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display a high angle of climb with both SlOSS and lee sides pre'.' :ed. Ripples in general
h,lVe a variable wavelength ranging from 3 to 10 em and amplitudes of 1 to 3 em. Some
or the thick-bl:ddedsandsfonesare cross-stratified either at their bases ot:lboveagraded
interval at the base of lhe b«'s.
The cross-beds are planar or tangential in sets
approximately 30 em thick, and occur in very coarse sandstone (0 granule conglomerate.
UnimodalJy aligned graptolites are abundant in Facies 4 at a few localilie5.
notably Black Cove (Schilleterf, I!f80). Graptolites are less common al other localities
and orientation is va.:iable, but Tuke (1966) measured orientations of graptolites in
sandstone in the Pistolet Bay area and cOlICluded that they show an overall preferred
orientation parallel to tile regional paleocurrent direction (northeast-southwest).
The presence of classical Bouma (1962) sequences clearly places both subfacies
in classes C2.1 and C2.2 (very lhick/thick-bedded sand-mud couplets and medium-bedded
sand-mud couplets) of the c1assificalion of Pickering et al. (1986). Deposition by high
concentration IlIrbidilY currents is indicaled. The facies classification of Pickering el al.
([986/ does nm directly deal with amalgamation of beds. but il is implied by lhose
authors that the lhicklle5s of sediment deposited by each depositional event is lhe
fundamental unit. Thus. some beds of AT4 may also represent facies class C2.3 (thinbedded
sand-mud couplets) whose mud divisions have been truncated or eroded. C2.3
beds were deposiled from more dilule lurbidily currents. Subfacies a) above is therefore
dominaTed by C2.2 and C2.3 (relatively dilule), and subfacies b) is dominafed by C2.1
and C2.2 (relaTively higher concentration). The high rate of net deposition indicated by
the high angle of climb of the climbing ripples is considered typical of deposition by