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Carbon-isotope stratigraphy of the Furongian (stage 10; Upper Cambrian) and Tremadocian (lowermost Ordovician) reveals distinct variations from the carbonates of the Berry Head and Watts Bight formations of the East Isthmus Bay section that accumulated in a shallow-marine setting on the eastern Laurentian platform in a passive margin setting in western Newfoundland, Canada. The East Isthmus Bay δ13C values show insignificant correlation with their Sr (R2 = 0.04), Mn (R2 = 0.001) and Fe (R2 = 0.02) counterparts, implying preservation of at least near-primary C-isotope compositions. The investigated section is largely fossil poor, but the δ13C profile shows a pattern with distinct variations that can be matched with those of the western Laurentian Lawson Cove Auxiliary Boundary Stratigraphic Section and Point (ASSP) section, Utah, USA. Therefore, it was possible to reconstruct a conodont biozonal scheme by matching the δ13C profile with its counterpart from the Lawson Cove ASSP section. At the base of the East Isthmus Bay section, the δ13C profile exhibits a broad excursion (the top of the Herllnmaria – Red Tops Boundary), which can be matched with the base of the Eoconodontus Zone (mid-Furongian), followed by an enrichment trend through the Cordylodus intermedius Zone (top Furongian). A positive excursion (Hirsutodontus simplex spike) is recorded in the Cordylodus intermedius Zone (top Cambrian), and a prominent positive peak characteristic for the Cordylodus lindstromi Zone is recorded from the top of the investigated section. The δ13C values of the Newfoundland carbonates are generally ∼1‰ Vienna Pee Dee Belemnite lower than those of Lawson Cove, which is likely attributable to a relatively higher productivity and (or) organic burial in the Utah region.

A large, resistant buildup at the top of the Upper Ordovician (Hirnantian?) Red Head Rapids Formation on Southampton Island (Nunavut, Arctic Canada) is dominated by massive boundstone and cementstone facies. These massive facies have more in common with the sponge–microbial reefs that dominated worldwide in the Early Ordovician, including the following primary components: early calcified sponge material, microbial elements, and synsedimentary cement. A close spatial relationship between sponge and microbial framework elements suggests that a poorly preserved decaying sponge framework provided substrates for the attachment and development of microbes and that the microbes played essential roles as reef consolidators. Centimetre-scale colonial metazoans are present and locally intergrown with the sponge and microbial components. Other mound-dwelling invertebrates or calcareous algae are rare. Although altered now to calcite, cement fabrics suggest that aragonite was ubiquitous as seafloor precipitate. Prior to its subaerial exposure in the latest Ordovician, the Red Head Rapids Formation buildup developed on the margin of a shallow-marine evaporative epicratonic basin where a diverse community of reef-building metazoans was unable to flourish.

Tunnel valleys are an erosional channel characterized by anastomosing, steep-sided channel systems formed by subglacial, confined meltwater flow. Our study uses two-dimensional (2D) industry reflection seismic on the Scotian Shelf near Sable Island to better constrain the geometry of tunnel valleys in the area. Here, U- to V-shaped buried channels north and west of Sable Island extensively branch, reconnect, and meander. They average 2–5 km wide and 150–700 m deep (below sea level) and have a dominantly north–south orientation. Immediately to the south and southwest of Sable Island, the channels become narrower (1–1.5 km), shallower (300–400 m maximum) and more widely spaced. Multiple tunnel valley generations may be present, but could not be separately mapped. There is a notable gap of 20–30 km between the ends of the detectable tunnel valleys and the shelf edge south of Sable Island. An exception is erosive features at the shelf edge at the head of Logan Canyon, but these channels are disconnected from the tunnel valley network further north and may not be tunnel valleys. The reason for the gap south of Sable Island is not clear; however, we do not believe it is due to data coverage or resolution issues. If the tunnel valleys genuinely end south of Sable Island, then the gap between them and the shelf edge means that between The Gully and Logan Canyon these subglacial meltwater channels did not empty directly at the shelf edge. This implies direct meltwater and sediment delivery by tunnel valleys to the Scotian Slope during the Pleistocene may have been limited in this area.

We report a diverse assemblage of trace fossils from the Lower(?) Cambrian High Head member of the Church Point Formation near Yarmouth, Nova Scotia. Based on the presence of sharp-based beds, load casts, and flute casts, along with other sedimentological criteria, the strata are interpreted to have a turbidite origin. Other characteristics, including wrinkle structures and high fidelity of trace-fossil preservation, suggest that the inter-episode biotope was influenced by the presence of biomats. The trace-fossil assemblage includes (in approximate order of abundance) Planolites , Helminthopsis , Oldhamia , Chondrites , Gordia , Cladichnus , Psammichnites gigas , Treptichnus , Phycodes , Lorenzinia , Palaeophycus , and Teichichnus . Trace fossils are increasingly abundant upwards in the section, but they are ultimately mitigated by an increase in (inferred) sedimentation rates. The trace-fossil assemblage, which bears many similarities to other Lower Cambrian locales (e.g., Puncoviscana Formation of northwest Argentina, Chapel Island Formation of southeastern Newfoundland), and the distribution of ichnofossils strongly support an earliest Cambrian age for the studied strata. More importantly, evolutionary trends can be interpreted from the trace-fossil assemblage, namely (1) an increase in size and diversity of animals in deep water; (2) an expansion of motile strategies used to coexist with biomats; and, (3) increasingly complex mining strategies below the sediment-biomat interface.

