Russell L. Hall

Late Bajocian and Bathonian (Middle Jurassic) ammonites from the Fernie Formation, Canadian Rocky Mountains

The name Chubutolithes was proposed by Ihering (1922) for an unknown type of fossil occurring in Eocene continental rocks of Patagonia, Argentina. Bown and Ratcliffe (1988) demonstrated that Chubutolithes is a trace fossil; specifically, it is the fossil nest of a mud-dauber. The latter authors also suggested that Chubutolithes was constructed by an insect belonging to the hymenopteran family Sphecidae, and coined the specific name C. gaimanensis for the unusual trace fossil. Comparison with a Recent nest of the mud-dauber Auplopus (Pompilidae; Figure 1.1) suggests that Auplopus is a much more likely candidate as the architect of Chubutolithes than are any sphecid mud-daubers.

The Gordondale Member: designation of a new member in the Fernie Formation to replace the informal “Nordegg Member” nomenclature of the subsurface of west-central Alberta

New biostratigraphic data and revised lithostratigraphic correlations reveal that the current stratigraphic nomenclature for the Lower Jurassic portions of the Fernie Formation in the subsurface of west-central Alberta is inadequate. This paper introduces a new member, the Gordondale Member, for highly radioactive, fine-grained strata previously referred to as either the lower Fernie Formation, the Lower Fernie shelf limestone and clastics, the Nordegg Member, or the “Nordegg Member”. A new occurrence of a late Toarcian ammonite, which constrains the age of the top of the Gordondale Member, is also reported. The Hettangian to upper Toarcian Gordondale Member is an important hydrocarbon source rock and consists of dark brown, finely laminated, organic-rich, phosphatic and highly radioactive calcitic mudstones, calcilutites and fine-grained calcarenites. Fish fragments, pectinoid bivalves, Ostrea , belemnoids, ammonites, coccoliths and radiolarians are abundant. The Gordondale Member is laterally extensive and thins westward from a maximum thickness of approximately 50 m in the subsurface of west-central Alberta to 19 m at Pink Mountain in northeastern British Columbia.

INTEGRATED STRATIGRAPHY OF THE LOWER AND MIDDLE FERNIE FORMATION IN ALBERTA AND BRITISH COLUMBIA, WESTERN CANADA

The lower and middle parts of the Fernie Formation in central-western Alberta and south-eastern British Columbia, ranging from Pliensbachian to ?Bathonian (Early to Middle Jurassic) in age, and consisting mainly of fossiliferous dark shales and black limestones, contain bentonitic clay horizons which have yielded radiometric ages using U-Pb analysis of zircon crystals. Here we report six new ages from the lowermost Red Deer Member (188.3 +1.5/-1 Ma); Highwood Member (ca. 173 Ma and 166.6 ± 0.2 Ma); and Grey Beds (167.0 ± 0.2 Ma, 165.6 ± 0.3 Ma, and 165.4 ± 0.3 Ma). Some of these bentonites are associated with ammonites and coccoliths which provide biostratigraphic constraints. Strontium and carbon and oxygen isotopes measured from belemnite rostra have been compared in two sections and the resulting curves are compared with those from western Europe.

Ammonite and Bivalve assemblages in Bathonian through Oxfordian strata of Northern Bowser Basin, Northwestern British Columbia, Canada

Abstract Stratigraphic and structural studies of the Middle Jurassic through Lower Cretaceous Bowser Basin in northwestern British Columbia are progressing with the aid of detailed ammonite biostratigraphy. Bathonian through Oxfordian cardioceratid and perisphinctid ammonites from the northwest corner of the basin permit correlation and development of a preliminary regional zonation. These faunas are unusually rich in perisphinctids and phylloceratids, perhaps indicating open access to the Pacific Ocean. One Callovian fauna studied in detail includes dimorphic pairs assigned to Cadoceras (Stenocadoceras?) stenoloboide Pompeckj ,, C. comma Imlay ,, and Choffatia sp.

NEW HETTANGIAN AMMONITE FAUNAS AND A TRIASSIC - JURASSIC BOUNDARY SUCCESSION, FERNIE FORMATION, WILLISTON LAKE, BRITISH COLUMBIA

