FN Archimer Export Format
PT J
TI The Norfolk Ridge seamounts: Eocene–Miocene volcanoes near Zealandia’s rifted continental margin
BT 
AF Mortimer, N.
   Patriat, Martin
   Gans, P. B.
   Agranier, Arnaud
   Chazot, Gilles
   Collot, Julien
   Crundwell, M. P.
   Durance, P. M. J.
   Campbell, H. J.
   Etienne, S.
AS 1:1;2:2;3:3;4:4;5:4;6:5;7:6;8:6;9:6;10:5;
FF 1:;2:PDG-REM-GM-LAD;3:;4:;5:;6:;7:;8:;9:;10:;
C1 GNS Science, Dunedin, New Zealand
   IFREMER, Unité Géosciences Marines, Plouzané, France
   Geological Sciences, University of California, Santa Barbara, USA
   Laboratoire Domaines Océaniques UMR/CNRS 6538, IUEM, Université de Bretagne Occidentale, Technopôle Brest-Iroise, Plouzané, France
   Service Géologique de Nouvelle-Calédonie, Nouméa, New Caledonia
   GNS Science, Lower Hutt, New Zealand
C2 GNS SCIENCE, NEW ZEALAND
   IFREMER, FRANCE
   UNIV CALIF SANTA BARBARA, USA
   UBO, FRANCE
   SERV GEOL NOUVELLE CALEDONIE, FRANCE
   GNS SCIENCE, NEW ZEALAND
SI BREST
SE PDG-REM-GM-LAD
UM LGO
IN WOS Ifremer UPR
   copubli-france
   copubli-univ-france
   copubli-int-hors-europe
IF 1.36
TC 9
UR https://archimer.ifremer.fr/doc/00646/75834/76889.pdf
LA English
DT Article
CR TECTA
   VESPA
BO L'Atalante
DE ;Southwest Pacific;Zealandia;Norfolk Ridge;seamounts;guyots;volcanoes;geochronology;geochemistry;Cenozoic
AB New age and geochemical data are used to investigate the origin of a ∼670 km-long line of eight seamount volcanoes along the western side of the Norfolk Ridge between New Caledonia and New Zealand. Altered lavas and limestones were dredged from three volcanoes during the 2015 Volcanic Evolution of South Pacific Arcs cruise of N/O l’Atalante, so a total of four, including the northernmost and southernmost, have now been directly sampled and analysed. Dating of lava and volcanic breccia clasts by Ar–Ar methods gives north-to-south ages from these sites of 31.3 ± 0.6, 33 ± 5, 21.5 ± 1.0 and 26.3 ± 0.1 Ma. These ages, along with supporting stratigraphic data on a fifth seamount from IODP borehole U1507, provisionally refute the hypotheses that the seamounts represent a southward-younging, age-progressive, intraplate volcanic chain on the Australian Plate or a subduction-related chain of restricted age range. Geochemically, the upper Eocene to lower Miocene lavas have alkaline and subalkaline basaltic compositions, and some could be shoshonitic. The location of the volcanoes along the western side of the Norfolk Ridge suggests an origin related to late Eocene and early Miocene melting near an intracontinental lithosphere–asthenosphere step. Involvement of a deep slab in petrogenesis is also possible. KEY POINTS Eight seamounts form a line along the Norfolk Ridge. Dating and geochemistry indicate the seamount line is not a hotspot track. A rift-related origin, possibly with influence by subduction, is proposed. 
PY 2021
PD APR
SO Australian Journal Of Earth Sciences
SN 0812-0099
PU Informa UK Limited
VL 68
IS 3
UT 000566921100001
BP 368
EP 380
DI 10.1080/08120099.2020.1805007
ID 75834
ER

EF