The New Market Library has announced its program, "An Unseen World Beneath Our Feet--Caves, Sinkholes, and Springs," recently was presented by Randall Orndorff, director, Eastern Geology and Paleoclimate Science Center, U.S. Geological Survey, Reston. Randall has been with the USGS since 1981; he received undergraduate and graduate degrees in Geology from Old Dominion University; specializes in Appalachian and Ozarks geology, geologic mapping, and cave and sinkholes studies; has published 80 papers and geologic maps.
Participants learned that about 20 percent of the United States is underlain by rock types that can dissolve to form caves, sinkholes and other features. Nearly every state has rock layers of limestone, gypsum, salt, and other soluble rocks we call "karst." Almost half of the groundwater used for drinking comes from karst aquifers, and karst regions such as the Shenandoah Valley are some of the most productive agricultural lands in the nation. However, the rock layers underneath karst dissolve easily, sometimes creating sinkholes that can be a threat to life and property.
A follow up program on geology of the Shenandoah Valley will be presented by Orndorff next year.
Adult programs continue monthly at the library; the program for August will be held on Aug. 17 at 3 p.m. at the library and will feature Charles Welsh of Stuarts Draft with "Treasures from the Attic," a World War II Memoir of his parents, a sailor and journalist, which was compiled from letters found in the attic which he edited into a book. All programs are free of charge and no advanced registration is needed.