The mineralogy, petrology and rare earth element geochemistry of the Maw Zone, Athabasca Basin, Canada

Author

Adrienne Joyce Hanly

Abstract

"The Maw Zone is an yttrium and heavy rare earth element (YHREE) enriched zone in the southeastern Athabasca Basin, Saskatchewan, Canada. Petrographic studies including transmitted and reflected light microscopy, cathodoluminescence, electron microprobe, and scanning electron microscopy were carried out to determine the mineralogy and paragenetic sequence of mineral deposition of the Maw Zone. The rare earth elements were determined by whole-rock analysis of select samples from the Maw Zone and from two drill holes outside the Maw Zone, ZM-10 and ZK-17. These two drill holes were selected for comparison due to their proximity to the Maw Zone and contrasting mineralization. Drill hole ZM-10 contains uranium mineralization, and drill hole ZK-17 contains copper mineralization. The results from the petrographic studies and rare earth element geochemistry were used to assess the relationship of the Maw Zone to unconformity-type uranium mineralization in the Athabasca Basin. Unconformity-type uranium mineralization in the Athabasca Basin occurs at or near the unconformity between the Middle Proterozoic sediments and underlying Archean and Aphebian basement rocks. Mineralization at the Maw Zone occurs as the mineral xenotime, (YHREE)PO₄, approximately 130 metres above the unconformity and extends to the surface outcrop exposure. This indicates that the mineralizing fluids in the Maw Zone have extended to shallower stratigraphic levels than those normally associated with uranium mineralization. However, no uranium mineralization has been found within the Maw Zone. The Maw Zone shows similar alteration features to those reported for unconformity-type uranium deposits and therefore, is interpreted to be a near surface expression of the same hydrothermal processes that are responsible for uranium mineralization. The lack of accompanying uranium mineralization at the Maw Zone could indicate that the sources for HREE and uranium are different or alternatively, that the physiochemical conditions at the Maw Zone were not favorable for uranium precipitation. The latter seems more likely since a significant source of HREE would be required for the enrichment observed at the Maw Zone. Based upon this research, it is postulated that the HREE were largely derived from earlier uranium mineralization in an area close to the Maw Zone and that highly oxidizing fluids dissolved and transported the uranium and HREE but a stationary redox front that is necessary for the accumulation of uranium was not present so that only HREE were deposited"--Abstract, page iii.

Advisor(s)

Hagni, Richard D.

Committee Member(s)

Wronkiewicz, David J.
Mariano, Anthony N.

Department(s)

Geosciences and Geological and Petroleum Engineering

Degree Name

M.S. in Geology and Geophysics

Publisher

University of Missouri--Rolla

Publication Date

Summer 2001

Pagination

xiii, 168 pages

Note about bibliography

Includes bibliographical references (pages 155-167).

Rights

© 2001 Adrienne Joyce Hanly, All rights reserved.

Document Type

Thesis - Restricted Access

File Type

text

Language

English

Subject Headings

Mineralogy -- Saskatchewan -- Athabasca Mining DistrictPetrology -- Saskatchewan -- Athabasca MiningRare earths -- Saskatchewan -- Athabasca MiningGeochemistry -- Saskatchewan -- Athabasca Mining

Thesis Number

T 7938

Print OCLC #

48101666

Electronic OCLC #

905726479

Recommended Citation

Hanly, Adrienne Joyce, "The mineralogy, petrology and rare earth element geochemistry of the Maw Zone, Athabasca Basin, Canada" (2001). Masters Theses. 2068.
https://scholarsmine.mst.edu/masters_theses/2068