CONODONTS OF THE WILLIAMS ISLAND AND LONG RAPIDS FORMATIONS (UPPER DEVONIAN, FRASNIAN-FAMENNIAN) OF THE ONAKAWANA B DRILLHOLE, MOOSE RIVER BASIN, NORTHERN ONTARIO, WITH A REVISION OF LOWER FAMENNIAN SPECIES

Journal of Paleontology, Mar 2004 by Klapper, G, Uyeno, T T, Armstrong, D K, Telford, P G

ABSTRACT-The upper part of cores of the Onakawana B Drillhole in the Moose River Basin in northern Ontario includes the upper part of the upper member of the Williams Island Formation (22.5 m, 16 samples), and the entire overlying Long Rapids Formation (75.1 m, 49 samples). The sequence of conodonts from the drillhole was analyzed by graphic correlation as well as conventional zonation.

The upper carbonate member of the Williams Island Formation correlates with lower Frasnian zones 2 to 5. Below this, mixed Frasnian and Fainennian conodont faunas occur partly in a brecciated interval within the member and represent stratigraphic leak below the Frasnian. The lower member of the Long Rapids Formation correlates in its lowest part with Zone 5, followed by a hiatus of zones 6 to 8. This is succeeded by zones 9 and 10. Zone 11 is missing, followed by an interval that correlates with upper Frasnian zones 12 and 13 to within the lower Famennian Middle triangularis Zone. The Frasnian-Famennian boundary occurs within a narrow interval in the lower member. The Upper triangularis Zone and perhaps part of the Middle triangularis Zone are missing.

The middle member of the Long Rapids Formation correlates with the Lower to Uppermost crepida zones. A sequence from high in the rhomboidea Zone to within the Lower marginifera to perhaps slightly into the Upper niarginifera Zone occurs in the tipper member of the formation.

Sixteen species are described, of which seven are new: Palmalolepis angularis, P. angusta, P. mystica, P. nodosa, P. parva, PaImatolepis n. sp. A, and Mehlina? imica. Two species that affect definition and identification of the Frasnian-Famennian boundary, P. triangularis and P. ultima ( = P. praetriangularis), are revised.

INTRODUCTION

LOCATION AND brief history of the Onakawana B Drillhole.-The conodonts described in this report are from cores of the Ontario Geological Survey Onakawana B Drillhole (OGS 85D), in the eastern part of the Moose River Basin, northern Ontario. The drillhole is located at latitude 50�34'24'' N and longitude 81�29' 10'' W, approximately 5 km west of the Onakawana railway siding, on the Ontario Northland Railway. The siding is situated 1 18 km north of Cochrane and 91 km south of Moosonee (Fig. 1; Bezys, 1989).

The Onakawana B Drillhole was completed in March 1985. It lies at approximately the same site as the Onakawana A Drillhole, drilled by the Ontario Department of Mines in 1930. The reasons for the new drilling were succinctly summarized by Bezys (1989), so suffice it to say that, over the years, the original set of the important and much-used cores was either lost or destroyed.

The first preliminary lithological log of the drillhole was published in Sanderson and Telford (1985). The detailed log made by J. W. Sanderson in 1985 was later published in Bezys (1989, p. 44-56). Subsequently to Sanderson's log, the interval of the Long Rapids Formation was further examined by Bezys (1987, p. 178-191). The drillhole traversed the Cretaceous Mattagami Formation, Devonian Long Rapids, Williams Island, Murray Island, and Moose River formations, and bottomed out in the Precambrian. The studied interval represents the upper carbonate member of the Williams Island Formation, and the Long Rapids Formation. Sanford and Grant (1998, fig. 4) showed the positioning of the Onakawana B Drillhole in their cross section through the Hudson Bay Lowlands.

Previous conodont research.-Insofar as is known, the earliest reporting of Devonian conodonts from the Moose River Basin was by E. M. Kindle (in Dyer, 1931, p. 90). he reported PoIygnathellus cf. curvatus Ulrich and Bassler, 1926, from an unspecified level within the Long Rapids Formation in the Onakawana A well. The collection was subsequently recxamincd by A. E. Wilson (1953, p. 75, 77) and listed as Polvgnailiellus sp. (listed under Vermes) from the interval of 836 to 873 ft (254.8 to 266.1 m) in that well.

Devonian conodonts from the Moose River Basin resulting from a large-scale GSC (Geological Survey of Canada) mapping project (Operation Winisk) in 1967, were listed by Uyeno (in Sanford and Morris, 1975). Listings included conodonts from the Stooping River, Kwataboahegan, Murray Island, Williams Island, and Long Rapids formations.

The lower parts of the type section of the Long Rapids Formation were sampled by P. G. Tel ford and R. K. A. Bezys in 1984. Based on that collection, Uyeno and Tel lord (in Morris et al., 1992) made a more extensive taxonomic and biostratigraphic study of conodonts from the uppermost Williams Island and lower Long Rapids formations (Frasnian, zones 2 to 12). Locality Ab6 (GSC locality 100799) at 8.2 m above the base of the formation, yielded Manticoceras cf. sinuosum (Hall) of Miller ( 1938). There, it is associated with conodonts assigned to zones 10 to II. Becker and House (2000, p. 125, 128) questionably assigned this locality to the Probeloceras lutheri Zone, which was equated with upper Zone 5 and lower Zone 6.

Uyeno and Bullynck (1993) made a similar study of conodonts from the Jaab Lake well, located near the dcpocentcr of the Moose River Basin. The well encompassed, in ascending order, the Stooping River, Kwataboahegan, Moose River, Murray Island, and Williams Island formations (late Emsian to possibly earliest Givetian). The faunas were found to be dominated by icriodontans, most of which are endemic to North America. In the absence of polygnathids, reference to standard conodonl zonation was made only indirectly.