The mill sits beside Mill Creek which flows north to connect with the Mahoning River which is located south of Youngstown.
During the movement of the Great Glacial Ice Cap, which steadily moved down from the Laurentian Highlands, the Mahoning river actually flowed toward the present bed of Lake Erie. The Ice Cap disrupted many of the drainage lines along with severely changing the topography of the Ohio region, and was the reason the river was flowing in a reversed direction then it is today.
The Great Glacial Ice Cap was part of the Ice Age, the time period is also named the Pleistocene Epoch which occurred roughly 2 million years ago. The period consisted not of one event of ice invasion but of a succession of ice advancements within the Northern part of the United States. The ice advanced south for a period of time then gradually receded to the north, the water draining from the melting ice cap drained to the south.
As the Ice Cap melted the climate became warmer, this is known as the Interglacial Interval, it occurred at the end of the Pleistocene around 11,700 years ago. The warmer climate didn't last as the ice cap pushed south again. The new interval of advancing ice was known as the Wisconsin Glacial Stage, which occurred only 10,000 years ago during the Holocene. The Wisconsin Glacial Stage affected the Mill Creek area the most.
The Massillon Sandstone is stained by Iron Oxide, uppermost layers of sandstone are more bedded than the lower layers. Cross-Bedding is also visible in the sandstone layers. The Massillon Sandstone is Pennsylvanian age so around 290 million years old.
The Massillon Sandstone is rather patchy in its distribution as it was once channel fill, this means that the amount of sand accumulating in a stream was too much for the water to move it along. The locations where the sandstone is not developed is a mix of shale layers with intervals of sandstone. Fossils are present in the Massillon Sandstone layers, the fossils are mainly of plants that got caught in the sand and were buried over a prolonged amount of time.
At the beginning of its formation, the meltwater flow could not cut into the solid rock upstream, so at first, it was a set of rapids. Over time the water flow carried the softer rock material in the valley downstream and the overhangs eventually fell to the force of gravity.
The waterfall has been retreating upstream ever since the Wisconsin Glacial Stage came to an end. The falls may not have even formed if there was no difference in the hardness of the rocks below.
CAVE OF THE WINDS
The Cave Of The Winds is the weathered Meadville Shale below the falls. The Massillon Sandstone overhangs the creek in many locations around the mill because of the shale eroding out from the flow of the creek.
The eroded shale is taken downstream and deposited at the mouth of a river and is set in a basin, later that sediment will be put under heat and pressure and the cycle continues again.
Lanterman's Mill was constructed between 1845 - 1846 and ground flour till its closure in 1888. In 1892 the Abandoned structure became part of the new park and got restored, its the highlight of the park today.
Roadside Geology of Ohio
Mark J. Camp, Ohio Uplands - Allegheny Plateau, Page 238 - 239 (Youngstown's Natural Jewel), Mountain Press Publishing Company (2006)
John S. Petrek,(Advisor) Dr. Sidney E. White, Geological Features in Mill Creek Park Youngstown, Ohio, Partial requirements for BS Degree & geology 570, Chapter V Page 8 - 9 (Iron Ore), Chapter VI page 10 (Massillon Sandstone), Chapter VIII page 16 - 17 (Ice Age)