9:30 AM - 9:45 AM
★ [SIT07-03] Exhumation history of Taiwan and Mindoro orogenic belts and its implication to plate motion of the Philippine Sea plate
Keywords:Taiwan orogenic belt, Mindoro orogenic belt, Philippine Sea plate, exhumation histroy, Luzon arc
In northern Mindoro the Mesozoic green schist facies strata show the oldest zircon fission track reset ages of ca.4-6 Ma, which is consistent with the Pliocene Punso conglomerate deposition in southern Mindoro Island and therefore indicative of the beginning of collision at ca.5-6 Ma.
Meanwhile the zircon fission track ages also imply similar exhumation history in Taiwan orogenic belt. The oldest reset zircon fission track ages are also 5-6 Ma and are consistent with deposit ages of the foreland basin. In addition, the Philippine trench and Okinawa trough started to develop from ca. 5-6 Ma.
Our new data support the model of the Philippine Sea plate has changed its moving direction to NW around 5-6 Ma, which had been suggested by Hall (2002).