The Cambrian of Malaysia is best represented by the quartzose Machinchang Formation in Langkawi, Kedah, northwest Peninsular Malaysia. It is divisible into three members. The oldest Hulor Member (>1260 m thick) is a coarsening upward succession of rhythmically interlayered graded siltstone, mudstone and clayey
sandstone deposited as a prograded prodelta deposit. The middle Chinchin Member (>1575 m thick) is a fining upward succession of quartzose conglomerate and
sandstone subdivisible into three beds. The lowest Anak Datai Bed (575 m thick) is made up of graded bedded, cross-bedded pebbly
sandstone and conglomerate of estuarine channel-fills and thin to thick beds of low angle, planar cross-bedded
sandstone with heavy mineral concentrations deposited as upper shoreface to
beach deposits. The Temurun Bed (340 m thick) is of upper estuarine deposits of wavy-bedded
sandstone and pebbly
sandstone, fine tuffs and thin argillites. The upper Tengkorak Bed (>200 m thick) spans the Cambro-Ordovician boundary and consists of thick tabular bedded upper shoreface to
beach fine
sandstone with interbeds of fine rippled
sandstone, acid tuff beds and mudstone belonging to a series of
barrier
beach complexes. The youngest Jemurok Member (>420 m thick) is a fining upward succession of siltstone, mudstone and hummocky cross-bedded
sandstone and thin limestone deposited in storm influenced shoreface to back
barrier lagoon with tidal channel environments. It has fragmentary trilobites, brachiopods, abundant trace fossils and the Kinneyian wrinkle marks.
The overall sequence belongs to a highly destructive, wave-influenced delta deposit with a series of preserved beach-ridge complexes. Clastic sedimentation was reduced by peneplation of the source area as shown by the finer and thinner beds that grade into limestone of the overlying Ordovician Setul Formation.