FN Archimer Export Format
PT J
TI What causes low magnetization at basalt-hosted hydrothermal sites? Insights from inactive site Krasnov (MAR 16°38′N)
BT 
AF SZITKAR, Florent
   DYMENT, Jerome
   CHOI, Yujin
   FOUQUET, Yves
AS 1:1;2:1;3:1;4:2;
FF 1:;2:;3:;4:PDG-REM-GM-LGM;
C1 Univ Paris Diderot, Sorbonne Paris Cite, CNRS, Inst Phys Globe Paris, Paris, France.
   IFREMER Ctr Brest, Plouzane, France.
C2 UNIV PARIS 07, FRANCE
   IFREMER, FRANCE
SI BREST
SE PDG-REM-GM-LGM
IN WOS Ifremer jusqu'en 2018
   copubli-france
   copubli-univ-france
IF 2.923
TC 26
UR https://archimer.ifremer.fr/doc/00188/29915/28375.pdf
LA English
DT Article
CR SERPENTINE
BO Pourquoi pas ?
DE ;Magnetic anomalies;Hydrothermalism;Alteration;Modeling
AB High-resolution magnetic surveys acquired near the seafloor show that active basalt-hosted hydrothermal sites are associated with zones of lower magnetization. This observation may reflect the thermal demagnetization of a hot hydrothermal zone, the alteration of basalt affected by hydrothermal circulation, and/or the presence of thick, nonmagnetic hydrothermal deposits. In order to discriminate among these inferences, we acquired vector magnetic data 50 m above inactive hydrothermal site Krasnov using the Remotely Operated Vehicle (ROV) Victor. This deep hydrothermal site, located 7 km east of the Mid-Atlantic Ridge (MAR) axis at 16°38′N, is dissected by major normal faults and shows no evidence of recent hydrothermal activity. It is therefore a perfect target for investigating the magnetic signature of an inactive basalt-hosted hydrothermal site. Krasnov exhibits a strong negative magnetic anomaly, which implies that the lower magnetization observed at basalt-hosted hydrothermal sites is not a transient effect associated with hydrothermal activity, but remains after activity ceases. Thermal demagnetization plays only a secondary role, if any, in the observed magnetic low. Forward models suggest that both the nonmagnetic hydrothermal deposits and an altered zone of demagnetized basalt are required to account for the observed magnetic low. The permanence of this magnetic signature makes it a useful tool to explore midocean ridges and detect inactive hydrothermal sites.
PY 2014
PD APR
SO Geochemistry Geophysics Geosystems
SN 1525-2027
PU Amer Geophysical Union
VL 15
IS 4
UT 000336493400037
BP 1441
EP 1451
DI 10.1002/2014GC005284
ID 29915
ER

EF