Rock-water systems, with special reference to the water-deficient region
- Creators
- Robertson, J. K.
- Wyllie, P. J.
Abstract
The four types of subsolidus assemblages in silicate-water systems are: Type I, water-absent; assemblage of anhydrous minerals with no vapor phase. Type II, water-deficient and vapor-absent; assemblage of minerals including hydrous minerals, but with no vapor phase. Type III, water-deficient and vapor-present; an assemblage of minerals, with or without hydrous minerals, with a vapor phase; there is insufficient water present to saturate the liquid when the crystalline assemblage is completely melted at the existing pressure. Type IV, water-excess; an assemblage of minerals and vapor with at least enough water to saturate the liquid when the crystalline assemblage is completely melted at the existing pressure. Water-deficient systems of types II and III are significant for magma generation and crystallization; there are few experimental results. Water-deficient phase relationships can be estimated by interpolation between available experimental data for systems of types I and IV. Mantle magmas are generated in type I, II, or III systems. The first liquid produced in type III systems is H_20-saturated, and the first liquid in type II systems is H_2O-undersaturated. It appears that the normal product of partial fusion of many continental crustal rocks is a H_2O-undersaturated granite liquid in a crystal mush, and that liquids of intermediate composition are not generated because temperatures required are too high. Phase relationships are depicted for granodiorite in a pressure-temperature- water diagram.
Additional Information
© 1971 American Journal of Science. We thank the National Science Foundation for Grant GA-10459 which has supported this research, Advanced Research Projects Agency Grant SD-89 to the Physical Sciences Division for a research assistantship for J. K. Robertson, many colleagues for discussion of the scheme developed, G. L. Millhollen for a critical review, and two anonymous reviewers whose comments led to this revised version with more explanation and justification of claims than the first manuscript submitted in August, 1970.Additional details
- Eprint ID
- 63972
- DOI
- 10.2475/ajs.271.3.252
- Resolver ID
- CaltechAUTHORS:20160126-111825527
- GA-10459
- NSF
- SD-89
- Advanced Research Projects Agency (ARPA)
- Created
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2016-01-26Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences