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An echinoderm association is reported from the ?early late Albian Paddy Member of the Peace River Formation of British Columbia, Canada. The association includes Frasericrinus mauricensis gen. et sp. nov., two additional distinctive crinoid column types, a poorly preserved asteroid, and an umbilical fragment of the cephalopod Stelckiceras. This is the first report of a Cretaceous isocrinid from North America. The echinoderm fossils are from the top of a succession of storm-deposited sandstones and mudstones (Boulder Creek Formation) that can be correlated southward into nearshore and terrestrial facies of the Paddy Member of the Peace River Formation. The echinoderm fossils were buried (and probably lived) about 12-14 km from the contemporaneous shoreline in an estimated water depth of 10-20 m. Integration of biostratigraphic and allostratigraphic schemes suggests that the echinoderms are of earliest late Albian age. The association of the echinoderm fauna with ammonites of Boreal affinity indicates deposition in northern waters, although the presence of Tethyan inoceramids in apparently coeval Paddy Member strata 270 km to the east suggests that northward-advancing water from the Gulf of Mexico had reached northwestern Alberta, if not actually merged with the Boreal embayment. The nearshore occurrence of Cretaceous stalked crinoids is indicative of an asynchronous, gradual migration of stalked crinoids to deep-water habitats, to which they are restricted in modern oceans. Une association d'echinodermes est signalee du Membre de Paddy du ?debut de l'Albien tardif de la Formation de Peace River, en Colombie-Britannique (Canada). L'association comprend Frasericrinus mauricensis gen. et sp. nov., deux autres types de colonnes de crinoide distinctives, un asteride mal preserve et un fragment ombilical du cephalopode Stelckiceras. Il s'agit du premier signalement d'un isocrinide d'age cretace en Amerique du Nord. Les fossiles d'echinodermes proviennent du haut d'une sequence de gres et de mudstones deposes par des tempetes (Formation de Boulder Creek) qui peuvent etre correles vers le sud aux facies littoraux et terrestres du Membre de Paddy de la Formation de Peace River. Les fossiles d'echinodermes ont ete ensevelis (et ont probablement vecu) a environ de 12 a 14 km de la cote contemporaine dans des eaux d'une profondeur estimee de 10 a 20 m. L'integration de schemas biostratigraphiques et allostratigraphiques donne a penser que les echinodermes sont du tout debut de l'Albien tardif. L'association de la faune a echinodermes avec des ammonites d'affinite boreale indique un depot dans des eaux septentrionales, bien que la presence d'inoceramides tethysiens dans des strates apparemment contemporaines du Membre de Paddy, a 270 km a l'est, donne a penser que des eaux s'avancant vers le nord a partir du golfe du Mexique avaient atteint le nord-ouest de l'Alberta et avaient meme peut-etre rejoint l'echancrure boreale. La presence en milieu littoral de crinoides pedoncules d'age cretace indique une migration asynchrone graduelle de crinoides pedoncules vers des habitats d'eau profonde, habitats auxquels ils se limitent dans les oceans modernes. [Traduit par le Redaction], Introduction A new Albian crinoid, Frasericrinus mauricensis gen. et sp. nov., is reported herein from western Canada. Relatively little is known about Cretaceous stalked crinoids from North America, thus the [...]

During the middle Albian, a southward incursion of the Boreal Ocean flooded northern Alberta and adjacent British Columbia, forming a large embayment known as the Hulcross Sea. Marine mudstones of the Hulcross Formation and Harmon Member of the Peace River Formation record transgression, whereas sandstones of the Cadotte Member of the Peace River Formation record shoreline regression to the north. Abundant hummocky and swaley lamination in the Cadotte sandstone attest to the influence of storms on a shallow shelf. The Cadotte sandstone undergoes a lateral facies change from mud-free shoreface sandstone in the south to heterolithic offshore facies in the north. An articulated crinoid was found within a hummocky sandstone bed about 15 km seaward (north) of the shoreface-shelf facies transition. The articulated state of the crinoid indicates that it was buried very rapidly, and never exhumed. The arms through 20 mm of the column are preserved, but because the details of the aboral cup are not well preserved, this specimen must be left in open nomenclature. The elliptical columnals with a concave latus in the distal portion of the preserved column ally this specimen to the Bourgueticrinida, although with details of the aboral cup lacking and other characters atypical for Mesozoic bourgueticrinids, the Canadian specimen is placed in Bathycrinidae indeterminate. The oldest previously recorded bathycrinids were from the Upper Cretaceous (Maastrichtian), thus this report extends their range to the Lower Cretaceous (Albian). Durant l'Albien moyen, une incursion vers le sud de l'ocean Boreal a inonde le nord de l'Alberta et de la Colombie-Britannique, formant une grande echancrure appelee mer de Hulcross. Des mudstones marins de la Formation de Hulcross et du membre de Harmon de la Formation de Peace River font etat d'une transgression, alors que les gres du membre de Cadotte de la Formation de Peace River documentent une regression du littoral au nord. L'abondance de laminas bosselees et en gouttieres dans le gres de Cadotte temoigne de l'action des tempetes sur un milieu de plate-forme peu profond. Cette unite presente un changement lateral de facies, passant d'un gres d'avant-plage sans argiles au sud a un facies extracotier heterolithique au nord. Un crinoide articule a ete trouve dans un lit de gres bossele a environ 15 km au large (au nord) de la transition entre le facies d'avant-place et celui de plate-forme. La nature articulee du crinoide indique qu'il a ete enseveli tres rapidement et n' a jamais ete exhume. Bien que les bras soient preserves sur 20 mm du pedoncule, ce specimen doit etre laisse en nomenclature ouverte etant donne la pietre conservation des details du calice. Les articles elliptiques avec une plaque laterale concave dans la portion distale du pedoncule preserve allient ce specimen aux Bourgueticrinides, mais etant donne l'absence de details du calice et la presence d'autres caracteres non typiques des bourgueticrinides mesozoiques, le specimen canadien est affecte aux Bathycrinides indetermines. Les bathycrinides les plus anciens recenses anterieurement etant du Cretace superieur (Maastrichtien), la presente etude repousse les limites de leur repartition jusqu'au Cretace inferieur (Albien). [Traduit par la Redaction], Introduction Cretaceous stalked crinoids are relatively rare fossils, especially from North America. Meyer and Macurda (1977) argued that stalked crinoids became restricted to deep-water habitats by the Late Cretaceous; and [...]

