Maurizot P., Robineau B., Jeanpert J., Iseppi M., Lesimple S., Juillot Farid, Meyer M., Fullenwarth P., Mardhel V. (2023). Anatomy of an obducted ultramafic unit (Tiebaghi Massif - Peridotite Nappe - New Caledonia) : polyphase brittle tectonics constrained by fault-slip data and crack seal mineralogy. New Zealand Journal of Geology and Geophysics, [Early access], p. [21 p.]. ISSN 0028-8306.
Titre du document
Anatomy of an obducted ultramafic unit (Tiebaghi Massif - Peridotite Nappe - New Caledonia) : polyphase brittle tectonics constrained by fault-slip data and crack seal mineralogy
Maurizot P., Robineau B., Jeanpert J., Iseppi M., Lesimple S., Juillot Farid, Meyer M., Fullenwarth P., Mardhel V.
Source
New Zealand Journal of Geology and Geophysics, 2023,
[Early access], p. [21 p.] ISSN 0028-8306
New data collected in the mining areas of the Tiebaghi Massif, a klippe of the Peridotite Nappe located in the north of New Caledonia, are presented. Data were collected in open cast nickel mine pits and chromite underground works, notably along a 1.2-km long tunnel which penetrates the deep geological structure of the massif. Surface and sub-surface geology, microtectonic observations and kinematic analysis of fracture planes, Electrical Resistivity Tomography, micron-scale Raman spectroscopy and Transmission Electron Microscopy were used to characterise the different tectonic regimes and associated mineralisations. Three stages of deformation and their kinematic axes are identified. Fractures coated with antigorite-tremolite minerals are associated to supra-subduction melt intrusions in a compressional regime characterised mainly by thrust and transcurrent faults. They are followed by fractures coated with polygonal serpentine formed in an extensional regime. The two former mineral phases are commonly superimposed on the same plane. Third-stage consist of fractures associated with supergene minerals deposited in an extensional regime, associated with gravity driven normal faulting. Fractures associated with this supergene stage have reactivated the former hypogene network.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020]
;
Géologie et formations superficielles [064]
