Abstract
Chemical data are presented for 49 muscovites from high and low Al specimens collected form N.W. Maine at metamorphic grades ranging from the upper staurolite to the upper sillimanite zone. Data also are presented for two muscovite from St. Paul Island, two muscovites+three paragonites from Gassetts, Vermont, and one muscovite from an adamellite in N. W. Maine. These data given further information on the effects of P, T, and bulk composition on muscovite composition. Specifically, temperature clearly influences the Na/Na+K ratio of muscovite in limiting assemblages but may not have much effect on the phengite content. Increase in pressure clearly does cause an increase in phengite content. Bulk composition (assemblage) has a very great effect on both Na/Na+K ratio and phengite content so that attempts to use either of these factors to monitor metamorphic grade should generally be done in the context of a limiting assemblage.
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.
