Table of Contents
Advances in Geology
Volume 2014, Article ID 571895, 17 pages
http://dx.doi.org/10.1155/2014/571895
Research Article

A Comparison of Maceral and Microlithotype Indices for Interpretation of Coals in the Samarinda Area, Lower Kutai Basin, Indonesia

1Department of Geological Engineering, Gadjah Mada University, Yogyakarta, Indonesia
2Department of Geology, East Yangon University, Yangon, Myanmar
3Department of Earth Resources Engineering, Kyushu University, Fukuoka, Japan

Received 21 April 2014; Revised 11 July 2014; Accepted 1 August 2014; Published 31 August 2014

Academic Editor: Thierry Sempere

Copyright © 2014 Chaw Thuzar Win et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Strata of the Middle Miocene Balikpapan Formation from the Lower Kutai basin are well exposed in a section near the Samarinda city, East Kalimantan, Indonesia. The succession is characterized by thick sandstone bodies alternating with shales and coal beds. A 250 m thick composite section of exposed sediments (not including the soil interval) was measured, from which 25 coal samples were collected. Petrographic, microlithotype, and maceral analyses were performed in order to determine the depositional environment of the Samarinda coals. In order to assess the development of paleomires, coal facies diagrams were obtained from microlithotype and maceral composition. According to the organic petrologic results, the Samarinda coals represent a highly degraded humodetrinite-rich group deposited from terrestrial into telmatic condition of peat formation with vegetation characteristics of highly degraded woody forest type evolved under alternate oxic to anoxic moor conditions. These formed with intermittent moderate to high flooding as the paleopeat environment shifted from mesotrophic to ombrotrophic.