country rock is a term used in the field to indicate the mineralogy available for observation on the surface. like most places east of the mississippi,the country rock of the cohutta is largely concealed by the riotous vegetation it supports. it is visible in rock outcrops and as river cobbles. my own experience has been of a largely schistose layer, with the attendant garnets and kyanite. i have also found pyrite cuboids. in addition to this metamorphic stone i have also found cobbles of limestone in the jacks river, though i have yet to discover the exposed layers of their genesis. more field trips to the area and my growing understanding of geology and mineralogy will no doubt provide more data on this topic.
the underlying rock is important in discovering and understanding the biodiversity of the area. it is, of course, the firmament upon which the thin membrane of the earth's biosphere exists. it's chemical composition will dictate which varieties of plants and fungus can subsist. this, in turn, will affect which animals can live there. mycological and botanical diversity are what concern us here.
life adapts to niches. these isolated and semi-isolated environments are what drive the diversification of phenotype and eventual speciation. one of the most influential factors in the capacity for, and nature of, any niche is the topography of the area. this is, of course, largely determined by the stone of which it is built.