GENERAL GEOLOGY OF JERANTUT-JENGKA TRANSECT WITH EMPHASIS ON DEPOSITIONAL ENVIRONMENT

Deep marine rocks of the Semantan Formation (Middle to Upper Triassic) at the
Jerantut-Jengka, Pahang shows two sections with four different of facies types, which
are characterized by grain fabric, bed thickness and sedimentary structure. The main
facies types consist of (F1) thick-bedded sandstone with floating mudclasts, (F2) thickbedded
sandstone with mud lamination, (F3) thin-rippled sandstone interbedded with
mudstone and (F4) shale. The facies is interpreted in relation to a submarine fan model,
where the section 1 is medial position while the section 2 shows the deposition in the
outer of the part of the system. Features, such as “floating” mudclasts, scour and fill
structures indicates debris flow processes whereas normal graded bedding (fining
upward) and sand laminate with shale indicates turbidity current processes. This study
involves the study of the sedimentology, petrography, geochemistry and
biostratigraphy of the study area of Jerantut-Jengka. Three samples were gathered from
different localities to determine their lithology and construct geology map by
comparing the thin section of the rock samples from the locations while six samples
were collected from the carbonaceous shale and sand of the main outcrop for
biostratigraphy and geochemistry analyses.