Next Article in Journal
Warning System Options for Landslide Risk: A Case Study in Upper Austria
Next Article in Special Issue
On the Extraction of Rare Earth Elements from Geothermal Brines
Previous Article in Journal
The Ortelius Incident in the Hinlopen Strait—A Case Study on How Satellite-Based AIS Can Support Search and Rescue Operations in Remote Waters
Previous Article in Special Issue
Rare Earth Element Deposits of Alkaline Igneous Rocks
Article Menu

Export Article

Open AccessArticle
Resources 2017, 6(3), 36; doi:10.3390/resources6030036

Speculations Linking Monazite Compositions to Origin: Llallagua Tin Ore Deposit (Bolivia)

Department of Geological Sciences, Jackson School of Geosciences, The University of Texas at Austin, 1 University Sta. C9000, EPS 1.130, Austin, TX 78712, USA
*
Author to whom correspondence should be addressed.
Received: 3 May 2017 / Revised: 24 July 2017 / Accepted: 25 July 2017 / Published: 29 July 2017
View Full-Text   |   Download PDF [4245 KB, uploaded 1 August 2017]   |  

Abstract

Monazite [(Ce,Th)PO4] from the Llallagua tin ore deposit in Bolivia is characterized by low radiogenic element contents. Previously reported field evidence and mineral associations suggest the mineral formed via direct precipitation from hydrothermal fluids. Monazite compositions thus may provide insight into characteristics of the fluids from which it formed. Chemical compositions of three Llallagua monazite grains were obtained using Electron Probe Microanalysis (EPMA), n = 64] and laser ablation mass spectrometer (LA-ICP-MS, n = 56). The mineral has higher amounts of U (123 ± 17 ppm) than Th (39 ± 20 ppm) (LA-ICP-MS, ±1σ). Grains have the highest amounts of fluorine ever reported for monazite (0.88 ± 0.10 wt %, EPMA, ±1σ), and F-rich fluids are effective mobilizers of rare earth elements (REEs), Y, and Th. The monazite has high Eu contents and positive Eu anomalies, consistent with formation in a highly-reducing back-arc environment. We speculate that F, Ca, Si and REE may have been supplied via dissolution of pre-existing fluorapatite. Llallagua monazite oscillatory zoning is controlled by an interplay of low (P + Ca + Si + Y) and high atomic number (REE) elements. We suggest monazite compositions provide insight into fluid geochemistry, mineral reactions, and tectonic settings of ore deposits that contain the mineral. View Full-Text
Keywords: monazite; rare earth elements; geochemistry; Bolivia; apatite; Llallagua monazite; rare earth elements; geochemistry; Bolivia; apatite; Llallagua
Figures

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Supplementary materials

  • Supplementary File 1:

    ZIP-Document (ZIP, 119 KB)

  • Externally hosted supplementary file 1
    Doi: N/A
    Link: http://N/A
    Description: Excel file of EPMA and LA-ICP-MS analyses of the monazite grains.

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Catlos, E.J.; Miller, N.R. Speculations Linking Monazite Compositions to Origin: Llallagua Tin Ore Deposit (Bolivia). Resources 2017, 6, 36.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Resources EISSN 2079-9276 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top