Ediacaran body and trace fossils in Miette Group (Windermere Supergroup) near Salient Mountain, British Columbia, CanadaRevision of the paper was carried out by Dr. Guy Narbonne following the passing away of both Hans Hofmann (†deceased May 19, 2010) and Eric Mountjoy (†deceased June 18, 2010) after manuscript submission.

2010 ◽  
Vol 47 (10) ◽  
pp. 1305-1325 ◽  
Author(s):  
Hans J. Hofmann ◽  
Eric W. Mountjoy

Siliciclastic beds in the upper part of the Miette Group in southeastern British Columbia have yielded an assemblage of late Ediacaran soft-bodied macrofossils and trace fossils. The macrofossils comprise Aspidella , Bradgatia ?, and Miettia salientensis gen. et sp. nov. The ichnofossils include Archaeonassa , Cochlichnus , Didymaulichnus ?, Gordia , Halopoa , Helminthoidichnites , Helminthopsis , Planolites , and a large, unnamed crawling trace. In addition, two types of unidentified problematica are recorded, representing either tubular Vendotaenia -like body fossils, or trace fossils. The Bradgatia? constitutes the youngest occurrence of this type of fossil, and is the first to be recorded from Laurentia, having previously been noted only in Avalonia. With Cloudina and Namacalathus in associated shallow-water platform carbonates, the Miette biota in the study area contains a combination of Namibian-type and Avalonian-type elements.

1991 ◽  
Vol 28 (10) ◽  
pp. 1541-1552 ◽  
Author(s):  
H. J. Hofmann ◽  
E. W. Mountjoy ◽  
M. W. Teitz

Shallow-water clastic beds flanking stromatolitic carbonate mounds in the upper part of the Vendian Miette Group (Windermere Supergroup) of the Rocky Mountains contain a poorly preserved, soft-bodied fauna that comprises morphologically very variable discoid remains; these include the taxa Beltanella sp., cf. B. grandis, Charniodiscus? sp., Irridinitus? sp., Nimbia occlusa, Protodipleurosoma sp., cf. P. rugulosum, and Zolotytsia? sp. and seven types of dubiofossils.


1988 ◽  
Vol 25 (1) ◽  
pp. 1-19 ◽  
Author(s):  
William J. Devlin ◽  
Gerard C. Bond

The uppermost Proterozoic–Lower Cambrian Hamill Group of southeastern British Columbia contains geologic evidence for a phase of extensional tectonism that led directly to the onset of thermally controlled subsidence in the Cordilleran miogeocline. Moreover, the Hamill Group contains the sedimentological record of the passage of the ancient passive margin from unstable tectonic conditions associated with rifting and (or) the earliest phases of thermal subsidence to post-rift conditions characterized by stabilization of the margin and dissipation of the thermal anomaly generated during the rift phase (the rift to post-rift transition). Widespread uplift that occurred prior to and during the deposition of the lower Hamill Group is indicated by an unconformable relation with the underlying Windermere Supergroup and by stratigraphic relations between Middle and Upper Proterozoic strata and unconformably overlying upper Lower Cambrian quartz arenites (upper Hamill Group) in the southern borderlands of the Hamill basin. In addition, the coarse grain size, the feldspar content, the depositional setting, and the inferred provenance of the lower Hamill Group are all indicative of the activation of basement sources along the margins of the Hamill basin. Geologic relations within the Hamill Group that provide direct evidence for extensional tectonism include the occurrence of thick sequences of mafic metavolcanics and rapid vertical facies changes that are suggestive of syndepositional tectonism.Evidence of extensional tectonism in the Hamill Group directly supports inferences derived from tectonic subsidence analyses that indicate the rift phase that immediately preceded early Paleozoic post-rift cooling could not have occurred more than 10–20 Ma prior to 575 ± 25 Ma. These data, together with recently reported isotopic data that suggest deposition of the Windermere Supergroup began ~730–770 Ma, indicate that the rift-like deposits of the Windermere Supergroup are too old to represent the rifting that led directly to the deposition of the Cambro-Ordovician post-rift strata. Instead, Windermere sedimentation was apparently initiated by an earlier rift event, probably of regional extent, that was part of a protracted, episodic rift history that culminated with continental breakup in the latest Proterozoic – Early Cambrian.


