TY  - STD
AU  - Geoffroy, L.
AU  - Aubourg, C.
AU  - Callot, J-P
AU  - Barrat, J-A
PY  - 2007//
TI  - Mechanisms of crustal growth in large igneous provinces: The north Atlantic province as a case study
BT  - Geological Society of America Special Papers
SP  - 747
EP  - 774
VL  - 430
PB  - Geological Society of America
KW  - traps
KW  - volcanic margin
KW  - dike swarm
KW  - small-scale convection
KW  - AMS
N2  - The mechanisms of magma crust accretion at large igneous provinces (LIPs) are questioned using arguments based on the north Atlantic case. Published and new data on the calculated flow vectors within dike swarms feeding the early traps and subsequent seaward-dipping reflector lavas suggest that most of the mafic magmas forming the north Atlantic LIP transited through a small number of igneous centers. The magma was injected centrifugally in dike swarms at some distance away from individual igneous centers along the trend of the maximum horizontal stress acting in the crust, feeding lava piles via dikes intersecting the ground surface. This mechanism is similar to that observed in present-day Iceland and, more generally, in mafic volcano-tectonic systems. The absence of generalized vertical magma transit in a LIP has major geodynamic consequences. We cannot link the surface extent of LIP magmas to the dimensions of the mantle melting zone as proposed in former plume head models. The distribution of LIP magmas at the surface is primarily controlled by the regional stress field acting within the upper crust, but is also affected by magma viscosity. The igneous centers feeding LIPs most likely represent the crustal expression of small-scale convective cells of the buoyant mantle naturally located beneath the mechanical lithosphere.
SN  - 0072-1077
UR  - http://dx.doi.org/10.1130%2F2007.2430%2834%29
N1  - exported from refbase (http://publi.ipev.fr/polar_references/show.php?record=5504), last updated on Fri, 17 Apr 2009 10:18:28 +0200
ID  - Geoffroy_etal2007
ER  -