Geodynamic and plate kinematic context of South China Sea subduction during Okinawa trough opening and Taiwan orogeny

The geodynamics and plate tectonics of the South China Sea (SCS)-Taiwan region since Miocene times are uncertain because former extent tectonic configuration subducted easternmost SCS along Manila trench is uncertain. Here we unravel regional kinematic context from main offshore constraints including published unfolding slab seismic tomography, which provides insight on restoring part SCS. We reconstruct a bayonet-shaped, stepped northern continent-ocean boundary (COB) that consists northeastern COB segment call ‘S3’, trending N070° roughly parallels present shelf; 350-km long ~N-S S2 steps north to Hualien; and, third S1 extends east Hualien beneath Ryukyu subduction zone N085° ends near Miyako Island in Ryukyus. distance between gives extension through time Okinawa trough, with maximum ~100 ± 20 km late (10 Ma). interpret as weakness ~18 Ma ruptured tear fault, Huatung basin-Philippine (HB-PSP) subducting northwestward two sides fault. transcurrent fault initiated ago at onset progressively moved eastward, creating intra-oceanic Luzon arc, began collision ~7 EU margin. From 6.5 Taiwan was uplifted west Longitudinal valley. arc forearc basins were shortened within Coastal range. Plate reconstructions Present synthesized terms continental or oceanic nature PSP-HB entities before their provide new understanding Taiwan, PSP-SCS kinematics, histories.