Hikurangi Trough late Pleistocene palaeoceanography, biostratigraphy and Cretaceous Ocean Anoxia Events (OAEs)
Lead Research Organisation:
University of Leeds
Department Name: School of Earth and Environment
Abstract
Part I:
The regions of the world's oceans, which border Antarctica, are critical for controlling the Earth's climate. Firstly, the largely unhindered transit of ocean currents (the Antarctic circumpolar current, ACC) that circle and Antarctic continent enables the continued maintenance of its huge continental ice sheets. Secondly, a permanent thermal boundary between water masses extends to the ocean surface within the Subtropical Convergence (STC) in this region. Consequently, this is a region of high biological productivity due to the mixing of micronutrient-rich subtropical waters (STW) with macronutrient-rich subantarctic waters (SAW). As such the STC is a highly important sink for atmospheric CO2 due to high levels of primary productivity.
This region is also influenced by the presence and extent of the Western Antarctic Ice Sheet (WAIS). The extent of this ice sheet has been shown to alter the latitudinal positioning of the Southern Hemisphere STC by up to 7 degrees from stadial-interstadial cycles of the Late Pleistocene epoch (last 800 ka), and may subsequently partially decouple global climate from atmospheric partial pressure of carbon dioxide. Previous studies highlighting the Late Pleistocene evolution of sea surface and intermediate waters within the southwest Pacific have indicated complex behaviour of the subtropical front (STF) throughout this interval.
Utilizing samples from site U1520D from within the Hikurangi Trough (Expedition 375), we propose a high resolution (<1 kyr) study of late Pleistocene foraminifera to better constrain the regional paleoceanography over the last 130 ka, and how this relates to climate forcing. We aim to better understand the STC through paired measurements of oxygen isotopes and Mg/Ca trace element ratios of both planktonic (Globigerina bulloides) and benthic foraminifera (Uvigerina peregrina). G. bulloides is a symbiont-barren, opportunistic species which often dominates the foraminifer fauna, and sediment assemblage of the ocean floor, and is therefore an important source of geochemical information for palaeoceanographic studies. U. peregrina is an infaunal benthic species, which has also been used extensively to calculate intermediate water properties throughout the Pliocene-Pleistocene. These stable isotope and trace metal records are required to assess the scale and timing of surface and intermediate water temperature, and salinity across the STC. This data will subsequently contribute to our knowledge of the extent and influence of the WAIS and meridional gradient variability response to orbital forcing during a critical period of cryosphere development.
Part II:
The Cenomanian-Turonian boundary (CTB) can be correlated globally in pelagic carbonate facies by a major turnover in fossil groups, and by a positive carbon isotope excursion, typically associated with dark marls or shales enriched in organic carbon. The dramatic changes within lithology are attributed to increased rates of oceanic-turnover and upwelling of nutrient-rich deep water masses, and high surface-water productivity.
Oxygen depletion and eutrophication of the Earth's oceans has been associated with warming in the geological past, and current observations show expansion of modern oxygen minimum zones. Clarifying the nature and mechanism of these oceanic anoxia events (OAEs), and there effect upon life is imperative to our understanding the possible implications that anthropogenic climate forcing may have upon the biodiversity of the modern ocean.
We plan to utilize samples sourced from IODP Expedition 375 Hole 1520C, within the Hikurangi Trough, where an expanded section is been identified detailing the Cenomanian-Turonian boundary. Through foraminiferal faunal analysis and paired measurements of oxygen and carbon isotopes we aim to elucidate the nature of the CTB within the Hikurangi Trough, which represents a rare, well-preserved high-latitude example of a Cretaceous OAEs.
The regions of the world's oceans, which border Antarctica, are critical for controlling the Earth's climate. Firstly, the largely unhindered transit of ocean currents (the Antarctic circumpolar current, ACC) that circle and Antarctic continent enables the continued maintenance of its huge continental ice sheets. Secondly, a permanent thermal boundary between water masses extends to the ocean surface within the Subtropical Convergence (STC) in this region. Consequently, this is a region of high biological productivity due to the mixing of micronutrient-rich subtropical waters (STW) with macronutrient-rich subantarctic waters (SAW). As such the STC is a highly important sink for atmospheric CO2 due to high levels of primary productivity.
This region is also influenced by the presence and extent of the Western Antarctic Ice Sheet (WAIS). The extent of this ice sheet has been shown to alter the latitudinal positioning of the Southern Hemisphere STC by up to 7 degrees from stadial-interstadial cycles of the Late Pleistocene epoch (last 800 ka), and may subsequently partially decouple global climate from atmospheric partial pressure of carbon dioxide. Previous studies highlighting the Late Pleistocene evolution of sea surface and intermediate waters within the southwest Pacific have indicated complex behaviour of the subtropical front (STF) throughout this interval.
