| Abstract Submission No. | ABS-1.2-0202 |
| Title of Abstract | Tectono-Magmatic Controls on Near-Axis Seafloor Evolution at the Central Indian Ridge: Fine-Scale Geomorphology and its Geodynamic Insights |
| Authors | Sreenidhi KS*, V. Sunil, C. M. Bijesh , P. John Kurian |
| Organisation | National Centre for Polar and Ocean Research, Goa |
| Address | Deep Sea Exploration Group, National Centre for Polar and Ocean Research Vasco Da Gama, Goa, India Pincode: 403804 E-mail: sreenidhi@ncpor.res.in |
| Country | India |
| Presentation | Oral |
| Abstract | Goa, India The interplay between tectonic faulting and magmatism fundamentally controls the structure and evolution of spreading centres. At the southern Central Indian Ridge, with its intermediate spreading rate, this interaction manifests through the co-development of fractures and volcanic centres. We examine an ~50 km² area at ~23.50°S, 69.40°E using ultra-high-resolution Autonomous Underwater Vehicle (AUV) bathymetry and backscatter data to characterise the coupling between tectonic extension and magmatic supply. Semi-automated fracture identification reveals 1,564 faults and 169 fissures, defining a system in the growth stage with emerging coalescence. Fault dip patterns show coexisting west- and east-dipping populations, likely associated with tectonic extension and magmatic intrusions, respectively. Spatial variations in fracture density, mapped via kernel density estimation, highlight clusters of concentrated strain, many coinciding with eruptive centres. Terrain classification indicates that most of the surveyed area is hummocky and volcanically overprinted, reflecting strong coupling between faulting and resurfacing processes. Apparent tectonic strain, estimated from fault scarps and fissures, shows that ~19% of the extension forming the young seafloor is accommodated by tectonic activity. Strain partitioning is evident: ~25% of the measured strain occurs on east-dipping faults, probably linked to dike intrusions rather than pure extension, while the remaining strain on west-dipping faults is underestimated due to lava flows burying pre-existing structures. Integration with regional geophysical data provides insights into magmatic episodes and the broader geodynamics of this ridge segment |
| Keywords | Central Indian Ridge, Seafloor morphology, Tectono-magmatic interactions, Fracture system, AUV Bathymetry |