Sedimentology and stratigraphy of the Tukau Formation, NW Sarawak, Malaysia

Abstract

This study investigates the Tukau Formation in northwest Sarawak, revealing a fluvial to marine transition zone within a deltaic setting. Analysis of 28 outcrops identified diverse lithofacies, tidal influences, and quartz-rich sandstones. Palynology indicates mangrove-dominated vegetation under brackish conditions. Amber suggests Dipterocarpaceae sources, while ichnofossils reflect reduced salinity. A single shark tooth was recovered. Findings highlight complex depositional processes shaped by fluvial, tidal, and wave interactions during sediment accumulation.