TY  - JOUR
A1  - Van der Meer, Q. H. A.
A1  - Scott, James M.
A1  - Waight, T. E.
A1  - Sudo, Masafumi
A1  - Schersten, A.
A1  - Cooper, Alan F.
A1  - Spell, Terry L.
T1  - Magmatism during Gondwana break-up: new geochronological data from Westland, New Zealand
JF  - New Zealand journal of geology and geophysics : an international journal of pacific rim geosciences
N2  - Newly determined Late Cretaceous Ar-40/Ar-39 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.
KW  - Gondwana break-up
KW  - geochronology
KW  - lamprophyre
KW  - central Westland
KW  - Fraser Complex
Y1  - 2013
U6  - https://doi.org/10.1080/00288306.2013.826699
SN  - 0028-8306
SN  - 1175-8791
VL  - 56
IS  - 4
SP  - 229
EP  - 242
PB  - Routledge, Taylor & Francis Group
CY  - Abingdon
ER  -