Stratigraphic correlation of fine-grained successions is not always straightforward. Complicating factors, such as unconformities, structural complexity, subsidence and especially minimal grain-size variation, make the application of traditional correlation methods to fine-grained successions problematic. Alternatively, the analysis of detailed geochemical data can allow for the determination of variations in sediment provenance, mineralogy, detrital flux and hydrothermal input. When compared with modelled clay input over time, these geochemical indicators can be used to determine changes in relative sea-level and palaeoclimate, allowing for the identification of clinoform surfaces. As an example, this study outlines detailed correlations of chemostratigraphic packages within the lower Triassic Montney Formation in Western Canada to demonstrate the effectiveness of chemostratigraphy in defining and correlating fine-grained clinoforms across a sedimentary basin. The data set used includes five wells and one outcrop succession, from which geochemical profiles were generated and tied directly to mineralogical data and well logs. These analyses reveal 13 distinct chemostratigraphic packages that correlate across the basin. Observed elemental and inferred mineralogical changes highlight trends in relative sea-level and palaeoclimate, as well as episodes of inferred hydrothermal input to the Montney basin. Cross-plots of La/Sm and Yb/Sm further suggest hydrothermal input as well as the scavenging of middle rare earth elements by phosphatic fish debris. Additionally, plots of La/Sm versus Yb/Sm, which show volcanic arc input within the Doig Formation, suggest an additional sediment source from the west during the Anisian. Pairing detrital and clay proxies demonstrates changes in relative sea-level and, at the Smithian/Spathian boundary, the lowest relative sea-level in the Montney Formation is observed, corresponding to a change in climate.

The examination of 730 borings within 88 brachiopod hosts form the Middle Devonian of central New York State revealed four ichnospecies belonging to three ichnogenera that have taxonomic histories riddled with confusion, controversy and contradiction. New observations of the ichnotaxa question long-held views of a simple morphologic differentiation between sponge borings and worm borings. Clionoides Fenton and Fenton, 1932 is here considered a sponge boring, which is comprised of a complex, multi-dimensional system of tunnels, shafts, canals, microterraced bowl-shaped structures and cone extensions, and is a senior synonym of Paleosabella (McCoy 1855) and Vermiforichnus Cameron, 1969a. Clionolithes Clarke, 1908 is a sponge boring possessing a rosette, branching network extending from a central node and is a senior synonym of Nododendrina Vogel et al., 1987 and Ramodendrina Vogel et al., 1987. The creation of Canaliparva circularis n. ichnogen. n. ichnosp. is needed to accommodate simple, vertically oriented, U-shaped tunnels that are indicative of worm activity. Paleoecologic evidence supports a commensal relationship between the endoliths and hosts based upon boring site frequencies in the hosts, boring patterns and five inter-specific co-occurrences between traces. These new data suggest greater diversity and ecologic complexity in ichnofaunal paleocommunities from the Middle Devonian than previously recognized.

The Middle Triassic Sunset Prairie Formation has been recently identified between the Lower Triassic Montney Formation and the Middle Triassic Doig Formation in the Western Canada Sedimentary Basin. Due to its recent recognition, the Sunset Prairie Formation has yet to be incorporated into sequence stratigraphic frameworks of the Triassic. Through the investigation of 25 cored wells, facies characteristics, vertical facies stacking and lateral facies distributions have been identified and described. Sequence stratigraphic surfaces were identified in core and extrapolated to geophysical wireline log signatures of 248 wells within the basin. The Sunset Prairie Formation can be divided into three, upward-coarsening parasequences that exhibit a retrogradational stacking pattern. All parasequences of the Sunset Prairie Formation are truncated at their tops by the Doig phosphate zone. The Sunset Prairie Formation truncates the underlying Montney Formation, suggesting that the stratigraphic interval is unconformity bound by sequence boundaries and their correlative conformities. The addition of the Sunset Prairie Formation reveals a discrete sequence of transgressive deposits previously unaccounted for within the Triassic sequence stratigraphic framework of the Western Canada Sedimentary Basin. K E Y W O R D S Doig phosphate zone, ichnology, Montney Formation, sedimentology, stratigraphy, Sunset Prairie Formation, Triassic 384 | FURLONG et aL.

Late Triassic (Carnian–Norian) echinoids from the Aksala Formation in the Lake Laberge area of the Whitehorse Trough, Yukon Territory, Canada, are described. These echinoids comprise the first description of Triassic echinoids from Canada and, with the exception of fragmentary material from Utah, are the only Upper Triassic echinoids on the western coast of Pangaea north of Peru. Triassicidaris peruviensis Smith is identified from a coronal fragment that consists of an ambulacral column and five attached interambulacral plates from a Carnian outcrop succession. Parvicidaris sp., also from Carnian strata, is identified based on a coronal fragment that consists of two ambulacral and three interambulacral columns. This occurrence extends the range of this typically Norian taxon both north to the Yukon and earlier into the Carnian. Additional specimens, identified as Triassicidaris sp., occur within Norian strata of the Aksala taxa, one of which (‘Cidaris’ labergensis sp. nov.) is new. Both the corona‐based taxa and the spine form taxa show mixed affinities with Tethyan and southern New World populations and reinforce the association between Triassic echinoid faunas and reefal settings.