Magnetic and bathymetric investigations over the Vema Region of the Central Indian Ridge: tectonic implications

Magnetic and bathymetric data were collected along N50 degrees E profiles in the Vema Region (7-12 degrees S, 64-70 degrees E) across five ridge segments of the Central Indian Ridge (CIR). Anomalies up to A5 (10 Ma), identified by generating synthetics for each profile, show asymmetric spreading. Though inter-segmental variations in spreading rate have been observed, the mean half-spreading rate increases from 1.8 cm/yr in the region north of Vema Transform to 2.1 cm/yr south of the Vema Transform. The average spreading rate for the last 10 Ma has not always been symmetric. The interpretation of magnetic and bathymetric data shows the complex nature of this part of the CLR which could probably be attributed to: (i) the short ridge segment; (ii) interaction with Fracture zone; and (iii) interaction between the CIR and the Wide Boundary Zone (WBZ) separating the Indian and Australian plates. (C) 2000 Elsevier Science B.V. All rights reserved.