The origin of celestine-quartz-calcite geodes associated with a basaltic dyke, Makhtesh Ramon, Israel

Michael Anenburg, Or M. Bialik, Yevgeny Vapnik, Hazel J. Chapman, Gilad Antler, Yaron Katzir, Mike J. Bickle

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

Spectacular celestine geodes occur in a Jurassic peri-evaporitic sequence (Ardon Formation) exposed in Makhtesh Ramon, southern Israel. The geodes are found only in one specific location: adjacent to an intrusive contact with a Lower Cretaceous basaltic dyke. Celestine, well known in sedimentary associations worldwide and considered as a low temperature mineral, may therefore be associated with magmatic-induced hydrothermal activity. Abundant fluid inclusions in celestine provide valuable information on its origin: gas-rich inclusions in celestine interiors homogenized at T≥200°C whereas smaller liquid-rich inclusions record the growth of celestine rims at T≤200°C. Near 0°C melting temperatures of some fluid inclusions and the occurrence of hydrous Ca-sulphate solid crystals in other inclusions indicate that celestine precipitated from variably concentrated Ca-sulphate aqueous solutions of meteoric origin. Celestine crystallized from meteoric water heated by the cooling basaltic dyke at shallow levels (c. 160 m) during a Lower Cretaceous thermal perturbation recorded by regional uplift and magmatism. The 87Sr/86Sr ratio of geode celestine, 0.7074, is similar to that measured in the dolostones of the host Jurassic sequence, but differs markedly from the non-radiogenic ratio of the dyke. Strontium in celestine was derived from dolostones preserving the 87Sr/86Sr of Lower Jurassic seawater, while sulphur (δ34S = 19.9‰) was provided by in situ dissolution of precursor marine gypsum (δ 34S = 16.8‰) indicated by relict anhydrite inclusions in celestine. Low-temperature meteoric fluid flow during the Campanian caused alteration of the dyke into secondary clays and alteration of geodal celestine into quartz, calcite and iron oxides.

Original languageEnglish
Pages (from-to)798-815
Number of pages18
JournalGeological Magazine
Volume151
Issue number5
DOIs
StatePublished - 1 Jan 2014

Keywords

  • alabaster
  • calcite
  • celestine
  • geodes
  • quartz

ASJC Scopus subject areas

  • Geology

Fingerprint

Dive into the research topics of 'The origin of celestine-quartz-calcite geodes associated with a basaltic dyke, Makhtesh Ramon, Israel'. Together they form a unique fingerprint.

Cite this