TY - JOUR
T1 - Magmatism during Gondwana breakup
T2 - new geochronological data from Westland, New Zealand
AU - van der Meer, Quinten
AU - Scott, J.M.
AU - Waight, Tod Earle
AU - Sudo, M.
AU - Schersten, A.
AU - Cooper, A.F.
AU - Spell, T.L.
PY - 2013/12/1
Y1 - 2013/12/1
N2 - Newly determined Late Cretaceous 40Ar/39Ar ages on megacrystic kaersutite from four lamprophyre dikes, and a U-Pb zircon age on a trachyte, from central and north Westland (New Zealand) are presented. These ages suggest that the intrusion of mafic dikes (88-86 and 69 Ma) was not necessarily restricted to the previously established narrow age range of 80-92 Ma. The younger lamprophyre and trachyte dikes (c. 68-70 Ma) imply that tensional stresses in the Western Province were either renewed at this time, or that extension and related magmatism continued during opening of the Tasman Sea. Extension-related magmatism in the region not only preceded Tasman seafloor spreading initiation (starting at c. 83 Ma, lasting to c. 53 Ma), but may have sporadically continued for up to 15 Ma after continental break-up.
AB - Newly determined Late Cretaceous 40Ar/39Ar ages on megacrystic kaersutite from four lamprophyre dikes, and a U-Pb zircon age on a trachyte, from central and north Westland (New Zealand) are presented. These ages suggest that the intrusion of mafic dikes (88-86 and 69 Ma) was not necessarily restricted to the previously established narrow age range of 80-92 Ma. The younger lamprophyre and trachyte dikes (c. 68-70 Ma) imply that tensional stresses in the Western Province were either renewed at this time, or that extension and related magmatism continued during opening of the Tasman Sea. Extension-related magmatism in the region not only preceded Tasman seafloor spreading initiation (starting at c. 83 Ma, lasting to c. 53 Ma), but may have sporadically continued for up to 15 Ma after continental break-up.
U2 - 10.1080/00288306.2013.826699
DO - 10.1080/00288306.2013.826699
M3 - Journal article
SN - 0028-8306
VL - 56
SP - 229
EP - 242
JO - New Zealand Journal of Geology and Geophysics
JF - New Zealand Journal of Geology and Geophysics
IS - 4
ER -