Figure 5
Revised plate kinematic reconstructions. Maps: Generic Mapping Tools36. Grey fill: lost area (e.g. Greater India, shortened and/or subducted since Paleogene). Background: present-day topography and bathymetry33 (from https://topex.ucsd.edu/cgi-bin/get_data.cgi) and subglacial topography in Antarctica34. White outlines: present-day coastlines. Black lines: active plate boundaries. Yellow dotted lines: labelled magnetic isochrons. (a) Initial INDSRI-Antarctic fit. Abbreviations: EANT-East Antarctica; GD- Upper Ganges Delta; LG-Lambert Graben; LHB-Lützow Holm Bay; IND-India; SP-Shillong Plateau; SRI-Sri Lanka. (b) Chron M4 (~ 130 Ma) reconstruction. Differing rates of early (post-M9/ ~ 133.5 Ma) seafloor spreading in Prydz Bay (PB) and Princess Elizabeth Trough (PET) and slow oblique continental extension in LHB are accommodated by deformation within the Pranhita–Godavari (PG), northern Damodar (NDB), and eastern offshore Palar Margin, Cauvery, and Mannar basins (PM, CB, MB). Red text: maximum estimates of this deformation. (c) Reconstruction at chron M0 (~ 125 Ma). New seafloor may have formed within MB. Intracontinental motion within India had ceased except along the NDB, where the sense of strike-slip had reversed. (d) Reconstruction at 90 Ma. The Shillong Plateau (labelled SP in a) reached its present-day location with respect to India by NDB motion that ended around this time. A major regional plate reorganization saw directions of seafloor spreading change, producing prominent bends in the orientations of fracture zones (thin dotted black lines). Excess volcanism in the M0 to 90 Ma period led to the formation of large igneous provinces at Elan Bank (EB) and the Southern Kerguelen Plateau (SKP), and along the 85° E Ridge (85ER).
