Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published August 1970 | public
Journal Article

Phase equilibrium studies bearing on genetic links between alkaline and subalkaline magmas, with special reference to the limestone assimilation hypothesis

Abstract

The limestone assimilation hypothesis for forming alkaline, magmas from subakaline magmas is based on circumstantial petrological evidence. It requires (1) desilication, (2) alkali transfer by CO_2 and H_2O. Experimental results indicate that limestone assimilation causes crystallization, and that the thermal barrier between granitic and feldspathoidal liquids persists in the presence of H_2O and CO_2 to high pressures. Desilication of SiO_2-oversaturated magmas remains an unlikely process. Results in silicate-salt-volatile systems suggest that alkali transfer is only effective from liquids already enriched in alkalis. In general, experimental studies have failed to validate proposed genetic links between alkaline and subalkaline magmas through assimilation.

Additional Information

© 1970 Mineralogical Association of Canada. We are grateful to the National Science Foundation for their continuing support of the experimental program in silicate-carbonate systems with Grants GA-1289 and GA-15718.

Additional details

Created:
August 23, 2023
Modified:
October 17, 2023