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Sampling and seismic profiling in the Tofino Basin west of Vancouver Island show there is a thick sequence of Tertiary rocks ranging in age from late Eocene to Pliocene. The rocks are mainly mudstones containing abundant foraminifera indicating a bathyal depositional environment throughout most of the Tertiary. Subsequent uplift has exposed the deep water sediments on the shelf over much of the area. Eocene-Oligocene sediments occur in a belt along the inner shelf, while Miocene and Pliocene rocks lie seaward of this. Pliocene rocks form a regressive sequence overlapping the older Tertiary, with the greatest thickness in the south.At least two major periods of deformation resulted in faulting, folding, and diapirism on the continental shelf. Deformational patterns show a marked change from north to south. North of Brooks Peninsula sediments are undeformed by folding but are truncated by faulting along the steep continental slope. The Kyuquot Uplift south of Brooks Peninsula exposes Eocene-Oligocene sediments across the shelf. Farther south Mio-Pliocene sediments unconformably overlie the uplift. Folding increases southward culminating in an area of diapirism off Nootka Sound. Elongate diapirs trend parallel or subparallel to the coastline.Tectonic features on the shelf and slope appear to be related to present and earlier configurations of nearby offshore spreading centers, plates, and transform faults. Crustal plate movements may have been responsible for the observed shelf and slope deformations.

The best exposures of early Tertiary rocks on the west coast of Canada occur in the Nootka Sound area of Vancouver Island. A detailed study of these rocks was undertaken to understand the depositional and tectonic framework of readily accessible parts of the Tofino Basin. An exhaustive study of the microfaunas of the Escalante and Hesquiat formations of the Nootka Sound area led to the recognition of five foraminiferal assemblage zones within the succession. On the basis of the foraminifers, molluscs, and crustaceans, the ages assigned to the rocks range from Late Eocene to Early or Middle Oligocene. Local correlation with other west coast exposures are with rocks assigned to the Lincoln and Blakeley molluscan "stages" (Galvinian, Matlockian) and the Refugian and Zemorrian foraminiferal stages. The Escalante Formation is a diachronous basal sandstone unit of Late Eocene age whose depositional environment is interpreted to vary from lower neritic to upper bathyal water depths in the type area to exclusively bathyal water depths elsewhere. The Hesquiat Formation of Late Eocene to Early or Middle Oligocene age is represented by proximal turbidites, including partly fluxoturbidites, in the type area and distal facies elsewhere. Sediments, sedimentary structures, and fossil collections indicate deposition ·of the Hesquiat Formation occurred in bathyal water depths as a submarine fan complex. Previous estimates of the total thickness of the Hesquiat Formation in the Nootka Sound area are found to be far in excess of their true stratigraphie thickness. This is explained by a highly complex network of faults and the concomitant difficulty in recognizing lithologie equivalents due to rapid facies changes.

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Radiolaria are used to construct an informal zonation (seven zones, numbered one through seven) for Jurassic strata of late Pliensbachian to early Bajocian age from the Fannin, Whiteaves, Phantom Creek and Graham Island formations, Queen Charlotte Islands, British Columbia. The study emphasizes Toarcian Radiolaria, because hitherto little was known of their morphology and distribution; rich, well preserved assemblages of middle to late Toarcian radiolarians have now been recovered from limestones of the Whiteaves and Phantom Creek formations. Ammonites collected as part of a recently completed stratigraphic study of the Jurassic sequence provide excellent control for dating all radiolarian assemblages. Forty-two new species and five new genera of radiolarians are described herein. The sequence of co-occurring ammonites indicates that Zone 1 is late Pliensbachian (Carlottense Zone) and Zone 7 is early Bajocian (Docidoceras widebayense Assemblage Zone and an unnamed interval underlying the Parabigotites crassicostatus Assemblage Zone). Corresponding ammonite zones for radiolarian zones 2 to 6 (Toarcian to Aalenian) have not yet been worked out for North America; thus Zone 2 is early middle Toarcian, Zones 3 and 4 are late middle to early late Toarcian, Zone 5 is late T oarcian, and Zone 6 is Aalenian. Radiolaria from the Queen Charlotte Islands (part of the displaced terrane of Wrangellia) compare well with Tethyan assemblages from western North America, the Mediterranean area and Japan.