A wonderful slump structure at Sg Siput, Perak: Potential geosite en route for conservation

• Main Authors: Abd Kadir, Askury, Pierson, Bernard, Tuan Harith, Zuhar Zahor, Chow, Weng Sum
• Format: Conference or Workshop Item
• Published: 2010
• Subjects: QE Geology
• Online Access: http://eprints.utp.edu.my/5194/1/IMJGC2010_Slump_structures.doc; http://eprints.utp.edu.my/5194/

Submarine landslides with a rotational mode of failure may create slumped structures. The limestone hills in Sg Siput are mainly dominated by thinly laminated mudstone to wackestone with occasional breccia blocks. They are part of the Kinta Valley limestones which are relicts of thick Paleozoic carbonate deposits, mainly Carboniferous to Permian in age. Slumping is common throughout the section, and are enhanced by beds of chert which are initially interbedded with micritic limestone. Various types of slumping structures can be observed on the cut slabs and walls of the abandoned dimension stone quarry near Bt. Kemuning. A closed-up observation shows that the slump folds are synsedimentary structures and conspicuously missing are fractures, veins and cleavages, even though they have superficial geometric similarities to tectonic folds. They are generally tight to isoclinal folds or ptygmatic folds. The fold axes are commonly dispersed in the planes of the slump sheets where recumbent folds are dominant. Axial planar cleavages are faintly developed, particularly in the hinge regions not by compressional forces, but rather due to compaction. In general, slumps are subjected to an extensional stress at the rear whereas the front will have localized compression. Thus result in the formation of folds, thrust faults and imbrications. A preliminary interpretation indicates that the slump structures were formed with plastic-ductile deformation on a slope within deep marine environment. The slope is dipping to the west with an approximately N-S strike direction, suggesting the presence of a platform paleomargin, probably with grainy deposits. The slump features displayed in the Sg Siput limestone hills enhanced their scientific, educational and environmental value, and the hills should be protected and these spectacular sites be conserved for geoscientific researches.