Abstract
Lamellar intergrowths of actinolite and hornblende or aluminous actinolite occur in metamorphosed igneous rocks in the Hitachi metamorphic district, southern Abukuma Plateau. Electron microprobe analyses of five pairs are presented. The Fe-Mg partitioning and the miscibility gap are discussed in terms of an Mg-Fe-AlIV diagram. The Fe-Mg partition coefficients depend on the AlIV contents in hornblendes in a manner indicating that the pairs are close to equilibrium. Calcic amphibole pairs of high Fe/Mg ratio are richer in AlIV than those with low ratio. The AlIV content of the coexisting actinolite first increases with rising temperature, but then decreases as the temperature increases further. On the other hand, the AlIV content of coexisting hornblende-aluminous actinolite successively decreases with rising temperature.
Sign-in/Register to access full text options 
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 callDisclaimer: 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.
