Then around four hundred million years ago a small continent, long and thin, collided with proto-North America, compressing the bedrock. The Kittatinny Mountains were created due to folding and faulting of the Silurian Shawangunk conglomerate which is made of quartz. This stone was in a shallow sea above the Martinsburg shale when folding occurred, producing heat in which the quartz bent. Then the quartz was cemented together with other small stones from silica. Due to the hardness of the stone, this makes the mountain highly resistant to weathering.