The relationship between silicon isotope fractionation in sponges and silicic acid concentration: Modern and core-top studies of biogenic opal

Hendry, Katharine Rosemary and Robinson, Laura F. 2012. The relationship between silicon isotope fractionation in sponges and silicic acid concentration: Modern and core-top studies of biogenic opal. Geochimica Et Cosmochimica Acta 81 , pp. 1-12. 10.1016/j.gca.2011.12.010

Full text not available from this repository.

Abstract

Recent work has shown the siliconisotope composition, denoted by δ30Si, of deep-sea sponges reflects the concentration of ambient silicicacid (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 silicicacid 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 modernsponges. 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 modernsponge 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 silicicacid concentrations in the past.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Earth and Environmental Sciences
Subjects:	G Geography. Anthropology. Recreation > G Geography (General) G Geography. Anthropology. Recreation > GC Oceanography
ISSN:	0016-7037
Last Modified:	23 Mar 2017 03:26
URI:	https://orca.cardiff.ac.uk/id/eprint/27862

Citation Data

Cited 68 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item