Ludousou (Laodou)
Gansu, West Qinling Orogen, China
Other hydrothermalAu-Sb
- Type
- Diorite-related magmatic-hydrothermal Au-Sb
Magmatic-hydrothermal Au-Sb deposit (about 247 Ma, Palaeo-Tethys subduction) in diorites and quartz-tourmaline-sulfide veins. Zhang et al. (2026): gold stage 1 with tourmaline, arsenopyrite and pyrite, formed at about 410 to 310 °C; stage 2 with Au and stibnite, with sphalerite (254 to 291 °C), galena and calcite. Sb carried mainly as Sb(OH)3 then Sb2S2(OH)2; stibnite precipitates by cooling linked to mixing of magmatic and meteoric fluids (fluid δ18O of +5.1 to +11.2 ‰, δD of -91.2 to -45.1 ‰, earlier data). Stage 1 sulfide δ34S of -5.9 to +1.0 ‰: magmatic sulfur mixed with sulfur from reduced Sb-rich sedimentary sequences (Longwuhe Formation, diagenetic pyrite at -25.2 to -20.1 ‰). Coordinates not published.
δ34S in ‰ (per mil) Values of the same system
Standard : V-CDT
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| −5.7 / −2.5 ‰ | 7 | pyrite of the disseminated mineralised diorite (stage 1) Text range over 7 grains, -5.7 to -2.5 ‰; individual values in Table S3 (supplement not supplied). | Zhang et al. (2026), Antimony precipitation processes of orogenic and magmatic-hydrotherm… | |
| −2.5 ± 3.25 ‰ | −4.8 / −0.2 ‰ | 2 | pyrite of the quartz-tourmaline and quartz-sulfide veins (stage 1) Mean and standard deviation recalculated from 2 analyses, -4.80 to -0.20 (pyrite 1 -0.20; pyrite 2 -4.80); one sample per vein type, the text does not say which carries which value. | Zhang et al. (2026), Antimony precipitation processes of orogenic and magmatic-hydrotherm… |
| −4.8 / 1 ‰ | 6 | arsenopyrite of the disseminated mineralised diorite (stage 1) Text range over 6 grains, -4.8 to +1.0 ‰; pyrite-arsenopyrite fractionation below 1 ‰ at 200 to 400 °C, values close to the fluid. Individual values in Table S3 (supplement not supplied). | Zhang et al. (2026), Antimony precipitation processes of orogenic and magmatic-hydrotherm… |
Deposits of the same type
Cite this page
IsoFind Atlas (2026). Ludousou (Laodou), isotope signatures. https://www.isofind.tech/isotopes/en/deposits/ludousou-laodou/ (accessed 2026-10-16).
@misc{isofind2026ludousoulaodouisotopesignatur,
title = {Ludousou (Laodou), isotope signatures},
author = {{IsoFind Atlas}},
year = {2026},
url = {https://www.isofind.tech/isotopes/en/deposits/ludousou-laodou/},
note = {Accessed 2026-10-16}
}Updated : 2026-10-16