Decision on the Precambrian-Cambrian boundary stratotype

Brasier, Martin D.; Cowie, J. W.; Taylor, Michael H.

doi:10.18814/epiiugs/1994/v17i1.2/002

Cited by 205 publications

(108 citation statements)

References 0 publications

Supporting

Mentioning

107

Contrasting

Order By: Relevance

“…However, in the Angepena region, the Uratanna Formation continues for more than 80 km in the field (Coats 1973). The formation was recognised by Daily (1972Daily ( , 1973 and contains the trace fossils Phycodes, Rusophycus and soft-bodied metazoan Sabellidites, which Mount (1993) correlated with the basal Cambrian stratotype section in Newfoundland, Canada (Narbonne et al 1987;Brasier et al 1994). In the Castle Rock section of the northern Flinders Ranges, the Uratanna Formation contains a deltaic succession and consists of a lowstand wedge and submarine channel deposit, which passes up into prodelta/mid-shelf deep water laminated siltstone and grades upwards into a highstand delta front and shoreface siltstone and sandstone (Fig.…”

Section: Cambrian Successions In South Australiamentioning

confidence: 99%

“…The Precambrian-Cambrian boundary is defined on the basis of the trace fossil Trichophycus pedum Zone in Newfoundland (Brasier et al 1994), but this boundary has been seriously challenged by a study of ichnofossil assemblages from the Nama Group in Namibia, where a Trichophycus pedum (= Phycodes pedum) bearing assemblage occurs below the occurrence of Petalonamae and Cloudina (Geyer & Uchman 1995). In South Australia, the Precambrian-Cambrian boundary is also in dispute; it has been placed at either the base of the Uratanna Formation (Daily 1972(Daily , 1976Gravestock & Shergold 2001) or in the middle of the formation approximately level with the first appearance of Phycodes coronatum (Mount 1993).…”

Section: Review Of Faunal Biozonesmentioning

confidence: 99%

See 1 more Smart Citation

Early Cambrian acritarch assemblage zones in South Australia and global correlation

2007

Alcheringa: An Australasian J. of Palaeontology

View full text Add to dashboard Cite

Section: Cambrian Successions In South Australiamentioning

confidence: 99%

Section: Review Of Faunal Biozonesmentioning

confidence: 99%

Early Cambrian acritarch assemblage zones in South Australia and global correlation

2007

Alcheringa: An Australasian J. of Palaeontology

View full text Add to dashboard Cite

“…These Lower Cambrian correlations need to be assessed in the context of the definition of the Precambrian-Cambrian boundary at the base of the Phycodes pedum (ichnofossil) Zone, in the Chapel Island Formation, at Fortune Head, SE Newfoundland (Brasier et al 1994). That horizon also marks the base of the Placentian Series (Landing 1994), which probably represents most of Lower Cambrian time, and lies 1400 m below the first appearance of trilobites in the Branchian Series.…”

Section: Correlation Of the Durness Successionmentioning

confidence: 99%

“…All the biostratigraphical information relating to the age of the base of the Durness Group, therefore, comes from either the An t-Sron or Assynt areas. Brasier (1977) recorded sponge spicules with fragmentary trilobites, hyolithids, archaeocyathids (Ajacicyathacea), algal filaments, Renalcis and acritarchs from an horizon 10 m above the base of the Eilean Dubh Formation at Inchnadamph. The section there occurs in the same structural position as that containing the new olenellid specimen, between the Sole and Glencoul thrusts.…”

Section: Correlation Of the Durness Successionmentioning

confidence: 99%

Olenellus and conodonts from the Durness Group, NW Scotland, and the correlation of the Durness succession

Huselbee

Thomas

1998

SJG

View full text Add to dashboard Cite

Synopsis Olenellus is recorded from the basal Grudaidh Formation of the Durness Group for the first time, thus confirming the Lower Cambrian age of that part of the succession. Lower Ordovician conodonts have been collected from near the top of the Eilean Dubh Formation, showing that the Cambrian-Ordovician boundary must lie within that unit, at a level somewhat lower than formerly supposed. Previous correlations are reviewed in the light of these new data. There is no positive evidence for rocks of early Lower Cambrian (Placentian) age in NW Scotland. The occurrence of Salterella in the Pipe Rock Member (Eriboll Formation) and the An t-Sròn and basal Grudaidh formations, and of Olenellus in the second two, indicates that part of the sequence belongs to the Olenellus Biozone (Toyonian Stage, Branchian Series) of the late Lower Cambrian. The upper part of the Grudaidh and lower part of the Eilean Dubh formations are probably of Middle Cambrian age, while the upper part of the Eilean Dubh spans the Upper Cambrian to earliest Ordovican. If non-sequences are present within the Eilean Dubh Formation, they are of only short duration. Previously published evidence shows that the higher formations of the Durness Group range from Tremadoc to Llanvirn in age.

show abstract

“…Because trace fossils can constrain early Metazoan origins, and are used to defi ne the base of the Cambrian Period (Brasier et al, 1994), such a signifi cant claim requires justifi cation by careful interpretation of the material, and critical analysis, both of which appear wanting here. Although we agree that multiple biological and ecological revolutions took place during the late Ediacaran Period, we question whether those events can be tied to these problematic fossils.…”

mentioning

confidence: 99%