Bulletin of the Geological Society of Malaysia, Volume 20, August 1986, pp.149 – 177
Department of Geology, Universiti Kebangsaan Malaysia, Bangi, Selangor
Abstract: Fold asymmetry, isoclinal and recumbent folds, and low-angle reverse faults are unmistakable indicators of geologic transport direction. Some of the transport took place by gravity sliding when the sediments were still unconsolidated, but the majority was caused by tectonic processes. Five of the six major geologic settings may account for the transport directions determined in metasediments of various age groups of Peninsular Malaysia. Convergent transport occurs on limbs of anticlinoria. Divergent transport directions occur on limbs of warps developed by vertical uplift and in sediments that have been pressed out from sites between colliding continental plates. Three cases of unidirectional transport are possible and consist of overthrust and thrusts, subduction, and obduction. There is no indication that obduction ever took place in the peninsula. Cross-cutting structures, different fold sizes, and refolded folds are the main criteria for determining the relative ages of transport directions. From older to younger transport directions the movement was eastward, followed by movement towards south, then in a general westward direction (which is present in all geologic domains), succeeded by one towards east, and concluded by transport in south to southeast direction. The general westward transport probably took place during the Late Triassic-Early Jurassic deformation period and is interpreted as a consequence of eastward subduction of the Indian Ocean plate beneath the Eurasian plate in the vicinity of the peninsula. The cause of southward transport that probably occurred in two different deformation phases is an enigma.