Utilizing samples from site U1520D from within the Hikurangi Trough (Expedition 375), we propose a high resolution (<1 kyr) study of late Pleistocene foraminifera to better constrain the regional paleoceanography over the last 130 ka, and how this relates to climate forcing. We aim to better understand the STC through paired measurements of oxygen isotopes and Mg/Ca trace element ratios of both planktonic (Globigerina bulloides) and benthic foraminifera (Uvigerina peregrina). G. bulloides is a symbiont-barren, opportunistic species which often dominates the foraminifer fauna, and sediment assemblage of the ocean floor, and is therefore an important source of geochemical information for palaeoceanographic studies. U. peregrina is an infaunal benthic species, which has also been used extensively to calculate intermediate water properties throughout the Pliocene-Pleistocene. These stable isotope and trace metal records are required to assess the scale and timing of surface and intermediate water temperature, and salinity across the STC. This data will subsequently contribute to our knowledge of the extent and influence of the WAIS and meridional gradient variability response to orbital forcing during a critical period of cryosphere development.
Part II:
The Cenomanian-Turonian boundary (CTB) can be correlated globally in pelagic carbonate facies by a major turnover in fossil groups, and by a positive carbon isotope excursion, typically associated with dark marls or shales enriched in organic carbon. The dramatic changes within lithology are attributed to increased rates of oceanic-turnover and upwelling of nutrient-rich deep water masses, and high surface-water productivity.
Oxygen depletion and eutrophication of the Earth's oceans has been associated with warming in the geological past, and current observations show expansion of modern oxygen minimum zones. Clarifying the nature and mechanism of these oceanic anoxia events (OAEs), and there effect upon life is imperative to our understanding the possible implications that anthropogenic climate forcing may have upon the biodiversity of the modern ocean.
We plan to utilize samples sourced from IODP Expedition 375 Hole 1520C, within the Hikurangi Trough, where an expanded section is been identified detailing the Cenomanian-Turonian boundary. Through foraminiferal faunal analysis and paired measurements of oxygen and carbon isotopes we aim to elucidate the nature of the CTB within the Hikurangi Trough, which represents a rare, well-preserved high-latitude example of a Cretaceous OAEs.
Planned Impact
The key impacts will be the multi-disciplinary benefits to the over-arching academic community, the research outcome has a large scope for input into international policy and procedure, especially in reference to climate science. Most notably, there are currently huge efforts to better understand and predict the possible outcomes of continued anthropogenic climate forcing. Well-recovered, high-resolution (<1 kyr) records from the last glacial-interglacial cycle are imperative to provide high-quality data for inferences for more accurate climate reconstructions, to better constrain our understanding of future anthropogenic forcing. The Intergovernmental Panel on Climate Change (IPCC) will be of direct benefit from the data acquired, which will contribute towards future IPCC Assessment Reports, and consequently be accessory to possible future mitigation efforts.
The taxonomic and biostratigraphic framework which will be constructed through the post-cruise research efforts, by the PGR as well as the entire chronostratigraphic team, will yield vital contributions to the process of constructing the Atlas of Neogene Planktonic Foraminifera in the coming years. Building on from the huge success of the formation of the Palaeogene atlases, the publication is vital to the micropalaeontological and palaeoceanographic community, but specifically to research students in planktonic foraminifers. Additionally, the atlas will be used extensively within the petroleum sector, being the standard reference used by the industry for Neogene biostratigraphy.
The PGR will also be participating in multiple public outreach events including Lyme Regis and Yorkshire Fossil Festivals in the years to come, which will allow us to ensure the objectives of the expedition research, and the IODP as a whole can be promoted readily to the public, and encourage public engagement within the scientific community. These festivals have been incredibly effective in the past, especially when promoting regional and global scientific efforts to local schools and families.
The taxonomic and biostratigraphic framework which will be constructed through the post-cruise research efforts, by the PGR as well as the entire chronostratigraphic team, will yield vital contributions to the process of constructing the Atlas of Neogene Planktonic Foraminifera in the coming years. Building on from the huge success of the formation of the Palaeogene atlases, the publication is vital to the micropalaeontological and palaeoceanographic community, but specifically to research students in planktonic foraminifers. Additionally, the atlas will be used extensively within the petroleum sector, being the standard reference used by the industry for Neogene biostratigraphy.
