GEOLOGY OF THE PENGKALAN HULU-BETONG TRANSECT ...

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Lithology
The facies is characterized by the presence of medium- to thick-bedded sandstone,
quartzite and minor argillite with indeterminable thickness (Figures 15 and 16).
In the La Hat-Ai Yae Kem mountain range, the facies consists of thick- to very thickbedded,
light brown to light grey, recrystallized sandstone to quartzite (80%) intercalated
with thin- to moderate-bedded (10 – 60 cm in general), light greenish grey to blueish grey
phyllite, phylitic schist and schist (20%). The N-S quartz dykes are common. Strong S1
cleavages are developed in NE-SW and N-S directions, generally dipping north and west.
Kink bands and gash fractures are commonly found in the succession.
In the La Ong Rung-Ta Pa Yao-Bang Lang Dam range, the facies comprises thick- to
very thick-bedded, light greenish grey to grey, fine- to medium-grained, lithic and
quartzitic sandstone (90%) intercalated with very thin-bedded argillite. The upper portion
is composed predominantly of thin- to medium-bedded, grey to greenish grey mudstone
and siltstone (40%) intercalated with thin- to thick-bedded (20 – 60 cm in general) light
greenish grey to yellowish brown, fine- to medium-grained, laminated, lithic, arkosic and
quartzitic sandstone (60%) exhibiting diagnostic features of wavy and lenticular beds.
The strong S1 cleavages are developed in the N-S direction and generally dip westward.
Kink bands, quartz dykes and gash fractures are also commonly found.
The Arenaceous facies (Cyh1) of the Kubang Pasu/Yaha Formation (Ckp/yh) in the Sutan
Tanun area is strongly deformed by the N-S trending fault. These rocks generally show
kink bands and strongly developed cleavages. The rocks consist of thick- to very thickbedded,
light brown and greenish grey, laminated, quartzite, quartz schist, and minor
phyllite.
A
Figure 15: Photographs showing the arenaceous facies of the Kubang Pasu Formation/Yaha
Formation (Ckp/yh) in Malaysia.
A- Thick bedded sandstone at Batu 10, East-West highway Gerik to Jeli.
B- Quartz-arenite at Ayer Ganda, abandoned quarry, Gerik.
B