The Devonian-Carboniferous Boundary At Guar Sanai, Kampung Guar Jentik, Perlis: An Updated Map And Stratigraphic Section

Meor Hakif Amir Hassan

doi:10.7186/bgsm71202105

Abstract

The Sanai Hill B outcrop, exposed at Kampung Guar Jentik, Beseri district, Perlis, exposes one of the best-preserved Devonian-Carboniferous boundary successions in Malaysia. A new geologic map for the locality is presented, which is based on better exposure of the outcrop due to active quarrying, and was constructed using a combination of aerial drone imagery, three-dimensional photogrammetry, Google Earth satellite imagery and traditional field methods. The sedimentary strata include the Silurian Mempelam Limestone, the Lower Devonian Timah Tasoh Formation, the Upper Devonian Sanai Limestone, the Lower Carboniferous Telaga Jatoh Formation and the Lower Carboniferous Chepor Member of the Kubang Pasu Formation. The Devonian-Carboniferous boundary is marked by the contact between the Sanai Limestone and the Telaga Jatoh Formation. It shows an abrupt change from carbonate to siliceous (chert) deposition, with the contact represented by a paraconformity. This unconformity can be correlated to the Devonian-Carboniferous unconformity in the Kanthan Limestone of Perak. It can also be identified in many sections throughout the Western Belt, including in southern Thailand, Langkawi, Kedah, Perak and the Selangor-Kuala Lumpur area. The unconformity can be linked to a eustatic sea level fall at the end of the Devonian. N-S trending imbricate reverse faults and repeated sections have been interpreted as evidence for collisional tectonics associated with the Late Triassic Indosinian Orogeny. E-W trending normal faults mark a Tertiary extensional phase.

Highlights

A relatively complete Palaeozoic sedimentary succession is preserved in Perlis and Langkawi, northwest Peninsular Malaysia
Several un-deformed sections cross the boundary between strata of different geologic periods. This includes the Cambrian-Ordovician boundary in the Machinchang Formation on the west coast of Langkawi island (Lee, 1983), the Ordovician-Silurian boundary in the Tanjong Dendang Formation on Pulau Langgun (Jones, 1981; Cocks et al, 2005), the Silurian-Devonian boundary in the transition between the Mempelam Limestone and Timah Tasoh Formation, on Pulau Langgun (Jones, 1981; Cocks et al, 2005), and the Devonian-Carboniferous boundary at Sanai Hill B, Kampung Guar Jentik, Perlis (Hassan & Lee, 2002, 2003, 2005; Hassan et al, 2014)
This paper focuses on the Devonian-Carboniferous boundary section at Sanai Hill B, in Perlis, and has the following objectives: (1) to present an updated geological map of the Sanai Hill B site based on data from new excavations and drone-based aerial imagery; (2) to present updated sedimentary logs for the Sanai Hill B section, and (3) to summarize and review our current understanding of the Devonian-Carboniferous stratigraphy in Perlis and Malaysia

Summary

INTRODUCTION

A relatively complete Palaeozoic sedimentary succession is preserved in Perlis and Langkawi, northwest Peninsular Malaysia. Several un-deformed sections cross the boundary between strata of different geologic periods This includes the Cambrian-Ordovician boundary in the Machinchang Formation on the west coast of Langkawi island (Lee, 1983), the Ordovician-Silurian boundary in the Tanjong Dendang Formation on Pulau Langgun (Jones, 1981; Cocks et al, 2005), the Silurian-Devonian boundary in the transition between the Mempelam Limestone and Timah Tasoh Formation, on Pulau Langgun (Jones, 1981; Cocks et al, 2005), and the Devonian-Carboniferous boundary at Sanai Hill B, Kampung Guar Jentik, Perlis (Hassan & Lee, 2002, 2003, 2005; Hassan et al, 2014). Dropstones and diamictites in the Chepor Member record glacial marine conditions during the Early Carboniferous, which is an older event compared to the dropstone-bearing intervals of the Singa Formation in Langkawi (Hassan et al, 2014)

METHODS

Findings

CONCLUSIONS