The PGR will also be participating in multiple public outreach events including Lyme Regis and Yorkshire Fossil Festivals in the years to come, which will allow us to ensure the objectives of the expedition research, and the IODP as a whole can be promoted readily to the public, and encourage public engagement within the scientific community. These festivals have been incredibly effective in the past, especially when promoting regional and global scientific efforts to local schools and families.
Publications
Barnes PM
(2020)
Slow slip source characterized by lithological and geometric heterogeneity.
in Science advances
Fagereng Å
(2019)
Mixed deformation styles observed on a shallow subduction thrust, Hikurangi margin, New Zealand
in Geology
Woodhouse A
(2022)
Trench floor depositional response to glacio-eustatic changes over the last 45 ka, northern Hikurangi subduction margin, New Zealand
in New Zealand Journal of Geology and Geophysics
Description | Fossil investigations have revealed climate histories and changes in ocean chemistry for the two intervals of Earth History that were the focus of this grant. The work is currently being written up for publication. |
Exploitation Route | This work will underpin future understanding of the climate and ocean evolution of this previously under studied region of the world's oceans. |
Sectors | Environment |
Title | Planktonic foraminifera biostratigraphy |
Description | Biostratigraphic counts of planktonic foraminifera from the Cretaecous and Neogene sediments from the IODP Research Expedition 372. |
Type Of Material | Database/Collection of data |
Year Produced | 2019 |
Provided To Others? | No |
Impact | WIll form key outputs from the cruise reporting |
Title | Stable isotope analyses of planktonic foraminifera |
Description | Carbon and Oxygen isotope analyses of planktonic foraminifera from the Cretaceous and Neogene sediments from IODP Exp. 372 |
Type Of Material | Database/Collection of data |
Year Produced | 2019 |
Provided To Others? | No |
Impact | Will form key outputs from IODP Exp. 372 for Cretaceous and Neogene palaeoclimate reconstructions |
Description | Cenozoic Biostratigraphy Group |
Organisation | GNS Science |
Country | New Zealand |
Sector | Public |
PI Contribution | Adam Woodhouse, Research Associate at Uni. of Leeds and collaborators at GNS have been conducting biostratigraphic analyses of the cores drilled on IODP Exp. 375. |
Collaborator Contribution | Adam Woodhouse, Research Associate at Uni. of Leeds and collaborators at GNS have been conducting biostratigraphic analyses of the cores drilled on IODP Exp. 375. |
Impact | Biostratigraphic reports in progress. |
Start Year | 2018 |
Description | Cretaceous Organic Rich Sediment Group |
Organisation | Smithsonian Institution |
Country | United States |
Sector | Public |
PI Contribution | Adam Woodhouse, Research Associate at Uni. of Leeds and collaborators have been conducting biostratigraphic analyses of the cores drilled on IODP Exp. 375 and geochemical investigation into ocean anoxia in the Cretaceous. |
Collaborator Contribution | Adam Woodhouse, Research Associate at Uni. of Leeds and collaborators have been conducting biostratigraphic analyses of the cores drilled on IODP Exp. 375 and geochemical investigation into ocean anoxia in the Cretaceous. |
Impact | Outputs in progress |
Start Year | 2018 |
Description | Cretaceous Organic Rich Sediment Group |
Organisation | University of Montpellier |
Country | France |
Sector | Academic/University |
PI Contribution | Adam Woodhouse, Research Associate at Uni. of Leeds and collaborators have been conducting biostratigraphic analyses of the cores drilled on IODP Exp. 375 and geochemical investigation into ocean anoxia in the Cretaceous. |
Collaborator Contribution | Adam Woodhouse, Research Associate at Uni. of Leeds and collaborators have been conducting biostratigraphic analyses of the cores drilled on IODP Exp. 375 and geochemical investigation into ocean anoxia in the Cretaceous. |
Impact | Outputs in progress |
Start Year | 2018 |
Description | Does climate influence the frequency of volcanic activity and earthquakes? |
Organisation | University of Auckland |
Country | New Zealand |
Sector | Academic/University |
PI Contribution | Contributing to written publishable outputs and student supervision |
Collaborator Contribution | Lead scientist, managing PhD students, collecting and analysing data and contributing to written publishable outputs |
Impact | None as yet, only started two months ago |
Start Year | 2021 |
Description | Yorkshire Fossil Festival 2018 |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | Regional |
Primary Audience | Public/other audiences |
Results and Impact | A open public event aimed at raising the profile of palaeontology and its applications. A general public attendance. |
Year(s) Of Engagement Activity | 2018 |