San Vicente
Central Peru, Junín (Pucará basin), Peru
Mississippi Valley TypeZn-Pb
- Type
- Mississippi Valley-type (MVT)
The largest MVT deposit of the San Vicente district, in Upper Triassic to Lower Jurassic dolostones of the Pucará basin (Alfonso, San Vicente and San Judas units). Mixing of a hot, saline, slightly acidic, radiogenic fluid with formation water; late dolomite III and sphalerite III form by CO2 degassing. Native sulfur with very light calcites replacing evaporitic sulfates indicates thermochemical sulfate reduction. Other district occurrences have very homogeneous values. Indicative coordinates.
δ13C in ‰ (per mil) Values of the same system
Standard : V-PDB
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 1.7 ‰ | 0.9 / 2.5 ‰ | 11 | dark replacement dolomite (I) Median of the San Vicente unit and range across all units, Table 4 (11 samples). In the table, the San Judas δ18O range is shifted into the δ13C column. | Spangenberg et al. (1996), Carbon and oxygen isotope study of hydrothermal carbonates in … |
| 1.1 ‰ | −0.1 / 1.7 ‰ | 115 | white sparry dolomite (II), main stage Median of the San Vicente unit and range across all units, Table 4 (115 samples). The abstract gives -0.1 to +1.7 ‰ and +18.7 to +23.4 ‰ for main-stage dolomites. | Spangenberg et al. (1996), Carbon and oxygen isotope study of hydrothermal carbonates in … |
| −0.8 ‰ | −11.5 / 0.7 ‰ | 25 | late void-filling calcite (IIIc) Median of the San Vicente unit and range across all units, Table 4 (25 samples). Down to -11.5 ‰ next to native sulfur. | Spangenberg et al. (1996), Carbon and oxygen isotope study of hydrothermal carbonates in … |
| −2.6 ‰ | −4.5 / 0.8 ‰ | 11 | calcite replacing evaporitic sulfates (EPc) Median of the San Vicente unit and range across all units, Table 4 (11 samples). | Spangenberg et al. (1996), Carbon and oxygen isotope study of hydrothermal carbonates in … |
| −0.3 / 1.1 ‰ | 10 | late void-filling dolomite (IIId) Range across all units, Table 4 (10 samples). In the table, medians of this row are shifted by one column and are not used. | Spangenberg et al. (1996), Carbon and oxygen isotope study of hydrothermal carbonates in … | |
| 0.4 / 1 ‰ | 7 | dolomite replacing evaporitic sulfates (EPd) Range from Table 4 (7 samples); the printed median (+0.3 ‰) lies outside the range. | Spangenberg et al. (1996), Carbon and oxygen isotope study of hydrothermal carbonates in … | |
| −27 / −26.4 ‰ | 3 | host-rock organic matter Range of 3 samples, Table 4. | Spangenberg et al. (1996), Carbon and oxygen isotope study of hydrothermal carbonates in … | |
| −27 / −23 ‰ | 6 | hydrothermal bitumen Range of 6 samples, Table 4; heavier than the native organic matter. | Spangenberg et al. (1996), Carbon and oxygen isotope study of hydrothermal carbonates in … |
δ18O in ‰ (per mil) Values of the same system
Standard : V-SMOW
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 23.6 ‰ | 22.9 / 24.3 ‰ | 11 | dark replacement dolomite (I) Median of the San Vicente unit and range across all units, Table 4 (11 samples). In the table, the San Judas δ18O range is shifted into the δ13C column. | Spangenberg et al. (1996), Carbon and oxygen isotope study of hydrothermal carbonates in … |
| 21.1 ‰ | 18.7 / 23.4 ‰ | 115 | white sparry dolomite (II), main stage Median of the San Vicente unit and range across all units, Table 4 (115 samples). The abstract gives -0.1 to +1.7 ‰ and +18.7 to +23.4 ‰ for main-stage dolomites. | Spangenberg et al. (1996), Carbon and oxygen isotope study of hydrothermal carbonates in … |
