Publication

2008

English

http://archimer.ifremer.fr/doc/2008/publication-3878.pdf (1.20 Mo)

2008 by the American Geophysical Union

Geli Louis¹, Lee T², Cochran J³, Francheteau J⁴, Abbott D³, Labails Cinthia¹, Appriou D¹

1 : IFREMER, Marine Geosci Dept, F-29280 Plouzane, France.
2 : Univ Calif Riverside, Dept Earth Sci, Riverside, CA 92521 USA.
3 : Columbia Univ, Lamont Doherty Geol Observ, Palisades, NY 10964 USA.
4 : Inst Univ European De La Mer, F-29280 Plouzane, France.

Journal of Geophysical Research - Solid earth (0148-0227) (American Geophysical Union), 2008 , Vol. 113 , N. B1 , P. NIL_1-NIL_23

1

Geology

mid ocean ridges, heat flow, marine geophysics

We analyze available heat flow data from the flanks of the Southeast Indian Ridge adjacent to or within the Australian-Antarctic Discordance (AAD), an area with patchy sediment cover and highly fractured seafloor as dissected by ridge- and fracture-parallel faults. The data set includes 23 new data points collected along a 14-Ma old isochron and 19 existing measurements from the 20- to 24-Ma old crust. Most sites of measurements exhibit low heat flux (from 2 to 50 mW m(-2)) with near-linear temperature-depth profiles except at a few sites, where recent bottom water temperature change may have caused nonlinearity toward the sediment surface. Because the igneous basement is expected to outcrop a short distance away from any measurement site, we hypothesize that horizontally channelized water circulation within the uppermost crust is the primary process for the widespread low heat flow values. The process may be further influenced by vertical fluid flow along numerous fault zones that crisscross the AAD seafloor. Systematic measurements along and across the fault zones of interest as well as seismic profiling for sediment distribution are required to confirm this possible, suspected effect.