| Reference Type | Journal (article/letter/editorial) |
|---|
| Title | C2/c pyroxene from two alkaline sodic suites (Western Ross Embayment – Antarctica): crystal chemical characterization and its petrologic significance |
|---|
| Journal | Mineralogical Magazine | ISSN | 0026-461X |
|---|
| Authors | Salviulo, Gabriella | Author |
|---|
| Secco, Luciano | Author |
| Antonini, Paolo | Author |
| Piccirillo, Enzo Michele | Author |
| Year | 1997 (June) | Volume | 61 |
|---|
| Issue | 406 |
|---|
| Publisher | Mineralogical Society |
|---|
| Download URL | https://rruff.info/doclib/MinMag/Volume_61/61-406-423.pdf+ |
|---|
| DOI | doi:10.1180/minmag.1997.061.406.08Search in ResearchGate |
|---|
| Generate Citation Formats |
|---|
| Mindat Ref. ID | 181 | Long-form Identifier | mindat:1:5:181:8 |
|---|
|
| GUID | 0 |
|---|
| Full Reference | Salviulo, Gabriella, Secco, Luciano, Antonini, Paolo, Piccirillo, Enzo Michele (1997) C2/c pyroxene from two alkaline sodic suites (Western Ross Embayment – Antarctica): crystal chemical characterization and its petrologic significance. Mineralogical Magazine, 61 (406) 423-439 doi:10.1180/minmag.1997.061.406.08 |
|---|
| Plain Text | Salviulo, Gabriella, Secco, Luciano, Antonini, Paolo, Piccirillo, Enzo Michele (1997) C2/c pyroxene from two alkaline sodic suites (Western Ross Embayment – Antarctica): crystal chemical characterization and its petrologic significance. Mineralogical Magazine, 61 (406) 423-439 doi:10.1180/minmag.1997.061.406.08 |
|---|
| In | (1997, June) Mineralogical Magazine Vol. 61 (406) Mineralogical Society |
|---|
| Abstract/Notes | AbstractTwo C2/c pyroxene suites from sodic alkaline rocks (Basanite-Phonolite: B-Ph and Alkali basalt-Trachyphonolite: AB-T) belonging to the McMurdo Volcanic Group (Mt. Melbourne province and Mt. Erebus, Antarctica) were investigated by single-crystal X-ray diffraction combined with electron probe microanalysis which together provide accurate site occupancy and site configuration parameters. Variations in site volumes distinguish the clinopyroxenes belonging to the more alkaline B-Ph suite from those of the AB-T suite. The former have higher VM2 and, for similar cell volume, lower VM1 and higher VT. In these C2/c pyroxenes, the bond lengths of M1 depend on R3+ content, necessary to balance AlIV in the T site. M1 geometric variations are similar for both B-Ph and AB-T suites. However, the M2 site is crucial for variations in polyhedral configurations. The increase in AlIV affects the shortest M2-O bond lengths in different ways depending on (Ca+Na) contents in the M2 site. Thus, the clinopyroxenes were distinguished in two different groups not related to the two suites. The first group is characterized by (Ca+Na) higher than 0.90 atoms per formula unit but shows a good positive correlation between the shortest M2-O bond lengths and AlIV content, at quite constant (Ca+Na). The second group has (Ca+Na) less than 0.90 atoms per formula unit but shows a poor correlation between the shortest M2-O bond lengths and AlIV content. In general, shortening of the longest M2-O bond lengths is associated with increase in AlIV. The cell and M1 volumes suggest that the clinopyroxenes, including the larger and sometimes resorbed macrocrysts, crystallized at a pressure lower than 5 kbar, fitting the petrography and evolved character of the rocks in question. |
|---|
These are possibly similar items as determined by title/reference text matching only.