A giant short-faced bear ( Arctodus simus ) ulna fragment was found at the base of exposed Quaternary sediments at Cowichan Head, southern Vancouver Island, British Columbia. In this paper, the ulna fragment and its geological context are described and a reasonable taphonomic trajectory is presented. The radiocarbon age of 22 750 ± 140 BP on the bone indicates that these bears were on Vancouver Island during the late Wisconsinan. A likely source for the Cowichan Head A. simus was from the mainland to the southeast.

The north–south-trending Clarence Head dyke swarm, located on Devon and Ellesmere Islands in the Canadian High Arctic, has a trend orthogonal to that of the Neoproterozoic Franklin swarm that surrounds it. The Clarence Head dykes are dated by the U–Pb method on baddeleyite to between 716 ± 1 and 713 ± 1 Ma, ages apparently younger than, but within the published age range of, the Franklin dykes. Alpha recoil in baddeleyite is considered as a possible explanation for the difference in ages, but a comparison of the U–Pb ages of grains of equal size from both swarms suggests that recoil distances in baddeleyite are lower than those in zircon and that the Clarence Head dykes are indeed a distinctly younger event within the period of Franklin magmatism. The Clarence Head dykes represent a large swarm tangential to, and cogenetic with, a giant radiating dyke swarm ∼800 km from the indicated source. The preferred mechanism for the emplacement of the Clarence Head dykes is the exploitation of concentric zones of extension around a depleting and collapsing plume source. While the paleomagnetism of most Clarence Head dykes agrees with that of the Franklin dykes, two dykes have anomalous remanence directions, interpreted to be a chemical remanent magnetization carried by pyrrhotite. The pyrrhotite was likely deposited from fluids mobilized southward from the Devonian Ellesmerian Orogeny to the north that used the interiors of the dykes as conduits and precipitated pyrrhotite en route.

Kimberlite-sourced bentonite layers have been discovered in Late Cretaceous sedimentary drill cores located within the Buffalo Head Hills kimberlite field, north-central Alberta. Two bentonites are unambiguously differentiated from “common” intermediate to felsic volcanic-derived Alberta bentonite by having similar whole-rock geochemical composition to ultramafic rocks from the Buffalo Head Hills kimberlite field and worldwide crater-facies kimberlite. The results demonstrate that the geochemical analysis of bentonite can provide a quick, cost-effective means of testing for low-volume kimberlite volcanism. The kimberlite-sourced bentonite is associated with a cluster of Buffalo Head Hills kimberlites known as the K14 complex. The K14A kimberlite occurrence has a previously reported206Pb/238U perovskite emplacement age of 86.8 ± 2.1 Ma. This age is compatible with early or mid-Cenomanian (∼99–96 Ma) and mid-Coniacian to Santonian (∼88–84 Ma) palynological results for mudstone underlying and bracketing the K14A and K14B kimberlites, respectively. Conversely, biostratigraphically significant palynomorphs in host rock cores bracketing the K14C kimberlite indicate emplacement during the Cenomanian or Turonian (∼96–92 Ma). U–Pb detrital zircon ages from syndepositional kimberlite-sourced bentonite directly adjacent to the K14C kimberlite contains a high frequency of young (∼99–92 Ma) zircon with a best maximum206Pb/238U depositional age of 91.7 ± 2.9 Ma. Thus, this innovative approach may provide evidence of multiple episodes of kimberlite emplacement within or near the K14 complex.

A single boulder (PH 8.14), recovered from unit 8 on the Point of Head, Cow Head Peninsula, Shallow Bay Formation (Cow Head Group), contains a unique olenid-dominated trilobite fauna composed of the following taxa: Boeckaspis geordii n. sp., Leiobienvillia terranovica (Rasetti, 1954), hystricurid n. gen. n. sp., Tulepyge sp. A, Tulepyge sp. B, Tulepyge? sp. C, and Symphysurina sp. The pelturine trilobite B. geordii dominates the assemblage. Boulder PH 8.14 consists of light grey-brown packstone to grainstone. This is atypical for olenid-dominated faunas, which usually occur in dark laminated limestones and shales. The fauna is likely earliest Ordovician in age, but a latest Cambrian age cannot be entirely ruled out. Regardless, this assemblage is unique in that it is the only known olenid-dominated fauna from Cambrian–Ordovician boundary sediments in Laurentia. A phylogenetic analysis of Boeckaspis and other putatively closely related taxa ( Westergaardia Raymond, 1924 and Jujuyaspis Kobayashi, 1936) was conducted. The results of the analysis indicate that Westergaardia is not monophyletic and as such it is considered a junior synonym of Boeckaspis herein.

