Originally posted by george:
Dave, from a geologic standpoint, major reservoirs are not a good example of local water quality.
Lake Toledo Bend, an East Texas Lake, has it�s headwaters in the alkaline Cretaceous carbonate rocks, whereas lake Fork's headwaters are transitional Cretaceous/Tertialry, and marginal alkaline...
That makes perfect sense, george; the big reservoirs have too much water in them for it to be all (or even mostly) local water.
Cretaceous, Tertius - I thought maybe you were gonna mention the Jackass period.