It wouldn't flourish because there are no more decomposers. With no decomposition there cannot be a food chain because it all depends on that specific part of the link. You see, the plant population would die. Due to the lack of fungus(decomposers)
To tell you the truth, all rocks can melt under heat and pressure. For example, if a volcano erupts, the magma that is flowing can melt the rocks because of extreme heat.