Sole markings of extraordinary size and variety in Crocker sandstones of Sabah


Author : H.D. TjiaPublication : Bulletin of the Geological Society of MalaysiaVolume : 61Page : 11 - 21Year : 2015


Description

Bulletin of the Geological Society of Malaysia, Volume 61, December 2015, pp. 11 – 21

Sole markings of extraordinary size and variety in Crocker sandstones of Sabah

H.D. Tjia

Universiti Kebangsaan Malaysia (The National University of Malaysia)
43600 Bangi, Selangor
tjiahd@gmail.com

Abstract: Sole markings are arenaceous casts of impressions, typically scoured by water currents on cohesive mud surfaces. Scouring may be effected by clear or by debris-laden moving medium. Debris carried along in traction, in saltation and in suspension leave unmistakable imprints that often manifest as indicators of stratigraphic facing, flow direction, or relative distance from source. The Eocene-Lower Miocene Crocker Formation of Sabah hosts an exceptional assemblage of large to gigantic sole markings near Kaung Village on the mid-slope of Mount Kinabalu. Two forms, hitherto unmentioned in publications, are enterolithic casts and preserved effects of turbulent flow. Representatives of the Nereites-Zoophycos ichnofacies at this locality, along nearby Samalang River and in the heart of Kota Kinabalu confirm bathyal-abyssal depth of deposition. Where determined in other localities of the Crocker Formation in Sabah, paleocurrents ran Northward. The only exception of southerly directed sediment transport near Kaung Village poses a formidable challenge to understanding Sabah’s tectonic evolution.

Keywords: sole marking, Crocker Formation, enterolithic cast, turbulent flow, palaeocurrent