Heat flow and bending-related faulting at subduction trenches: Case studies offshore of Nicaragua and Central Chile

Ingo Grevemeyer, Norbert Kaul, JUAN LORENZO DIAZ NAVEAS, Heinrich W. Villinger, Cesar R. Ranero, Christian Reichert

Research output: Contribution to journalArticlepeer-review

84 Scopus citations

Abstract

Detailed heat flow surveys on the oceanic trench slope offshore Nicaragua and Central Chile indicate heat flow values lower than the expected conductive lithospheric heat loss and lower than the global mean for crust of that age. Both areas are characterised by pervasive normal faults exposing basement in a setting affected by bending-related faulting due to plate subduction. The low heat flow is interpreted to indicate increased hydrothermal circulation by the reactivation and new creation of faults prior to subduction. A previous global approach [1] [Stein C.A., Heat flow and flexure at subduction zones, Geophys. Res. Lett. 30 (2003) doi:10.1029/2003GL018478] failed to detect similar features in the global but sparse data set. Detailed inspection of the global data set suggests that the thickness of the sedimentary blanket on the incoming plate is an important factor controlling the local hydrogeological regime. Areas with a relatively thick sedimentary cover do not show any heat flow anomaly while areas where normal faulting exposes basement suffer from increased hydrothermal activity. Both geochemical data from arc volcanoes and seismological evidence from intra slab events suggest that the flux of water into the deep subduction zone is larger in areas characterised by reactivated hydrothermal circulation. It is reasonable to assume that the larger water flux is caused by serpentinization of the upper mantle, facilitated by bending-related faults cutting into the upper mantle.

Original languageEnglish
Pages (from-to)238-248
Number of pages11
JournalEarth and Planetary Science Letters
Volume236
Issue number1-2
DOIs
StatePublished - 30 Jul 2005
Externally publishedYes

Keywords

  • Fluid flow
  • Global water cycle
  • Heat flow
  • Normal faulting
  • Serpentinization
  • Subduction

Fingerprint

Dive into the research topics of 'Heat flow and bending-related faulting at subduction trenches: Case studies offshore of Nicaragua and Central Chile'. Together they form a unique fingerprint.

Cite this