Brooks Run section, From memory. Le Roy mines drawing made to scale. Four cycles of marine deposits and continental deposits, each of which is followed by erosion cycles. These in turn end in river form sandstone (fine grains), then a clay then bedded sandstone. On the Buffalo -- the clay comes in suddenly. Cow Run Sandstone. Micaceous. Buffalo micaceous sandstone. Micaceous. Upper Cow Run Creek shale R.R. to Fort Wayne Ind. the clay at Pine Creek is are worked out. Therefor the two sandstones represent erosions on a level as in each case the strata show marine character.