Placement of the Wenlockian/Ludlovian boundary in western New York State
Geography and Geology
Despite many years of detailed examination focused on the Silurian strata of New York State, the position of the Wenlockian/Ludlovian boundary has, to date, not been satisfactorily established. Recent discovery of early Ludlovian graptoloid graptolites, however, provides the first conclusive biostratigraphic evidence for placement of this chronostratigraphic boundary within the New York sections. The early Ludlovian genera Saetograptus and Spinograptus were recovered from a thin, but laterally persistent bed of argillaceous dolostone located near the base of the Goat Island Formation. This occurrence indicates that the Wenlockian/Ludlovian boundary is at or near the contract between the Goat Island Formation and the underlying Gasport Formation, considerably lower than had previously been suspected.
Link to Published Version
LoDuca, S. T., & Breit, C. E. (1991). Placement of the Wenlockian/Ludlovian boundary in western New York State. Lethaia, 24(3), 255–264. doi:10.1111/j.1502-3931.1991.tb01476.x