The oldest sequence of skeletal fossils in the Lower Cambrian of southeastern Newfoundland

1983 ◽  
Vol 20 (4) ◽  
pp. 525-536 ◽  
Author(s):  
Stefan Bengtson ◽  
Terence P. Fletcher
Keyword(s):  
Siberian Platform ◽  
Lower Cambrian ◽  
Short Interval ◽  
Time Span ◽  
Early Cambrian ◽  
Late Precambrian ◽  
Complete Sequences ◽  
Continuous Sedimentation

Sections on the Burin Peninsula in southeastern Newfoundland show a record of continuous sedimentation during the Late Precambrian–Early Cambrian transition. These may be correlated lithologically and biostratigraphically with less complete sequences on the Avalon and Bonavista Peninsulas. Below the oldest known trilobites in southeastern Newfoundland (of the Callavia Zone) two consecutive assemblages of skeletal fossils are recognizable: an Aldanella attleborensis assemblage and the succeeding Coleoloides typicalis assemblage. The shift between the two assemblages takes place within the Bonavista Formation in the Avalon–Bonavista region and in a similar succession of mudstones near St. Lawrence on the Burin Peninsula. The quartzitic Random Formation appears to have been deposited during a short interval within the time span represented by the A. attleborensis assemblage, and there is no conclusive biostratigraphical evidence of any major diachronism of this unit. The A. attleborensis assemblage contains taxa known from the lower part of the Tommotian Stage on the Siberian Platform. It is interpreted to be of Tommotian age, and the subsequent shift to the C. typicalis assemblage is tentatively correlated with the Tommotian–Atdabanian boundary as recognized in Siberia.

Late Precambrian–Early Cambrian stratigraphic and faunal succession of eastern California and the Precambrian–Cambrian boundary

1978 ◽  
Vol 115 (2) ◽  
pp. 121-126 ◽  
Author(s):  
C. A. Nelson
Keyword(s):  
Siberian Platform ◽  
Death Valley ◽  
Early Cambrian ◽  
Late Precambrian ◽  
Faunal Succession

SummaryThe Late Precambrian and Early Cambrian strata in eastern California and Nevada can be divided into 3 facies – the eastern Craton, the White-Inyo, and the Death Valley. These 3 facies supply evidence of 3 trilobite zones – the Fallotaspis, the Nevadella and the Bonnia-Olenellus; the inter-relationships are outlined. Correlations with the Siberian Platform successions are discussed and the Precambrian–Cambrian boundary is tentatively placed within the beds of the upper Reed Dolomite in the White-lnyo Range.

scholarly journals Palaeomagnetism of the Bayan Gol Formation, western Mongolia

1996 ◽  
Vol 133 (4) ◽  
pp. 487-496 ◽  
Author(s):  
D. A. Evans ◽  
A. Yu. Zhuravlev ◽  
C. J. Budney ◽  
J. L. Kirschvink
Keyword(s):  
Pacific Ocean ◽  
Siberian Craton ◽  
Siberian Platform ◽  
Lower Cambrian ◽  
High Coercivity ◽  
Early Cambrian ◽  
Thermal Demagnetization ◽  
Magnetic Components ◽  
Western Mongolia ◽  
Oriented Samples

AbstractOriented samples of the Lower Cambrian Bayan Gol Formation from Salaany Gol, Mongolia, were collected at roughly 5 m stratigraphic intervals for palaeomagnetic analysis. Progressive alternatingfield and thermal demagnetization isolated two magnetic components: a present-field overprint, typically removed by 10 mT fields and ~200°C heating; and a high-coercivity, high-unblocking-temperature (550–600 °C), predominantly single-polarity component that was imparted to the rocks prior to early or middle Palaeozoic deformation. Single-polarity magnetization at Salaany Gol contrasts with results from Lower Cambrian rocks on the Siberian platform, previously considered correlative with the Bayan Gol Formation, which show a prominent change in polarity bias near the top of the Tommotian Stage. Two hypotheses can explain this discrepancy. First, the entire Bayan Gol Formation may correlate with the predominantly reversely polarized, lower half of the Tommotian Stage in Siberia. This model is consistent with plausible interpretations of δ13C profiles for the Zavkhan basin and the Siberian platform. Alternatively, the characteristic magnetic direction from our samples may be a pre-fold overprint. If post-accretionary, then comparison with Siberian palaeomagnetic results suggest a Silurian–Devonian remagnetization age, and existing bioand chemostratigraphic correlations provide the most reliable spatial and temporal links between the Zavkhan basin and the Siberian platform. If the observed magnetic directions are primary or an immediate overprint then they may be used to constrain the early Cambrian palaeogeography of the Zavkhan basin and the Palaeo-Pacific Ocean. Mean inclination of 62 ±4° corresponds to a palaeolatitude of 44 ±5°, several thousand kilometres from the equatorial Siberian craton

Hydrocarbon biomarkers and diamondoid hydrocarbons from late Precambrian and lower Cambrian rocks of the Katanga saddle (Siberian Platform)

