Stage 10 of the Cambrian is the still unnamed third and final stage of the Furongian series. It follows the Jiangshanian and precedes the Ordovician Tremadocian Stage.[3] The proposed lower boundary is the first appearance of the trilobite Lotagnostus americanus around 489.5 million years ago, but other fossils are also being discussed (see below). The upper boundary is defined as the appearance of the conodontIapetognathus fluctivagus which marks the beginning of the Tremadocian and is radiometrically dated as 485.4 million years ago.[4]
The 10th stage of the Cambrian has not been formally named by the ICS yet, although a number of local names exist.[3] Several authors favor the name "Lawsonian" after Lawson Cove, in the Wah Wah Mountains of Utah.[5][6] The lower part of the North American Skullrockian Stage corresponds roughly to the Cambrian Stage 10.[7]
Stratotypeedit
The ICS is still discussing which geological section and biostratigraphic marker will be used to define the base of the 10th Cambrian stage.
Likely candidates for the section are still investigated. A first proposal was a section near Duibian, Zhejiang province (China). Note recent publications favor Steamboat Pass in the House Range of Utah. If a conodont is used for the base the stage then many more sections would be likely candidates for the GSSP, e.g. in Australia, Kazakhstan and Canada.[5]
Candidates for the biostratigraphic marker are the first appearance of a trilobite or conodont species. The trilobite Lotagnostus americanus was first suggested by the ICS, but has proven to be problematic.[4][5] In 2006 another working group proposed the first appearance of Cordylodus andresi.[8] Currently the first appearance of Eoconodontus notchpeakensis is favored by many authors because it is globally widespread and is independent of facies (known from continental rise to peritidal environments).[5]
The Eoconodontus notchpeakensis proposal would also incorporate a non-biostratigraphic marker to correlate the beginning of stage 10 globally. A carbon isotope excursion (the HERB-event) occurs in the lower part of the E. notchpeakensis]] range.[5]
Subdivisionsedit
Cambrian Stage 10 can be subdivided using different biostratigraphic zones. Several conodont zone and subzones can be distinguished. The same is true for trilobites.[5]
Referencesedit
^"Chart/Time Scale". stratigraphy.org. International Commission on Stratigraphy.
^Cooper, Roger; Nowlan, Godfrey; Williams, S. H. (March 2001). "Global Stratotype Section and Point for base of the Ordovician System" (PDF). Episodes. 24 (1): 19–28. doi:10.18814/epiiugs/2001/v24i1/005. Retrieved 6 December 2020.
^ ab. International Commission on Stratigraphy. Archived from the original on 2012-10-30. Retrieved 17 November 2012.
^ abcdefLanding, E.; Westrop, S.R.; Adrain, J.M. (19 September 2011). "The Lawsonian Stage - the Eoconodontus notchpeakensis FAD and HERB carbon isotope excursion define a globally correlatable terminal Cambrian stage". Bulletin of Geosciences: 621–640. doi:10.3140/bull.geosci.1251.
^Miller, J.F.; Evans, K.R.; Freeman, R.L.; Ripperdan, R.L.; Taylor, J.F. (4 August 2011). "Proposed stratotype for the base of the Lawsonian Stage (Cambrian Stage 10) at the First Appearance Datum of Eoconodontus notchpeakensis (Miller) in the House Range, Utah, USA". Bulletin of Geosciences: 595–620. doi:10.3140/bull.geosci.1255.
^Freeman, Rebecca L.; Miller, James F.; Dattilo, Benjamin F. (September 2018). "Linguliform brachiopods across a Cambrian–Ordovician (Furongian, Early Ordovician) biomere boundary: the Sunwaptan–Skullrockian North American Stage boundary in the Wilberns and Tanyard formations of central Texas". Journal of Paleontology. 92 (5): 751–767. Bibcode:2018JPal...92..751F. doi:10.1017/jpa.2018.8. S2CID 134012657.
^Miller, James F.; Ethington, Raymond L.; Evans, Kevin R.; Holmer, Lars E.; Loch, James D.; Popov, Leonid E.; Repetski, John E.; Ripperdan, Robert L.; Taylor, John F. (31 July 2006). "Proposed stratotype for the base of the highest Cambrian stage at the first appearance datum of Cordylodus andresi, Lawson Cove section, Utah, USA". Palaeoworld. 15 (3–4): 384–405. doi:10.1016/j.palwor.2006.10.017.
