CaltechAUTHORS
  A Caltech Library Service

A paired apatite and calcite clumped isotope thermometry approach to estimating Cambro-Ordovician seawater temperatures and isotopic composition

Bergmann, Kristin D. and Finnegan, Seth and Creel, Roger and Eiler, John M. and Hughes, Nigel C. and Popov, Leonid E. and Fischer, Woodward W. (2018) A paired apatite and calcite clumped isotope thermometry approach to estimating Cambro-Ordovician seawater temperatures and isotopic composition. Geochimica et Cosmochimica Acta, 224 . pp. 18-41. ISSN 0016-7037. http://resolver.caltech.edu/CaltechAUTHORS:20180130-140846187

[img] MS Excel - Supplemental Material
See Usage Policy.

1442Kb

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20180130-140846187

Abstract

The secular increase in δ^(18)O values of both calcitic and phosphatic marine fossils through early Phanerozoic time suggests either that (1) early Paleozoic surface temperatures were high, in excess of 40 °C (tropical MAT), (2) the δ^(18)O value of seawater has increased by 7–8‰ VSMOW through Paleozoic time, or (3) diagenesis has altered secular trends in early Paleozoic samples. Carbonate clumped isotope analysis, in combination with petrographic and elemental analysis, can deconvolve fluid composition from temperature effects and therefore determine which of these hypotheses best explain the secular δ^(18)O increase. Clumped isotope measurements of a suite of calcitic and phosphatic marine fossils from late Cambrian- to Middle-late Ordovician-aged strata–the first paired fossil study of its kind–document tropical sea surface temperatures near modern temperatures (26–38 °C) and seawater oxygen isotope ratios similar to today’s ratios.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1016/j.gca.2017.11.015DOIArticle
https://www.sciencedirect.com/science/article/pii/S0016703717307287PublisherArticle
ORCID:
AuthorORCID
Fischer, Woodward W.0000-0002-8836-3054
Additional Information:© 2017 Elsevier Ltd. Received 8 February 2017, Accepted 10 November 2017, Available online 6 December 2017. We thank Ethan Grossman, Cedric John and an anonymous reviewer for helpful comments that improved the manuscript. The Los Angeles County Museum of Natural History, the Waikiki Aquarium and Norene Tuross provided samples of modern linguliform and calcitic brachiopods. Victoria Orphan provided the calcitic brachiopod from Monterey Canyon. Matthew Robles and Gerry Gunderson provided Eau Claire materials and collaborated on fieldwork in the Eau Claire Formation. Norlene Emerson, Clint Cowan, and Pat McLaughlin provided invaluable assistance on the Decorah Formation in the field. Nami Kitchen, Joel Hurowitz, Chi Ma and Katie Eiler assisted with analytical measurements and method development. Page Quinton and Ken MacLeod are responsible for phosphate δ^(18)O measurements on splits of the ancient linguliform brachiopod samples and two of our modern linguliform samples. A National Science Foundation Graduate Research Fellowship was provided to K. Bergmann. Support for analyses was provided by a National Science Foundation award (EAR-1053523) to WWF and JME. WWF acknowledges support from the Agouron Institute and a David and Lucile Packard Fellowship for Science and Engineering. LEP acknowledges logistical support from the National Museum of Wales, Cardiff.
Funders:
Funding AgencyGrant Number
NSF Graduate Research FellowshipUNSPECIFIED
NSFEAR-1053523
Agouron InstituteUNSPECIFIED
David and Lucile Packard FoundationUNSPECIFIED
Subject Keywords:Clumped isotope; Apatite; Calcite; Seawater; Oxygen isotope
Record Number:CaltechAUTHORS:20180130-140846187
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20180130-140846187
Official Citation:Kristin D. Bergmann, Seth Finnegan, Roger Creel, John M. Eiler, Nigel C. Hughes, Leonid E. Popov, Woodward W. Fischer. A paired apatite and calcite clumped isotope thermometry approach to estimating Cambro-Ordovician seawater temperatures and isotopic composition, Geochimica et Cosmochimica Acta, Volume 224, 2018, Pages 18-41, ISSN 0016-7037, https://doi.org/10.1016/j.gca.2017.11.015. (http://www.sciencedirect.com/science/article/pii/S0016703717307287)
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:84587
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:31 Jan 2018 00:06
Last Modified:31 Jan 2018 00:06

Repository Staff Only: item control page