Archive for March 19th, 2018

A geological and archaeological hike in northeastern Ohio on the last day of winter

March 19th, 2018

It was a beautiful latest-winter day in Wooster. Nick Wiesenberg had the great idea of taking an afternoon to hike through Pee Wee Hollow, a wooded area of ravines, streams and rocky exposures a few miles northwest of Wooster near the village of Congress. Greg Wiles, his faithful dog Arrow, and I went along. We had an excellent time with no agenda but to explore. Above is Dr. Wiles standing at an outcrop of Lower Carboniferous sandstones, shales and conglomerates making up the Logan Formation. The rocks are similar to those exposed in Spangler Park.

Pee Wee Hollow has three small Native American mounds on an upper plateau. Nick and Arrow are standing on one above. They were excavated in the 1950s, and possibly pillaged long before that. Dr. Nick Kardulias, Dr. Wiles and several others wrote a paper on these mounds. I can quote the abstract entirely: “While a great deal is known about the many earthworks of central and southern Ohio, there is a gap in our data about such features in the northern part of the state. The present report is an effort to bring work on one such site in Wayne County into the literature. The Pee Wee Hollow Mound group consists of three small circular earthen structures and a possible fortification trench on a high bluff overlooking the main stream that drains the county. Systematic excavation by avocational archaeologists in the 1950s revealed the structure of the mounds and retrieved a small assemblage of artifacts, some charcoal, and pockets of red ochre. Recent analysis of the artifacts, coupled with radiocarbon dating, indicates that the site was a location of some local importance from the Late Archaic through the Middle to Late Woodland periods.” (Pennsylvania Archaeologist 84(1):62-75; 2014)

Another of the mounds with Greg and Arrow for scale.
The very fine sandstones of the Logan Formation are especially well exposed in the creek beds. Here are a set of joints our structural geologist Dr. Shelley Judge would appreciate.

There are even some nice Bigfoot field structures. Who knew?We spent most of our time walking up Shade Creek. The creek bed is mostly Logan Formation sandstones.

Greg is standing here on a bedding planes of sandstone with nice ancient ripple marks. Note, by the way, the chunk of ice above his head. Still winter, but not for long.

Here’s a closer view of those ripples.Arrow here contemplates a thick exposure of dark gray shale. Greg found some nice crinoid columns in it, and I found several molds of bivalves.

The more resistant units in the Logan have the best fossils. This slab of very fine sandstone cemented with iron carbonates (a type of siderite concretion) has several internal molds of brachiopods and white calcitic crinoid columns. I described the remarkable preservation of similar crinoids in an earlier series of blog posts.

A nice, uncomplicated walk in a beautiful bit of nature.