Lowermost Cambrian Ichnofabrics from the Chapel Island Formation, Newfoundland: Implications for Cambrian Substrates
Bioturbation long has been `blamed ' for eliminating late Proterozoic-style sedimentary structures and fabrics. While the presence of diverse and complex burrows in lowermost Cambrian strata is indisputable, analysis of Precambrian± Cambrian successions in southeast Newfoundland demon-strate th...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.519.3406 2023-05-15T17:21:55+02:00 Lowermost Cambrian Ichnofabrics from the Chapel Island Formation, Newfoundland: Implications for Cambrian Substrates Mary L. Droser Soè Ren Jensen James G. Gehling Paul M. Myrow Guy M. Narbonne The Pennsylvania State University CiteSeerX Archives application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.519.3406 http://earthsciences.ucr.edu/docs/DroserM_et_2002.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.519.3406 http://earthsciences.ucr.edu/docs/DroserM_et_2002.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://earthsciences.ucr.edu/docs/DroserM_et_2002.pdf text ftciteseerx 2016-01-08T10:00:45Z Bioturbation long has been `blamed ' for eliminating late Proterozoic-style sedimentary structures and fabrics. While the presence of diverse and complex burrows in lowermost Cambrian strata is indisputable, analysis of Precambrian± Cambrian successions in southeast Newfoundland demon-strate that this burrowing style did not produce typical Phanerozoic-style ichnofabrics. Three hundred meters of the siltstone/sandstone facies of member 2 of the Chapel Island Formation were examined in the area of the Precambrian±Cambrian boundary stra-totype. Gyrolithes, Planolites, and Skolithos occur as sand in®lls ubiquitously throughout siltstone beds, most com-monly without direct contact with an overlying sandstone bed, as if ``¯oating' ' in the siltstone. In contrast, Treptichnus pedum occurs as sand in®lls adhering onto the base of thin sandstone beds that have different grain size and texture than the burrow in®lls. Both of these burrow types repre-sent a style of preservation in which the burrows are unat-tached to an overlying bed of the casting sediment. These styles of preservation occur frequently in the Treptichnus pedum Zone and continue into the Rusophycus avalonen-sis Zone in spite of an increase in trace fossil diversity. The sandstone beds are bioturbated only very rarely. The resul-tant fabric produced by ¯oating and, in particular, adher-ing burrows in these shallow marine deposits appears to be characteristic of many Lower Cambrian rocks. Silt layers appear to have been ®rm enough to have supported open burrows, likely as a result of a negligible mixed layer. This line of reasoning would predict that preservation of this type would be uncommon in younger strata deposited in open marine settings. Text Newfoundland Unknown Burrows ENVELOPE(163.650,163.650,-74.300,-74.300) Chapel Island ENVELOPE(-55.715,-55.715,52.467,52.467) |
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Open Polar |
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Unknown |
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ftciteseerx |
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English |
description |
Bioturbation long has been `blamed ' for eliminating late Proterozoic-style sedimentary structures and fabrics. While the presence of diverse and complex burrows in lowermost Cambrian strata is indisputable, analysis of Precambrian± Cambrian successions in southeast Newfoundland demon-strate that this burrowing style did not produce typical Phanerozoic-style ichnofabrics. Three hundred meters of the siltstone/sandstone facies of member 2 of the Chapel Island Formation were examined in the area of the Precambrian±Cambrian boundary stra-totype. Gyrolithes, Planolites, and Skolithos occur as sand in®lls ubiquitously throughout siltstone beds, most com-monly without direct contact with an overlying sandstone bed, as if ``¯oating' ' in the siltstone. In contrast, Treptichnus pedum occurs as sand in®lls adhering onto the base of thin sandstone beds that have different grain size and texture than the burrow in®lls. Both of these burrow types repre-sent a style of preservation in which the burrows are unat-tached to an overlying bed of the casting sediment. These styles of preservation occur frequently in the Treptichnus pedum Zone and continue into the Rusophycus avalonen-sis Zone in spite of an increase in trace fossil diversity. The sandstone beds are bioturbated only very rarely. The resul-tant fabric produced by ¯oating and, in particular, adher-ing burrows in these shallow marine deposits appears to be characteristic of many Lower Cambrian rocks. Silt layers appear to have been ®rm enough to have supported open burrows, likely as a result of a negligible mixed layer. This line of reasoning would predict that preservation of this type would be uncommon in younger strata deposited in open marine settings. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Mary L. Droser Soè Ren Jensen James G. Gehling Paul M. Myrow Guy M. Narbonne |
spellingShingle |
Mary L. Droser Soè Ren Jensen James G. Gehling Paul M. Myrow Guy M. Narbonne Lowermost Cambrian Ichnofabrics from the Chapel Island Formation, Newfoundland: Implications for Cambrian Substrates |
author_facet |
Mary L. Droser Soè Ren Jensen James G. Gehling Paul M. Myrow Guy M. Narbonne |
author_sort |
Mary L. Droser |
title |
Lowermost Cambrian Ichnofabrics from the Chapel Island Formation, Newfoundland: Implications for Cambrian Substrates |
title_short |
Lowermost Cambrian Ichnofabrics from the Chapel Island Formation, Newfoundland: Implications for Cambrian Substrates |
title_full |
Lowermost Cambrian Ichnofabrics from the Chapel Island Formation, Newfoundland: Implications for Cambrian Substrates |
title_fullStr |
Lowermost Cambrian Ichnofabrics from the Chapel Island Formation, Newfoundland: Implications for Cambrian Substrates |
title_full_unstemmed |
Lowermost Cambrian Ichnofabrics from the Chapel Island Formation, Newfoundland: Implications for Cambrian Substrates |
title_sort |
lowermost cambrian ichnofabrics from the chapel island formation, newfoundland: implications for cambrian substrates |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.519.3406 http://earthsciences.ucr.edu/docs/DroserM_et_2002.pdf |
long_lat |
ENVELOPE(163.650,163.650,-74.300,-74.300) ENVELOPE(-55.715,-55.715,52.467,52.467) |
geographic |
Burrows Chapel Island |
geographic_facet |
Burrows Chapel Island |
genre |
Newfoundland |
genre_facet |
Newfoundland |
op_source |
http://earthsciences.ucr.edu/docs/DroserM_et_2002.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.519.3406 http://earthsciences.ucr.edu/docs/DroserM_et_2002.pdf |
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Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766107918256570368 |