Carbonates in Skeleton-poor Seas: New Insights From Cambrian and Ordovician Strata of Laurentia
Calcareous skeletons evolved as part of the greater Ediacaran–Cambrian diversification of marine animals. Skeletons did not become permanent, globally important sources of carbonate sediment, however, until the Ordovician radiation. Representative carbonate facies in a Series 3 (510–501 Ma) Camb...
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ftcaltechauth:oai:authors.library.caltech.edu:42w3z-kak53 2024-10-13T14:09:09+00:00 Carbonates in Skeleton-poor Seas: New Insights From Cambrian and Ordovician Strata of Laurentia Pruss, Sara B. Finnegan, Seth Fischer, Woodward W. Knoll, Andrew H. 2010 https://doi.org/10.2110/palo.2009.p09-101r unknown Society for Sedimentary Geology eprintid:17600 info:eu-repo/semantics/openAccess Other Palaios, 25(2), 73-84, (2010) info:eu-repo/semantics/article 2010 ftcaltechauth https://doi.org/10.2110/palo.2009.p09-101r 2024-09-25T18:46:35Z Calcareous skeletons evolved as part of the greater Ediacaran–Cambrian diversification of marine animals. Skeletons did not become permanent, globally important sources of carbonate sediment, however, until the Ordovician radiation. Representative carbonate facies in a Series 3 (510–501 Ma) Cambrian to Tremadocian succession from western Newfoundland, Canada, and Ordovician successions from the Ibex area, Utah, USA, show that, on average, Cambrian and Tremadocian carbonates contain much less skeletal material than do post-Tremadocian sediments. Petrographic point counts of skeletal abundance within facies and proportional facies abundance in measured sections suggest that later Cambrian successions contain on average <5% skeletal material by volume, whereas the skeletal content of post-Tremadocian Ordovician sections is closer to ~15%. A compilation of carbonate stratigraphic sections from across Laurentia confirms that post-Tremadocian increase in skeletal content is a general pattern and not unique to the two basins studied. The long interval (~40 myr) between the initial Cambrian appearance of carbonate skeletons and the subsequent Ordovician diversification of heavily skeletonized organisms provides an important perspective on the Ordovician radiation. Geochemical data increasingly support the hypothesis that later Cambrian oceans were warm and, in subsurface water masses, commonly dysoxic to anoxic. We suggest that surface waters in such oceans would have been characterized by relatively low saturation states for calcite and aragonite. Mid-Ordovician cooling would have raised oxygen concentrations in subsurface water masses, establishing more highly oversaturated surface waters. If correct, these links could provide a proximal trigger for the renewed radiation of heavily skeletonized invertebrates and algae. © 2010 SEPM Society for Sedimentary Geology. Accepted September 28, 2009. We thank the Agouron Institute (postdoctoral fellowship to SP) and NSF Grant DES 0420592 (AHK) for partial funding of ... Article in Journal/Newspaper Newfoundland Caltech Authors (California Institute of Technology) Canada PALAIOS 25 2 73 84 |
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Calcareous skeletons evolved as part of the greater Ediacaran–Cambrian diversification of marine animals. Skeletons did not become permanent, globally important sources of carbonate sediment, however, until the Ordovician radiation. Representative carbonate facies in a Series 3 (510–501 Ma) Cambrian to Tremadocian succession from western Newfoundland, Canada, and Ordovician successions from the Ibex area, Utah, USA, show that, on average, Cambrian and Tremadocian carbonates contain much less skeletal material than do post-Tremadocian sediments. Petrographic point counts of skeletal abundance within facies and proportional facies abundance in measured sections suggest that later Cambrian successions contain on average <5% skeletal material by volume, whereas the skeletal content of post-Tremadocian Ordovician sections is closer to ~15%. A compilation of carbonate stratigraphic sections from across Laurentia confirms that post-Tremadocian increase in skeletal content is a general pattern and not unique to the two basins studied. The long interval (~40 myr) between the initial Cambrian appearance of carbonate skeletons and the subsequent Ordovician diversification of heavily skeletonized organisms provides an important perspective on the Ordovician radiation. Geochemical data increasingly support the hypothesis that later Cambrian oceans were warm and, in subsurface water masses, commonly dysoxic to anoxic. We suggest that surface waters in such oceans would have been characterized by relatively low saturation states for calcite and aragonite. Mid-Ordovician cooling would have raised oxygen concentrations in subsurface water masses, establishing more highly oversaturated surface waters. If correct, these links could provide a proximal trigger for the renewed radiation of heavily skeletonized invertebrates and algae. © 2010 SEPM Society for Sedimentary Geology. Accepted September 28, 2009. We thank the Agouron Institute (postdoctoral fellowship to SP) and NSF Grant DES 0420592 (AHK) for partial funding of ... |
format |
Article in Journal/Newspaper |
author |
Pruss, Sara B. Finnegan, Seth Fischer, Woodward W. Knoll, Andrew H. |
spellingShingle |
Pruss, Sara B. Finnegan, Seth Fischer, Woodward W. Knoll, Andrew H. Carbonates in Skeleton-poor Seas: New Insights From Cambrian and Ordovician Strata of Laurentia |
author_facet |
Pruss, Sara B. Finnegan, Seth Fischer, Woodward W. Knoll, Andrew H. |
author_sort |
Pruss, Sara B. |
title |
Carbonates in Skeleton-poor Seas: New Insights From Cambrian and Ordovician Strata of Laurentia |
title_short |
Carbonates in Skeleton-poor Seas: New Insights From Cambrian and Ordovician Strata of Laurentia |
title_full |
Carbonates in Skeleton-poor Seas: New Insights From Cambrian and Ordovician Strata of Laurentia |
title_fullStr |
Carbonates in Skeleton-poor Seas: New Insights From Cambrian and Ordovician Strata of Laurentia |
title_full_unstemmed |
Carbonates in Skeleton-poor Seas: New Insights From Cambrian and Ordovician Strata of Laurentia |
title_sort |
carbonates in skeleton-poor seas: new insights from cambrian and ordovician strata of laurentia |
publisher |
Society for Sedimentary Geology |
publishDate |
2010 |
url |
https://doi.org/10.2110/palo.2009.p09-101r |
geographic |
Canada |
geographic_facet |
Canada |
genre |
Newfoundland |
genre_facet |
Newfoundland |
op_source |
Palaios, 25(2), 73-84, (2010) |
op_relation |
eprintid:17600 |
op_rights |
info:eu-repo/semantics/openAccess Other |
op_doi |
https://doi.org/10.2110/palo.2009.p09-101r |
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73 |
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84 |
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1812816013386842112 |