Determining gypsum growth temperatures using monophase fluid inclusions-Application to the giant gypsum crystals of Naica, Mexico

Yves Krüger, Juan Manuel García-Ruiz, Àngels Canals, Dominik Marti, Martin Frenz, Alexander E.S. Van Driessche

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Determining the formation temperature of minerals using fluid inclusions is a crucial step in understanding rock-forming scenarios. Unfortunately, fluid inclusions in minerals formed at low temperature, such as gypsum, are commonly in a metastable monophase liquid state. To overcome this problem, ultra-short laser pulses can be used to induce vapor bubble nucleation, thus creating a stable two-phase fluid inclusion appropriate for subsequent measurements of the liquid-vapor homogenization temperature, Th. In this study we evaluate the applicability of Th data to accurately determine gypsum formation temperatures. We used fluid inclusions in synthetic gypsum crystals grown in the laboratory at different temperatures between 40 °C and 80 °C under atmospheric pressure conditions. We found an asymmetric distribution of the Th values, which are systematically lower than the actual crystal growth temperatures, Tg; this is due to (1) the effect of surface tension on liquid-vapor homogenization, and (2) plastic deformation of the inclusion walls due to internal tensile stress occurring in the metastable state of the inclusions. Based on this understanding, we have determined growth temperatures of natural giant gypsum crystals from Naica (Mexico), yielding 47 ± 1.5 °C for crystals grown in the Cave of Swords (120 m below surface) and 54.5 ± 2 °C for giant crystals grown in the Cave of Crystals (290 m below surface). These results support the earlier hypothesis that the population and the size of the Naica crystals were controlled by temperature. In addition, this experimental method opens a door to determining the growth temperature of minerals forming in low-temperature environments. © 2013 Geological Society of America.
Original languageEnglish
JournalGeology
Volume41
Issue number2
Pages (from-to)119-122
ISSN0091-7613
DOIs
Publication statusPublished - 2013
Externally publishedYes

Keywords

  • GYPSUM
  • Research
  • Atmospheric pressure
  • Caves
  • Crystal growth
  • Growth temperature
  • Mineralogy
  • Minerals
  • Surface tension
  • Vapors
  • Gypsum
  • Asymmetric distribution
  • Experimental methods
  • Fluid inclusion
  • Formation temperature
  • Gypsum crystals
  • Homogenization temperatures
  • Liquid state
  • Liquid-vapor
  • Low temperatures
  • Me-xico
  • Meta-stable state
  • Synthetic gypsum
  • Two phase fluid
  • Vapor bubble

Fingerprint Dive into the research topics of 'Determining gypsum growth temperatures using monophase fluid inclusions-Application to the giant gypsum crystals of Naica, Mexico'. Together they form a unique fingerprint.

Cite this