2017 ◽  
Vol 55 (4) ◽  
pp. 360-366 ◽  
Author(s):  
G. N. Gordadze ◽  
V. Yu. Kerimov ◽  
A. V. Gaiduk ◽  
M. V. Giruts ◽  
M. A. Lobusev ◽  
...  
Keyword(s):  
Siberian Platform ◽  
Lower Cambrian ◽  
Late Precambrian ◽  
Hydrocarbon Biomarkers

On the Late Precambrian–Early Cambrian Hartshill Formation of Warwickshire

1978 ◽  
Vol 115 (1) ◽  
pp. 21-36 ◽  
Author(s):  
M. D. Brasier ◽  
R. A. Hewitt ◽  
C. J. Brasier
Keyword(s):  
Shallow Water ◽  
Lower Cambrian ◽  
Volcanic Rocks ◽  
Trace Fossils ◽  
Early Cambrian ◽  
Late Precambrian

SummaryThe Hartshill Formation (c. 270 m) consists largely of shallow-water feldspathic sandstones and greywackes lying unconformably on Precambrian (Vendian?) volcanic rocks and below shales with the first olenellid trilobites. Five members are recognized. The Park Hill Member is conglomeratic and arkosic near the base, passing up into green-grey megarippled quartzites with some thick shale bands. The Tuttle Hill Member is more shaly and glauconitic with conspicuous bioturbation. The Jee's Member is of distinctly cross-laminated glauconitic, feldspathic greywackes and shales with numerous trace fossils. Conglomerates, shales, sandstones, phosphorites and limestones comprise the Home Farm Member, withadiverse Tommotiantype shelly fauna and stromatolites near the top. Massive arkoses and greywackes of the Woodlands Member yield similar shelly fossils in calcareous beds at the base and top while the overlying Purley Shale yields the first Lower Cambrian trilobites.

Features of paleohydrogeochemistry of the lower cambrian deposits of the Siberian Platform

2020 ◽  
Author(s):  
Anatoly V. Chernykh ◽  
◽  
Dmitry A. Tokarev ◽  
Dmitry A. Novikov ◽  
Fedor F. Dultsev ◽  
...  
Keyword(s):  
Calcium Chloride ◽  
Siberian Platform ◽  
Lower Cambrian ◽  
Early Cambrian ◽  
Potassium Salts ◽  
Modern Chemistry ◽  
Host Rocks

The results of paleohydrogeochemical reconstructions of the Lower Cambrian deposits of the Siberian platform are presented. The characteristic of the main biota groups of the Early Cambrian time of the Siberian paleobasin is given. The conditions of formation and compositional features of syngenetic waters are considered. The modern chemistry of the inter–salt brines is mainly of an inherited nature, while the appearance of super–strong brines of calcium chloride composition is due to the processes of deep interaction of the initial sea brine with the host rocks. Based on the analysis of the hydrogeochemical features of the Lower Cambrian sediments, the prediction of the zones of distribution of potassium salts is given.

Earliest skeletal fossils from Precambrian–Cambrian boundary strata, Elburz Mountains, Iran

1989 ◽  
Vol 126 (3) ◽  
pp. 283-289 ◽  
Author(s):  
B. Hamdi ◽  
M. D. Brasier ◽  
Jiang Zhiwen
Keyword(s):  
Central Asia ◽  
South China ◽  
Siberian Platform ◽  
Early Cambrian ◽  
Late Precambrian

AbstractThe lithological and biotic succession across the late Precambrian to early Cambrian interval is outlined for the Dalir and Valiabad successions of the Elburz Mountains of Iran. The Lower Dolomite Member contains an assemblage of phosphatic tubes and other poorly preserved remains. The succeeding Lower Shale Member bears macroscopic chuariamorphid algae. Early skeletal fossil diversity rises through the Middle Dolomite Member, with the successive appearance ofProtohertzina anabarica, Cambrotubulus decurvatusandAnabarites trisulcatus, culminating near the top of the dolomites with the appearance ofPurellasp.,Maikhanella multa, Tiksitheca licisand circothecids. This succession is compared with lower to upper parts of the Nemakit-Daldyn Formation of Siberia. The overlying Upper Shale Member bears phosphatic beds at its base with allathecids and an uncoiled pelagiellid (?Aldanellasp.) that suggest comparison with lower Tommotian strata and the Precambrian–Cambrian boundary phosphorite event of southern and central Asia. A rich assemblage of molluscs appears high in the Upper Shale Member, including theLatouchella korobkovigroup and thePelagiella lorenzigroup. The succession is broadly homotaxial with those from the Siberian Platform and Mongolia and those platforms bordering Gondwana (India, Kazakhstan, South China).

