A NEW GEOLOGICAL MAP FOR FORMATION DISTRIBUTION ON SOUTHERN PART OF SOUTH CHINA SEA: WEST KALIMANTAN, INDONESIA

Abstract

West Kalimantan province is located in Kalimantan Island. It is bounded by the East
Malaysian state of Sarawak at the north and Indonesian provinces of East Kalmantan at the northeast and
Central Kalimantan at the southeast. The Muller Mountains and the Schwaner Mountains run sequentially
from northeast to southwest. Geological setting in the Kalimantan occurs is a result of Mesozoic accretion of
ophiolitic, island arc and microcontinental fragments of south China and Gondwana origin. The aim of this
study is to observe and update the geological conditions in West Kalimantan. The distribution and
significance of sediment and igneous rocks were not known to the few exposures in the West Kalimantan
(Pontianak, Sanggau, Sintang, and Sambas) were sampled and analyzed. There are 5 units or formations;
Alluvium (Q), Oligocen sediments (Po), Cretaceous sediments (K), Lower Cretaceous Meta-Igenous (Kl2),
and Pre-Carboniferous Pinoh Metamorphic (Pzm). In the western part of West Kalimantan there lying
alluvium deposit that consists of gravel, sand, silt and peat. Po is a sedimentary rock unit that has an
Oligocene age consists of sandstone, siltstone and mudstone that spread from western to the eastern part of
West Kalimantan. Cretaceous sediments (K) exposed at the northwest part of West Kalimantan consist of an
alternation of sandstone, siltstone and mudstone. Distribution of Lower Cretaceous Meta-Igneous (Kl2) is on
the western part of West Kalimantan consist of granite-granodiorite and tonality. Pre-Carboniferous Pinoh
Metamorphic (Pzm) exposed randomly at the western and center part of West Kalimantan. This geological
survey is able to update new information for the geological condition in West Kalimantan.