The Taconian Humber Zone stretches from western Newfoundland to southern Quebec. The Early Cambrian slope succession in Newfoundland is found in the Curling Group, whereas in Quebec, various units were deposited during that first time slice. Biostratigraphic data allow correlation of the Curling Group with the Labrador Group in Newfoundland and with the newly time-constrained slope succession in Quebec. The end of the rift–drift transition is marked by a sea-level lowstand at the end of the Early Cambrian. The Middle Cambrian to latest Early Ordovician passive margin history recorded five cyclic sea-level fluctuations. Three of these cycles are recorded in the shallow-marine Middle to Late Cambrian platform (Port au Port Group) and slope sediments preserved in the Cow Head and Northern Head groups in Newfoundland. The biostratigraphic information assists correlation with Cambrian passive margin units in Quebec. Major sea-level lowstands are recognized along the continental margin in early–middle Late Cambrian (Steptoan) and in late Late Cambrian (Sunwaptan). Even if the Quebec succession can be tied with its Newfoundland correlative, some significant differences in the nature of Upper Cambrian slope conglomerates argue for a tectonic control on the depth of erosion of the Cambrian continental margin. The Lower Ordovician record of the passive margin consists of two depositional cycles (Tremadocian–Arenigian) separated by a sea-level lowstand. This last event is well expressed in platform succession and is also recognized in conglomerate units found in the slope succession.

The Sops Head Complex of Badger Bay, central Newfoundland, includes olistostromal and tectonized mélanges and marks the Red Indian Line, the boundary between the peri-Gondwanan Exploits and peri-Laurentian Notre Dame subzones of the oceanic Dunnage Zone. Basalts in the olistostromal mélange preserve peperitic contacts with mudstone and limestone within slumped sedimentary units, demonstrating that magmatism was coeval with olistostrome formation. Conodonts from the limestones date these events as late Darriwilian ("Llandeilian," Middle Ordovician) in age. The conodont fauna consists entirely of North Atlantic Faunal Realm elements, suggesting a peri-Gondwanan or mid-Iapetan provenance for limestone of the Sops Head Complex. Basalt geochemistry suggests magmatism in a mature volcanic-arc to back-arc setting. The Sops Head Complex shows similarities in age, provenance, and stratigraphic setting to the Dunnage Mélange, suggesting that the two units are correlative.

Three crinoids are described from the Table Point Formation, Table Head Group (Whiterockian-Llanvirn) from Aguathuna quarry, Port au Port Peninsula, western Newfoundland, including Trichinocrinus terranovicus Moore and Laudon, Isotomocrinus apheles n.sp., and Brechmocrinus eos n.gen. and n.sp. Trichinocrinus terranovicus is one of the oldest camerate crinoids known. It was previously described from a single specimen, and the numerous additional specimens confirm that this crinoid had few fixed calyx plates, demonstrate that the small "pinnulets" are spines, and reveal that this crinoid had a very unusual posterior. The posterior interradius may indicate that all crinoids had homologous plating in the posterior interray rather than the camerate posterior interray being distinct from other crinoids. Isotomocrinus apheles n.sp. is the oldest species of this Ordovician genus, and Brechmocrinus eos n.gen. and n.sp. is the third known Arenig to Llanvirn cladid with a compound radianal.

A scolecodont (polychaete jaw) fauna from the latest Tremadoc and Arenig strata of the Cow Head Group includes some of the earliest representatives of these fossils in the world. No biostratigraphically useful changes seem to occur within the interval, although rapid diversification follows their appearance in the latest Tremadoc. Insufficient data were recovered to permit conclusions regarding ecological control of assemblages in early Paleozoic, down-slope environments.

The Loomis Member (Mount Head Formation) yields an abundant microflora of Viséan marine calcareous algae. A new udoteacean alga is recognized on the basis of the morphology of the tripartite lateral tubes. Tertiary fusiform filaments are disposed as hemispheric tufts and are attached by thin peduncles.

