FN Archimer Export Format
PT J
TI Tectonics at the axis of the very slow spreading Southwest Indian Ridge: Insights from TOBI side-scan sonar imagery
BT 
AF GOMEZ, O
   BRIAIS, Anne
   SAUTER, D
   MENDEL, V
AS 1:1;2:1;3:2;4:2;
FF 1:;2:;3:;4:;
C1 Observ Midi Pyrenees, CNRS, UMR 5566, LEGOS, F-31400 Toulouse, France.
   CNRS, ULP, EMR 7516, Inst Phys Globe, F-67084 Strasbourg, France.
C2 LEGOS, FRANCE
   CNRS, FRANCE
IF 2.384
TC 6
UR https://archimer.ifremer.fr/doc/00234/34567/33236.pdf
LA English
DT Article
CR CAPSING
   EDUL-MD107
   FUJI-MD108
BO L'Atalante
   Marion Dufresne
DE ;mid-ocean ridges;side-scan sonar;tectonics;discontinuities
AB We present the analysis of the deformation in the axial valley of two contrasted regions of the very slow spreading Southwest Indian Ridge based on side-scan sonar images. Our objective is to investigate how the obliquity is accommodated along the system. We show that the robust magmatic segments have axial valleys and major faults subperpendicular to spreading. The other sections show fault populations with various degrees of obliquity, often arranged in left-stepping echelons, accommodating part of the strike-slip deformation. Side-scan sonar reveals the presence of a corrugated surface near 59 degrees E interpreted to be an incipient detachment fault. We show that the large width of the SWIR oblique sections, and the difference in tectonic style between the robust volcanic segments and the magma-starved sections, is accounted for by large variations in the thickness of the brittle lithosphere. We suggest that the emplacement of mantle rocks in the surveyed amagmatic ridge sections can occur by alternating conjugate faults. Serpentinization of outcropping peridotites might also play a significant role in the development of faults in thin crust regions and the distribution of deformation in space and time.
PY 2006
PD MAY
SO Geochemistry Geophysics Geosystems
SN 1525-2027
PU Amer Geophysical Union
VL 7
IS 5
UT 000237445800001
BP 1
EP 24
DI 10.1029/2005GC000955
ID 34567
ER

EF