Delaware Water Gap National Recreation Area: Paleontological resources inventory

Miranda, Ariana; Tweet, Justin; Santucci, Vincent; Deutsch, Kara

The Delaware Water Gap National Recreation Area (DEWA) offers scenic views, cultural landscapes, abundant wildlife and recreational activities near the most densely populated region of New Jersey, New York, and Pennsylvania. The area offers a rich history of human habitation in the valley boasting several thousand archeological sites spanning nearly 12,000 years. Much of the paleontology in the park has been overlooked since the park’s inception in 1965, although it has been rigorously studied in the past, especially by the New Jersey Geological Survey and the New Jersey State Museum (Parris and Albright 1979, 1980; Parris and Cruikshank 1984). The purpose of this inventory is to document existing paleontological localities in the park, as well as to assess new fossil sites and their condition to ensure that they are preserved for future generations, public education and scientific research. All geological formations in the park date from the early to middle Paleozoic Era, ranging from 440 to 360 million years ago (Hozik 1987; Epstein 2006). Most of the formations represent marine environments with fossilized corals, trilobites and crinoids, among other ancient organisms. Throughout the Paleozoic, the Appalachian Mountains were built in a series of orogenies, two of which are represented in the park. Evidence of the Taconic and Acadian orogenies can be seen at DEWA, with the oldest rocks located in the southeast, decreasing in age to the northwest. The Late Ordovician is represented solely by the Martinsburg Formation. The Martinsburg Formation was deposited at the end of the Taconic Orogeny, about 440 Ma (million years ago) (Epstein 2006). The entirety of the Silurian is represented in the park by the Shawangunk, Bloomsburg, Poxono Island, Bossardville and Decker formations, primarily found on the New Jersey side of the recreation area. The Silurian marked an era of deposition as the newly created Taconic Mountains were weathered away, deposited into a continental basin and eventually giving way to extensive shallow seas that supported reefs (Epstein 2006). Overlying the Silurian formations are Lower Devonian rocks represented by the Rondout, Coeymans, New Scotland, Minisink, Port Ewen, Oriskany, Esopus and Schoharie formations. The Oriskany Group, made of the Shriver Chert and Ridgeley Sandstone, is a transition from the Early Devonian to the Middle Devonian. The Marcellus Shale, Mahantango and Trimmers Rock formations all were deposited during the Middle to Late Devonian, during the beginning of the Acadian Orogeny (Epstein 2001a). Along with Paleozoic formations, DEWA contains many surficial deposits of Pleistocene and Holocene material. Pleistocene fossils have been discovered in areas adjacent to DEWA, such as “Miss Matilda Mastodon” (Mammut americanum) found in Vernon, New Jersey, in 1954 (Jepsen 1960) and the Marshalls Creek Mastodon found in Marshalls Creek, Pennsylvania (Hoff 2001). Hartman’s Cave, located 8 km (5 mi) south of the park in Cherry Valley, preserved bones and teeth likely from the late Pleistocene or early Holocene (Mercer 1894). These fossil occurrences near DEWA are included in this report as well due to their proximity to the park with the possibility that similar fossils may be found in the park in the future.

Delaware Water Gap National Recreation Area: Paleontological resources inventory

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