During the Early to Late Ordovician the Taconic foredeep in west-central Newfoundland evolved from an underfilled to an overfilled state in response to cratonward advance, thickening, and erosion of the Taconic Orogen. Early orogen-derived sediment in the foreland basin consisted of middle(?) to lake Arenigian deep-water mudstones that accumulated on an inner (craton-facing) slope prism (uppermost parts of Shallow Bay and Green Point formations and correlative units). These deposits are interbedded with and overlie passive-margin slope sediments. In the middle Arenigian to early Llanvirnian, sand from the orogen formed several small, sand-rich submarine fans (Lower Head Formation and correlative units) on the lower reaches of the inner slope and basin plain. The fans may have been fed by closely spaced rivers draining the orogen, as presently occurs in western South America. Only proximal portions of these fans are now exposed. The flysch basin was narrow, constricted by the inner slope and the passive-margin slope, and located a short distance seaward from the buried hingeline of the proto-North American craton. As the orogen thickened sufficiently to override the crustal ramp, the carbonate shelf on the craton drowned, clastic depocentres migrated onto the foundered craton, and a thicker flysch (Mainland Sandstone) accumulated in Llanvirnian-Llandeilian time. In the Caradocian the foreland basin was overfilled with shallow-marine terrigenous sediments (Long Point Formation). Regional flysch dispersal was from a St. Lawrence promontory to a Quebec reentrant.

The paper presents the results of an experiment in the use of hydrological parameters to study the internal structure of a rock glacier. The rock glacier selected for the study lies at the head of Grizzly Creek in the southwest Yukon Territory. The hydrological network suggests two independent drainage systems, which demonstrate the occurrence of a planar impervious structure at depth and independent lines of drainage controlled by the flow structures in the near-surface deposits. Chemical changes in the water are inconclusive with respect to the evaluation of ice contents of the landform although the physical evidence strongly suggests no massive ice component. Chemical characteristics of each drainage system are sufficiently different that chemical tests can be used to differentiate sources of the drainage.

We have studied 85 limestone and dolostone samples from 21 sites of the St. George and Table Head groups (Lower and Middle Ordovician) on Port au Port Peninsula (Humber Zone). Their gentle (~15°) tilt is probably Devonian. A steep viscous component dominant in the natural remanence is removed by thermal and (less efficiently) alternating-field demagnetization. In about 60% of all samples, the thermal treatment yielded a southeasterly reverse component ("A"), which typically remained blocked to 450–500 °C and then decayed to noise. Mean A component directions calculated from Zijderveld plots and referred to bedding are D, I = 148.5°, +33.6 °for N = 9 St. George sites and D, I = 150.0°, I = +40.7 °for N = 5 Table Head sites. Corresponding antipoles are 17.5°N, 152.3°E, dp, dm = 2.8°, 4.9 °and 13.4°N, 149.2°E, dp, dm = 2.9°, 4.7°, respectively. We interpret these results as representative of the geomagnetic field in the Early and mid-Ordovician. In 14 samples, mainly from the older St. George strata, thermal treatment yielded a reverse ("B") component with mean direction D, I = 167.9°, −9.2°, corresponding to an antipole at 44.9°N, 138.2°E, dp, dm = 3.6°, 7.1°. We interpret this as a late Paleozoic overprint in diagenetic hematite. The 30° anticlockwise rotation of Newfoundland proposed by Wegener is not supported by our data.

Two lithostratigraphic units, Quadra Sand and the Cowichan Head Formation, are overlain by Vashon till and associated glacial sediments and underlain by Dashwood and Semiahmoo drift deposits in coastal southwest British Columbia. Each unit is formally described and stratotypes are presented.Quadra Sand consists of cross-stratified, well-sorted sand, minor gravel, and silt deposited as outwash in front of glaciers advancing into the Georgia Depression at the beginning of the Fraser Glaciation. It is diachronous, deposition having commenced earlier than 29 000 years BP at the north end of the Georgia Depression but not until after 15 000 years BP at the south end of the Puget Lowland.The Cowichan Head Formation, deposited during the Olympia nonglacial interval, underlies Quadra Sand and consists of parallel-bedded silt, sand, and gravel, in part plant-bearing. The unit is divisible into a lower marine member and an upper fluvial and estuarine member.

Scanning electron microscope examination of quartz grains separated from conglomerates in an alluvial fan sequence within the Pennsylvanian Fowler Head Formation of Nova Scotia revealed surface characteristics that are typical of those obtained from modern tropical environments. This evidence suggests that a similar tropical climate may have existed in eastern Canada during Middle Pennsylvanian time.

A recently excavated quarry in the middle Table Head Formation (Middle Ordovician) on the Port-au-Port Peninsula, western Newfoundland, has provided a rich and varied fauna of graptolites associated with trilobites, inarticulate brachiopods, and crustacean remains. The graptolite fauna includes Atlantic province species in an otherwise characteristically Pacific assemblage, thereby enabling the correlation of provincially distinct zonal classifications.

