Blackford Till Member, here named, is assigned to the Jessup Formation in eastern Indiana and Ohio, and to the Banner Formation in western Indiana. The Marion Valley is filled mostly by sediments of the Blackford Member. Includes a western ice-proximal facies, a central lacustrine facies (type section), and an eastern ice-proximal facies. Lacustrine facies consists of stratified clays and silts; ice-proximal facies consist of sand to gravel to boulder gravel and tills. Intertongues to the west with the West Lebanon Till Member (new name) of the Banner Formation and to the east with the Wilshire Till Member (new name) of the Jessup Formation. Age is pre-Illinoian.

Source: GNU records (USGS DDS-6; Reston GNULEX).