Making ends meet in Gondwana: retracing the transforms of the Indian Ocean and reconnecting continental shear zones

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Abstract
Interpretation of the detailed patterns of ocean‐floor transforms revealed by satellite altimetry enables the creation of the Indian Ocean to be described quantitatively as four consecutive plate‐tectonic regimes separated at 200, 136, 89 and 43 Ma. Each regime is reversed in turn by keeping transform termini coincident and colinear until conjugate points on the margins of pre‐existing plates regain their pre‐regime integrity. Progressive elimination of the Indian Ocean, demonstrable as a smooth computer animation (http://www.kartoweb.itc.nl/gondwana), leads to a refined re‐assembly of the continental fragments of central Gondwana that is substantiated by new geological data. A sequence of Euler interval poles that describes the dispersal of the Gondwana fragments, time‐calibrated against available magnetic anomaly data, is given. The model requires a mid‐Cretaceous position for India’s southern tip about 1000 km south of Madagascar, prior to India’s rapid northward migration.