Limestone itself is quarried in lots of places for a setting up stone, for use in roads, and to be used in reducing sulfur emissions from coal-burning energy crops. Phosphates are actually mined for fertilizer from Ordovician limestones, particularly where by weathering has concentrated the phosphate, as in central Tennessee. https://epz00477722109.blog2news.com/28886824/d-lin-mc3-dma-an-overview