Unit 9 Assignment 1
Geology of the Area

Mill Creek Park, located in southern Mahoning County Ohio, is as area of approximately
4,400 acres. It was founded in 1891 by a local attorney. Some parks are founded based on natural features such as the Grand Canyon. Mill Creek Park was founded by purchasing large tracts of private lands. The natural features of the park consist of streams, deep ravines, valleys, and plains. The lakes at the park are man-made. Certain areas of the park reveal geological formations of the Mississippian and
Pennsylvanian divisions of the Carboniferous era of geological time frame. These eras were
From 350 million to 300 million years ago. Originally, the area was at the bottom of an ancient ocean. Over millions of years the land surface changed and plant life formed in higher areas. As the sea flooded into low areas, swamps and bogs were formed.
Eventually, trees and plants fell into the water and decayed. The decaying matter was buried by sand and clay. The pressure caused by the weight of the decaying matter formed fossils and coal. The main type of rock found in Mill Creek Park is sedimentary. Sandstone cliffs are visible throughout the park as well as shale. The sandstone shows signs of weathering as yellow and reddish brown streaks are visible. Fossils of plant life can found near Lanterman
Bridge. Coal and iron ore are also present in the park. The effects of the Ice Age can be seen at the area of present day Lanterman’s Gorge.
The glaciers could not cut into the solid rock easily. Through the passage of time, the softer material was washed away causing rapids then a waterfall. It is also believed that the Mahoning
River originally flowed north towards present day Lake Erie. After the glaciers came through they caused a reversal in the way water drained.

References
John S. Pertek.