The stratigraphic significance of trace fossils from the Lower Paleozoic Baskahegan Lake Formation near Woodstock, west-central New Brunswick

Abstract

The first indication o f organic activity in Lower Paleozoic siliciclastic turbidites of the Miramichi Terrane has been found in a small quarry at Grafton Hill, near Woodstock, west-central New Brunswick. These previously unnamed turbidites are assigned to the Baskahegan Lake Formation defined in adjacent Maine. The Grafton Hill site has yielded the ichnotaxa Circulichnis montanus, Gordia? marina, Helminthopsis hierogiyphica, Planolites annularius and Planolites montanus. The presence of Circulichnus montanus supports previous circumstantial evidence that a considerable part of the Baskahegan Lake Formation is Early Ordovician in age and substantiates correlation with other quartz-rich peri-Gondwanan sequences elsewhere in the Appalachian-Caledonide Orogen.La premiere indication d'une activity organique dans les turbidites silicoclastiques du Paldozoi'que inferieur du terrane de Miramichi a dtd observee dans une petite carriere de Grafton Hill, pres de Woodstock, dans la region du centre ouest du Nouveau Brunswick. Ces turbidites non identifies prdcedemment sont attributes h la formation de Baskahegan Lake, circonscrite dans la rtgion limitrophe du Maine. Le site de Grafton Hill contenait des traces fossilisees des esptces Circulichnis montanus, Gordia? marina, Helminthopsis hierogiyphica, Planolites annularius et Planolites montanus. La presence de l'espece Circulichnus montanus corrobore des observations circonstancielles anterieures voulant qu'une partie considerable de la formation de Baskahegan Lake appartienne a l'Ordovicien inferieur et confirme la correlation existant avec d'autres sequences lithologiques fortement quartziques en bordure de la Gondwanie ailleurs dans l'orogenese appalachienne et caltdonienne.

Stratigraphy and geochemistry of Ordovician volcanic rocks of the Eel River area, west-central New Brunswick

“…On the basis of this tentative correlation and the presence of the trace fossil Oldhamia in the red shale of the Grand Pitch Formation (Neuman 1984), the Baskahegan Lake Formation is likely partly Early to Middle Cambrian in age. However, the recent discovery of the trace fossil Circulichnus montanus in the Baskahegan Lake Formation south of Woodstock suggests that the upper part of the section is as young as Ordovician (Pickerill and Fyffe 1999).…”

“…The continuation of this belt of rocks into adjacent Maine is referred to as the Baskahegan Lake Formation (Ludman 1991;Ludman et al 1993) and this terminology has been adopted in New Brunswick by Pickerill and Fyffe (1999). The base of the Baskahegan Lake Formation is not exposed either in New Brunswick or Maine.…”

A cautionary note on the use of invertebrate trace fossils for correlation in the Triassic-Jurassic Fundy Group

“…For example, first-appearance data are key elements of Ediacaran-Cambrian trace-fossil biozones (Crimes 1987;MacNaughton and Narbonne 1999). Even long-ranging ichnotaxa or low-diversity ichnofaunas can provide this kind of age control in an appropriate situation (e.g., Pickerill and Fyffe 1999). However, the probable Triassic age of the Lepreau and Honeycomb Point formations is well within the age ranges of the ichnotaxa that are common to both successions.…”

Insights into the Acadian orogeny, New England Appalachians: a provenance study of the Carrabassett and Kittery formations, Maine

“…Erosion and transportation yielded sediments with westward paleocurrent directions Hanson 1989, 2002) and geochemical signatures and a detrital zircon suite consistent with a Ganderian passive margin source. Potential specific Ganderian source regions include the Miramichi, a known Ganderian highland at that time (Pickerill and Fyffe 1999), and the Liberty-Orrington and St. Croix sequences (van Staal et al 1996;Tucker et al 2001;Reusch et al 2006).…”