In one of our recent posts, “All Names Marcellus,” we mentioned the town of Marcellus, New York. Not far outside of the town center is a shale rock outcropping. The Marcellus Shale was actually named for the town where the visible shale rock was found during a geological survey in 1839.
Shale is a sedimentary rock that formed from years of compaction of silt and clay-size mineral particles, like mud. Unlike other types of mudstones, shale is identifiable by its “laminated” quality. Laminated categorizes rock which contains many layers of compacted sediment, shale is the onion of sedimentary rocks. Shale rock can be found in a variety of colors, red, brown, gray, black even green. The color of the rock is determined by the type of specific materials that the rock was exposed to. Red shale for example, can get its color from exposure to just a small amount of iron. Black shale rock indicates exposure to organic materials. The presence of organic matter is a sign that shale rock is a candidate for oil and gas drilling. While most the shale rock that makes up the Marcellus Shale field is buried far beneath the surface there are instances where Marcellus Shale rock is actually visible.
The Shale Outcropping
The outcropping looks like a cliff with a steep wall of exposed rock. Once the rock is exposed to the elements it turns to a darker shade of gray or black. Personally, when I first saw pictures the outcropping looked like a coal bed, of shiny black, flakey rock. Other outcrops of shale rock were mined during the early 19th century in hopes of finding coal seams. The institute for Energy and Environmental Research for Northeastern Pennsylvania produced a map that shows where outcrops have formed across the entire Susquehanna River Basin.
The following are pictures of the shale outcrop in Marcellus, NY.