English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/3439
Share/Impact:
Statistics
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:
Title

Formation of natural gypsum megacrystals in Naica, Mexico

AuthorsGarcía Ruiz, Juan Manuel ; Villasuso, Roberto; Ayora, Carlos; Canals, Angels; Otalora, Fermín
KeywordsGypsum
Crystallization
Mineral growth
Anhydrite
Naica mine
Nucleation
Issue DateApr-2007
PublisherGeological Society of America
CitationGeology, April 2007; v. 35; no. 4; p. 327–330
AbstractExploration 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.
DescriptionContains 4 figures.
URIhttp://hdl.handle.net/10261/3439
DOI10.1130/G23393A.1
ISSN0091-7613
Appears in Collections:(IACT) Artículos
(ICTJA) Artículos
Files in This Item:
File Description SizeFormat 
garciaruiznaica.pdf337,2 kBAdobe PDFThumbnail
View/Open
Show full item record
Review this work
 

Related articles:


WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.