Abstract

The Tsukuba metamorphic area is underlain mostly by mica schists and gneisses derived from pelitic and psammitic sedimentary rocks of middle-late Triassic to late Jurassic. Three progressive zones A, B and C are classified on the basis of systematic variation of mineral parageneses. The representative assemblages of each zone are as follows. A: muscovite+orthoclase+plagioclase+andalusite B: fibrolite+muscovite+orthoclase+plagioclase+cordierite C: fibrolite+orthoclase+plagioclase+cordierite+almandine Biotite, quartz and graphite are found in almost all specimens studied. The geothermometry and geobarometry based on the dehydration reaction of muscovite and quartz, the polymorphic transition of Al2SiO5 minerals, the Fe-Mg partition between garnet and cordierite, and the two feldspar relation, enabled us to estimate the metamorphic con-ditions as 550° to 600°C, 3 to 4.5 Kb and 0.4-0.5 XH2O in the fluid phase.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.