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Reply to ‘Uppermost Cambrian carbon chemostratigraphy: the HERB and undocumented TOCE events are not synonymous’

Published online by Cambridge University Press:  12 October 2020

Maoyan Zhu Open the ORCID record for Maoyan Zhu [Opens in a new window] ,
Loren E. Babcock ,
Shanchi Peng  and
Per Ahlberg
Maoyan Zhu*
Affiliation:
State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology & Center for Excellence in Life and Palaeoenvironment, Chinese Academy of Sciences, Nanjing210008, China College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing100049, China
Loren E. Babcock
Affiliation:
School of Earth Sciences, The Ohio State University, Columbus, OH43210, USA
Shanchi Peng
Affiliation:
State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology & Center for Excellence in Life and Palaeoenvironment, Chinese Academy of Sciences, Nanjing210008, China
Per Ahlberg
Affiliation:
Department of Geology, Lund University, SE 22362, Lund, Sweden
*
Author for correspondence: Maoyan Zhu, Email: [email protected]
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Abstract

In a recent communication on carbon isotope chemostratigraphy of the uppermost Cambrian strata, it was claimed that the Top of Cambrian Excursion (TOCE) is (1) an undocumented negative δ13Ccarb excursion; (2) ambiguously defined; (3) deliberately fictitious or, in the authors’ words, a ‘nihilartikel’; and (4) not synonymous with the Hellnmaria–Red Tops Boundary (HERB) Event. As the authors who have been involved in much of the discussion surrounding the TOCE since its introduction and in subsequent clarification, we wish to emphasize that the recent communication overlooks the fact that the TOCE is in fact a well-documented and clearly defined negative δ13Ccarb excursion, and that the term ‘HERB Event’ was originally used informally, without definition or reference data, for a negative δ13Ccarb peak, a peak later shown to occur within the TOCE excursion. Nearly a decade after the TOCE was named, the concept of the HERB Event was modified from a negative δ13Ccarb peak to a negative δ13Ccarb excursion, making it conceptually synonymous with the TOCE excursion. The recently published commentary is misleading and replete with misconceptions, as we discuss here.

Keywords

CambrianChemostratigraphyTOCEHERB
Type
Discussion - Reply
Information
Geological Magazine , Volume 158 , Issue 7 , July 2021 , pp. 1323 - 1326
Copyright
© The Author(s), 2020. Published by Cambridge University Press