Lithostratigraphic nomenclature of early Middle Ordovician strata from western Newfound land is formally revised. The present Table Head Formation is raised to group status and extended to include overlying interbedded terrigenoclastic-rich calcarenites and shales with lime megabreccias. Four new formation names are proposed: Table Point Formation (previously lower Table Head); Table Cove Formation (previously middle Table Head); Black Cove Formation (previously upper Table Head); and Cape Cormorant Formation (previously Caribou Brook formation). The Table Point Formation comprises bioturbated, fossiliferous grey, hackly limestones and minor dolostones; the Table Cove Formation comprises interbedded lime mudstones and grey–black calcareous shales; the Black Cove Formation comprises black graptolitic shales; and the Cape Cormorant Formation comprises interbedded terrigenoclastic and calcareous sandstones, siltstones, and shales, punctuated by massive or thick-bedded lime megabreccias. The newly defined Table Head Group rests conformably or disconformably on dolostones of the Lower Ordovician St. George Group (an upward-migrating diagenetic dolomitization front commonly obscures the contact) and is overlain concordantly by easterly-derived flysch deposits. Upward-varying lithologic characteristics within the Table Head Group result from fragmentation and subsidence of the Cambro-Ordovician carbonate platform and margin during closure of a proto-Atlantic (Iapetus) Ocean.

A radiocarbon date of 12 600 ± 140 years BP (GSC-2295) is reported on marine shells from sands within the Robinson's Head kame moraine at Stephen ville, Newfoundland. The moraine was deposited simultaneously with a delta-kame distal to it during a brief interval of increased ice marginal activity. This is marked at Stephenville by a temporary halt in landward marginal recession, but in some other localities around St. George's Bay by a lobate readvance into the late-glacial sea. The date refers to the time of moraine and delta-kame construction and confirms an earlier estimation. Other radiocarbon dates from the area, relating more or less closely to past sea level positions at Robinson's, south of Stephenville, are used, with an hypothetical isostatic uplift curve and a published eustatic sea level curve, to produce a first approximation to postglacial changes of local sea level in the St. George's Bay region.

A small outcrop belonging to an unnamed shale unit in the Buffalo Head Hills of north-central Alberta has yielded marine microfossils of Senonian, most probably Campanian, age.The foraminiferal fauna, including Haplophragmoides fraseri, Verneuilinoides bearpawensis, Praebulimina carseyae and Cassidella tegulata, suggests equivalence with that of the upper Campanian Bearpaw fauna of southern Alberta.The radiolarian assemblage includes Spongurus (Spongurantha) sp., Spongodiscus (Spongodisus) sp. cf. S. (S.) renillaeformis, Spongostaurus sp., Spongotripus (Spongotripus) sp. cf. S. (S.) morenoensis and Dictyomitra (Dictyomitra) multicostata, which are present in the Bearpaw Formation of southern Alberta, and in an interval of the Schrader Bluff Formation of northern Alaska, considered middle Senonian in age.Among the dinoflagellates recorded from the outcrop, three species of Dinogymnium – D. acuminatum, D. longicornis and D. sibiricum, and four species of Deflandrea – D. granulifera, D. minor, D. spectabilis and D. victoriensis are restricted to strata of Senonian age (inclusive of Maestrichtian Stage). Of this group, Dinogymnium longicornis, Deflandrea granulifera and D. spectabilis are present in the Bearpaw Formation of southern Alberta. The dinoflagellate assemblage has four species in common with that of the Senonian or younger beds in western Siberia.The pollen assemblage is dominated by species of Aquilapollenites – A. dolium, A. trialatus and A. turbidus – strongly indicative of a Campanian age. A megaspore, Balmeisporites rarus, suggests a Senonian age.The microfossil assemblage provides corroborative evidence in support of J. A. Jeletzky's hypothesis that a marine connection existed between the Arctic and Western Interior regions through northern Alberta during the Santonian and Campanian.

The Cow Head Group in western Newfoundland includes a record of continuous graptolite evolution across the Cambrian–Ordovician boundary. In sections at Broom Point, interbedded breccias contain blocks with rich platform trilobite faunas which give a complete succession of North American zones. The stratigraphic relationship between graptolites and trilobites clearly establishes that the base of the type Tremadoc Series lies above that of the Missisquoia Zone. The sequence of earliest planktonic graptolites is the most complete known and serves to remove objections to the selection of Dictyonema flabelliforme, or one of its subspecies, as an index for the base of the Ordovician System.

In the Talbot Lake area, the Upper Mississippian carbonate sequence comprises, in ascending order, the Turner Valley and Mount Head formations. The Mount Head Formation is informally divided into lower and upper members. The rocks of the Upper Mississippian originated by sedimentation associated with successive shallowing-upward sequences. On the basis of the fossils, lithologies, textural characters, and sedimentary structures, the Turner Valley Formation apparently resulted from sedimentation on open marine shoals and in a lagoon, the lower member of the Mount Head Formation from sedimentation in shallow subtidal to lower supratidal environments, and the upper member of the Mount Head Formation from deposition in upper intertidal to supratidal environments.The paraconformity between the lower and upper members of the Mount Head Formation records a short erosional break. A disconformity between the Upper Mississippian carbonates and the Upper Permian Ishbel Group displays paleotopographic relief and paleokarstic features developed during exposure in post-Mississippian times. The disconformity is overlain by a condensed sequence of Pennsylvanian to Permian strata.Major diagenetic modifications of the Upper Mississippian strata include dolomitization, silica replacement and cementation, carbonate cementation, and dedolomitization. A diagenetic realm comprising sea water, fresh water, and hypersaline brine was probably responsible for some of the complex diagenesis in these rocks.

