THE CLASSIC NEW YORK DEVONIAN: TOWARD A NEW STRATIGRAPHIC SYNTHESIS AND CHRONOSTRATIGRAPHIC CHART

The classic New York Devonian succession comprises a key global reference section, referred to by geological researchers worldwide. Since publication of Rickard’s (1975) NY Devonian correlation chart, various high-resolution stratigraphic analyses, employing sequence-, bio-, event-, and chemostratigraphic approaches, sometimes at bed-by-bed scale, along with geochronologic dating of airfall volcanic tephras, have led to many new understandings of the succession. This symposium is a working session, a charge to produce a new Devonian stratigraphic synthesis for New York.

The new publication will include a series of large graphic charts and accompanying text that outline the current understanding of NY Devonian stratigraphy. The overall NY Devonian rock strata succession will be plotted on two x-y charts, with geography along the x-axis. The y-axis of one will plot equal spacing for Lower, Middle and Upper Devonian strata, as used on the international Devonian Correlation Table. On the other, the y-axis will utilize a recent Devonian time scale. Intervals with high resolution stratigraphic data will be split out into separate charts, where finer detail will be visible. In addition, one or more additional charts will provide data on the timing and duration of various key geological and biological events reported from NY Devonian strata. These will include sequence stratigraphic third and fourth order cycles, changes in sediment composition/petrology, events in the Acadian orogeny as interpreted from foreland basin sediments and airfall volcanic tephras, major and minor biological extinctions and other global bioevents, ecological–evolutionary faunas, and faunal epiboles.

A number of significant gaps remain in our knowledge of NY’s Devonian record. A partial list includes: Devonian terrestrial strata; correlations between the terrestrial and marine strata; Upper Devonian “Chemung”-type facies; Famennian (upper Upper Devonian) rocks in southwestern NY; the Pragian Stage (middle Lower Devonian) in the Port Jervis region; and biostratigraphy through numerous intervals of the Devonian succession (including palynological analyses).