Lithofacies, Geophysical and Depositional Settings Studies of Radiolarian Cherts and Associated Siliceous Rocks of the Telaga Jatoh Formation, Lower Carboniferous (Mississippian), Kedah, Malaysia

ABSTRACT This work integrates electrical resistivity tomography (ERT) and lithostratigraphic analysis to better understand sedimentary processes and basin development in the Telaga Jatoh Formation. Data were collected using a 2D ERT Wenner configuration with an electrode spacing of 1.5 m. The ERT results highlight the significant geophysical horizons in the outcrops by identifying resistivity variations in the area. Resistivity values indicate that bedded chert (ribbon cherts) ranges from 0 to 100 Ωm, whereas sandstone ranges from 100 to 350 Ωm. However, the depositional context of radiolarian chert indicates that the proliferation of siliceous organisms, the amalgamation of hydrothermal silica with silica dissolved from seawater and riverine sources, and the episodic transport of calcareous allochthonous sediments significantly influenced the deposition and formation of cherts within the trough basin during the Early Carboniferous period. The upward lithological transition from bedded chert to siliceous mudstone above provides evidence for the continuous landward migration of the oceanic plate. This alteration also indicates that the environment is transitioning from pelagic to hemipelagic continental limits. The Telaga Jatoh formation at the Bukit Tobiar outcrop in Keda consists of organically rich black siliciclastic mudstones. These mudstones are interlaced with thin strata of black chert that accumulated in hemipelagic to pelagic settings. The formation comprises five distinct facies, which can be classified into two associations. The basin's deepest and calmest areas (pelagic settings) are characterised by very fine‐grained, massive to faintly laminated mudstone interbedded with radiolarian chert. Conversely, lenses of grey mudstone and large sandstone strata imply a shallower, less calm and more proximal offshore environment (hemipelagic settings). Based on the results above, the Telaga Jatoh Formation was characterised using lithostratigraphic and ERT approaches to enhance understanding of its stratigraphic evolution and depositional conditions in the area.