Specimens of in situ lingulids have been discovered in carbonates of the Middle Ordovician Table Head Group of northwestern Newfoundland and Trenton Group of the St. Lawrence Lowland of Quebec. The discoveries have two important implications regarding Palaeozoic lingulid ecology. First, they represent one of the few recordings of in situ lingulids in carbonate substrates of Palaeozoic age and, second, they occur mainly in outer shelf and upper slope sediments (Grondines Member of Neuville Formation, Trenton Group, and Table Cove Formation, Table Head Group), deposited in presumed considerable water depths. Caution must be observed with the use in the fossil record of lingulids as palaeo-environmental indicators.

Brachiopods from shallow-water limestone boulders in beds 12, 13, and 14 of the allochthonous Cow Head Group belong in the earliest Whiterockian Orthidiella Zone. Brachiopods of the autochthonous intertidal to deep-water Table Head Group are equivalent to those of the younger Whiterockian Anomalorthis Zone. The Cow Head is older than the Table Head.Integration of the brachiopod data from western Newfoundland with those from the type Whiterockian in Nevada, combined with the evidence of graptolites from both areas, indicates that the Orthidiella Zone spans the Australian Castlemainian, Yapeenian, and lower Darriwilian Dal zones.

The Brookville Gneiss is a medium- to high-grade quartz–feldspar–biotite and hornblende–quartz–feldspar–biotite gneiss found north and northeast of Saint John, New Brunswick. The Green Head Group, a sequence of low-grade metasediments, surrounds the Brookville Gneiss. Analyses of zircons with euhedral to subhedral overgrowths and rounded to subrounded cores from the Brookville Gneiss yield an upper intercept age on concordia of 1641 Ma, considered to be the age of the source area for the zircons. The zircon analyses also indicate two Pb-loss events at approximately 780 and 370 Ma. These ages are confirmed by zircon analyses of a quartz diorite gneiss from Green Head Island, which yields ages of 827 and 333 Ma. A small euhedral single zircon from the Brookville Gneiss, believed to be formed during metamorphism, gives a concordant age of 814 Ma corresponding to the first Pb-loss event. Rb–Sr whole-rock analyses of a granite from the east side of Musquash Harbour southwest of Saint John give an age of 392 Ma and an initial Sr ratio of 0.7187 substantiating the second Pb-loss event.The results indicate that the Brookville Gneiss and Green Head Group are older than 800 Ma and probably younger than 1200 Ma. The zircon source area age (1641 Ma) and first Pb-loss event (800 Ma) are similar to ages found in rocks of the eastern margin of the Appalachian orogen from Massachusetts and Cape Breton Island, respectively. They suggest a setting and tectonic event correlated in time for the Late Precambrian of the eastern margin distinct from the younger so-called "Avalonian."

The Vendom Fiord Formation near the head of Cañon Fiord, central Ellesmere Island, hitherto thought to be unfossiliferous, contains mid to late Emsian trilete spores. Strata below the Vendom Fiord Formation, separated from it by an unconformity, contain a less diverse assemblage of spores that suggests a mid to late Gedinnian age. The spores are the only fossils known from these beds, and the first palynomorphs to be reported from the Early Devonian rocks of Ellesmere Island.

Chitinozoan and acritarch assemblages from Caradocian and Ashgillian strata forming part of the White Head Formation of the Percé region, Gaspé Peninsula, Québec, contain species known from the central United States, eastern Canada, and northwestern Europe. One new species, Orthosphaeridium gaspesianum, is described.

The upper part of an intact sequence of Lower to Middle Ordovician deep-water sediments, which now form a large, disrupted raft within the Rocky Harbour Mélange at Lobster Cove Head, is interpreted as having been deposited downslope from a drowned carbonate platform margin. The entire 50 m thick section is Arenig (late Canadian or Ibexian to early Whiterock) in age; graptolite biostratigraphy demonstrates a correlation with upper parts of the Cow Head Group to the north. The basal part of the section is a proximal facies of the Cow Head Group (Shallow Bay Formation, Factory Cove Member, Beds 9, 10, and part of Bed 11). The upper part of the section consists of interbedded dolostone and shale and is unlike any other sequence in the Cow Head Group. This upper sedimentary sequence is defined as the Lobster Cove Head Member of the Shallow Bay Formation, Cow Head Group. Contact between the two sedimentary packages is also marked by a faunal break and coincides with emplacement of megaconglomerate Bed 12 at Cow Head.This break marks the change from a uniform to complex carbonate platform margin configuration and is here interpreted as the result of synsedimentary faulting. The margin upslope from Cow Head remained in shallow water during the final stages of Cow Head Group deposition, whereas that upslope from Lobster Cove Head was drowned and shed little sediment into deep water. The synsedimentary faulting, which led to rapid subsidence and platform-margin drowning upslope from Lobster Cove Head and possibly the deposition of megaconglomerate Bed 12 at Cow Head, coincides with the onset of the Taconic Orogeny in western Newfoundland.

