Abrupt thermal transition reveals hydrothermal boundary and role of seamounts within the Cocos Plate

• Published in: Geophysical research letters Vol. 30; no. 11; pp. 1550 - n/a
• Main Authors: Fisher, A. T., Stein, C. A., Harris, R. N., Wang, K., Silver, E. A., Pfender, M., Hutnak, M., Cherkaoui, A., Bodzin, R., Villinger, H.
• Format: Journal Article
• Language: English
• Published: American Geophysical Union 01.06.2003; Blackwell Publishing Ltd
• Subjects: Heat flow (benthic) and hydrothermal processes; Marine; Marine Geology and Geophysics; Cocos Plate; ISE, East Pacific Rise
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2002GL016766

New thermal data from 18–24 Ma lithosphere on the Cocos Plate delineate contrasting subsurface thermal conditions in adjacent sections of crust. Heat flow through seafloor created at the East Pacific Rise is generally suppressed by ∼70% relative to conductive lithospheric cooling models, whereas heat flow through adjacent, similarly‐aged lithosphere generated at the Cocos‐Nazca Spreading Center is consistent with these models. The transition between thermal regimes is remarkably abrupt, only 2–5 km wide, indicating a shallow hydrothermal origin. The transition is more closely associated with differences in the distribution of basement outcrops than with tectonic boundaries, demonstrating the importance of the former in extracting heat from the lithosphere on a regional basis.