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References

Ahlberg, P, Lundberg, F, Erlström, M, Calner, M, Lindskog, A, Dahlqvist, P and Joachimski, MM (2019) Integrated Cambrian biostratigraphy and carbon isotope chemostratigraphy of the Grönhögen-2015 drill core, Öland, Sweden. Geological Magazine 156, 935–49, doi: 10.1017/S00167568180002.CrossRefGoogle Scholar
Babcock, LE, Peng, SC, Geyer, G and Shergold, JH (2005) Changing perspectives on Cambrian chronostratigraphy and progress toward subdivision of the Cambrian System. Geosciences Journal 9, 101–106.CrossRefGoogle Scholar
Buggisch, W, Keller, M and Lehnert, O (2003) Carbon isotope record of Late Cambrian to Early Ordovician carbonates of the Argentine Precordillera. Palaeogeography, Palaeoclimatology, Palaeoecology 195, 357–73, doi: 10.1016/S0031-0182(03)00365-1.CrossRefGoogle Scholar
Geyer, G (2019) A comprehensive Cambrian correlation chart. Episodes 42, 321–32, doi: 10.18814/epiiugs/2019/019026.Google Scholar
Gradstein, FM, Ogg, JG, Schmitz, M and Ogg, G (eds) (2012) The Geologic Time Scale 2012. Amsterdam: Elsevier BV, 1144 pp.Google Scholar
Gradstein, FM, Ogg, JG, Schmitz, M and Ogg, G (eds) (in press) The Geologic Time Scale 2020. Amsterdam: Elsevier BV.Google Scholar
Harper, DAT, Topper, TP, Cascales-Miñana, B, Servais, T, Zhang, Y-D and Ahlberg, P (2019) The Furongian (late Cambrian) biodiversity gap: real or apparent? Palaeoworld 28, 4–12, doi: 10.1016/j.palwor.2019.01.007.CrossRefGoogle Scholar
International Commission on Zoological Nomenclature (1999) International Code of Zoological Nomenclature, 4th ed. London: International Trust for Zoological Nomenclature, 306 pp.Google Scholar
Landing, E, Ripperdan, RL and Geyer, G (2020) Uppermost Cambrian carbon chemostratigraphy: the HERB and undocumented TOCE events are not synonymous. Geological Magazine, 157, 1373–77, doi: 10.1017/S0016756820000382.CrossRefGoogle Scholar
Landing, E, Westrop, SR and Adrain, JM (2011) The Lawsonian Stage—the Eoconodontus notchpeakensis (Miller, 1969) FAD and HERB carbon isotope excursion define a globally correlatable terminal Cambrian stage. Bulletin of Geosciences 86, 621–40, doi: 10.3140/bull.geosci.1251.CrossRefGoogle Scholar
Li, DD, Zhang, XL, Chen, K, Zhang, G, Chen, XY, Huang, W, Peng, SC and Shen, Y (2017) High resolution C-isotope chemostratigraphy of the uppermost Cambrian stage (Stage 10) in South China: implications for defining the base of Stage 10 and palaeoenvironmental change. Geological Magazine 154, 1232–43, doi: 10.1017/S0016756817000188.CrossRefGoogle Scholar
Miller, JF, Ethington, RL, Evans, KR, Holmer, LE, Loch, JD, Popov, LE, Repetski, JE, Ripperdan, RL and Taylor, JF (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, 384–405, doi: 10.1016/j.palwor.2006.10.017.CrossRefGoogle Scholar
Miller, JF, Evans, KR, Freeman, RL, Loch, JD, Ripperdan, RL and Taylor, JF (2018) Combining biostratigraphy, carbon isotope stratigraphy and sequence stratigraphy to define the base of Cambrian Stage 10. Australasian Palaeontological Memoirs 51, 19–64.Google Scholar
Miller, JF, Evans, KR, Freeman, RL, Ripperdan, RL and Taylor, JF (2014) The proposed GSSP for the base of Cambrian Stage 10 at the First Appearance Datum of the conodont Eoconodontus notchpeakensis (Miller, 1969) in the House Range, Utah, USA. GFF 136, 189–92, doi: 10.1080/11035897.2013.862853.CrossRefGoogle Scholar
Miller, JF, Ripperdan, RL, Loch, JD, Freeman, RL, Evans, KR, Taylor, JF and Tolbart, ZC (2015) Proposed GSSP for the base of Cambrian Stage 10 at the lowest occurrence of Eoconodontus notchpeakensis in the House Range, Utah, USA. Annales de Paléontologie 101, 199–211, doi: 10.1016/j.annpal.2015.04.008.CrossRefGoogle Scholar
Murphy, MA and Salvador, A (1999) International stratigraphic guide—An abridged version. Episodes 22, 255–73.CrossRefGoogle Scholar
