Carbonate platforms in wedge-top basins:An example from the Gunung Mulu National Park,Northern Sarawak(Malaysia)

摘要

The Melinau carbonate platform initiated during the Mid-Eocene on a rotating slice of the Rajang accretionary prism.The differential sedimentary loading enhanced a rotation of the mobile substratum and created an elongated,asymmetrical wedge-top basin.The extensional southern margin of the basin consists of a 2100-2200-m-thick section of Eocene-to-Oligocene carbonates.These thin laterally towards the northern margin of the basin,where a carbonate factory was active on a postulated underlying thrust.Backstepping and dismemberment of the carbonate system started during the latest Oligocene and deep-marine sedimentation became prevalent over the entire region during the Early Miocene.