Himalaya (Mesa Grande district)
San Diego County, California, United States
Magmatic (Ni-Cu-PGE, carbonatites)Gemmes (tourmaline), Li
- Type
- Gem-pocket granitic pegmatite-aplite (LCT type)
Late Cretaceous (about 100 Ma) pegmatite-aplite dikes of the Southern California batholith, 1 to 3 m thick and gently dipping, with a basal aplite zone, a pocket zone (tourmaline, beryl, quartz) and graphic pegmatite. Crystallisation from 730-700 to 565 °C, pockets at 565-525 °C under about 2 kbar, nearly closed system. System of two dikes (lower, then upper enriched in 18O by 0.5 ‰) traced for nearly 2 km in the San Marcos gabbro norite, worked at the Himalaya and San Diego mines. Group A: quartz near +10.5 ‰, exchanged with the gabbroic host before the end of crystallisation. Angel Field dike, in the same district but hosted by metasediments: quartz +11.1 to +11.2 ‰ (5 samples). Indicative coordinates.
δ18O in ‰ (per mil) Values of the same system
Standard : V-SMOW
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 10.5 ± 0.4 ‰ | 9.8 / 11.1 ‰ | 43 | quartz (aplite, pockets, graphic pegmatite) Mean and standard deviation recalculated from 43 analyses, 26 in the aplite zone, 7 in the pocket zone, 10 in the graphic pegmatite. δ18O rises by 0.5 ‰ towards the pocket zone. | Taylor et al. (1979), Stable isotope and fluid inclusion studies of gem-bearing granitic … |
δD in ‰ (per mil) Values of the same system
Standard : V-SMOW
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| −65 ± 6 ‰ | −76 / −50 ‰ | 39 | muscovite Mean and standard deviation recalculated from 39 analyses, all zones. δD decreases from the walls towards the centre of the dikes as temperature falls. | Taylor et al. (1979), Stable isotope and fluid inclusion studies of gem-bearing granitic … |
Deposits of the same type
- Little Three (Ramona district) United States
- Tourmaline Queen (Pala district) United States
- Stewart (Pala district) United States
- Ocean View (Pala district) United States
- Stillwater Complex (J-M Reef) United States
- Magnet Cove alkaline complex United States
- Carolina tin-spodumene belt United States
- Sudbury Canada
Cite this page
IsoFind Atlas (2026). Himalaya (Mesa Grande district), isotope signatures. https://www.isofind.tech/isotopes/en/deposits/himalaya-district-de-mesa-grande/ (accessed 2026-10-13).
@misc{isofind2026himalayamesagrandedistrictiso,
title = {Himalaya (Mesa Grande district), isotope signatures},
author = {{IsoFind Atlas}},
year = {2026},
url = {https://www.isofind.tech/isotopes/en/deposits/himalaya-district-de-mesa-grande/},
note = {Accessed 2026-10-13}
}Updated : 2026-10-13