• journal_title：Geochemistry ; Exploration ; Environment ; Analysis
• Contributor：Tang Yong ; Zhang Hui ; Su Guizhen
• Publisher：Geological Society of London
• Date：2013-02-01
• Format：text/html
• Language：en
• Identifier：10.1144/geochem2012-139
• journal_abbrev：Geochemistry: Exploration, Environment, Analysis
• issn：1467-7873
• volume：13
• issue：1
• firstpage：3
• section：Thematic set article

The phosphorus contents of alkali feldspars of 80 pegmatite veins from the Chinese Altay, NW China, were determined by electron microprobe in this study. The alkali feldspars of the barren pegmatites are poor in phosphorus and range from <0.01–0.05 wt% P₂O₅. Alkali feldspars from the fertile (rare-metal mineralized) LCT-class pegmatites are characterized by P₂O₅ in the range 0.10–0.40 wt% P₂O₅ for K-feldspars (Kfs), and 0.10–0.30 wt% P₂O₅ for albites (Ab). In the Qunkuer Be-Nb-Ta mineralized pegmatite, a value of 2.89 wt% P₂O₅ in K-feldspars was determined, the highest value of P₂O₅ in alkali feldspars reported.

According to the statistical results, 0.1 wt% P₂O₅ in alkali feldspars separate the fertile pegmatites from the barren pegmatites, and more than 0.1 wt% P₂O₅ in the alkali feldspars, especially in K-feldspars, can be used as an indicator for prospecting for LCT-class pegmatite-type rare-metal ore deposits.