Multiple choice Which one of the following statements is not correctly matched ? Vindhyan system mostly consists of sandstones, limestones and shale. Gneiss and schist of archaeans are the oldest rocks in India. Rocks of Gondwana system are of fluvial or lacustrine origin. Deccan trap formations were due to volcanic eruption during Oligocene. Reveal answer Fill a bubble to check yourself D Correct answer Explanation The Deccan Trap formations were the result of volcanic eruptions during the late Cretaceous to early Paleocene period, not the Oligocene.