GSA Annual Meeting, November 5-8, 2001

Paper No. 0
Presentation Time: 1:30 PM-5:30 PM

APPLICATION OF CLIMATOSTRATIGRAPHY TO THE FUNDY RIFT BASIN, CANADIAN MARITIMES


FISHER, Linda and TANNER, Lawrence H., Geography and Geosciences, Bloomsburg Univ, Bloomsburg, PA 17815, lfisher@bloomu.edu

Strata deposited in the Fundy rift basin record changes in climate during Permian to Lower Jurassic time. This record can be used to correlate geographically isolated outcrop sections whose age is poorly constrained by other means. A semi-arid to arid climate during Middle Permian to Middle Triassic (Anisian or older) time is recorded by interbedded fluvial and eolian sandstones of the Honeycomb Point Formation in the Chignecto subbasin of the Fundy basin and the 'Lower Wolfville' in the Minas subbasin. Moister conditions prevailed by the beginning of the Late Triassic (Early to Middle Carnian) during deposition of fluvial strata of the Quaco and Echo Cove Formations and the main body of the Wolfville Formation in the Chignecto and Minas subbasins, respectively. The return of more arid conditions during the remainder of the Late Triassic and Early Jurassic (Late Carnian to Hettangian) is recorded by interbedded eolian and fluvial sandstones and dry to saline mudflat mudstones and sandstones of the uppermost Wolfville and overlying Blomidon and McCoy Brook Formations in the Minas subbasin.

Unpublished outcrop sections that lack identifiable faunal remains or ichnotaxa occur in the Chignecto subbasin at Martin Head and Waterside. The 120+ m outcrop section at Martin Head consists of fining-upward sequences of cross-bedded fluvial sandstones and lacustrine mudstones, contains coalified wood, and lacks definitive eolian strata. The 100+ m section at Waterside comprises almost entirely cross-bedded fluvial sandstones and minor conglomerates. Deposition of these strata likely took place during a subhumid to humid interval and are therefore correlated to the start of the Late Triassic (Early to Middle Carnian).