Preliminary synthesis of the geology of Bangka Island, Indonesia

Author : U Ko Ko
Publication : Bulletin of the Geological Society of Malaysia
Page : 81-96
Volume Number : 20
Year : 1987

Bulletin of the Geological Society of Malaysia, Volume 20, August 1986, pp. 81 – 96

Preliminary synthesis of the geology of Bangka Island, Indonesia


SEATRAD Centre, Ipoh, Malaysia


Abstract: The paper reviews previous work and presents new data on the geology of Bangka Island based on photogeological and field investigations.

Stratigraphy of Bangka Island consists of four major units:

Ranggam Group – Upper Tertiary-Quaternary;

Fan Formation – Lower Tertiary;

Tempilang Sandstone – Middle to Upper Triassic; and

Pemali Group -Upper Palaeozoic.

The Pemali Group is thought to have been deposited in a deep marine environment whereas the overlying Tempilang Sandstone reflects shallower conditions and is probably a slope deposit. At the latest stage of the position of the Tempilang Sandstone, thrusting, granitization and uplift took place (Upper Triassic to Lower Cretaceous). In the following relaxation period, north-south high angle cross faulting occurred with major horizontal movements. Some minor fine grained leucogranites were emplaced during this period. The fluvial sedimentation took place during and after the cross faulting. The Fan Formation of Lower Tertiary age, which is the older fluvial unit, is unconformably overlain by the Ranggam Group. Since the latest stage of Ranggam Group deposition, several static sea level changes resulted in deposition of the marine sediments that are now found at low elevations around the island.