A late Triassic Ar-40/Ar-39 age for the El Hammam high-REE fluorite deposit (Morocco): mineralization related to the Central Atlantic Magmatic Province?

作者：Cheilletz Alain; Gasquet Dominique^*; Filali Fouad; Archibald Douglas A; Nespolo Massimo

来源：Mineralium Deposita, 2010, 45(4): 323-329.

DOI：10.1007/s00126-010-0282-y

• Fluorite
• Rare earth elements
• Central Atlantic Magmatic Province
• Morocco
• El Hammam

El Hammam is the only fluorite mine in Morocco (production 100,000 t/year). The fluorite mineralization is in an array of fluorite-calcite veins and is characterized by unusually high REE content in carbonate minerals (1,400 ppm in calcite; up to 2,000 ppm in siderite) and in fluorite (about 600 ppm). Since the 1960s, the genesis of the deposit has been attributed to a mesothermal hydrothermal event connected with late-Variscan granitic intrusions. Precise Ar-40/Ar-39 dating of hydrothermal K-feldspar yields an age of formation of the El Hammam deposit at 205 +/- 1 Ma. Its genesis is therefore associated in time and space with the development of the Triassic-Jurassic basins and the associated anorogenic continental flood basalts of the Moroccan Mesetian Middle Atlas. The source of the hydrothermal mineralization (magmatic and/or metamorphic) is discussed.

• 出版日期2010-4