A possible path in the rock cycle is starting with granitic rock such as found in the Coast Mts beside Vancouver, BC which have weathered and eroded over the milennia and given rise to sediments such as sand and gravel and clay which have been buried and compacted into sandstone, conglomerate and shale in the Georgia Basin below Vancouver, BC which forms the foundation of Vancouver, BC. and into which the tall new buildings in downtown Vancouver are sunk into the sandstone for rooting on bedrock to reduce earthquake damage. The marble in many of the historic buildings in Vancouver comes from the metamorphosis of the limestone by thermal metamorphism making the limestone much more coarse grained than original. Similarly slate comes from shale and with increasing metamorphism, slate becomes phyllite and finally schist and gneiss. The older the rocks are the more likely there will be metamorphism so the Canadian Precambrian Shield is mostly metamorphic.