Skip to Main content Skip to Navigation
Journal articles

Palaeointensity determinations and rock magnetic properties on basalts from Shatsky Rise: new evidence for a Mesozoic dipole low

Abstract : IODP Expedition 324 cored igneous rocks from Shatsky Rise, an oceanic plateau in the northwest Pacific Ocean that formed mainly during late Jurassic and Early Cretaceous times. We selected 60 samples from 3 different holes for Thellier-Thellier palaeointensity determinations. Induced and remanent magnetization curves measured at low- and high-temperature suggest a diverse and complex magnetic mineralogy, with large variations in Ti content and oxidation state. Hysteresis and FORC measurements show that most samples contain singledomain magnetic grains. After carrying out the palaeointensity determinations, only 9 samples satisfied all reliability criteria. These gave palaeointensity values between 16.5 and 21.5 μT, which correspond to average VDM values of (4.9 ± 0.2) × 1022 Am2 for an estimated age of 140-142 Ma. This value is lower than that for the recent field, which agrees with the hypothesis of a Mesozoic Dipole Low.
Document type :
Journal articles
Complete list of metadata

https://hal.archives-ouvertes.fr/hal-00795491
Contributor : Danielle Thomas <>
Submitted on : Thursday, June 10, 2021 - 5:17:55 PM
Last modification on : Tuesday, July 13, 2021 - 3:26:44 AM

File

ggs100.pdf
Publisher files allowed on an open archive

Licence


Distributed under a Creative Commons Attribution 4.0 International License

Identifiers

Citation

C. Carvallo, P. Camps, M. Ooga, G. Fanjat, W.W. Sager. Palaeointensity determinations and rock magnetic properties on basalts from Shatsky Rise: new evidence for a Mesozoic dipole low. Geophysical Journal International, Oxford University Press (OUP), 2013, 192 (3), pp.986-999. ⟨10.1093/gji/ggs100⟩. ⟨hal-00795491⟩

Share

Metrics

Record views

646

Files downloads

22