Unit Name: Maclean Strait Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: Early Jurassic (199.6 - 175.6 ma)
Age Justification: Biostratigraphy: "In the King Christian - Ellef Ringnes area the lower two intervals of the formation are dated as Hettangian on the basis of their stratigraphic equivalence with the Grosvenor Island formation. The upper interval is dated as Sinemurinan on the basis of its intertonguing relationship with the Lougheed Island Formation, which contains Sinemurian palynomorphs and ammonites. In the Lougheed Island area the formation is considered to be almost entirely Hettangian on the basis of stratigraphic relationships." (Embry, 1983a)
Province/Territory: Arctic Offshore; Northwest Territories; Nunavut
Originator: Embry, 1983a
Type Locality:
The type locality is in the Sun Skybattle Bay C-15 well, where the formation is 38 m thick.
Distribution:
"The Maclean Strait Formation thins westward from a maximum of 370 m on western Ellef Ringnes Island to a shale-out edge west of Lougheed Island. Eastwards it merges with the Fosheim Member of the Heiberg Formation. A narrow band of Maclean Strait Formation may occur along the southwestern to northwestern basin margins." (Embry, 1983a)
Locality Data:
WELL 300C157720105000; SKYBATTLE BAY C-15. Interval(m): From 2043, To 2081.
Lithology:
"In the King Christian-Ellef Ringnes area the Maclean Strait Formation consists of three lithologic intervals: a lower interval of interbedded, very fine- to fine-grained sandstone, siltstone and shale with the lithologies arranged in coarsening upward cycles; a middle interval of massive, fine- to coarse-grained sandstone with rare interbeds of carbonaceous siltstone and shale; and an upper interval of interbedded, fine-to coarse-grained sandstone, siltstone and shale also arranged in coarsening-upward cycles. The sandstones are quartzose, with varying amounts of quartz, calcite and clay cement." (Embry, 1983a)
Relationship:
The Maclean Strait Formation gradationally overlies the Grosvenor Island Formation and is overlain by the Lougheed Island Formation. This upper contact is generally conformable, though it becomes unconformable along basin margins where the Lougheed Island oversteps the Maclean Strait.
History:
Within the western Sverdrup Basin, Embry (1983a) noted that the Heiberg Formation was divisible into five definable units which he formally described, elevating the Heiberg Formation to group status in the western portion of the basin. The five units include the Skybattle, Grosvenor Island, Maclean Strait, Lougheed Island and King Christian formations. The Maclean Strait Formation is named after Maclean Strait, which separates Lougheed Island from King Christian and Ellef Ringnes Island.
References:
Embry, A.F. 1983a. The Heiberg Group, western Sverdrup Basin, Arctic Islands; Geological Survey of Canada, Paper 83-1B, pp. 381-389.
Source: GEOLOGICAL SURVEY OF CANADA, CALGARY
Contributor: G.E. McCune
Entry Reviewed: No
Name Set: Lithostratigraphic Lexicon
LastChange: 14 Dec 2009