Faunal assemblages of the autochthonous, shelf carbonate sequences belonging to the St. George and Table Head groups are dominated by shelly macrofossils and conodonts. Rare, usually monotypic graptolitic horizons enable correlation with the allochthonous Cow Head Group, which was deposited on the middle to lower slope, and the shelly, conodont, and graptolitic zonal schemes elsewhere in North America.The Catoche Formation of the St. George Group is of Ibexian (Canadian) age and yields graptolites indicative of the Tetragraptus approximatus and Tetragraptus akzharensis zones (early Arenig). The basal Aguathuna Formation belongs to the Pendeograptus fruticosus Zone, whereas higher parts span the Ibexian–Whiterock boundary. Graptolites suggest that the Table Head Group entirely postdates the Cow Head Group. This is supported by a Whiterock (early Llanvirn) trilobite, conodont, and brachiopod fauna.

Carbonate bedrock surfaces recently exposed at Cow Head, Newfoundland (50°14′N, 57°35′W) are densely riddled with boreholes of Hiatella arctica (Linné), many of which are occupied by subfossil specimens of this bivalve as well as with vermiform burrows of a sponge (? Cliona sp.). A radiocarbon date of 8250 ± 320 years BP (GSC-3433) on several Hiatella valves from the burrows gives the age of a sea-level stand at 8 m asl at the locality, during which penecontemporaneous surf erosion or beach gravel deposition led to the demise of the shells. Other unoccupied cavities in longer exposed bedrock outcrops on Cow Head are contrasted in form and distribution with those of Hiatella and are argued to be boreholes of another marine invertebrate, not positively identified.

The Cow Head Group, interpreted as a southeast-dipping base-of-slope carbonate apron, contains intraformational truncation surfaces and slide masses. Synsedimentary shear zones are formed (1) below intraformational truncation surfaces; (2) in the basal parts of slide masses; and (3) in the shallow subsurface because of downslope creep. Shear zones are characterized by a variety of synsedimentary deformation structures. Limestones are subject to folding, brecciation, rotation of fragmented beds, and the development of fitted-lenticular bedding. In the interbedded shales, there is both disruption of fine laminations and small-scale isoclinal folding and faulting. Outcrops characterized by these features and the lack of truncation surfaces or slide masses may reflect minor downslope creep. The presence of truncation surfaces, slide masses, and shear zones indicates deposition on an unstable sloping surface.The recognition of intraformational truncation surfaces and slide masses usually requires extensive strike exposure, which when lacking, (e.g., drill cores), limits the potential of these large-scale features as useful indicators of slope deposition. In the Cow Head Group, the recognition and proper interpretation of the common, small-scale deformation structures of synsedimentary shear zones provides evidence for slope deposition that is independent of other sedimentologic, stratigraphic, and regional data.In some parts of the Cow Head Group, "wrinkled" limestones characterized by a prominent dome-and-basin morphology reflect layer-parallel shortening related to tectonic deformation. The deformation of these limestones was previously considered to be synsedimentary, but their association with late-diagenetic precipitates and tectonic stylolites, in conjunction with their continuity and regularity, distinguishes these folds from those produced during synsedimentary deformation.

A new species of brachiopod, Foliomena joliensis, has been found in the White Head Formation of Percé, Quebec. The genus has previously been reported only in Europe where it occurs in deep-water communities. As in Europe, the assemblage containing Foliomena is dominated by vagile animals, and the assemblage has only rare, very small sessile animals. Some associated brachiopods are described and illustrated.

One hundred and nineteen rock glaciers were identified in an aerial photograph inventory of 4632 km2 in Jasper National Park, Alberta. Morphological subdivision indicated 33 lobate, 76 tongue-shaped and 10 spatulate rock glaciers, whereas a 'genetic' classification identified 65 'glacial' (ice-cored) and 54 'non-glacial' (ice-cemented) rock glaciers. Head elevations of the glacial group (mean 2318 m) are significantly higher than the non-glacial group (mean 2256 m). The total elevation range of rock glaciers is 1710–2670 m.Optimal rock glacier sites are below north- or northeast-facing quartzite cliffs in cirques or on valley walls. These topographic and geologic controls produce a greater concentration of rock glaciers in the Main Ranges than the Front Ranges. Rock glacier head elevations rise eastwards and, to a lesser extent, southward across the area in response to regional climatic and latitudinal effects. Two phases of pre-'Little Ice Age' rock glacier activity are recognized on morphologic grounds and, since Little Ice Age glaciers overrode most of the evidence of Holocene glacier fluctuation, provide a major source of information on Holocene climatic fluctuations. Preliminary data suggest most rock glacier activity pre-dates the Little Ice Age and the oldest phases probably occurred between 6600 and 9000 BP.

