Post-emplacement tilting of lava flows inferred from magnetic fabric study: the example of Oligocene lavas in the Jeanne d’Arc Peninsula (Kerguelen Islands)     

B. Henry  G. Plenier  P. Camps 《Journal of Volcanology and Geothermal Research》2003,127(1-2):153-164

Statistical analysis of the magnetic fabric of samples from several successive lava flows emplaced under similar conditions can allow determination of the mean flow direction when magnetic fabric data from individual flows do not lead to reliable results. A difference between the obtained flow direction and the present dip direction indicates that the flows were tilted after emplacement. For 2 successive series of flows on the Jeanne d’Arc Peninsula presently NNW dipping, this method shows lava emplacement along a SSW–NNE direction. This indicates a gentle tilting acquired during a period of weak deformation in the whole archipelago. Additionally, the magnetic fabric data allow the reconstruction of the different conditions of emplacement of these two series of lava flows and of formation of the local thick conglomerate interbedded between these series.  相似文献   

Absolute palaeointensity of Oligocene (28–30 Ma) lava flows from the Kerguelen Archipelago (southern Indian Ocean)     

G. Plenier  P. Camps  R. S. Coe  M. Perrin 《Geophysical Journal International》2003,154(3):877-890

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Determination of flow directions by combining AMS and thin-section analyses: implications for Oligocene volcanism in the Kerguelen Archipelago (southern Indian Ocean)     

G. Plenier  P. Camps  B. Henry  B. Ildefonse 《Geophysical Journal International》2005,160(1):63-78

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Rotation of the Semail ophiolite (Oman): Additional Paleomagnetic data from the volcanic sequence     

Perrin  Mireille  Plenier  Guillaume  Dautria  Jean-Marie  Cocuaud  Emmanuel  Prévot  Michel 《Marine Geophysical Researches》2000,21(3-4):181-194

Thirty-two flows (247 cores) were sampled in the V1 (Geotimes) and V2 (Lasail) volcanic units of the Semail ophiolite, Oman (Aswad, Fizh, Hilti, Sarami, Wuqbah, and Tayin massifs). Paleomagnetic analysis of the samples was complicated by a large overlap of the two components of magnetization carried by the rocks: a crystalline remanent magnetization (CRM) acquired in the present day field, probably during weathering, and an older CRM probably produced by oxidation of the original titanomagnetites during hydrothermal event(s). If the magnetization carried by the V1 samples was acquired during the hydrothermal event related to the emplacement of these lava, e.g., during and/or shortly after cooling, the tectonic unity of the northern domain has to be questioned and a differential rotation considered between the Aswad and Hilti-Sarami massifs but, by the time of emplacement of the V2 series, this northern area seems to behave as one large unit. As only one set of data is available for the southern Tayin-Sumail massif, it is premature but a possible relative rotation on the order of 90° can be suspected between the Hilti-Sarami and Tayin-Sumail massifs, rotation which would have occurred after emplacement of the V2 series.  相似文献