Conodont biostratigraphy of the Java Formation (Upper Devonian) and the Frasnian-Famennian boundary in western New York State

Abstract

Conodonts from black shale beds and carbonate intervals in the JavaFormation (Pipe Creek Shale, Hanover Shale, and Wiscoy Sandstone) of the West Falls Group enable recognition of global event horizons: Lower Kellwasser interval, Upper Kellwasser interval, and the Frasnian-Famennian boundary. Palmatolepis winchelli, P. aff. P. hassi, and Polygnathus samueli indicate the Pipe Creek Member is in MN Zone 12 and equivalent to the lower Kellwasser interval in Europe. The lower and middle Hanover Shale contain conodonts indicative of MN Zone 13; the uppermost Hanover contains Famennian conodonts of the Lower and Middle triangularis zones. The Frasnian-Famennian boundary is resolved across western New York in the upper Hanover Shale Member to a discrete horizon within a black shale bed, marked by a cryptic disconformity. This black shale bed is equivalent to the upper Kellwasser interval. The occurrence of Palmatolepis triangularis, P. clarki, P. delicatula delicatula, and P. subperlobata in the basal Dunkirk Shale of the Canadaway Group indicates assignment to the Middle triangularis Zone or younger. Ancyrodella buckeyensis and Palmatolepis subperlobata are viable taxa; Ancyrognathus sp. A is a new species.

Revised correlation of the Frasnian–Famennian boundary and Kellwasser Events (Upper Devonian) in shallow marine paleoenvironments of New York State

“…We tentatively place the F-F boundary and UK equivalent in the shalier interval between the two sandy pulses of the Canaseraga (Fig. 8), consistent with the disappearance of atrypids from the lower to upper sands and the placement of the boundary below the Hanover-Dunkirk contact in the western sections studied by Over (1997Over ( , 2002.…”

“…However, the conodont Palmatolepis winchelli (Fig. 7A), a wide-ranging upper Frasnian taxon known from the Pipe Creek and upper Hanover further to the west (Over, 1997), occurs in the dark shale above the Wiscoy (Fig. 4A).…”

“…International biostratigraphic correlation in the Upper Devonian is based primarily on conodonts (e.g., Ziegler, 1962;Klapper, 1989Klapper, , 1997Ziegler and Sandberg, 1990;Klapper et al, 1994;Over, 1997Over, , 2002, and several were located via visual inspection of rock samples.…”

Sequence stratigraphic hierarchy of the Upper Devonian Foreknobs Formation, central Appalachian Basin, USA: Evidence for transitional greenhouse to icehouse conditions

“…Fourth-order sequences (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12) recognized between the Elkins, WV, and Briery Gap, WV, sections from this study. F/F (=Frasnian-Famennian boundary) noted on Filer's (1994) Noble, Co., electric log from conodont biostratigraphy by Over (1997Over ( , 2002. F/F noted on Briery Gap section (Pound Sandstone Member) from brachiopod biostratigraphy by McGhee (1977).…”

“…The Foreknobs Formation approximately spans the middle part of Conodont Zone 11 through the middle part of the triangularis Zone of the Montagne Noire standard, based on correlation with the upper Rhinestreet through lower Dunkirk interval (Over, 1997). By comparison of these conodont zones with detailed Devonian chronostratigraphy established by Kaufmann (2006), the Foreknobs Formation is inferred to have been deposited during a time span of approximately 4.5 Myr, thus permitting reliable estimates of the temporal duration of the cyclicity.…”