COAL SEAM ANALYSIS WEST BATURAJA SUB-DISRICT, SOUTH SUMATERA

Abstract

Sumatera island is located between 3 NH to 6 SH and 96 EL to 106 EL, along 1,700 km northern
to the South, parallel to the subduction zone between the Sunda plate and Indian Oceanic plate on
the western part of Sumatera Island. The western part of Sumatera Island is a fore deep basin.
Parallel to it is the Bukit Barisan chain. Towards the eastern part, there is the foreland basin of
Neogen. At the central zone of Bukit Barisan chain, there is the in-between basin. The South
Sumatera Basin starts from the eastern part of Bukit Barisan stretching to the south-east of the
ocean and adjoining to the basin at the boundary of Bukit Barisan in the south-west and tertiary
Sunda Basin in the south-east. Coal at the basin or on this formation with low rank is generally
lignite. It is only at the young andesite intrusion (at Bukit Asam) where this lignite is altered to be
high rank coal. On this formation coal is divided into three groups, namely, upper part (6 – 7 seams),
central part, and lower part (8 – 10 seam). The coal development is mainly autochthon, in the forest
environment where there is no indication of the existence of swamp vegetation element. Based on
the data, it can be concluded that coal resource at the survey location has quite good quality, with
moderate calorific value and low sulphuric content. Thus, it can be classified into the ‘brown coal’.