Abstract

The Savik Formation comprises marine shale and siltstone deposited in the axial part of the Sverdrup Basin. The thickest (1785 feet, 544 metres) exposed section of the unit is located at Vantage Point on western Axel Heiberg Island. There the Savik ranges in age from Toarcian to Kimmeridgian or younger.

Study of closely spaced samples through the Vantage Point section of the Savik established the ranges of several key microplankton entities which facilitate correlation within the Sverdrup Basin. Most important among these entities are the following: (1) Nannoceratopsis gracilis, which is abundant through the Toarcian and Bajocian; (2) two previously undescribed species of Pareodinia which characterize the Bathonian; (3) a previously undescribed monotypic genus which characterizes the Lower Callovian; (4) Nannoceratopsis pellucida which, in the Sverdrup Basin, is confined to the Upper Bathonian and Callovian; (5) two previously undescribed species of Acanthaulax which, in combination with Gonyaulacysta jurassica var. longicornis and Wanaea fimbriata, characterize the Lower Oxfordian; (6) G. Jurassica var. longicornis which is assumed to characterize the Oxfordian; (7) G. jurassica and Pareodinia ceratophora which were the only dinoflagellates recovered from the post-Oxfordian Savik.

Reworked microplankton and correlations with sections on Bjarnason Island and Ellesmere Island indicate that Middle Jurassic regression in the eastern part of the basin reached a maximum in the early Bathonian whereas maximum regression did not occur in the western part of the basin until the Callovian.