Abstract

At the type section the Table Head Formation is about 1110 feet thick, resting disconformably on the Lower Ordovician St. George Formation, overlain apparently conformably by unnamed gray siltstones and green sandstones. An informal subdivision of the Table Head Formation into lower, middle, and upper parts is followed here. Lower Table Head (810 feet) limestones yielded 12 trilobite species; stratigraphical range of each is given. Middle Table Head limestones and black shales (270 feet) show contemporaneous deformation. Stratigraphical ranges of 24 trilobite species are given; only one of these is also present in the lower Table Head. The upper Table Head (30 feet) is black shale which yielded about 17 species of graptolites. In Table Cove middle Table Head rocks are exposed, and Raymond's “isolated limestone” locality is identified. Lower Table Head strata are exposed at Pointe Riche, and a sequence of limestones and shales of lower and middle Table Head age northeast of Port au Port. Conglomerates of the upper part of the Cow Head Group crop out near Portland Creek and at Daniel's Harbour. Boulders of limestone from the Table Head Formation were contributed to these conglomerates by submarine sliding.

The Table Head Formation is correlated with the Antelope Valley Limestone, Nevada, and parts of it with the Kanosh Shale and Lehman Formation of western Utah and with the Swan Peak Formation of eastern Utah. Affinities between trilobites of the Table Head and the Chazy Group, New York, are not strong. Some affinities, not necessarily indicative of age equivalence, are noted among trilobites from the Table Head and those from the Lenoir, Tumbez, and Whitesburg formations of the southern Appalachians. Both trilobites and graptolites from the higher beds of the middle part and from the upper part of the Table Head Formation correlate with those from zone D of the Lévis Shale, Quebec. The graptolites resemble those of the lower Llanvirn of Europe. The Arenig-Llanvirn boundary may thus fall within, or immediately below, the Table Head Formation.

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