Which of the following are true with respect to the Indian Peninsular Plateau? 1. The southern plateau block is formed mainly of granite and gneiss 2. The Deccan lava plateau is an elevated tableland consisting of horizontally arranged lava sheets 3. The Malwa plateau dominates the Vindhyam scraps, forming the northern flank of the plateau 4. The trough of the Narmada and Tapti are interposed between the Vindhyan and the Satpura ranges