| Reference Type | Journal (article/letter/editorial) |
|---|
| Title | Formation of tourmaline-rich pockets in miarolitic pegmatites |
|---|
| Journal | American Mineralogist | ISSN | 1945-3027 |
|---|
| Authors | London, D. | Author |
|---|
| Year | 1986 | Volume | < 71 > |
|---|
| Issue | < 3-4 > |
|---|
| Original Entry | London, D. (1986), Formation of tourmalin-rich pockets in miarolitic pegmatites. In: American Mineralogist, Vol. 71, p. 386–405. |
|---|
| Classification | Not set | LoC | Not set |
|---|
| Mindat Ref. ID | 16179789 | Long-form Identifier | mindat:1:5:16179789:8 |
|---|
|
| GUID | 0 |
|---|
| Full Reference | London, D. (1986) Formation of tourmaline-rich pockets in miarolitic pegmatites. American Mineralogist, 71 (3-4) 386-405 |
|---|
| Plain Text | London, D. (1986) Formation of tourmaline-rich pockets in miarolitic pegmatites. American Mineralogist, 71 (3-4) 386-405 |
|---|
| In | Link this record to the correct parent record (if possible) |
|---|
| Abstract/Notes | Analysis of fluid inclusions in spodumene, beryl, tourmaline, and quartz from miarolitic pegmatites of Afghanistan, coupled with lithium aluminosilicate stability relations and with previous studies from gem pegmatites of San Diego County, California, indicate that pocket development in tourmaline-rich, miarolitic rare-element pegmatites occurs between approximately 475 and 425°C and between 2800 and 2400 bars. This range of P and T is comparable to the conditions of late-stage crystallization in geochemically similar massive (nonmiarolitic) pegmatites. Whether gem pockets form may be dependent largely on the timing of tourmaline crystallization. Formation of tourmaline removes an alkali borate component from residual pegmatitic melt, with the consequent deposition of other alkali aluminosilicate and oxide-forming minerals and exsolution of copius amounts of H2O. If tourmaline crystallization is inhibited until the late stages of pegmatite consolidation, the large quantities of H2O that are liberated may form pegmatitic pockets. |
|---|
These are possibly similar items as determined by title/reference text matching only.
