Sedimentology of the Early Neogene Sarawak Basin (Onshore at Tatau Town to RumahSupitAkSeriang), Bintulu, Sarawak, Malaysia

This study focuses on the geology of the Neogene rocks of Sarawak Basin that
overlies the unconformity on top of the Belaga Formation at Tatau Town to
RumahSupitAkSeriang with the focal study on sedimentology to acquire a detailed
analysis on the facies of the Tatau formation, and to evaluate the facies succession of
the studied area as well as to re-construct a depositional environment of the Neogene
succession in the Tatau area. Tatau formation is deposited from the sediments of the
Belaga Formation during the Neogene age. A detailed framework of the depositional
history of the study area is now possible with more exposed outcrops and hence will
create better data collection and contribute to a better understanding on the geology of
the Neogene rocks at Tatau Town to RumahSupitAkSeriang. There are generally eight
facies observed in the field: (1) Coal; (2) Parallel laminated sandstone; (3) Cross
laminated sandstone; (4) Massive sandstone; (5) Heterolithic siltstone interbedded
with cross-stratification sandstone; (6) Parallel laminated siltstone and sandstone; (7)
Parallel laminated siltstone with climbing ripple sandstone; (8) Parallel laminated
siltstone. The eight facies were described and interpreted in this research and
concluded that the Neogene rocks of the Tatau town area are deposited at a
transitional environment of a deltaic depositional setting with related to tidal
dominated energy.