February 16, 2024
cambrian, stage, stage, cambrian, still, unnamed, third, final, stage, furongian, series, follows, jiangshanian, precedes, ordovician, tremadocian, stage, proposed, lower, boundary, first, appearance, trilobite, lotagnostus, americanus, around, million, years,. Stage 10 of the Cambrian is the still unnamed third and final stage of the Furongian series It follows the Jiangshanian and precedes the Ordovician Tremadocian Stage 3 The proposed lower boundary is the first appearance of the trilobite Lotagnostus americanus around 489 5 million years ago but other fossils are also being discussed see below The upper boundary is defined as the appearance of the conodont Iapetognathus fluctivagus which marks the beginning of the Tremadocian and is radiometrically dated as 485 4 million years ago 4 Cambrian Stage 10 489 5 485 4 1 9 Ma PreꞒ Ꞓ O S D C P T J K Pg N Chronology 540 535 530 525 520 515 510 505 500 495 490 485 N PaleozoicEdiacaranCambrianOTerreneuvianSeries2Miaoling Furong EFortunian Stage 2 Stage 3 Stage 4 WuliuanDrumianGuzhangianPaibianJiangshanian Stage 10 Tremadocian Orsten Fauna Burgess Shale Kaili biota Archaeocyatha extinction Emu Bay Shale Sirius Passet biota Chengjiang biota First Trilobites SSF diversification first brachiopods amp archaeocyatha First halkieriids mollusss hyoliths SSF Baykonurian glaciation Dresbachian extinction Major Glacial periodSubdivision of the Cambrian according to the ICS as of 2022 1 Vertical axis scale millions of years agoEtymologyName formalityInformalUsage informationCelestial bodyEarthRegional usageGlobal ICS Time scale s usedICS Time ScaleDefinitionChronological unitAgeStratigraphic unitStageTime span formalityFormalLower boundary definitionNot formally definedLower boundary definition candidatesFAD of the Trilobite Lotagnostus americanusLower boundary GSSP candidate section s Duibian Zhejiang ChinaUpper boundary definitionFAD of the Conodont Iapetognathus fluctivagus Upper boundary GSSPGreenpoint section Green Point Newfoundland Canada49 40 58 N 57 57 55 W 49 6829 N 57 9653 W 49 6829 57 9653Upper GSSP ratified2000 2 Contents 1 Naming 2 Stratotype 3 Subdivisions 4 ReferencesNaming editThe 10th stage of the Cambrian has not been formally named by the ICS yet although a number of local names exist 3 Several authors favor the name Lawsonian after Lawson Cove in the Wah Wah Mountains of Utah 5 6 The lower part of the North American Skullrockian Stage corresponds roughly to the Cambrian Stage 10 7 Stratotype editThe ICS is still discussing which geological section and biostratigraphic marker will be used to define the base of the 10th Cambrian stage Likely candidates for the section are still investigated A first proposal was a section near Duibian Zhejiang province China Note recent publications favor Steamboat Pass in the House Range of Utah If a conodont is used for the base the stage then many more sections would be likely candidates for the GSSP e g in Australia Kazakhstan and Canada 5 Candidates for the biostratigraphic marker are the first appearance of a trilobite or conodont species The trilobite Lotagnostus americanus was first suggested by the ICS but has proven to be problematic 4 5 In 2006 another working group proposed the first appearance of Cordylodus andresi 8 Currently the first appearance of Eoconodontus notchpeakensis is favored by many authors because it is globally widespread and is independent of facies known from continental rise to peritidal environments 5 The Eoconodontus notchpeakensis proposal would also incorporate a non biostratigraphic marker to correlate the beginning of stage 10 globally A carbon isotope excursion the HERB event occurs in the lower part of the E notchpeakensis range 5 Subdivisions editCambrian Stage 10 can be subdivided using different biostratigraphic zones Several conodont zone and subzones can be distinguished The same is true for trilobites 5 References edit Chart Time Scale stratigraphy org International Commission on Stratigraphy Cooper Roger Nowlan Godfrey Williams S H March 2001 Global Stratotype Section and Point for base of the Ordovician System PDF Episodes 24 1 19 28 doi 10 18814 epiiugs 2001 v24i1 005 Retrieved 6 December 2020 a b Stratigraphic Chart International Commission on Stratigraphy Archived from the original on 2012 10 30 Retrieved 17 November 2012 a b GSSP Table Paleozoic Era Geologic Timescale Foundation Retrieved 17 November 2012 a b c d e f Landing E Westrop S R Adrain J M 19 September 2011 The Lawsonian Stage the Eoconodontus notchpeakensis FAD and HERB carbon isotope excursion define a globally correlatable terminal Cambrian stage Bulletin of Geosciences 621 640 doi 10 3140 bull geosci 1251 Miller J F Evans K R Freeman R L Ripperdan R L Taylor J F 4 August 2011 Proposed stratotype for the base of the Lawsonian Stage Cambrian Stage 10 at the First Appearance Datum of Eoconodontus notchpeakensis Miller in the House Range Utah USA Bulletin of Geosciences 595 620 doi 10 3140 bull geosci 1255 Freeman Rebecca L Miller James F Dattilo Benjamin F September 2018 Linguliform brachiopods across a Cambrian Ordovician Furongian Early Ordovician biomere boundary the Sunwaptan Skullrockian North American Stage boundary in the Wilberns and Tanyard formations of central Texas Journal of Paleontology 92 5 751 767 Bibcode 2018JPal 92 751F doi 10 1017 jpa 2018 8 S2CID 134012657 Miller James F Ethington Raymond L Evans Kevin R Holmer Lars E Loch James D Popov Leonid E Repetski John E Ripperdan Robert L Taylor John F 31 July 2006 Proposed stratotype for the base of the highest Cambrian stage at the first appearance datum of Cordylodus andresi Lawson Cove section Utah USA Palaeoworld 15 3 4 384 405 doi 10 1016 j palwor 2006 10 017 Retrieved from https en wikipedia org w index php title Cambrian Stage 10 amp oldid 1182620562, wikipedia, wiki, book, books, library,
