The Blachly series consists of very deep, well drained soils that formed in colluvium mainly from basalt or sandstone.
Blachly soils are on broad ridges and steep side slopes.
Slopes are 0 to 75 percent. Blachly silty clay loam, forested. The soils are usually moist and are dry for less than 45 consecutive days during the summer between depths of 4 and 12 inches. Thickness of the solum ranges from 5 to 6 feet. Depth to bedrock ranges from 5 to over 12 feet.