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  - 
TY  - JOUR
A1  - Ryberg, Trond
A1  - Braeuer, Benjamin
A1  - Weber, Michael
T1  - Upper mantle structure at Walvis Ridge from P-n tomography
JF  - Tectonophysics : international journal of geotectonics and the geology and physics of the interior of the earth
N2  - Passive continental margins offer the unique opportunity to study the processes involved in continental extension and break-up. Within the LISPWAL (Llthospheric Structure of the Namibian continental Passive margin at the intersection with the Walvis Ridge from amphibious seismic investigations) project, combined on- and offshore seismic experiments were designed to characterize the Southern African passive margin at the Walvis Ridge in northern Namibia. In addition to extensive analysis of the crustal structures, we carried out seismic investigations targeting the velocity structure of the upper mantle in the landfall region of the Walvis Ridge with the Namibian coast. Upper mantle P-n travel time tomography from controlled source, amphibious seismic data was used to investigate the sub-Moho upper mantle seismic velocity. We succeeded in imaging upper mantle structures potentially associated with continental break-up and/or the Tristan da Cunha hotspot track. We found mostly coast-parallel sub-Moho velocity anomalies, interpreted as structures which were created during Gondwana break-up. (C)2016 Published by Elsevier B.V.
KW  - Seismic investigations
KW  - P-n tomography
KW  - passive continental margin
KW  - Gondwana break-up
Y1  - 2017
U6  - https://doi.org/10.1016/j.tecto.2016.08.009
SN  - 0040-1951
SN  - 1879-3266
VL  - 716
SP  - 121
EP  - 129
PB  - Elsevier
CY  - Amsterdam
ER  -