| Abstract: | Five magma types occur as sills in the footwall of the Stillwater Complex, all of them coeval with the Stillwater Complex, all of them coeval with the Stillwater in age. Two of the magma types have compositions that suggest they are similar to the magmas from which the cumulates of the Stillwater‘s Basal and Ultramafic series crystallized. Melting experiments show that the crystallization sequence inferred from the Ultramafic series cumulates is matched only in the mixture of the two sill types at 1.5-3 kbar. Thus, the observed stratigraphy of the Basal and Ultramafic series may result from mixing of two distinct magmas rather than fractionation of a single magma. The permissible pressure range of 1.5-3 kbar implies that the depth of the Stillwater magma chamber was similar to that of subvolcanic magma chambers such as that of Kilauea Volcano, which raises the possibility that the Stillwater magma body may also have been a subvolcanic reservoir. -from Author |
| Genre: | Article |
| ProdID: | 70018876 |
| Citation Author: | Helz, R. T. |
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| Citation End Page: | 1346 |
| Citation Issue: | 11-12 |
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| Citation Language: | English |
| Citation Larger Work Title: | American Mineralogist |
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| Citation Number Of Pages: | 4 |
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| Citation Search Results Text: | The Stillwater Complex, Montana: a subvolcanic magma chamber?; 1995; Article; Journal; American Mineralogist; Helz, R. T. |
| Citation Start Page: | 1343 |
| Citation Volume: | 80 |
| Citation Year: | 1995 |
| Type: | citation/reference |
| Text: | The Stillwater Complex, Montana: a subvolcanic magma chamber?; 1995; Article; Journal; American Mineralogist; Helz, R. T. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Sun, 1 Jan 1995 00:00 -0600 |
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