Los Santos
Salamanca Province, Spanish Central System (Central Iberian Zone), Spain
SkarnsW
- Type
- Reduced calcic scheelite skarn
Second largest tungsten deposit of the Iberian Peninsula after Panasqueira (3.09 Mt at 0.54 % WO3): stratabound scheelite skarn lenses at the contact between the Variscan granodiorite-monzogranite of the Béjar pluton and Lower Cambrian marbles and hornfelses. Prograde skarn at about 550 to 680 °C, retrograde at about 300 to 400 °C, 18O-rich fluid (9.1 to 12.0 ‰) equilibrated with the deep crust, without surface water. Tungsten and fluorine attributed to a concealed leucogranite, like the nearby leucogranite dikes, rather than to the barren granodiorite. Coordinates estimated near the village of Los Santos. Indicative coordinates.
δ18O in ‰ (per mil) Values of the same system
Standard : V-SMOW
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 7.8 ± 0.4 ‰ | 7.5 / 8.4 ‰ | 4 | prograde skarn hedenbergite (pyroxene exoskarn) Mean and standard deviation recalculated from 4 samples, Table 2. Calculated fluid from 9.5 to 10.5 ‰ (550 to 680 °C, Zheng, 1993). | Tornos et al. (2008), Geochemistry and origin of calcic tungsten-bearing skarns, Los Sant… |
| 7.8 ± 0.1 ‰ | 7.8 / 7.9 ‰ | 2 | prograde skarn grandite (garnet exoskarn) Mean and standard deviation recalculated from 2 samples, Table 2. Calculated fluid from 10.7 to 10.9 ‰. | Tornos et al. (2008), Geochemistry and origin of calcic tungsten-bearing skarns, Los Sant… |
| 7.5 ± 1.1 ‰ | 6.4 / 8.6 ‰ | 3 | retrograde skarn biotite Mean and standard deviation recalculated from 3 samples, Table 2. Calculated fluid from 9.1 to 11.3 ‰ (300 to 400 °C). | Tornos et al. (2008), Geochemistry and origin of calcic tungsten-bearing skarns, Los Sant… |
| 9.2 ± 0.2 ‰ | 9 / 9.3 ‰ | 3 | retrograde skarn ferro-actinolite Mean and standard deviation recalculated from 3 samples, Table 2. Calculated fluid from 10.3 to 12.0 ‰. | Tornos et al. (2008), Geochemistry and origin of calcic tungsten-bearing skarns, Los Sant… |
| 12.3 ± 0.5 ‰ | 11.8 / 12.8 ‰ | 3 | amphibole skarn calcite Mean and standard deviation recalculated from 3 samples, Table 3. Calculated fluid from 8.5 to 9.5 ‰ at 400 °C. | Tornos et al. (2008), Geochemistry and origin of calcic tungsten-bearing skarns, Los Sant… |
| 12.9 ± 0.1 ‰ | 12.8 / 12.9 ‰ | 2 | host limestone next to the wollastonite skarn Mean and standard deviation recalculated from 2 samples, Table 3. Probably reset by the retrograde skarn fluid (regional Cambrian limestones: 10.5 to 16 ‰). | Tornos et al. (2008), Geochemistry and origin of calcic tungsten-bearing skarns, Los Sant… |
δ13C in ‰ (per mil) Values of the same system
Standard : Non précisé dans la publication
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| −5.3 ± 2.2 ‰ | −6.9 / −2.8 ‰ | 3 | amphibole skarn calcite Mean and standard deviation recalculated from 3 samples, Table 3. Carbon mostly from the host limestone, with some light carbon from the metapelites. | Tornos et al. (2008), Geochemistry and origin of calcic tungsten-bearing skarns, Los Sant… |
| −5 ‰ | −5 / −5 ‰ | 2 | host limestone next to the wollastonite skarn Mean and standard deviation recalculated from 2 samples, Table 3. | Tornos et al. (2008), Geochemistry and origin of calcic tungsten-bearing skarns, Los Sant… |
87Sr/86Sr isotope ratio, no unit Values of the same system
Standard : NIST SRM 987