Magnetostratigraphy of lower Cambrian strata from the Siberian Platform: a palaeomagnetic pole and a preliminary polarity time-scale

1984 ◽  
Vol 121 (3) ◽  
pp. 189-203 ◽  
Author(s):  
Joseph L. Kirschvink ◽  
A. Yu. Rozanov
Keyword(s):  
Siberian Platform ◽  
Time Scale ◽  
Lower Cambrian ◽  
Early Cambrian ◽  
Polar Wander ◽  
Lena River ◽  
Apparent Polar Wander Path ◽  
Geographical Position ◽  
Geomagnetic Polarity ◽  
Geomagnetic Polarity Time Scale

AbstractFour sedimentary sections seen in continuous exposures along the Lena River on the Siberian Platform in Yakutia contain a record of the geomagnetic field during the Tommotian and Atdabanian stages of Early Cambrian time. The direction of the stable remanent magnetization indicates that the Siberian platform was located on the equator, and the corresponding palaeomagnetic pole provides a well-dated extension of the Siberian apparent polar wander path. A belt of archaeocyathid bioherms which separates two major facies zones in the lower Cambrian was positioned on and aligned more or less parallel with the palaeoequator. The geographical position of this belt appears to have tracked the southward motion of the Siberian platform during post-Tommotian time. These palaeomagnetic results combined with the extensive biostratigraphy of the Siberian Platform provide a provisional geomagnetic polarity time scale for this part of Early Cambrian time. Comparison of these results with data of similar age from Central Australia suggests that strata of Tommotian and lower Atdabanian age are not present in the Amadeus Basin of Australia.

scholarly journals New Archaeocyatha Findings from the Oldyndinskaya Suite (Western Transbaikalia)

2021 ◽  
Vol 20 (1) ◽  
pp. 1-10
Author(s):  
M. S. Skripnikov ◽  
◽  
L. I. Vetluzhskikh ◽  
Keyword(s):  
Siberian Platform ◽  
Lower Cambrian ◽  
Early Cambrian ◽  
Western Transbaikalia ◽  
First Time

Archaeocyatha Sajanolynthus desideratus, Nochoroicyathus arteintervallum, Sibirecyathus abacanicus, Stapicyathus abakanensis, Leptosocyathellus mirandus, Cyclocyathella jakovlevi, Plicocyathus admirabilis, Sanarkocyathus sp., Annulocyathella lavrenovae, Clathricoscinus vassilievi, Usloncyathus sp. Indet in the limestones of the Lower Cambrian Oldynda Suite (Western Transbaikalia) were discovered for the first time that makes it possible to contribute to the characteristics of the Oldyndinskaya Suite biodiversity, and determine a closer relationship between paleobasins of the margins of the Siberian Platform in the Early Cambrian.

Pre-Tommotian age of the lower Pestrotsvet Formation in the Selinde section on the Siberian platform: carbon isotopic evidence

2005 ◽  
Vol 142 (4) ◽  
pp. 319-325 ◽  
Author(s):  
ARTEM KOUCHINSKY ◽  
STEFAN BENGTSON ◽  
VLADIMIR PAVLOV ◽  
BRUCE RUNNEGAR ◽  
ANATOLIJ VAL'KOV ◽  
...  
Keyword(s):  
Siberian Platform ◽  
Fossil Record ◽  
Lower Cambrian ◽  
Early Cambrian ◽  
Isotopic Data ◽  
Southeastern Part ◽  
Marine Transgression ◽  
Isotopic Evidence ◽  
Carbon Isotopic ◽  
Isotopic Profile

Carbon isotopic data from the Selinde section in the southeastern part of the Siberian platform area are correlated with the reference isotopic profile from the Lower Cambrian stratotype sections of the Lena–Aldan region, but also show additional δ13C excursions unrecognized there. The chemostratigraphic correlation suggests that the geological and fossil record of the lower Pestrotsvet Formation in the Selinde section has a deeper history than the stratotype region. This conclusion is important for both constraining the age of the earliest Cambrian marine transgression on the Siberian platform and providing a clearer understanding of the pace and order of early Cambrian geochemical and biological events.

The problematic fossil Triplicatella from the Early Cambrian of Greenland, Canada, and Siberia

2004 ◽  
Vol 41 (11) ◽  
pp. 1273-1283 ◽  
Author(s):  
Christian B Skovsted ◽  
John S Peel ◽  
Christian J Atkins
Keyword(s):  
New Species ◽  
Functional Morphology ◽  
Lower Cambrian ◽  
Early Cambrian ◽  
Taxonomic Affinity ◽  
East Greenland ◽  
North East ◽  
Close Proximity ◽  
Two New Species

The cap-shaped Early Cambrian fossil Triplicatella, previously known only from Australia, is reported from the upper Lower Cambrian of North and North-East Greenland, western Newfoundland, and Siberia. The occurrence of Triplicatella in Laurentia strengthens faunal ties between Laurentia and the Australian margin of Gondwana in late Early Cambrian times and supports hypotheses advocating the close proximity for the two palaeocontinents. Two new species, Triplicatella sinuosa n. sp., and T. peltata n. sp. are described, morphological details of which help elucidate the functional morphology and taxonomic affinity of the group. Three opercular types attributable to Triplicatella are left in open taxonomy. The postulated affinity of Triplicatella to hyoliths is confirmed, although the genus can not be placed within either of the two orders of hyoliths currently recognized.

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