Abstract
Fluid flow of up to 200 m/myr is documented in thick (about 500 m) deep-sea carbonate sections by numerical modeling of the porewater Sr 2+ and 87Sr/ 86Sr profiles at DSDP Sites 572, 573 and 574. These sites were selected as likely candidates for significant fluid flow in the sedimentary part of the section because it had already been shown that they are underlain by rapidly flowing fresh seawater in the basaltic basement. The nature of the exercise is to fit the porewater Sr properties at these sites by finding a common rate of Sr exchange as a function of sediment age and a local rate of vertical fluid flow. The flow rates determined in this way are 20 m/myr upwards at Site 574, 20 m/myr downwards at Site 573 and 200 m/myr downwards at Site 572. Because of uncertainties of about a factor of 2 in the assumption of a common rate of Sr exchange at all sites, and trade-offs between the Sr exchange and fluid flow in determining the shape of Sr 2+ and 87Sr/ 86Sr profiles at a given site, the precision of the method is of the order of 10 m/myr. Thus at least at Site 572, the Sr properties of the interstitial waters provide a convincing measure of vertical fluid flow through a thick carbonate section.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: 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.