Low pressure experiments with basanite, hawaiite, and phonolite from Mt. Erebus, Antarctica [microform]
- Bib ID:
- 3287840
- Format:
- Book and Microform
- Author:
- Gerke, Tammie Lee
- Description:
- 259 p.
- Summary:
-
I conducted melting experiments with a basanite, two hawaiites (DVDP2 and 83415), and a phonolite from Mt. Erebus, Antarctic. All experiments were carried out a 1 atmosphere from 1224$\sp\circ$ to 1049$\sp\circ$C at oxygen fugacity near QFM buffer. I have tested two hypothesis: (1) can a basanite parent magma differentiate at low pressures to produce hawaiite and phonolite magmas, and (2) do the Mt. Erebus rocks represent low pressure differentiation of a parental basanitic magma. Microprobe analyses of glasses and coexisting crystals were used to test these hypotheses. Crystal-melt equilibria in basanite experiments are represented by olivine+melt (1224$\sp\circ$C), olivine+clinopyroxene+melt (1138$\sp\circ$C), and olivine+clinopyroxene+plagioclase+melt (1104$\sp\circ$C). In experiments with DVDP2 hawaiite from 1104$\sp\circ$ to 1049$\sp\circ$C, olivine+clinopyroxene+plagioclase+melt coexists.
Data from 83415 hawaiite experiments show that at 1160$\sp\circ$C melt coexists with plagioclase; below 1104$\sp\circ$C with olivine+plagioclase. Liquid lines of descent established using the compositions of melts on a T-Mg# plot show that basanite melt merges into hawaiite composition at about 1104$\sp\circ$C and melt of hawaiite composition merges into phonolite composition at 1049$\sp\circ$C. These data confirm the hypothesis that low pressure differentiation of a basanitic melt can produce melts of hawaiite and phonolite composition. Mt. Erebus rock compositions produce a continuous data array on K$\sb2$O-SiO$\sb2$, TiO$\sb2$-SiO$\sb2$, MgO-SiO$\sb2$, Al$\sb2$O$\sb3$-SiO$\sb2$, Na$\sb2$O-SiO$\sb2$, and P$\sb2$O$\sb5$-SiO$\sb2$ plots. Liquid lines of descent established from the experiments define a vector. I interpret the coincidence of this vector with the Mt. Erebus rock data array as the results of low-pressure fractionation of the basanitic parental magma.
- Notes:
-
- (UnM)AAI9614491
- Source: Dissertation Abstracts International, Volume: 57-01, Section: B, page: 0187.
- Thesis (Ph.D.)--University of Cincinnati, 1995.
- Reproduction:
- Microfiche. Ann Arbor, Mich.: University Microfilms International.
- Subject:
- Geochemistry
- Other authors/contributors:
- University of Cincinnati
- Copyright:
-
In Copyright
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Copyright status was determined using the following information:
- Material type:
- Literary Dramatic Musical
- Published status:
- Unpublished
- Creation date:
- 1995
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