The Tembeling Formation - a litho-stratigraphic description (West Malaysia)

Abstract

The name "Tembeling Formation" is introduced for fluviatile-deltaiclacustrine sediments of post-orogenic origin in West Malaysia (Malaya). A type section is described in the Tekai River (Pahang), where the total thickness of the formation is over 3,000 meters. The age of the formation is probably late Triassic to Jurassic. A basal member, the "Murau Conglomerate", is described from the Mersing area (Johore); it consists of coarse red purple polymict conglomerates of fluviatile origin. These conglomerates decrease in thickness from east to west and vary in composition. The Murau Conglomerate is overlain in the Tahan Range by a sequence of red to grey shales and mudstones alternating with thick bands of arenaceous-rudaceous rocks. The top of the formation is formed by typical argillaceous red-beds, deposited under warm continental conditions. The Tembeling Formation overlies rocks of varied composition and age. An angular unconformity well developed in the east of the Peninsula decreases in importance westward. Along the east coast in the State of J ohore, the formation unconformably overlies metasediments of probable Carboniferous age, whereas to the northwest in the type area in central Pahang Triassic rocks are underlying. The folded Tembeling Formation is unconformably overlain by flat-lying beds of the late Jurassic to early Cretaceous Gagau Group.

Later Mesozoic flora from Maran, Pahang, West Malaysia. Part 1: Geologic considerations

“…From data presently available, it would appear that the sequence of physical events relative to later Mesozoic sedimentation was (1) A Permo-Triassic uplift with granitic instrusion, followed by a period of erosion; (2) development of a troughlike basin in the Triassic, essentially parallel to the axis of the present Malay Peninsula, with deposition of clastic sediments that appear to be shallow marine in origin. This Triassic belt seems to have been bounded on the west by a positive area of older granites and Paleozoic sediments, and on the east by a positive area of chiefly Paleozoic deposits; (3) in late Triassic and possibly continuing into early Jurassic, an episode of regional diastrophism resulted in cessation of deposition, folding of Triassic sediments, and subsequent erosion to depths that denuded at least some of the Triassic plutons; (4) volcaruc activity resulting in lava flows and pyroclastics may have terminated this episode of diastrophism; (5) during the Jurassic a second trough-like basin developed generally parallel to the earlier one and along its eastern Koopmans (1968). Yih River section and Maran River section after Ayob (1968).…”

“…margin, with deposition of non-marine clastics that are predominantly red or white in color, and commencing with a basal conglomerate. The later Mesozoic trough was bounded on the east by a positive area of granites and Paleozoic sediments which may have been the principal source area of the basal conglomerates (Koopmans, 1968). On the west, in the general area of the present Main Range, was an upland of granites and Paleozoic sediments with folded Triassic deposits along its eastern flanks; (6) following later Mesozoic deposition, regional faulting took place on a large scale, resulting in a series of generally east-west en-echelon faults and an eastward displacement of the southern end of the Malay Peninsula.…”

“…Rock units have been studied in varying degrees of detail in three parts of the later Mesozoic belt: (1) the G. Gagau area on the north, by the Geological Survey of Malaysia (files of unpublished field reports); (2) the Maran-S. Tembeling area in the middle portion of the belt, by Koopmans (1968) and M. Ayob (1968); (3) the Johore area on the south, presently under study by S. S. Rajah and T. Suntharalingam of the Geological Survey of Malaysia.…”

“…The Murau Conglomerate, named by Koopmans (1968) for rocks exposed ill the east coastal Mersing area of Johore, is here considered as a formally established rock unit. Whether the basal conglomerates in the Maran-Tembeling area are equivalents of the Murau Conglomerate as proposed originally by Koopmans has not been demonstrated by lateral tracing.…”

“…The localities were discovered by Ayob (1968) during his field studies on lateral equivalents of the Tembeling Formation recently described by Koopmans (1968). Rocks of probably equivalent age crop out in the G. Gagau area of northern Pahang (Geological Survey of West Malaysia files), and sample fossil collections from several Kon'no (1967Kon'no ( , 1968.…”