The Main Range of post traissic biotic granite intrusion, having narrow valleys and steep crest., occurs in the north-east of Selangor. Occurring on the fringe of this range is a metamorphic zone of schists and quartzites with hilly to steep terrain. Away from the range and towards the straits of Malacca, where the folded sedimentary zone was least altered, the topography is mainly undulating. Overlying the sedimentary plain are quaternary marine alluvia.