DR. PAUL POTTER AND THE MAP OF THE LITTLE MIAMI RIVER WATERSHED: A LEGACY

During his long tenure at the University of Cincinnati, Dr. Paul Potter frequently visited the Ohio Geological Survey in Columbus. Dr. Potter shunned the Interstate highways, instead taking back roads where he “could see the landscape and hopefully, some geology.” Over these many trips, he became fascinated with the Little Miami River and its watershed. He was interested in the geologic controls of the river itself, its tributaries, and the variable landscape of the watershed.

The 111-mile-long river sources in southeastern Clark County and flows southwest, emptying into the Ohio River east of Cincinnati. The northern portion of the river overlies resistant Silurian-age dolomites and limestones, whereas the central and southern portions overlie easily eroded interbedded Ordovician-age limestones and shale. In the northern portion, the Little Miami has created the scenic Clifton Gorge near the village of Clifton. The bedrock high adjacent to Clifton Gorge marked a former local divide that was breached by meltwater from the Wisconsinan-age ice sheet. The rolling Wisconsinan terrain, marked by numerous end moraines, overlies the thinner and flatter-lying Illinoian-age drift, which extends well past the Wisconsinan margin.

Dr. Potter discussed creating a map with Survey staff in 2010, using GIS techniques to depict the Little Miami River and its many tributaries. The map also would show the Wisconsinan ice margin, as Dr. Potter felt there was a marked difference in the landscape between the Wisconsinan-age drift and the Illinoian-age drift. An excellent amateur photographer, he envisioned the map having photographs of scenic segments of the river.

In the fall of 2020, the Survey released Miscellaneous Geology (MG) Map 6: The Little Miami River Watershed. The map includes two inset maps. One shows where select portions of the Little Miami River and its tributaries follow lineaments in the rock. The second shows how these lineaments follow the preferred northeast–southwest orientation common to the Paleozoic rocks of Ohio and North America.

Map MG-6 marks the last collaboration of Dr. Potter with the Survey. The Survey is proud of the long association with Dr. Potter and is indebted to his mentorship.