Of the 3 main classes of rock, this one accounts for about 75% of all the exposed rocks on land
The crust is the coldest layer upon all the layers because it is 
exposed to the... [DOC] [TLE] GG101 Sedimentary Rocks [PAR] We know that sedimentary rocks cover about 75 percent of all of the continental ... 
We know, for example, that the land surfaces on the continents are formed from 
.... To geologists