Water Well Record Studies of Geologic History in Indiana Including Examples of Geomorphology of Buried River Valleys, Geomorphic Expression of Earthquake Faults, and Deep Groundwater Flow Paths.

The Indiana Department of Natural Resources water well record data base is used to produce maps exploring aspects of the geologic history of the state with a emphasis on East Central Indiana. This study includes the geomorphology of buried preglacial valleys, the geomorphic expression of possible fairly recent fault lines in East Central Indiana, and suggestion for the deep groundwater circulation paths. An excellent region to study geology and groundwater configuration the Midwest is East Central Indiana as there is are almost equal numbers of glacial and bedrock wells ranging over 300 feet depth. There is over 600 feet of relief on the bedrock surface with deep glacial drift in two distinctly different buried valleys, and two distinctly different till plains. The focus of this work uses over 33000 UTM located water well records from a 17250 km2, 13 county area. Over several years we have studied details of bedrock topography, bedrock and glacial geology and groundwater productivity, horizontal and vertical flow using static water level information, buried preglacial cavern systems, and applications to groundwater modeling. In the southern more maturely developed Anderson River valley there are larger numbers of deep glacial wells in many tributaries while in the north deep wells are restricted to just the deep course of the Teays River valley with less glacial productivity in the shorter less mature tributaries. To the north there many indications of a paleokarst history with sinkhole entrances on the plateaus above the Teays and outlet into the Teays tributaries. Details of the buried bedrock surface show a linear N28E trend parallel to several bedrock faults and also to recent stream valleys. Other studies by the author have shown the dominant Paleozoic bedrock fracture directions in this area to be N78E and N12W. Therefore the N28E trend is distinctly different and can be related to trends seen in active earthquake areas in northwest Ohio and southwest Indiana. The possibility of late Cenozoic seismicity related to other activity in the Midwest will be summarized. Maps comparing static water levels in shallow versus deep wells show areas of vertical downward or upward gradient which indicate three dimensional flow directions. The major deep groundwater recharge from the till plains moves to areas of upward gradient in the Wabash and Whitewater River valleys rather than other vallies on the till plains. The interpreted paths allow for discussion of ground water travel times.