J 2017

Formation of pretulite (ScPO4) by recrystallization of Sc-rich precursors in Dolni Bory pegmatite: Evidence for different mobility of Sc, Y, REE and Zr in hydrothermal conditions

VÝRAVSKÝ, Jakub, Milan NOVÁK and Radek ŠKODA

Basic information

Original name

Formation of pretulite (ScPO4) by recrystallization of Sc-rich precursors in Dolni Bory pegmatite: Evidence for different mobility of Sc, Y, REE and Zr in hydrothermal conditions

Authors

VÝRAVSKÝ, Jakub (203 Czech Republic, guarantor, belonging to the institution), Milan NOVÁK (203 Czech Republic, belonging to the institution) and Radek ŠKODA (203 Czech Republic, belonging to the institution)

Edition

Chemical Geology, Amsterdam, Elsevier Science BV, 2017, 0009-2541

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10504 Mineralogy

Country of publisher

Netherlands

Confidentiality degree

není předmětem státního či obchodního tajemství

Impact factor

Impact factor: 3.570

RIV identification code

RIV/00216224:14310/17:00096296

Organization unit

Faculty of Science

UT WoS

000393001800003

Keywords in English

Pretulite; Zircon; Scandium; Hydrothermal alteration; Mobilization of scandium; Granitic pegmatite

Tags

Tags

International impact, Reviewed
Změněno: 4/4/2018 08:49, Ing. Nicole Zrilić

Abstract

V originále

Three distinct types (A, B and C) of secondary pretulite (ScPO4) were found in a single andalusite-diaspore nodule from the quartz core of the pegmatite dyke No. 3, Dolni Bory, Czech Republic. Primary crystallization of the nodule containing pretulite precursors - Sc, Y, U, P-rich zircon and Sc,W-rich ixiolite- proceeded at T <= 410 degrees C and P <= 2 kbar. Subsequent subsolidus hydrothermal alteration at T approximate to 350-300 degrees C transformed part of the andalusite to pyrophyllite, and triggered complete dissolution of Sc, Y, U, P-rich zircon I. In-situ reprecipitation produced Y, U-depleted zircon II with common inclusions of xenotime II and pretulite A (0.88-0.92 apfu Sc, 0.04-0.07 apfu Zr, <0.03 apfuY). During the same process recrystallization of Sc, W-rich ixiolite produced heterogeneous pretulite B (0.21-0.89 apfu Sc, 0.09-0.78 apfu Zr, <= 0.07 apfu Y). The origin of pretulite C (almost ideal ScPO4) closely associated with pyrophyllite replacing andalusite and distant from the potential Sc-precursors is explained by the separation of Sc from other HFSE present in the original precursors, which were immobile probably due to absence of suitable strong ligands in the fluids. Saturation of any Sc-dominant mineral (except thortveitite, Sc2Si2O7) is almost never achieved during primary magmatic crystallization due to the extremely high compatibility of Sc; consequently, the processes of hydrothermal alteration of Sc-enriched precursors and the selective mobilization and fractionation of Sc from other HFSE are important for the formation of scandium minerals. (C) 2016 Elsevier B.V. All rights reserved.

Links

MUNI/A/1316/2015, interní kód MU
Name: Geologické, geodynamické a environmentální procesy východního okraje Českého masívu (Acronym: Geodyn)
Investor: Masaryk University, Category A