3 research outputs found
Investigating controls on boron isotope ratios in shallow marine carbonates
The boron isotope-pH proxy has been widely used to reconstruct past ocean pH values. In both planktic foraminifera and corals, species-specific calibrations are required in order to reconstruct absolute values of pH, due to the prevalence of so-called vital effects — physiological modification of the primary environmental signals by the calcifying organisms. Shallow marine abiotic carbonate (e.g. ooids and cements) could conceivably avoid any such calibration requirement, and therefore provide a potentially useful archive for reconstructions in deep (pre-Cenozoic) time. However, shallow marine abiotic carbonates could also be affected by local shifts in pH caused by microbial photosynthesis and respiration, something that has up to now not been fully tested. In this study, we present boron isotope measurements from shallow modern marine carbonates, from the Bahama Bank and Belize to investigate the potential of using shallow water carbonates as pH archives, and to explore the role of microbial processes in driving nominally ‘abiogenic’ carbonate deposition. For Bahama bank samples, our boron-based pH estimates derived from a range of carbonate types (i.e. ooids, peloids, hardground cements, carbonate mud, stromatolitic micrite and calcified filament micrite) are higher than the estimated modern mean-annual seawater pH values for this region. Furthermore, the majority (73%) of our marine carbonate-based pH estimates fall out of the range of the estimated pre-industrial seawater pH values for this region. In shallow sediment cores, we did not observe a correlation between measured pore water pH and boron-derived pH estimates, suggesting boron isotope variability is a depositional rather than early diagenetic signal. For Belize reef cements, conversely, the pH estimates are lower than likely in situ seawater pH at the time of cement formation. This study indicates the potential for complications when using shallow marine non-skeletal carbonates as marine pH archives. In addition, variability in δ11B based pH estimates provides additional support for the idea that photosynthetic CO2 uptake plays a significant role in driving carbonate precipitation in a wide range of shallow water carbonates.
•δ11B measured in a range of modern shallow marine carbonates.•Boron derived pH shows large variation compared to ambient pH.•Microbial mediation facilitates shallow marine carbonate precipitation.•Many types of shallow marine carbonates cannot be used as boron isotope pH archives
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Palaeontology from Australasia and beyond: Abstracts from Palaeo Down Under 3 Perth, Western Australia, July 2023
Palaeo Down Under 3 (PDU3), the now quadrennial conference of the Australasian Palaeontologists (AAP) association, was held in Perth, Western Australia, from the 10th-14th of July 2023. PDU3 showcased innovative research, outreach and education initiatives being conducted across Australasia and beyond by both local and international scientists. A total of 78 talks, 17 posters and 6 plenaries were presented across the five days, and covered a wide range of topics, geological timeframes, and fossil groups. AAP is proud to publish this compilation of PDU3 abstracts to illustrate the current and ongoing strength of Australasian palaeontology.
Sarah K. Martin [
[email protected]
], Geological Survey of Western Australia, Department of Energy, Mines, Industry Regulation and Safety, 100 Plain St, East Perth, Western Australia 6004, Australia; Michael Archer [
[email protected]
], School of Biological, Earth & Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia; Heidi J. Allen [
[email protected]
], Geological Survey of Western Australia, Department of Energy, Mines, Industry Regulation and Safety, 100 Plain St, East Perth, Western Australia 6004, Australia; Daniel D. Badea [
[email protected]
], Faculty of Geography and Geology, "Alexandru Ioan Cuza" University, Bulevard "Carol I", Nr.11, 707006, Iași, Romania; Eleanor Beidatsch [
[email protected]
], Palaeoscience Research Centre, University of New England, Armidale, New South Wales 2351, Australia; Marissa J. Betts [
[email protected]
], Palaeoscience Research Centre/LLUNE, University of New England, Armidale, New South Wales 2351, Australia; Maria Blake [
[email protected]
], School of Earth, Atmosphere and Environment, Monash University, 9 Rainforest Walk, Clayton, Victoria 3800, Australia; Phillip C. Boan [
[email protected]
], University of California, Riverside, Geology 1242, 900 University Ave, Riverside, CA 92521, U.S.A.; Tory Botha [
[email protected]
], School of Biological Sciences, Molecular Life Sciences Building, North Terrace Campus, The University of Adelaide, Adelaide, South Australia 5005, Australia; Glenn A. Brock [
[email protected]
], School of Natural Sciences, Macquarie University, New South Wales 2109, Australia; Luke Brosnan [
[email protected]
], WA Organic and Isotope Geochemistry Centre, The Institute for Geoscience Research, School of Earth and Planetary Sciences, Building 500, Curtin University, Kent St, Bentley, Western Australia 6102, Australia; Jack Castle-Jones [
[email protected]
], School of Natural Sciences, Macquarie University, New South Wales 2109, Australia; Jonathan Cramb [
[email protected]
], Queensland Museum, PO Box 3300, South Brisbane BC, Queensland 4101, Australia; Vanesa L. De Pietri [
[email protected]
], School of Earth and Environment, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand; Sherri Donaldson [
[email protected]
], School of Geosciences, University of Edinburgh, Grant Institute, The King's Buildings, James Hutton Road, Edinburgh, EH9 3FE, Scotland, U.K.; Elizabeth M. Dowding [
[email protected]
], Friedrich-Alexander-Universität Erlangen-Nürnberg, Loewenichstraße 28 91054 Erlangen, Germany; Ruairidh Duncan [
[email protected]
