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Index Geophysics

Paleomagnetic evidence from Mesozoic carbonate rocks for the rotation of Sardinia


Title (Dublin Core)

en-US Paleomagnetic evidence from Mesozoic carbonate rocks for the rotation of Sardinia

Description (Dublin Core)

en-US The remanent magnetizations have been analysed in Cretaceous and Jurassic limestones, and Triassic dolomites, from Eastern and Central Sardinia. Ore microscopy and rock magnetic studies, including the acquisition of isothermal remanent magnetization (IRM) and the behavior of IRM during high temperature treatment, indicated that magnetite and goethite determine the paleomagnetic properties of these carbonate rocks. At all Cretaceous sites the remanences were either too weak or too unstable to be used for a paleomagnetic study. AF and thermal demagnetization were used to isolate the characteristic remanent magnetization (ChRM) in the Jurassic and Triassic samples. Rejection criteria were used to eliminate about one third of these samples because of directional instability, or because only very stable secondary magnetizations associated with goethite were present. For the remaining samples the ChRM direction associated with primary magnetite was extracted with the aid of vector diagrams or vector difference calculations. The ChRM directions are rotated by 70°–90° counterclockwise relative to European directions and by 35°–45° counterclockwise relative to African directions. Part of this results from the 30° microplate rotation of Sardinia in the Miocene. The remainder is due to an earlier phase of microplate rotation which took place in post-Late Jurassic time.

Creator (Dublin Core)

Horner, F.
Lowrie, W.

Subject (Dublin Core)

en-US Rotation of Sardinia
en-US Mesozoic limestones
en-US paleomagnetism
en-US rock magnetism
en-US Geodynamics

Publisher (Dublin Core)

en-US Journal of Geophysics

Date (Dublin Core)


Type (Dublin Core)

en-US Peer-reviewed Article

Format (Dublin Core)


Identifier (Dublin Core)

Source (Dublin Core)

en-US Journal of Geophysics; Vol 49 No 1 (1981): Journal of Geophysics; 11-19

Language (Dublin Core)


Relation (Dublin Core)