In December 2007, Dr. William Dunne, professor of earth and planetary science and associate dean of the College of Arts and Sciences, took a small sample of the Rock and analyzed it.
His findings and observations were the following: The Rock has a layered nature consistent with being a sedimentary rock—these rocks are formed by the deposition of sediments, which are little grains of weathered/eroded rock that come to rest on beaches, in deltas, in lake bottoms, on the ocean floor, on floodplains of rivers, or even swamps. The Rock has layering that is currently oriented in a near vertical manner, consistent with the moving of the Rock from its nearby original spot to its present one.
The sample from the Rock has a crystalline/cemented appearance and is hard. It is medium gray in color. Using a hand lens with a 10X magnification, visible grains are not revealed, so the size of the grains in the specimen are quite small, perhaps 1/100s of an inch. Testing the Rock to see if it has a calcite composition, the Rock does not fizz when a 10 percent hydrochloric acid is applied, which means it is not calcite. If the Rock is scratched with a tempered chisel, two things happen: (1) the Rock scratches, so it is not rich in quartz; (2) the Rock powder fizzes when a 10 percent hydrochloric acid is applied, which is the common test for determining the composition of a rock composed of dolomite.
Given that much of the topography in and adjacent to campus is underlain by a Knox group of rocks that is dominated by dolomite, this identification is consistent with the local rock groups. Dolomite is sedimentary carbonate rock and a mineral, both composed of calcium magnesium carbonate. In the case of the Knox group, the dolomite was deposited about five hundred million years ago in a coastal/tidal/shelf environment near the equator on the margin of a continent called Laurentia. Laurentia would ultimately collide over the next 250 million years with a series of island arcs and continents to form the Appalachian Mountains (they were once taller than they now are) as part of the supercontinent that we call Pangaea. This collision would uplift the dolomite onto land and place it inland from the present shore of North America. The dolomite would retain its inland position on the “backside” of the Appalachians when Pangaea was split by the formation of the Atlantic Ocean about one hundred million years ago.
The Rock is Knox Dolomite and is around five hundred million years old.