The Devonian terrestrial system of New York
Authors: Ver Straeten Charles 
Published: July 2024

Late 18th to early 19th century reports on the rocks of the Catskill Mountains in eastern New York were followed by over 180 years of geological and paleobiological studies of the Devonian terrestrial succession, in the state and up and down eastern North America. Yet, nearly 230 years later these estimated ca. 2.4 km- (1.5 mi-) thick, homogenous strata remain a largely unknown frontier in many ways. Studies of Devonian terrestrial strata in New York over the last century include two different stratigraphic frameworks. The first, by George Chadwick (1930s–1940s), focused on the Catskill Front to the vicinity of Slide Mountain, highest peak in the Catskills. The second, by Fletcher and Rickard in the 1960s to mid-1970s, attempted to create a broader, more geographically inclusive chronostratigraphic nomenclature throughout the entire Catskills outcrop belt. Recent work indicates that in the field this latter model, based on thick lithosomes of red and gray rocks and conglomerates, is problematic. It can be seen as representing a “second draft” stratigraphic framework, in need of additional work and refinement. At this time, however, too little is known as to how to better ground the existing stratigraphy, or to propose a sound alternate stratigraphic framework for the Catskills succession. Other major foci in the Devonian terrestrial of New York include paleobotany (1950s–today), petrography (1960s–1980s), fluvial systems (1970s–1990s), and terrestrial arthropods (1980s–2000s). Broader paleobiological studies, in part associated with the Red Hill site in northern Pennsylvania, burgeoned in the 1990s and continue today. Recent Catskills terrestrial research of impact is perhaps largely paleobiological and includes the first complete Eospermatopteris (“Gilboa”) tree, mapping of well- preserved forest floors, and increasing research on paleosols. Difficulties in research of Devonian terrestrial strata in New York include: the lateral discontinuity of terrestrial facies and the lack of documented, distinctive marker beds for correlation; little biostratigraphic and geochronologic control; extensive cover in sometimes rugged terrain; too few researchers, and a need for greater cross-disciplinary perspectives and communication. The purpose of recent and ongoing research by the author is multifold. First to systematically gather various data, such as event deposits, petrography, detrital zircon dating, and palynological biostratigraphy, top to bottom through the succession, initially in the classic Catskill Front to the vicinity of Slide Mountain, in the New York State Department of Conservation “Slide Mountain Wilderness” of the Catskill Park. Second within that succession, to better document depositional history, provenance, and biostratigraphy, and to know the succession more closely. Through this, the larger goal is to test the existing stratigraphic framework and try to ground that stratigraphy in the regional rock record better, or to develop a new stratigraphic framework. Key issues that remain largely unresolved in Devonian terrestrial strata of New York include: lack of a well-tested, viable, and correlatable stratigraphic framework; a general lack of chronostratigraphic data from palynological/microvertebrate biostratigraphy and radiometric ages from altered air fall volcanic tephra beds; and no systematic documentation of the vertical Catskill succession. Other future studies could include lateral, interstate/province comparisons of variations in provenance/drainage evolution along the Acadian (Acadian-Neoacadian) Foreland Basin and its subbasin known as the Appalachian Basin, via petrography, detrital mineral dating and other methods.