New paleomagnetic results from sedimentary rock and basement of the Ninetyeast Ridge (Ocean Drilling Program Leg 121, Sites 756-758) detail the northward movement of the Indian plate for the past 80 m.y. Analysis of the combined paleolatitude-age profile indicates a distinct reduction in India's northward movement rate at 55+ Ma, interpreted as completion of suturing of Greater India and Asia. India's northward motion slowed from 18-19.5 cm/yr to 4.5 cm/yr for the location of Site 758. Comparison of this profile with paleomagnetic data from the wider Himalayan region indicates that initial contact between northwestern Greater India and southern Asia was already established by Cretaceous-Tertiary time. This supports a possible causal link between the India-Asia convergence and the Deccan Traps extrusion.
- Geological Society of America