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 0.7118 ± 0.0001 | 0.7117 / 0.7119 | 4 | scheelite (ore concentrate) Mean and standard deviation recalculated from 4 samples, Table 1. Initial ratios at 300 Ma. Measured ratios from 0.711850 to 0.712017. | Tornos et al. (2008), Geochemistry and origin of calcic tungsten-bearing skarns, Los Sant… |
| 0.7127 ± 0.0004 | 0.7124 / 0.7129 | 2 | plagioclase skarn Mean and standard deviation recalculated from 2 samples, Table 1. Initial ratios at 300 Ma. | Tornos et al. (2008), Geochemistry and origin of calcic tungsten-bearing skarns, Los Sant… |
| 0.7124 ± 0.0006 | 0.7119 / 0.7128 | 2 | pyroxene skarn Mean and standard deviation recalculated from 2 samples, Table 1. Initial ratios at 300 Ma. | Tornos et al. (2008), Geochemistry and origin of calcic tungsten-bearing skarns, Los Sant… |
| 0.713 ± 0.0026 | 0.7112 / 0.7149 | 2 | nearby leucogranite dikes (whole rock) Mean and standard deviation recalculated from 2 samples, Table 1. Initial ratios at 300 Ma. Very high Rb/Sr (87Rb/86Sr from 19 to 61): age correction sensitive. | Tornos et al. (2008), Geochemistry and origin of calcic tungsten-bearing skarns, Los Sant… |
| 0.7097 ± 0.0001 | 0.7096 / 0.7097 | 2 | host marble Mean and standard deviation recalculated from 2 samples, Table 1. Initial ratios at 300 Ma. | Tornos et al. (2008), Geochemistry and origin of calcic tungsten-bearing skarns, Los Sant… |
| 0.7187 ± 0.0029 | 0.7166 / 0.7207 | 2 | host pelitic hornfels Mean and standard deviation recalculated from 2 samples, Table 1. Initial ratios at 300 Ma. A calc-silicate hornfels gives 0.7124. | Tornos et al. (2008), Geochemistry and origin of calcic tungsten-bearing skarns, Los Sant… |
εNd(t) in ε units (parts per 10,000) Values of the same system
Standard : CHUR
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| −8.8 ± 0.4 ε | −9.4 / −8.5 ε | 4 | scheelite (ore concentrate) Mean and standard deviation recalculated from 4 samples, Table 1. More negative than the leucogranite: fluid equilibrated with the host metasediments. | Tornos et al. (2008), Geochemistry and origin of calcic tungsten-bearing skarns, Los Sant… |
| −8.3 ± 1.9 ε | −9.7 / −7 ε | 2 | plagioclase skarn Mean and standard deviation recalculated from 2 samples, Table 1. | Tornos et al. (2008), Geochemistry and origin of calcic tungsten-bearing skarns, Los Sant… |
| −8.6 ± 0.1 ε | −8.7 / −8.5 ε | 2 | pyroxene skarn Mean and standard deviation recalculated from 2 samples, Table 1. | Tornos et al. (2008), Geochemistry and origin of calcic tungsten-bearing skarns, Los Sant… |
| −5.1 ± 0.7 ε | −5.6 / −4.6 ε | 2 | nearby leucogranite dikes (whole rock) Mean and standard deviation recalculated from 2 samples, Table 1. Probable source of tungsten and fluorine (equivalent concealed leucogranite). | Tornos et al. (2008), Geochemistry and origin of calcic tungsten-bearing skarns, Los Sant… |
| −9 ± 0.1 ε | −9.1 / −8.9 ε | 3 | host hornfelses (calc-silicate and pelitic) Mean and standard deviation recalculated from 3 samples, Table 1. | Tornos et al. (2008), Geochemistry and origin of calcic tungsten-bearing skarns, Los Sant… |
Deposits of the same type
- Morille Spain
- Azegour Morocco
- Scalittas Italy
- Santa Lucia (Buggerru) Italy
- Su Zurfuru Italy
- Rosas Italy
- Sarrabus Italy
- Medenec Czechia
Cite this page
IsoFind Atlas (2026). Los Santos, isotope signatures. https://www.isofind.tech/isotopes/en/deposits/los-santos/ (accessed 2026-10-13).
@misc{isofind2026lossantosisotopesignatures,
title = {Los Santos, isotope signatures},
author = {{IsoFind Atlas}},
year = {2026},
url = {https://www.isofind.tech/isotopes/en/deposits/los-santos/},
note = {Accessed 2026-10-13}
}Updated : 2026-10-13