|
|||||
|
|
Application of scanning X-ray analytical microscope to the petrographic characterization of a ductile shear zone: an alternative method to image microstructures |
|
| Authors: | K Michibayashi S Togami M Takano M Kumazawa and T Kageyama |
| Institution: | a Laboratoire de Tectonophysique, Université Montpellier II, 34095 Montpellier, France b Institute of Geosciences, Shizuoka University, Shizuoka 422-8529, Japan c Department of Earth and Planetary Sciences, Nagoya University, Nagoya 464-8602, Japan |
| Abstract: | A ductile shear zone within a metasomatic biotite band in the Ryoke granite, Teshima, SW Japan, has been studied using the scanning X-ray analytical microscope (SXAM). This enabled the quantitative distributions of major elements, such as Si, K, Fe, Al and Ca, to be determined within the shear zone. These element maps were processed to transform them into images showing the distribution of minerals such as quartz, biotite, plagioclase and K-feldspar, which form the major minerals within the biotite band and the granite protolith. Mineral profiles based on these mineral maps compared with the simple shear strain profile reveal that the shear zone is most intense where quartz and biotite have been substituted for the primary mineral assemblage of the granite protolith, suggesting that the stresses imposed on the granite caused the shear strain to localize along the biotite band to produce the observed shear zone. It appears that the rheological behavior changed around 50–60% of quartz modal composition. |
| Keywords: | scanning X-ray analytical microscope shear zone image analysis granite Ryoke metamorphic belt Japan |
| 本文献已被 ScienceDirect 等数据库收录！ | |