Abstract
Recent work has shown the silicon isotope composition, denoted by δ30Si, of deep-sea sponges reflects the concentration of ambient silicic acid (Si(OH)4) in seawater. However, existing calibrations are based predominantly on living sponges collected from the Southern Ocean. These data cannot, however, be used to determine whether other parameters that correlate with silicic acid in the Southern Ocean, such as temperature and salinity, influence δ30Si of sponges. Furthermore, the published data do not demonstrate whether disaggregated core-top sedimentary spicules preserve the primary δ30Si signal recorded in living sponges. Here, we address both of these issues. We refine and widen the existing calibration by including a global distribution of modern sponges. In addition, we provide the first systematic calibration from spicules picked from core-top sediments that covers sites from different ocean basins. The relationship between Si(OH)4 and δ30Si in sponge spicules is the same in different ocean basins, between specimens that grew in different temperature and salinity conditions. Our core-top data agree well with the modern sponge calibration indicating there are no significant post-depositional effects or early diagenetic overprints. These two new datasets support the assertion that sponge δ30Si can be used as a proxy for silicic acid concentrations in the past.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
