Tertiary basins of inland Peninsular Malaysia: review and tectonic evolution

Abstract

Sedimentary rocks of Tertiary age have been reported from several areas of inland (or onshore) Peninsular Malaysia, though a review of published data indicates that only some of them are known, or likely, to be so (Table A).In the known and likely localities, which occur as a series of small basins along the West Coast, are found partly consolidated gravels and sands inter-bedded with soft, often carbonaceous, shales, clays and lignite seams, as well as rare limestone, calcareous shale and volcanic ash. The sediments are entirely continental deposits and mostly gently dipping, though dips of 30° to 45° occur with a synclinal or basinal structure shown by some of them. The sediments mostly unconformably overlie, much older, Palaeozoic to early Mesozoic, generally folded and partly metamorphosed, rocks. The sediments have been considered to have been of a more extensive distribution than they presently are, for in places dipping beds are truncated, at the surface, or along an unconformity, though it is doubtful ifthey ever formed a connected sheet.At Bukit Arang in Perlis and Kedah, the Tertiary strata form two broad, gently northward plunging, synclinal basins with moderate bedding dips « 35°). The strata consist of an upper sequence of poorly sorted gravels and boulders in a sandy to clayey matrix (Boulder Beds) that unconformably overlies a lower sequence of sand and clay layers with a few thin coal seams. The lower sequence has a minimum thickness of 130 m and was deposited in a lacustrine environment, whilst the Boulder Beds with a total thickness of some 90 m were deposited under fluvial conditions. At Enggor in Perak, the Tertiary strata form a small, circular, basin with a thin layer of surface wash sediments overlying a sequence of shales, sandstones and clays with two coal seams. The coal-bearing strata, which dip 10° towards the NW, have a minimum thickness of 65 m and unconformably overlie folded, Upper Palaeozoic sedimentary rocks.

Structural controls on polyphase hydrothermal dolomitization in the Kinta Valley, Malaysia: Paragenesis and regional tectono-magmatism

“…These and the fractures along the pluton margins are filled with felsic dykes of probable Cretaceous age in the Main Range Province (Sautter et al, 2017). Following this magmatic thermal event, a stage of regional extension affected both the onshore and offshore regions around the Malay Peninsula (Raj et al, 1998;Morley, 2012;Md. Ali et al, 2016;François et al, 2017).…”

Major structural unconformities across Malaysia: geodynamics and basin development of Lawin, Perak

“…Lawin conglomeratic beds rested on Bintang Granite following N-S and NE-SW normal fault directions and associated with the Bok Bak major fault. Its underlying rocks believed to be the Silurian-Ordovician Baling Group [11]. We have mapped our observations of fractures, faults and interpreted shear motions to the development of the Lawin basin and assembled the evidence according to the chronology of events following to their relationships.…”

“…More importantly, dating the early deposits will constraint the time of erosion of the Late Cretaceous to Paleogene and the beginning of the deposition of Cenozoic basins. Across Malaysia, several Tertiary onshore basins were identified in the literature [11]. Correlations were relative, hence proper dating and in-depth study on these basins are needed.…”

“…One correlation made on Cenozoic deposits was using marker of coal lignite seams sandwiched between sandstones/silt which was reported across the Peninsula [11]. They were in the composition of lignite, signifying a shallow deposition of peat.…”

Source and origin of Late Paleozoic dropstones from Peninsular Malaysia: First record of Mississippian glaciogenic deposits of Gondwana in Southeast Asia

“…The Carboniferous‐Permian dropstone‐bearing unit in the Selangor area is composed of argillaceous and arenaceous sediments of the Kenny Hill Formation. It is underlain by the Early Carboniferous bedded chert of the Telaga Jatoh Formation (Raj, Rahman, & Shuib, ).…”