Abstract: In north‐central Alberta and adjacent British Columbia, clastic strata of the middle to late Albian Peace River and Shaftesbury formations were deposited in alluvial to shallow‐marine environments across the foredeep of the Western Canada Foreland Basin. A high‐resolution, log and core‐based allostratigraphic framework for the Paddy Member of the Peace River Formation established nine allomembers, PA to PI, bounded by flooding surfaces and apparently equivalent non‐marine surfaces. Within the estimated 2 Myr. duration of the Paddy, allomembers allow the evolving palaeogeography and changing relationship between accommodation and sedimentation rates to be analysed on time‐steps on the order of 105 years. Paddy strata fill an arcuate depocentre ca 300 km wide, across which the rocks thin eastward from 125 m to ca 5 to 10 m. The northern part of the basin is occupied by muddy, offshore marine deposits that pass abruptly southward into a linear, WSW‐ENE‐trending body of sandstone deposited in a wave‐dominated barrier‐strandplain, at least 350 km long. Extending >200 km to the south of the strandplain was a region of shallow brackish to freshwater lagoons and lakes that graded to the SW into alluvial facies. Within the lagoon region, few‐m thick, elongate and patchy sandstones represent river‐dominated deltas. In allomembers PA to PG, these sandstones are concentrated in the west and south, implying supply from the western Cordillera. In allomembers PH and PI, sandstones are mainly in the east and have a distinctive, quartz‐rich composition. They can be correlated eastward into the coeval Pelican Formation, and were sourced probably from the Canadian Shield on the opposite side of the basin. In the western foredeep, alluvial rocks comprise aggradational, unconfined floodplain deposits with ribbon sandstones, dissected, on at least nine separate levels, by palaeovalleys that are confined to the proximal foredeep. Valleys are 10 to 30 m deep, few km wide, and filled with multi‐storey channel‐bars of pebbly coarse sandstone or conglomerate. Valleys cut down from well‐developed interfluve palaeosols that record a falling and then rising water table. Alternating aggradation and degradation, and advance and retreat of the alluvial gravel front is attributed to cycles of varying rainfall intensity, rather than tectonism or eustasy. Apparently, coeval transgressive‐regressive successions in the lagoon and marine regions are attributed to few‐m scale eustatic changes. On the NE margin of the basin, tidal sandstone fills a northward‐opening estuary cut on the basal Paddy unconformity. This sandstone contains the first well‐documented specimens of Gnesioceramus comancheanus (Cragin), proving contemporaneity with at least part of the marine Joli Fou Formation to the east. Paddy allomembers change shape upward from short blunt wedges, through more acutely tapered wedges, to sheets. This change reflects initially rapid flexural subsidence, attributed to active thickening of the adjacent orogenic wedge. A waning rate of deformation permitted wider dispersal of sediment across the basin, driving broad isostatic subsidence beneath increasingly sheet‐like rock bodies. A major hiatal surface, VE3, records non‐deposition or subtle erosion attributed to erosional unloading and uplift of the adjacent orogen. A subsequent marine transgression is attributed to renewed thickening of the tectonic wedge that triggered deposition of marine mudstone that thickens westward from 0 to >110 m over 300 km. A postulated Milankovitch‐band climatic control on both local gravel supply (via fluctuating rainfall), and shoreline movement (via ?Antarctic glacio‐eustasy or groundwater storage), might account for cycles of alternating incision and aggradation in the alluvial realm. The same mechanism may also explain why shallow‐marine units such as the Cretaceous Viking and Cardium formations contain abundant conglomerate in lowstand shoreface deposits (higher river discharge), yet have highstand shorelines dominated by sandstone (lower river discharge). [ABSTRACT FROM AUTHOR]