Ogg, JG, Ogg, GM and Gradstein, FM (2008) The Concise Geologic Time Scale 2008. Cambridge: Cambridge University Press, 177 pp.Google Scholar
Ogg, JG, Ogg, GM and Gradstein, FM (2016) A Concise Geologic Time Scale 2008. Amsterdam: Elsevier BV, 234 pp.Google Scholar
Peng, SC and Babcock, LE (2005) Two Cambrian agnostoid trilobites, Agnostotes orientalis (Kobayashi, 1935) and Lotagnostus americanus (Billings, 1860): Key species for defining global stages of the Cambrian System. Geoscience Journal 9, 107–15.CrossRefGoogle Scholar
Peng, S and Babcock, LE (2008) Cambrian Period. In The Concise Geologic Time Scale (eds Ogg, J, Ogg, G and Gradstein, FM), pp. 37–46. Cambridge: Cambridge University Press.Google Scholar
Peng, S, Babcock, LE and Ahlberg, P (in press) The Cambrian Period. In The Geologic Time Scale 2020 (eds Gradstein, FM, Ogg, JG, Schmitz, M and Ogg, G). Amsterdam: Elsevier BV.Google Scholar
Peng, S, Babcock, LE and Cooper, RA (2012) The Cambrian Period. In The Geologic Time Scale 2012 (eds Gradstein, FM, Ogg, JG, Schmitz, M and Ogg, G), pp. 437–88. Amsterdam: Elsevier BV.CrossRefGoogle Scholar
Ripperdan, RL (2002) The HERB Event: end of Cambrian carbon cycle paradigm? Geological Society of America, Abstracts with Programs 34, 413.Google Scholar
Ripperdan, RL, Magaritz, M, Nicoll, RS and Shergold, JS (1992) Simultaneous changes in carbon isotopes, sea level, and conodont biozones within Cambrian–Ordovician boundary interval at Black Mountain, Australia. Geology 20, 1039–42, doi: 10.1130/0091-7613(1992)020<1039:SCICIS>2.3.CO;2.2.3.CO;2>CrossRefGoogle Scholar
Ripperdan, RL and Miller, JF (1995) Carbon isotope ratios from the Cambrian–Ordovician boundary section at Lawson Cove, Wah Wah Mountains, Utah. In Ordovician Odyssey: Short Papers for the Seventh International Symposium on the Ordovician System (ed. Cooper, JD), pp. 129–32. Society for Sedimentary Geology, Tulsa, Pacific Section, 77.Google Scholar
Scorrer, S, Azmy, K and Stouge, S (2019) Carbon-isotope stratigraphy of the Furongian Berry Head Formation (Port au Port Group) and Tremadocian Watts Bight Formation (St. George Group), western Newfoundland, and its correlative significance. Canadian Journal of Earth Sciences 56, 223–34, doi: 10.1139/cjes-2018-0059.CrossRefGoogle Scholar
Sial, AN, Peralta, S, Ferriera, VP, Toselli, AJ, Aceñolaza, FG, Parada, MA, Gaucher, C, Alonso, RN and Pimental, MM (2008) Upper Cambrian carbonate sequences of the Argentine Precordillera and the Steptoean C-Isotope Positive Excursion (SPICE). Gondwana Research 13, 437–52, doi: 10.1018/j.gr.2007.05.001.CrossRefGoogle Scholar
Taylor, JF (2006) History and status of the biomere concept. Memoirs of the Association of Australasian Palaeontologists 32, 247–65.Google Scholar
Terfelt, F, Eriksson, ME and Schmitz, B (2014) The Cambrian–Ordovician transition in dysoxic facies in Baltica — diverse faunas and carbon isotope anomalies. Palaeogeography, Palaeoclimatology, Palaeoecology 394, 59–73, doi: 10.1016/j.palaeo.2013.11.021.CrossRefGoogle Scholar
Westrop, SR and Landing, E (2017) The agnostoid arthropod Lotagnostus Whitehouse, 1936 (late Cambrian; Furongian) from Avalonian Cape Breton Island (Nova Scotia, Canada) and its significance for international correlation. Geological Magazine 154, 1001–21, doi: 10.1017/S0016756816000571.CrossRefGoogle Scholar
Zhu, M, Yang, A, Yuan, J, Li, G, Zhang, J, Zhao, F, Ahn, S-Y and Miao, L (2019) Cambrian integrative stratigraphy and timescale of China. Science China Earth Science 62, 25–60, doi: 10.1007/s11430-017-9291-0.CrossRefGoogle Scholar
Zhu, M-Y, Babcock, LE and Peng, S-C (2006) Advances in Cambrian stratigraphy and paleontology: Integrating correlation techniques, paleobiology, taphonomy and paleoenvironmental reconstruction. Palaeoworld 15, 217–22, doi: 10.1016/j.palwor.2006.10.016.CrossRefGoogle Scholar