L. Geli, T. C. Lee, J. R. Cochran, J. Francheteau, D. Abbott, C. Labails and D. Appriou

Heat flow from the Southeast Indian Ridge flanks between 80 degrees E and 140 degrees E; data review and analysis

Journal of Geophysical Research( 2008), 113(B1)

Index Terms/Descriptors: Australian-Antarctic discordance; Cenozoic; depth; fault zones; faults; fluid dynamics; fractures; heat flow; igneous rocks; Indian Ocean; Mid-Indian Ridge; mid-ocean ridges; Miocene; Neogene; ocean floors; Southeast Indian Ridge; temperature; Tertiary

Latitude & LongitudeS60°00'00'' - S33°00'00'' and E78°30'00'' - E156°00'00''


[1] 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.