FN Archimer Export Format
PT J
TI Depth-Dependent Permeability and Heat Output at Basalt-Hosted Hydrothermal Systems Across Mid-Ocean Ridge Spreading Rates
BT 
AF BARREYRE, Thibaut
   OLIVE, Jean-Arthur
   CRONE, Timothy J.
   SOHN, Robert A.
AS 1:1,2;2:3;3:4;4:2;
FF 1:;2:;3:;4:;
C1 Univ Bergen, Dept Earth Sci, KG Jebsen Ctr Deep Sea Res, Bergen, Norway.
   Woods Hole Oceanog Inst, Woods Hole, MA 02543 ,USA.
   PSL Res Univ, Ecole Normale Super, Lab Geol, CNRS UMR 8538, Paris, France.
   Columbia Univ, Lamont Doherty Geol Observ, Palisades, NY 10964, USA.
C2 UNIV BERGEN, NORWAY
   WHOI, USA
   UNIV PSL, FRANCE
   UNIV COLUMBIA, USA
IF 2.946
TC 17
UR https://archimer.ifremer.fr/doc/00465/57688/59982.pdf
LA English
DT Article
CR MOMARSAT : MONITORING THE MID ATLANTIC RIDGE
DE ;permeability;heat output;mid-ocean ridges;hydrothermal;poroelasticity
AB The permeability of the oceanic crust exerts a primary influence on the vigor of hydrothermal circulation at mid-ocean ridges, but it is a difficult to measure parameter that varies with time, space, and geological setting. Here we develop an analytical model for the poroelastic response of hydrothermal exit-fluid velocities and temperatures to ocean tidal loading in a two-layered medium to constrain the discharge zone permeability of each layer. The top layer, corresponding to extrusive lithologies (e.g., seismic layer 2A) overlies a lower permeability layer, corresponding to intrusive lithologies (e.g., layer 2B). We apply the model to three basalt-hosted hydrothermal fields (i.e., Lucky Strike, Main Endeavour and 9 degrees 46N L-vent) for which the seismic stratigraphy is well-established, and for which robust exit-fluid temperature data are available. We find that the poroelastic response to tidal loading is primarily controlled by layer 2A permeability, which is about 3 orders of magnitude higher for the Lucky Strike site (approximate to 10(-10) m(2)) than the 9 degrees 46N L-vent site (approximate to 10(-13) m(2)). By contrast, layer 2B permeability does not exert a strong control on the poroelastic response to tidal loading, yet strongly modulates the heat output of hydrothermal discharge zones. Taking these constraints into account, we estimate a plausible range of layer 2B permeability between approximate to 10(-15) m(2) and an upper-bound value of approximate to 10(-14) (9 degrees 46N L-vent) to approximate to 10(-12) m(2) (Lucky Strike). These permeability structures reconcile the short-term response and long-term thermal output of hydrothermal sites, and provide new insights into the links between permeability and tectono-magmatic processes along the global mid-ocean ridge. 
PY 2018
PD APR
SO Geochemistry Geophysics Geosystems
SN 1525-2027
PU Amer Geophysical Union
VL 19
IS 4
UT 000434110500016
BP 1259
EP 1281
DI 10.1002/2017GC007152
ID 57688
ER

EF