A major unconformity exposed in Sungei Siput

Author : Wee Heng Tian and D. Taylor
Publication : Bulletin of the Geological Society of Malaysia
Page : 79-88
Volume Number : 7
Year : 1974
DOI : https://doi.org/10.7186/bgsm07197404

Bulletin of the Geological Society of Malaysia, Volume 7, June, 1974, pp. 79 – 88

A major unconformity exposed in Sungei Siput, Pahang


1Conzinc Riotinto Malaysia (Sdn.) Berhad.


Abstract: A distinct angular unconformity was located in Sungei Siput in the Pekan district of Pahang. The underlying rocks are cordierite-andalusite hornfels overlain unconformably by a younger sequence of unmetamorphosed conglomerates grading upwards into conglomeratic sandstone, orthoquartzite and arkosic sandstone interbedded with purplish to blue mudstone. Due to the absence of fossils the age of the sediments is not known but lithologically they can be correlated with the Tembeling Formation or the Gagau Group.

Lead-zinc and iron mineralization is present in the underlying rocks with a gossan exposed at the surface. The presence of gossanous hematite-magnetite pebbles in the conglomerates shows that the underlying mineralization was emplaced prior to the deposition of the overlying clastic sediments and was undergoing oxidation and erosion at the old land surface now represented by the plane of the unconformity.

Aerial photograph interpretation suggests that the younger sequence underlies at least 40 square miles on the north bank of the Sg. Pahang and is cut off by faults along the Sg. Lepar valley to the east.