| 19 ‰ | 15.3 / 21.5 ‰ | 25 | late void-filling calcite (IIIc) Median of the San Vicente unit and range across all units, Table 4 (25 samples). Down to -11.5 ‰ next to native sulfur. | Spangenberg et al. (1996), Carbon and oxygen isotope study of hydrothermal carbonates in … |
| 18.8 ‰ | 14.3 / 21.1 ‰ | 11 | calcite replacing evaporitic sulfates (EPc) Median of the San Vicente unit and range across all units, Table 4 (11 samples). | Spangenberg et al. (1996), Carbon and oxygen isotope study of hydrothermal carbonates in … |
| 18 / 20.8 ‰ | 10 | late void-filling dolomite (IIId) Range across all units, Table 4 (10 samples). In the table, medians of this row are shifted by one column and are not used. | Spangenberg et al. (1996), Carbon and oxygen isotope study of hydrothermal carbonates in … | |
| 19.4 ‰ | 18.4 / 20.8 ‰ | 7 | dolomite replacing evaporitic sulfates (EPd) Median and range, Table 4 (7 samples). | Spangenberg et al. (1996), Carbon and oxygen isotope study of hydrothermal carbonates in … |
δ34S in ‰ (per mil) Values of the same system
Standard : V-CDT
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 10.9 ± 1.1 ‰ | 9.4 / 13 ‰ | 18 | sphalerite Mean and standard deviation recalculated from 18 concentrates, Table 1. Slight δ34S decrease from generation I to generations IIa and IIb; abiogenic reduction of Triassic to Liassic evaporitic or marine sulfate (+12 to +18 ‰). | Gorzawski et al. (1990), Sulfur isotope studies in the zinc-lead mine San Vicente, centra… |
| 6.8 ± 0.1 ‰ | 6.8 / 6.9 ‰ | 2 | galena Mean and standard deviation recalculated from 2 concentrates, Table 1. Slightly depleted relative to associated sphalerite, consistent with isotopic equilibrium. | Gorzawski et al. (1990), Sulfur isotope studies in the zinc-lead mine San Vicente, centra… |
206Pb/204Pb isotope ratio, no unit Values of the same system
Standard : NIST SRM 981
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 19.001 ± 0.005 | 18.997 / 19.004 | 2 | MVT-type ore (?) Mean and standard deviation recalculated from 2 samples, Table 2 (L-248 et L-249). MVT type given with a question mark in the source. | Macfarlane et al. (1990), Lead isotope provinces of the Central Andes inferred from ores … |
207Pb/204Pb isotope ratio, no unit Values of the same system
Standard : NIST SRM 981
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 15.662 ± 0.002 | 15.661 / 15.664 | 2 | MVT-type ore (?) Mean and standard deviation recalculated from 2 samples, Table 2 (L-248 et L-249). MVT type given with a question mark in the source. | Macfarlane et al. (1990), Lead isotope provinces of the Central Andes inferred from ores … |
208Pb/204Pb isotope ratio, no unit Values of the same system
Standard : NIST SRM 981
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 38.913 ± 0.004 | 38.91 / 38.916 | 2 | MVT-type ore (?) Mean and standard deviation recalculated from 2 samples, Table 2 (L-248 et L-249). MVT type given with a question mark in the source. | Macfarlane et al. (1990), Lead isotope provinces of the Central Andes inferred from ores … |
Deposits of the same type
- Florcita Peru
- Florida Canyon Peru
- Central and East Tennessee MVT United States
- Southern Appalachians MVT United States
- Northern Arkansas district United States
- Tri-State district United States
- Upper Mississippi Valley district United States
- Gays River Canada
Cite this page
IsoFind Atlas (2026). San Vicente, isotope signatures. https://www.isofind.tech/isotopes/en/deposits/san-vicente/ (accessed 2026-10-13).
@misc{isofind2026sanvicenteisotopesignatures,
title = {San Vicente, isotope signatures},
author = {{IsoFind Atlas}},
year = {2026},
url = {https://www.isofind.tech/isotopes/en/deposits/san-vicente/},
note = {Accessed 2026-10-13}
}Updated : 2026-10-13