PALEOENVIRONMENTAL AND PALEOGEOGRAPHICAL RECONSTRUCTION OF THE UPPER OLIGOCENE-MIDDLE MIOCENE NYALAU FORMATION, SOUTH BINTULU, SARAWAK, MALAYSIS

This thesis presents the result of detailed integration study of sedimentology,
ichnology and palynology ofthe Upper Oligocene-Middle Miocene Nyalau Formation,
south Bintulu Sarawak, East Malaysia. The studies were carried out on eleven wellexposed
outcrops. Twenty facies were identified intheNyalau Formation and these are;
Fl-Tabular-planar cross bedded sandstone, F2-Trough cross bedded sandstone, F3-
Bidirectional cross bedded sandstone (Herringbone), F4- Flaser, wavy bedded
sandstone, F5- Heterolithic sandstone, F6- Bioturbated heterolithic sandstone, F7-
Ripple cross laminated sandstone, F8-Hummocky cross stratified sandstone, F9-
Swaley cross stratified sandstone, F10- Parallel laminated sandstone, Fll-Interbedded
hummocky cross stratified sandstone with bioturbated mudstone, F12- Laminated
mudstone, F13- Heterolithic mudstone, F14- Well bioturbated mudstone, F15-
Bioturbated heterolithic mudstone, F16- Carbonaceous rooted mudstone, F17- Dark
fissile mudstone, F18- Coal, F19- Paleosol (Underclay) and F20- Churned, condensed
bed.