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Metallogenic model of the Eocene Santa María and Antares Zn-Pb(-Ag) skarn deposits, Velardeña Mining District, Durango, Mexico.
- Source :
- Mineralium Deposita; Apr2024, Vol. 59 Issue 4, p671-698, 28p
- Publication Year :
- 2024
-
Abstract
- The Santa María and Antares Zn-Pb(-Ag) skarn deposits in the Velardeña Mining District are located in central–NW Mexico. They lie 470 m apart along the contact between Oligocene felsic intrusions and Cretaceous limestones, and were developed during prograde, retrograde, post-ore (Santa María), and late stages. Firstly, the prograde stage was formed by fluids at ~ 600 °C and 15 wt% NaCl equiv., and consists of garnet + wollastonite ± clinopyroxene and biotite ± K-feldspar assemblages. Secondly, the retrograde/ore stage was formed by fluids at 300–500 °C with salinities of 20–30 wt% CaCl<subscript>2</subscript> (Santa María) and > 40 wt% NaCl equiv. (Antares). It comprises assemblages of chlorite, amphibole, epidote, calcite, scapolite, quartz, sericite, adularia, fluorite, and muscovite associated with sphalerite, pyrite, galena, pyrrhotite, arsenopyrite, chalcopyrite, and Pb-Bi-Sb sulfosalts. Thirdly, the post-ore stage was formed by fluids at ~ 400 °C and 20–30 wt.% CaCl<subscript>2</subscript> and comprises poorly mineralized calcite veins. Fourthly, the late stage was formed by fluids at < 300 °C and 20–30 wt.% CaCl<subscript>2</subscript> (Santa María) and ~ 15 wt% NaCl equiv. (Antares), and crystallized tetrahedrite-group minerals and pyrite + marcasite. δ<superscript>18</superscript>O<subscript>fluid</subscript> between ~ 14‰ and 23‰ at Santa María and between ~ 12‰ and 17‰ at Antares show a less-modified magmatic affinity for mineralizing fluids at Antares; δ<superscript>13</superscript>C<subscript>fluid</subscript> between 0‰ and –6‰ register recycling of sedimentary C. Moreover, sulfides with δ<superscript>34</superscript>S<subscript>VCDT</subscript> between –3‰ and 2‰ reveal a magmatic source for S. Altogether, these data suggest that, at Santa María, magmatic-derived fluids actively interacted with the wall rocks, whereas at Antares the fluid-rock interaction was milder. In both deposits, metal deposition was triggered by the cooling and neutralization of ore-bearing fluids with carbonate rocks. Our <superscript>40</superscript>Ar/<superscript>39</superscript>Ar dates for adularia of ca. 37.5 Ma place the deposits within the Eocene–early Miocene metallogenetic epoch of central–NW Mexico, during which other world-class skarn-epithermal systems were emplaced (e.g., Concepción del Oro and Mazapil-Peñasquito). [ABSTRACT FROM AUTHOR]
- Subjects :
- MINING districts
SKARN
SULFIDE minerals
EOCENE Epoch
MIOCENE Epoch
ARSENOPYRITE
Subjects
Details
- Language :
- English
- ISSN :
- 00264598
- Volume :
- 59
- Issue :
- 4
- Database :
- Complementary Index
- Journal :
- Mineralium Deposita
- Publication Type :
- Academic Journal
- Accession number :
- 176033354
- Full Text :
- https://doi.org/10.1007/s00126-023-01225-4