FN Archimer Export Format
PT J
TI A moderate melting model for the Voring margin (Norway) based on structural observations and a thermo-kinematical modelling: Implication for the meaning of the lower crustal bodies
BT 
AF GERNIGON, Laurent
   LUCAZEAU, Francis
   BRIGAUD, Frederic
   RINGENBACH, Jean-Claude
   PLANKE, Sverre
   LE GALL, Bernard
AS 1:1,6;2:2;3:3;4:4;5:5;6:1,6;
FF 1:;2:;3:;4:;5:;6:;
C1 IFREMER, F-29280 Plouzane, France.
   CNRS, Inst Phys Globe, F-75252 Paris 05, France.
   Ctr Sci & Tech Jean Feger, Total Pau, F-64018 Pau, France.
   Total GSR PN, F-92078 Paris, France.
   VBPR, PGP, N-0349 Oslo, Norway.
C2 IFREMER, FRANCE
   CNRS, FRANCE
   TOTAL, FRANCE
   TOTAL, FRANCE
   VBPR, NORWAY
   UBO, FRANCE
SI BREST
SE PDG-DOP-DCB-GM
IN WOS Ifremer jusqu'en 2018
   copubli-france
   copubli-europe
   copubli-univ-france
IF 1.675
TC 68
UR https://archimer.ifremer.fr/doc/2006/publication-1042.pdf
LA English
DT Article
DE ;Mantle plume;Norwegian margin;Underplating;Breakup;Modelling;Rifting;Volcanic margins
AB High P-wave velocities (7.1-7.8 km/s) lower crustal bodies (LCBs) imaged along volcanic margins are commonly interpreted as plume and break-up-related thick mafic underplating. This interpretation is partly challenged in this paper based on new seismic observations and modelling of the outer Voring Basin (Norway). An exceptional strong amplitude reflection, the T Reflection, is particularly well defined below the North Gjallar Ridge (NGR) between 7 and 8 s TWT. The T Reflection is located near the volcanic lava flows emplaced during the NE Atlantic breakup (similar to 55-54 Ma ago) and coincides with the top of the LCB, forming a mid-crustal dome. Based on structural and temporal relationships, we show that the dome clearly influences the structural development of the NGR and predates the continental breakup at least by 10-15 Ma. Using a thermo-kinematical model, we tried also to investigate and quantify the relationships between the extension, LCB and the magmatic production. Modelling suggests that significant Paleocene-Early Eocene magmatism can be produced without any temperature anomaly in the mantle if differential stretching occurs during the break-up initiation. The conclusion of 2D thermo-kinematical parametric analysis is that the magmatic model predicts, either little extension (beta < 2) with no melting or high extension (beta > 5) with significant melting along the outer Voring Basin. We suggest that the continental part of the LCB could not necessarily be breakup-related and so magmatic, as has often been stated previously. It is concluded here that the continental part of the LCB observed beneath the outer Voring Basin may be partly (or fully) attributed to inherited, high-pressure granulite/eclogite lower crustal rocks. The real amount of mafic material emplaced along the outer Voring Basin could be 20-40% less than thought. 
PY 2006
SO Tectonophysics
SN 0040-1951
PU Elsevier
VL 412
IS 3-4
UT 000234844800009
BP 255
EP 278
DI 10.1016/j.tecto.2005.10.038
ID 1042
ER

EF