TY - JOUR
T1 - Base-up growth of ocean crust by multiple phases of magmatism : field evidence from Macquarie Island
AU - Dijkstra, A.H.
AU - Cawood, Peter
PY - 2004
Y1 - 2004
N2 - Macquarie Island preserves largely in-situ Miocene oceanic crust and mantle formed at a slow-spreading ridge. The crustal section on the island does not conform to a simple 'layer cake pseudo-stratigraphy', but is the result of multiple magmatic episodes. Macquarie Island crust did not grow by top-down cooling, but rather from the base up. Peridotites cooled first and formed the basement into which gabbro plutons were intruded. This was followed by cooling and deformation, and by intrusion of dykes that fed a sheeted dyke-basalt complex. Finally, lava-filled grabens were formed. These relative age relations rule out simple cogenetic relations between rock units.
AB - Macquarie Island preserves largely in-situ Miocene oceanic crust and mantle formed at a slow-spreading ridge. The crustal section on the island does not conform to a simple 'layer cake pseudo-stratigraphy', but is the result of multiple magmatic episodes. Macquarie Island crust did not grow by top-down cooling, but rather from the base up. Peridotites cooled first and formed the basement into which gabbro plutons were intruded. This was followed by cooling and deformation, and by intrusion of dykes that fed a sheeted dyke-basalt complex. Finally, lava-filled grabens were formed. These relative age relations rule out simple cogenetic relations between rock units.
U2 - 10.1144/0016-764904-033
DO - 10.1144/0016-764904-033
M3 - Article
VL - 161
SP - 739
EP - 742
JO - Journal of the Geological Society, London
JF - Journal of the Geological Society, London
SN - 0016-7649
IS - 5
ER -