Microstructure,c-axis pattern,microstrain and kinematics of some S-C mylonites in grenville gneiss |
| |
| Institution: | 1. General University Hospital of Castellon, Castellon, Spain;2. University of Valencia, Valencia, Spain;3. Instituto de Biomecánica (IBV), Universitat Politècnica de Valencia, Valencia. Spain;4. ASCIRES CAMPANAR, Valencia, Spain;5. Catholic University of Valencia, Saint Vincent Martyr, Valencia, Spain;6. General University Hospital of Valencia, Spain;7. Medius Klinik, Ostfildern-Ruit Klinik für Urologie, Hedelfinger Strasse 166, 73760 Ostfildern, Germany;1. Oregon Osteoporosis Center, Portland,OR, United States;2. Harvard Medical School, Boston, MA, United States;3. Department of Orthopedic Surgery, Harvard Medical School, Center for Advanced Orthopedic Studies, Beth Israel Deaconess Medical Center, Boston, MA, United States;1. Faculty of Mechanical Engineering, Institute of Machine and Industrial Design, Brno University of Technology, Technická 2896/2, 616 69 Brno, Czech Republic;2. Orthopaedic Clinic, University Hospital Olomouc, I. P. Pavlova 6, 775 20 Olomouc, Czech Republic |
| |
| Abstract: | In a major tectonic zone late extension related SC mylonites locally overprint the predominant coarser quartz microstructures, which are related to earlier thrusting. Some of the SC mylonites display a microstructural evolution which began with the formation of deformation bands in the coarser pre-existing microstructure and continued with the formation of asymmetric quartz microfoliations, either by continued formation of deformation bands or fine new grains oblique to the deformation band boundaries. The orientation of boudinaged and passively reoriented rutile needles show that (i) the formation of deformation bands was preceded and accompanied by the accumulation of strain; (ii) that the deformation bands and oblique microfoliation which formed directly from them lie close to the finite stretching direction; whereas (iii) other microfoliations form oblique to deformation bands and extended rutile needles near the probable instantaneous stretching direction. The latter are therefore interpreted to be strain insensitive, steady-state foliations. The crystallographic preferred orientation of the original deformation bands appears to determine that of the microfoliations, the two types of microfoliations showing distinct but related patterns. The element common to both types is the presence of two maxima near Y in a YZ girdle—a feature inherited from the deformation bands, which were formed in the initial stages of shortening of the aggregate, favourably disposing it for rhomb slip and providing nucleation sites for subsequent recrystallization.The data confirm that, despite the fact that a variety of microstructures and crystallographic microfabrics result from recrystallization processes, kinematic information is usually recoverable from the crystallographic microfabrics owing to the primacy of intracrystalline slip processes. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