2020 ◽  
Vol 94 (4) ◽  
pp. 653-680
Author(s):  
Brian D.E. Chatterton

AbstractA well-preserved fauna of largely articulated trilobites is described from three new localities close to one another in the Bull River Valley, southeastern British Columbia. All the trilobites from these localities are from the lower or middle part of the Wujiajiania lyndasmithae Subzone of the Elvinia Zone, lower Jiangshanian, in the McKay Group. Two new species are proposed with types from these localities: Aciculolenus askewi and Cliffia nicoleae. The trilobite (and agnostid) fauna from these localities includes at least 20 species: Aciculolenus askewi n. sp., Agnostotes orientalis (Kobayashi, 1935), Cernuolimbus ludvigseni Chatterton and Gibb, 2016, Cliffia nicoleae n. sp., Elvinia roemeri (Shumard, 1861), Grandagnostus? species 1 of Chatterton and Gibb, 2016, Eugonocare? phillipi Chatterton and Gibb, 2016, Eugonocare? sp. A, Housia vacuna (Walcott, 1912), Irvingella convexa (Kobayashi, 1935), Irvingella flohri Resser, 1942, Irvingella species B Chatterton and Gibb, 2016, Olenaspella chrisnewi Chatterton and Gibb, 2016, Proceratopyge canadensis (Chatterton and Ludvigsen, 1998), Proceratopyge rectispinata (Troedsson, 1937), Pseudagnostus cf. P. josepha (Hall, 1863), Pseudagnostus securiger (Lake, 1906), Pseudeugonocare bispinatum (Kobayashi, 1962), Pterocephalia sp., and Wujiajiania lyndasmithae Chatterton and Gibb, 2016. Pseudagnostus securiger, a widespread early Jiangshanian species, has not been previously recorded from southeastern British Columbia. Non-trilobite fossils collected from these localities include brachiopods, rare trace fossils, a complete silica sponge (Hyalospongea), and a dendroid graptolite. The faunas from these localities are more diverse and better preserved than those from other previously documented localities of the same age in the region.Additional specimens of a rare species, found by amateur collectors in previously documented localities of slightly younger age (upper part of Wujiajiania lyndasmithae Subzone) in the same region, are documented. These new specimens, when combined with an earlier discovered specimen, provide adequate type material to propose a new species of Labiostria, L. gibbae, which may be useful for biostratigraphy.UUID:http://zoobank.org/89551eac-b3af-4b2b-8ef3-7c2e106a560d


Facies ◽  
2016 ◽  
Vol 62 (4) ◽  
Author(s):  
Mehrangiz Naderi-Khujin ◽  
Ali Seyrafian ◽  
Hossein Vaziri-Moghaddam ◽  
Vahid Tavakoli

2021 ◽  
Author(s):  
Piotr Szrek ◽  
Patrycja G. Dworczak ◽  
Olga Wilk

Among the hundreds of collected Devonian vertebrate macrofossils in the Holy Cross Mountains, placoderms dominate and provide data on their morphology, distribution and taphonomy. So far 17 out of more than 500 studied specimens have revealed bones with surfaces covered by sediment-filled trace fossils. The traces have been made on the vertebrate remains before their final burial. The borings, oval in cross-section, include dendroidal networks of shallow tunnels or short, straight or curved individual scratches and grooves, which frequently create groups on the both sides of the bones. ?Karethraichnus isp. from Kowala and ?Osteocallis isp. from Wietrznia are the oldest record of these ichnogenera. Sedimentological clues indicate a shallow water environment, probably from the slope below the storm wave base.


1992 ◽  
Vol 6 ◽  
pp. 219-219 ◽  
Author(s):  
Guy M. Narbonne ◽  
Robert W. Dalrymple

Although most occurrences of Ediacaran fossils are from shallow-shelf deposits, taxonomically-similar assemblages have recently been described from a 2.5 km-thick succession of dark mudstones and turbiditic sandstones in the Windermere Supergroup of the Mackenzie Mountains, northwestern Canada. The paleogeographic position (20-40 km seaward of the shelf edge), abundant evidence of mass flow, and the complete absence of in situ shallow-water features imply that deposition took place on a slope considerably below storm wave-base. Ediacaran fossils were not observed in axial trough deposits (lower parts of the Twitya and Sheepbed formations), but megafossils occur sporadically in lower to middle slope deposits higher in the same formations. Megafossils and trace fossils are present in upper slope settings (Blueflower Formation) at the top of the Ediacaran succession. The megafossil assemblage varies stratigraphically, but in all formations is dominated by discoid forms (e.g. Cyclomedusa, Ediacaria, Nimbia); frondose forms and vendomiids are very rare.Megafossils are preserved mainly as positive features on the soles of thin turbidite beds. Most fossiliferous beds begin with the rippled layer of the turbidite (Tc), but a few begin with the graded (Ta) or parallel-laminated (Tb) layer. Consistent orientation and high relief of individuals, evidence of mutual deformation during growth of adjacent organisms, and other taphonomic features imply that virtually all of the taxa represent benthic polypoid and frond-like organisms (not jellyfish). Slump structures occur commonly in the sandstone fill of fossils, suggesting that many of the organisms were buried alive by the turbidite and later decomposed. Other individuals, even on the same bedding plane, exhibit graded to laminated fill identical to that of the overlying turbidite bed, indicating that the depressions on the sea bottom produced by these individuals were empty at the time of turbidite deposition. Escape structures are absent, suggesting that the Ediacaran organisms were not capable of burrowing up through even thin layers of sand.Ediacaran megafossils are invariably preserved on black, wrinkled surfaces similar to those elsewhere interpreted as microbial mats. Molding of delicate features (including tentacles), preservation of open molds as negative epireliefs, and sedimentological evidence of considerable cohesion of these surfaces relative to the underlying turbiditic muds (Td,e) supports this interpretation, and suggests that microbial mats were as important in the preservation of these deep-water Ediacara faunas as they were in their shallow-water equivalents. The presence of the wrinkled mats and their associated Ediacaran fossils almost exclusively in the pyritic intervals of the succession suggests that both may have lived under exaerobic conditions in this deep-water setting.


Sedimentology ◽  
1999 ◽  
Vol 46 (6) ◽  
pp. 969-984 ◽  
Author(s):  
Jordi Gimenez-Montsant ◽  
Francesc Calvet ◽  
Maurice E. Tucker

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