All Cenozoic basinsin the east margin of Eurasia Plate have delimited by Y

Rand R'fractures.Such geo metrical similarities between the basins of different magnitudes suggest that all of them are dextral pull apart basins. The dextral pulling apartstarted at the beginning of collision between India and Eurasia Plates and developed during the north retreat process of Eurasia Plate which led to right lateral shearing subduction zone between Pacific and Eura sia Plates.The unique backarc basins resulted from the unique collision between India and Pacific Plates.The tectonic evolution ofthem can be divided intothree first order stages:(1)pull-apart rifting (45 Ma～17 or 15 Ma)stage;(2) compression uplifting (around 17 Ma～15 Ma);(3)postrfifting (17 or 15 Ma～0 Ma)stage.