transferred to the
hydrosphere through thermal convection
related to volcanic and hydrothermal activity associated with mid oceanic ridges.
Ridge related research activities have been
undertaken by the Institute with limited
funding from DOD, DST and CSIR during
the ninth plan period. Enthused by the
preliminary results, an interdisciplinary
program was proposed as a major activity
for the tenth-five year period, with the
specific aim of studying in detail CR-CIR
and Andaman backarc spreading systems.
The inter-disciplinary exploration program
aims to understand the tectonic and
oceanic processes occurring at these
dynamic plate boundaries. The investigations
lead to the demarcation of the
zones of hydrothermal mineralization and
have scope for the identification of active
hydrothermal vent sites.
Scientific components and achievements:
Central Indian Ridge
Completed two multi-disciplinary cruises to the ridge
segment and mapped the ridge segment
encompassing the Vityaz and Vema Fracture zones.
The initial data reveal finer scale segmentation
pattern of an intermediate spreading ridge segment.
Rift valley floor, flanks and ridge-transform-intersection
highs are mapped and sampled. CTD
and water column samples collected
Mapped about 400 km long segment of the
ridge. The data reveal finer-scale
segmentation process and shallow mantle
characterized by rock assemblage of
serpentinites, peridotites and gabbros
within the axial valley zone. CTD and water
column samples collected along the
Andaman backarc basin
30,000 km2 area mapped. Finer scale
segmentation of the Andaman backarc
spreading center identified. Proposed
opening ~ 4 Ma (anomaly 3). Pyrite mineralisation found in rocks from
spreading center, seamounts and sediments
suggest hydrothermal activity