The Burin Peninsula exhibits an exceptionally thick and essentially continuous succession of marine strata through the Precambrian–Cambrian transition. Fossils are abundant and include trace fossils, small shelly fossils, vendotaenid algae, soft-bodied megafossils, and microfossils. The Burin Peninsula is readily accessible and has long been considered a potential area for a Precambrian–Cambrian boundary stratotype.A continuous section through the upper part of member 1 and all of member 2 of the Chapel Island Formation is exposed at Fortune Head, and this section is herein proposed as a global stratotype for the Precambrian–Cambrian boundary. The boundary horizon is located 2.4 m above the base of member 2 of the Chapel Island Formation. This horizon marks the base of the basal Cambrian Phycodes pedum (ichnofossil) Zone and immediately overlies the top of the Late Precambrian Harlaniella podolica (ichnofossil) Zone. Shelly fossils (sabelliditids) first appear a few metres below the proposed boundary. Soft-bodied megafossils, carbonaceous impressions of vendotaenid algae, and organic-walled microfossils occur both below and above this boundary and enhance global correlation with this section.Fossils of the Rusophycus avalonensis (ichnofossil) Zone first appear midway through member 2 (approximately 135 m above the proposed boundary) and occur commonly throughout the upper part of the Chapel Island Formation and the overlying Random Formation. Calcareous small shelly fossils (?Circotheca sp.) appear near the top of member 2 (approximately 400 m above the proposed boundary), and a more diverse Aldanella attleborensis small shelly fossil assemblage characterizes the uppermost strata of member 3 and all of member 4 of the Chapel Island Formation (approximately 550–650 m above the proposed boundary). The lowest trilobites, representatives of the Callavia broeggeri Zone, first appear more than 1000 m above the proposed Precambrian–Cambrian boundary.

As part of studies of anorthosites from the northern hemisphere, the paleomagnetism of two anorthosite inliers at Indian Head and Steel Mountain in western Newfoundland is described. The six sites at Indian Head retain a stable remanent magnetization and yield a paleomagnetic pole at 8 °S, 157½° E(δp = 15°, δm = 20°). This is close to poles for anorthositic and other rock units from within the Grenville Province that represent magnetization of age 1000 m. y., suggesting that there is no relative rotation between western Newfoundland and the southeastern part of the Canadian Shield, at least since the time of the Grenville orogeny. The ten sites at Steel Mountain also retain a stable magnetization, which yields a paleomagnetic pole at 22½° S, 41 °W (δp = 8°, δm = 14°). This position is closer to lower Paleozoic poles from Newfoundland and thus probably represents a lower Paleozoic magnetization.

A diverse and relatively prolific Lower Carboniferous algal microflora has been encountered in the Rocky Mountains and Foothills of southwestern Alberta. The algae occur in the Banff, Livingstone, Pekisko, Shunda, Turner Valley, Mount Head, and lower Etherington Formations. They are generally conspicuous throughout the Banff Formation, scarce in the Livingstone Formation, but are rather abundant in the upper parts of the Pekisko and Shunda Formations, and in the Loomis, Opal, Marston, and Carnarvon Members of the Mount Head Formation.The most favorable facies for algae are mixed skeletal and oolitic-skeletal packstones—grain-stones representing shallow, open sea shoals. Lagoonal deposits also yield a very rich microflora. The most unfavorable facies are echinoderm-bryozoan packstones, and sandy, silty mudstones and wackestones found in relatively deeper, offshore lithofacies.Twenty genera and at least 22 species are recognized, of which 6 genera and 9 species are new taxa. The new forms are: Orthriosiphonoides salterensis, n. gen., n. sp., Intextulella agglomerata n. gen., n. sp., Pseudokamaena armstrongi n. gen., n. sp., P. boulderensis n. sp., Stacheoides ? spissa n. sp., S. tenuis n. sp., Epistacheoides nephroformis n. gen., n. sp., Pseudostacheoides loomisi n. gen., n. sp., and Asphaltina cordillerensis n. gen., n. sp.The present study indicates that the associated Foraminifera offer a better detailed zonation of the Lower Carboniferous than the algae, although the latter appear to be more sensitive to facies change and, therefore, may be more useful to reconstruct paleoenvironments. However, five local algal assemblages, based on the succession of genera, seem stratigraphically consistent in Alberta.