A relatively new shoreline section on Peace Reach, Williston Lake, north-eastern British Columbia, provides continuous exposure through a Triassic-Jurassic boundary succession, with apparent stratigraphic continuity from the Pardonet Formation (Upper Norian) into the overlying Fernie Formation (Hettangian and younger). These rocks are part of autochthonous North America, deposited along the western margin of the Jurassic craton. The section at Black Bear Ridge consists of 22 m of flaggy-bedded, brown-weathering siltstones and several thick, resistant siltstones, and contains calcareous concretions which have yielded most of the three-dimensional ammonites. While it is clear these ammonites represent parts of the lower, middle and upper Hettangian, the sequence of faunas differs somewhat from those reported from the Queen Charlotte Islands and Nevada. This is the first record of an extensive sequence of Hettangian strata and ammonite faunas in the Fernie Formation. Lower Hettangian faunas include poorly preserved, laterally flattened Psiloceras ( P. majus, P. plicatum, P. cf. rectocostatum , P. cf. planocostatum ), occurring throughout the lower part of the section from 3.0 to 8.3 m. At 9.5 m Waehneroceras appears, representing the middle Hettangian, followed by Sunrisites sunrisense at 10.8 m, and the first Schlotheimia at 13.3 m. A single large specimen of Alsatites liasicus is associated with these faunas. Beds above 13.3 m yield several species of Schlotheimia ( S. angulata, S. angulata densicostata, S. cf. oxygonia ), Kammerkarites frigga and Laqueoceras sp., indicating the lower parts of the upper Hettangian. Uppermost Hettangian faunas occur at the top of the exposed section in beds from 21.0 to 21.7 m, and include Badouxia ( B. canadensis, B. striata, B. oregonensis ) and Pseudaetomoceras doetzkirchneri .

Lower Bajocian ammonites (Middle Jurassic; Soninniidae) from the Newmarracarra Limestone, Western Australia

Three species of sonniniid ammonites, previously described under Fontannesia Buckman, are placed in a new genus, Newmarracarroceras; Dorsetensia clarkei Crick is designated type species. These West Australian species differ from other known Fontannesia by having smooth body chambers, flanks which slope gradually toward the umbilical seam without development of an umbilical edge or wall, and simple septal sutures. Biometric studies show that ‘Fontannesia’ whitehousei Arkell is a smaller and more compressed variant of N. clarkei (Crick), with a complete gradation between the two ‘species’ for most morphological characters. While well-dated European Fontannesia occur in the uppermost Aalenian concavum Zone and lowermost Bajocian discites Zone, new dating of the circum-Pacific Pseudotoites faunas, with which Newmarracarroceras occurs in Western Australia, indicates correlation with the higher ovalis or laeviuscula Zones (lower Bajocian). An associated specimen of Sonninia playfordi Arkell is described.

Teudopsis cadominensis , a new teuthid squid from the Toarcian (Lower Jurassic) of Alberta

A new species of teuthid squid, Teudopsis cadominensis, is described from the Toarcian (Lower Jurassic) Poker Chip Shale of the Fernie Formation in central-western Alberta. Fossil squids are rare in the Mesozoic of North America; this species is the first record of the family Palaeololiginidae in North America and the first member of the suborder Mesoteuthina in the Jurassic of North America.

MIDDLE ALBIAN (LOWER CRETACEOUS) GASTROPLITINID AMMONITES AND DINOFLAGELLATES FROM THE CHRISTOPHER FORMATION (DRAGON MOUNTAIN, AXEL HEIBERG ISLAND, CANADIAN ARCTIC ISLANDS) AND A REVISION OF THE GENUS PSEUDOGASTROPLITES JELETZKY, 1980

Abstract A large sample of excellently preserved ammonites from concretions concentrated at a single horizon near the base of the Macdougall Point Member of the Christopher Formation (Aptian–Albian age; Early Cretaceous) is the basis for recognizing a new species of the boreal ammonite genus Pseudogastroplites (P. draconensis). The dimorphic nature of the genus is established, two variants are recognized (P. draconensis var. robusta and P. draconensis var. gracile), and the generic diagnosis is emended. Retention of the genus Pseudogastroplites Jeletzky, 1980 as distinct from Gastroplites McLearn, 1930 is proposed. The concretions also yield Pseudopulchellia flexicostata (Imlay, 1961), inoceramid bivalves, fish remains, and a palynological flora, and are dated as late middle Albian.

?Tethyaster albertensis, a Late Cretaceous (Turonian) sea star from the Cardium Formation, Alberta, Canada

Although many of the surviving lineages of sea stars appeared during an early Mesozoic radiation of the class and have undergone limited change since then, they have left a very poor fossil record, particularly in the Mesozoic of North America (Blake, 1981). This record from the Late Cretaceous of Alberta is made more significant by the fact that it is apparently only the second occurrence of a member of the family Astropectinidae in the Cretaceous of North America; Lophidiaster silentiensis was described by McLearn (1944) from the Lower Cretaceous (Albian) Hasler Formation, from a now-submerged locality on the Peace River in northern Alberta. All previously recorded fossil sea stars from the North American Cretaceous are representatives of the family Goniasteridae.