], Evans EvoMorph Lab, Room 226, 18 Innovation Walk, School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia; Amy L. Elson [
[email protected]
], WA Organic and Isotope Geochemistry Centre, The Institute for Geoscience Research, School of Earth and Planetary Sciences, Building 500, Curtin University, Kent St, Bentley, Western Australia 6102, Australia; Roy M. Farman [
[email protected]
], School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia; Mahala A. Fergusen [
[email protected]
], School of Biological Sciences, Benham Building, North Terrace Campus, The University of Adelaide, Adelaide, South Australia 5005, Australia; Alyssa Fjeld [
[email protected]
], School of Biological Sciences, 18 Innovation Walk, Monash University, Clayton, Victoria 3800, and School of Natural Sciences, Macquarie University, New South Wales 2109, Australia; David Flannery [
[email protected]
], School of Earth and Atmospheric Sciences, Queensland University of Technology, 2 George St, Brisbane, Queensland 4000, Australia; Timothy G. Frauenfelder [
[email protected]
], University of New England, Armidale, New South Wales 2351, Australia; John D. Gorter [
[email protected]
], PO Box 711, Claremont, Western Australia 6910, Australia; Michelle Gray [
[email protected]
], School of Life and Environmental Sciences, Deakin University, Geelong, Victoria 3216, Australia; Nigel Gray [
[email protected]
], GPO Box 2902, Brisbane, Queensland 4001, Australia; Peter Haines [
[email protected]
], Geological Survey of Western Australia, Department of Energy, Mines, Industry Regulation and Safety, 100 Plain St, East Perth, Western Australia 6004, Australia; Lachlan J. Hart [
[email protected]
], Australian Museum Research Institute, 1 William Street, Sydney, New South Wales 2010, Australia; Brooke E. Holland [
[email protected]
], School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia; James D. Holmes [
[email protected]
], Department of Earth Sciences, Palaeobiology, Uppsala University, Villavägen 16, Uppsala 752 36, Sweden; Lars Holmer [
[email protected]
], Department of Earth Sciences, Palaeobiology, Uppsala University, Villavägen 16, Uppsala 752 36, Sweden; Ashleigh V.S. Hood [
[email protected]
], School of Geography, Earth and Atmospheric Sciences, University of Melbourne, Parkville, Victoria 3010, Australia; Alexey P. Ippolitov [
[email protected]]
, School of Geography, Environment and Earth Sciences, Victoria University of Wellington | Te Herenga Waka, 21 Kelburn Parade, Wellington 6012, New Zealand; Christine M. Janis [
[email protected]
], Bristol Palaeobiology Group, School of Earth Sciences, University of Bristol, Wills Memorial Building, Bristol, BS8 1RJ, U.K.; Benjamin P. Kear [
[email protected]
], The Museum of Evolution, Uppsala University, Norbyvägen 16, SE-752 36 Uppsala, Sweden; Sophie Kelly [
[email protected]
], School of Earth and Environment, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand; Justin L. Kitchener [
[email protected]
], School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2351, Australia; John R. Laurie [
[email protected]
], Geoscience Australia, Symonston, Australian Capital Territory 2601, and School of Natural Sciences, Macquarie University, North Ryde, New South Wales 2109, Australia; Lucy G. Leahey [
[email protected]
], The University of Queensland, Brisbane, Queensland 4072, Australia; John A. Long [
[email protected]
], College of Science and Engineering, Flinders University, PO Box 2100, Adelaide, South Australia 5001, Australia; Daniel Mantle [
[email protected]
], MGPalaeo, Unit 1, 5 Arvida Street, Malaga, Western Australia 6090, Australia; David McB. Martin [
[email protected]
], Geological Survey of Western Australia, Department of Energy, Mines, Industry Regulation and Safety, 100 Plain St, East Perth, Western Australia 6004, Australia; Chris Mays [
[email protected]
], School of Biological, Earth and Environmental Sciences, Environmental Research Institute, University College Cork, Distillery Fields, Cork T23 N73K, Ireland; Matthew R. McCurry [
[email protected]
], Australian Museum, 1 William St, Sydney, New South Wales 2010, Australia; Peter McGoldrick [
[email protected]
], CODES, University of Tasmania, Locked Bag 66, Hobart, Tasmania 7001, Australia; Corinne L. Mensforth [
[email protected]
], Flinders University, GPO Box 2100, Adelaide, South Australia 5001, Australia; Rhys D. Meyerkort [
[email protected]
], University of Western Australia, 35 Stirling Hwy, Crawley, Western Australia 6009, Australia; Christina Nielsen-Smith [
[email protected]
], School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia; Ryan Nel [
[email protected]
], Geology Department, Rhodes University, Grahamstown, South Africa; Jake Newman-Martin [
[email protected]
], Curtin University, Kent St, Bentley, Western Australia 6102, Australia; Yeongju Oh [
[email protected]
], Division of Earth Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, 21990 Incheon, Republic of Korea, and Polar Science, University of Science and Technology, Daejeon, 34113, Republic of Korea; John R. Paterson [
[email protected]
], Palaeoscience Research Centre, School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2351, Australia; Jacob Pears [
[email protected]
], School of Molecular and Life Sciences, Curtin University, Kent St, Bentley, Western Australia 6102, Australia; Stephen F. Poropat [
[email protected]
], Western Australian Organic and Isotope Geochemistry Centre, School of Earth and Planetary Science, Curtin University, Kent St, Bentley, Western Australia 6102, and Australian Age of Dinosaurs Museum of Natural History, Winton, Queensland 4735, Australia; Catherine M. Reid [
[email protected]
], School of Earth and Environment, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand; R. Pamela Reid [
[email protected]
], Department of Marine Geosciences, Rosenstiel School of Marine, Atmospheric, and Earth Science, University of Miami, Miami, FL 33149, U.S.A., and Bahamas Marine EcoCentre, Miami, FL 3315