Lithological Facies Analysis And Sedimentology Of Semanggol Formation, West Malaysia
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Date
2017-03
Authors
Alias, Nabilah
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
Permian-Triassic Semanggol Formation is widely distributed in north Kedah,
south Kedah and north Perak, West Malaysia. However, its facies analysis and
sedimentology are still poor in the previous literatures. No regional correlations of the
formation among the three localities. In addition, the possible existence of the
Permian-Triassic Boundary (PTB) in this formation was not discussed before.
Therefore, several outcrops of the Semanggol Formation in the three regions were
subjected to detailed facies, petrographic and mineralogical analyses to establish a
regional correlation of Semanggol Formation in three areas discuss the sedimentology
and depositional environment of various facies in the formation and examine the
possible existence of PTB in the formation. Facies analysis shows similarities in
stratigraphic and lithological characteristics of the Permian to early Triassic in north
and south Kedah where black mudstone, interbedded sandstone and mudstone,
tuffaceous beds, bedded chert and siliceous shale facies have been identified. A
turbidites sequence that is composed of conglomerates, sandstone, mudstonesandstone
intercalations and black shales was reported in north Kedah as well as north
Perak. Based on these facies distributions, the regional correlations of the Semanggol
Formation in the studied three areas suggested a classification of the Semanggol
Formation into the Lower Member, Middle Member and Upper Member. The Lower
member of Semanggol Formation is represented by the black mudstone, interbedded
sandstone and mudstone, tuffaceous beds, bedded chert and siliceous shale facies that
are interpreted as deep marine environment. The Middle Member is composed of the
conglomerates, sandstone, mudstone-sandstone intercalations and black shales and
interpreted as turbidite sequence. The Upper Member comprises of varies types of
sandstone facies that are considered as shallow marine environment. The relative sea
level changes in Semanggol Formation is represented by two major high stands
events, referring to the deposition of Triassic chert and black shale in that consistent
to global sea level pattern during Triassic. Possible PTB in Semanggol Formation
from Permian to Triassic is supported with the abundance of tuffaceous rocks
especially in Pokok Pauh, north Kedah and Bukit Kukus, south Kedah that suggested
global volcanism that obliterate and caused a discontinuity in the stratigraphic
sequence.
Description
Keywords
Lithological facies analysis and Sedimentology , of semanggol formation, West malaysia