Page:The Journal of geology (IA journalofgeology21894univers).pdf/76

Rush and Decatur counties in southeastern Indiana are at present drained by Flat Rock creek and Clifty creek. The former has its source in Henry and the latter in Decatur county. Both flow in the same general southwesterly direction, and occupy deep channels which they have eroded in the hard and homogeneous limestone of the Niagara age. They discharge their waters into the east fork of the White river, the Flat Rock above the City of Columbus and the Clify below. During one of the later stages of the Pleistocene period, and perhaps extending into the recent period, these counties were drained by a stream whose channel had a width of forty rods and a depth of ten or twelve feet, as shown by its well-marked banks composed of coarse river gravel. The elevation of the upper part of this stream was thirty feet above that of the rock bed of the recent streams. It had a more southerly course than these, having its point of departure from the present Flat Rock creek near Rushville, and its point of union with the present Clifty creek near Milford. As indicated by the map, the river may be described in four sections.

1. From a point about three miles above Moscow P.O., the old channel, called in this region "Hurricane," may be traced in a southerly course midway between the Flat Rock creek and the Little Flat Rock creek until it encounters the latter near the county line where the latter's course is westerly. Throughout this stretch the old channel has an elevation considerably higher than the modern streams. Comparatively little water now runs through this channel except in flood time.
2. From the point where the old channel encounters the present Little Flat Rock creek to a point about a mile below