Characterization And Origin Of Dropstone In Peninsular Malaysia
Loading...
Date
2018-06
Authors
Anuar, Mohammad Noor Akmal
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
Depositional environment and mechanism of dropstones in Malaysia are still debatable whether they are of glaciomarine or non-glaciomarine in origin. In addition, the source of diamictites in these dropstones is not yet known. Therefore, this study was designed to integrate geological field observations and petrographic investigations on some of the dropstones in Peninsular Malaysia to examine their origin. In addition, characterization of diamictites in these dropstones can shed the light on the nature and composition of unexposed basement rocks in Malaysia. Field observations in this study indicated the widespread occurred of dropstones in West coast of Peninsular Malaysia including Langkawi archipelagos, Perlis, Kedah and Selangor of Carboniferous-Permian in age. Dropstone in these diamictite occur as rounded grains ranging in size from 2 cm to 20 cm that are scattered different lithological unit of black shales, black mudstone, sandstones and white shales. Mineralogical and petrographic investigations indicated that these dropstone are composed of granite, quartzite and sandstone. One of the host rock, Singa black shales is mainly composed of Illite and kaolinite. The current study suggests that the dropstones in Peninsular Malaysia are of glaciomarine origin. Older materials from the Precambrian granitic basement rocks as well as the quartzite from the Cambrian Machinchang and Cambrian Jerai quartzite were dragged by glacier to be dropped in both the relatively shallow marine sandstones and deeper shales. Varieties of colors of the host rock suggests the prevailing of relatively reducing and oxidizing conditions during the deposition of these dropstones in relation with the formation of its host rock. Although much are known about the global event of Late Paleozoic Ice Age, yet restricted data and research on Sibumasu as a part of LPIA realm still poorly understood.
Description
Keywords
Characterization and origin of dropstone , in peninsular Malaysia