English   español  
Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/3439
COMPARTIR / IMPACTO:
Estadísticas
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:
Título

Formation of natural gypsum megacrystals in Naica, Mexico

AutorGarcía Ruiz, Juan Manuel ; Villasuso, Roberto; Ayora, Carlos; Canals, Angels; Otalora, Fermín
Palabras claveGypsum
Crystallization
Mineral growth
Anhydrite
Naica mine
Nucleation
Fecha de publicaciónabr-2007
EditorGeological Society of America
CitaciónGeology, April 2007; v. 35; no. 4; p. 327–330
ResumenExploration in the Naica mine (Chihuahua, Mexico) recently unveiled several caves containing giant, faceted, and transparent single crystals of gypsum (CaSO4•2H2O) as long as 11 m. These large crystals form at very low supersaturation. The problem is to explain how proper geochemical conditions can be sustained for a long time without large fluctuations that would trigger substantial nucleation. Fluid inclusion analyses show that the crystals grew from low-salinity solutions at a temperature of ~54 °C, slightly below the one at which the solubility of anhydrite equals that of gypsum. Sulfur and oxygen isotopic compositions of gypsum crystals are compatible with growth from solutions resulting from dissolution of anhydrite previously precipitated during late hydrothermal mineralization, suggesting that these megacrystals formed by a self-feeding mechanism driven by a solution-mediated, anhydrite-gypsum phase transition. Nucleation kinetics calculations based on laboratory data show that this mechanism can account for the formation of these giant crystals, yet only when operating within the very narrow range of temperature identified by our fluid inclusion study. These singular conditions create a mineral wonderland, a site of scientific interest, and an extraordinary phenomenon worthy of preservation.
DescripciónContains 4 figures.
URIhttp://hdl.handle.net/10261/3439
DOI10.1130/G23393A.1
ISSN0091-7613
Aparece en las colecciones: (IACT) Artículos
(ICTJA) Artículos
Ficheros en este ítem:
Fichero Descripción Tamaño Formato  
garciaruiznaica.pdf337,2 kBAdobe PDFVista previa
Visualizar/Abrir
Mostrar el registro completo
 

Artículos relacionados:


NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.