The Mount Cap Formation is a geologic formation exposed in the Mackenzie Mountains, northern Canada. It was deposited in a shallow shelf setting in the late Early Cambrian,[1] and contains an array of Burgess Shale-type microfossils that have been recovered by acid maceration.[2]
| Mount Cap Formation | |
|---|---|
| Stratigraphic range: Cambrian | |
| Type | Formation |
| Lithology | |
| Primary | Shale, siltstone |
| Other | Sandstone |
| Location | |
| Coordinates | 63°24′23″N 123°12′22″W / 63.40639°N 123.20611°W |
| Region | Northwest Territories |
| Country |  Canada |
  Mount Cap formation (Canada) | |
Description
editThe formation is 100 to 300 metres (330 to 980 ft), and comprises shales, siltstones and sandstones with a high glauconite content.[1] It has been exposed to remarkably little metamorphic activity given its great age; it is dated to the Bonnia–Olenellus Trilobite Zone.[1] This zone lies within the Lower Cambrian Waucoban stage in North America, which is equivalent to the Caerfai in Wales, and thus the Comley of England,[3] and has yet to be formally ratified. Nevertheless, this makes it just younger than the earliest trilobites,[dubious – discuss] and thus the earliest known Burgess Shale-type deposit, though this is disputable when considering the age of Chengjiang County fauna. Its organic-walled fauna, known as the "Little Bear biota", includes both non-mineralized and originally-mineralized taxa, including hyolith and trilobite fragments, anomalocaridid claws, arthropod carapaces and brachiopods.[4]
See also
edit
References
edit- ^ a b c Butterfield, N. J. (1994). "Burgess Shale-type fossils from a Lower Cambrian shallow-shelf sequence in northwestern Canada". Nature. 369 (6480): 477–479. Bibcode:1994Natur.369..477B. doi:10.1038/369477a0. S2CID 4326311.477-479&rft.date=1994&rft_id=https://api.semanticscholar.org/CorpusID:4326311#id-name=S2CID&rft_id=info:doi/10.1038/369477a0&rft_id=info:bibcode/1994Natur.369..477B&rft.aulast=Butterfield&rft.aufirst=N. J.&rfr_id=info:sid/en.wikipedia.org:Mount Cap formation" class="Z3988">
- ^ Harvey, T.; Butterfield, N. (2008). "Sophisticated particle-feeding in a large Early Cambrian crustacean". Nature. 452 (7189): 868–871. Bibcode:2008Natur.452..868H. doi:10.1038/nature06724. PMID 18337723. S2CID 4373816.868-871&rft.date=2008&rft_id=info:doi/10.1038/nature06724&rft_id=https://api.semanticscholar.org/CorpusID:4373816#id-name=S2CID&rft_id=info:pmid/18337723&rft_id=info:bibcode/2008Natur.452..868H&rft.aulast=Harvey&rft.aufirst=T.&rft.au=Butterfield, N.&rfr_id=info:sid/en.wikipedia.org:Mount Cap formation" class="Z3988">
- ^ Siveter, D. J.; Williams, M. (1995). "An early Cambrian assignment for the Caerfai Group of South Wales". Journal of the Geological Society. 152 (2): 221–224. Bibcode:1995JGSoc.152..221S. doi:10.1144/gsjgs.152.2.0221. S2CID 140607675.221-224&rft.date=1995&rft_id=https://api.semanticscholar.org/CorpusID:140607675#id-name=S2CID&rft_id=info:doi/10.1144/gsjgs.152.2.0221&rft_id=info:bibcode/1995JGSoc.152..221S&rft.aulast=Siveter&rft.aufirst=D. J.&rft.au=Williams, M.&rfr_id=info:sid/en.wikipedia.org:Mount Cap formation" class="Z3988">
- ^ Butterfield, N. J.; Nicholas, C. J. (1996). "Burgess Shale-Type Preservation of Both Non-Mineralizing and 'Shelly' Cambrian Organisms from the Mackenzie Mountains, Northwestern Canada". Journal of Paleontology. 70 (6): 893–899. Bibcode:1996JPal...70..893B. doi:10.1017/S0022336000038579. JSTOR 1306492. S2CID 133427906.893-899&rft.date=1996&rft_id=info:doi/10.1017/S0022336000038579&rft_id=https://api.semanticscholar.org/CorpusID:133427906#id-name=S2CID&rft_id=https://www.jstor.org/stable/1306492#id-name=JSTOR&rft_id=info:bibcode/1996JPal...70..893B&rft.aulast=Butterfield&rft.aufirst=N. J.&rft.au=Nicholas, C. J.&rfr_id=info:sid/en.wikipedia.org:Mount Cap formation" class="Z3988">
External links
edit- Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Retrieved July 8, 2014.