Isotope and trace element evolution of the naica aquifer (Chihuahua, Mexico) over the past 60,000 yr revealed by speleothems
| Autor: | Paolo Forti, Fernando Gázquez, José María Calaforra, Fernando Rull, Heather Stoll, Antonio Domínguez Delgado, Jesús Martínez-Frías, Stein-Erik Lauritzen, Laura Sanna |
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| Rok vydání: | 2013 |
| Předmět: |
Calcite
geography geography.geographical_feature_category 010504 meteorology & atmospheric sciences Naica Mine Water table Aragonite Geochemistry Aquifer engineering.material 01 natural sciences chemistry.chemical_compound Arts and Humanities (miscellaneous) Cave chemistry engineering Deglaciation General Earth and Planetary Sciences 010503 geology Geomorphology Holocene Geology 0105 earth and related environmental sciences Earth-Surface Processes |
| Zdroj: | Quaternary Research. 80:510-521 |
| ISSN: | 1096-0287 0033-5894 |
| DOI: | 10.1016/j.yqres.2013.09.004 |
| Popis: | The “espada” speleothems of Cueva de las Espadas (Naica Mine, Chihuahua, Mexico) comprise a high-purity selenite core overlain by successive deposits of calcite, gypsum and aragonite. Gypsum precipitated under water from a hydrothermal solution (~ 58°C) when the water table was above the cave level ca. 57 ka, during the last glaciation, and some intervals during deglaciation and the Holocene. Aragonite was deposited at lower temperatures (~ 26°C) in a perched lake occupying the cave bottom, when the water table dropped below the cave level during brief dry intervals during deglaciation and the early Holocene. The isotopic composition of gypsum water of crystallization shows that the deglaciation–Holocene aquifer water was enriched in deuterium by 12.8–8.7‰ relative to water from the last glaciation. This is attributed to an increased relative moisture contribution from the Gulf of Mexico during deglaciation and the Holocene compared to the last glaciation. This indicates that drier conditions occurred in the Naica area during the Holocene than around 57 ka. Furthermore, trace element analyses of gypsum served to deduce the circulation regime of the Naica aquifer during the past 60,000 yr, and also suggest that higher aquifer recharge occurred during the last glaciation. |
| Databáze: | OpenAIRE |
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