Structural Controls on Fluid Flow During Compressional Reactivation of Basement Faults: Insights from Numerical Modeling for the Formation of Unconformity-Related Uranium Deposits in the Athabasca Basin, Canada

2017 ◽  
Vol 112 (2) ◽  
pp. 451-466 ◽  
Author(s):  
Zenghua Li ◽  
Guoxiang Chi ◽  
Kathryn M. Bethune ◽  
David Thomas ◽  
Gerard Zaluski
Keyword(s):  
Numerical Modeling ◽  
Fluid Flow ◽  
Uranium Deposits ◽  
Athabasca Basin ◽  
Structural Controls ◽  
Basement Faults

Synchronous egress and ingress fluid flow related to compressional reactivation of basement faults: the Phoenix and Gryphon uranium deposits, southeastern Athabasca Basin, Saskatchewan, Canada

2017 ◽  
Vol 53 (2) ◽  
pp. 277-292 ◽  
Author(s):  
Zenghua Li ◽  
Guoxiang Chi ◽  
Kathryn M. Bethune ◽  
Khalifa Eldursi ◽  
David Thomas ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Uranium Deposits ◽  
Athabasca Basin ◽  
Basement Faults ◽  
The Phoenix

The role of fault intersection in fluid flow patterns and the formation of world-class unconformity-related uranium deposits, Athabasca Basin, North Canada 

2021 ◽  
Author(s):  
Khalifa Eldursi ◽  
Luc Scholtes ◽  
Marianne Conin ◽  
Fabrice Golfier ◽  
Julien Mercadier ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Flow Patterns ◽  
Burial Depth ◽  
Uranium Deposits ◽  
Intersection Angle ◽  
Athabasca Basin ◽  
Basement Faults ◽  
Complex Models ◽  
Stress States ◽  
Secondary Fault

<p>The epigenetic uranium deposits in the eastern part of the Athabasca Basin are classified as unconformity-related ore deposits. Their explicit spatial association to reactivated basement faults is observed within the regional structural NNE trend Wollaston-Mudjatik transition zone, marked by elongated dravite, illite, and chlorite alteration zones. Accordingly, geochemical studies have advocated a circulation and focalization of large amount of one or more fluids to carry and precipitate aqueous chemical materials. At the deposit-scale, the uranium deposits are found mainly at the intersection between two or more fault sets, and described as elongated-like bodies varying in orientation from E-W to NNE direction along the regional transitional zone. Furthermore, some orebodies show a change of orientation and dip of their structures. Thus, what is the hydro-mechanical response of reactivated and inherited fault architecture (e.g., intersection zone) under different stress states (e.g., reverse, strike-slip, and normal faulting regime), and its potential contribution to the shape and orientation of orebodies at deposit scale?</p><p>Using hydro-mechanical numerical modeling, this project demonstrates the role that fault intersections play in controlling mineralized fluids by examining the various fluid flow patterns observed when reactivated intersected faults are under various stress states. Numerical modeling is performed using 3-Dimensional Distinct Element Code (3DEC). The numerical models are subdivided into two categories: 1) simplified 3-D models of two intersecting faults, 2) 3-D complex models of fault network at different deposits sites (e.g., the Cigar Lake deposit). While the first simple models attempt to evaluate the effects of intersection angle, burial depth, fluid pressure, basin permeability and stress states on the fluid flow patterns; the second models investigate the stress state under which certain orebodies may have formed.</p><p>Our preliminary results from simplified models show that at defined intersection angles, the fluid flow deviates from the main fault toward the secondary fault at their intersection point. The deviation in fluid flow is referred to the value of intersection angle at which the shear stress varies along the secondary fault, leading to the opening of secondary fault. Additionally, the burial depth does not affect the flow along the basement faults, whereas, the overlying highly permeable basin reduces the horizontal flow along the basement faults toward the intersection zone, and reorients a part of the flow toward the basin.  In the complex models (the Cigar Lake model), considering a compressional regime, the E-W fault set is reactivated once the maximum stress is oriented N40W to N65W, which is in agreement with field observations.</p>

Fluid evolution along the Patterson Lake corridor in the southwestern Athabasca Basin: constraints from fluid inclusions and implications for unconformity-related uranium mineralization

2021 ◽  
pp. geochem2020-029
Author(s):  
M. Rabiei ◽  
G. Chi ◽  
E.G. Potter ◽  
V. Tschirhart ◽  
C. MacKay ◽  
...  
Keyword(s):  
Fluid Inclusion ◽  
Fluid Inclusions ◽  
Fluid Pressure ◽  
Uranium Deposits ◽  
Hydrothermal Conditions ◽  
Content Type ◽  
Athabasca Basin ◽  
Link Type ◽  
Basement Faults ◽  
Supplementary Material

The Patterson Lake corridor (PLC) in the southwestern margin of the Athabasca Basin hosts several high-grade uranium deposits. These deposits are located in the basement up to 900 m below the unconformity surface, raising questions about their affiliation with typical unconformity-related uranium (URU) deposits elsewhere in the basin. Based on cross-cutting relationships four pre- and three syn- to post-mineralization quartz generations were identified. Fluid inclusion analyses indicate that pre-mineralization fluids have salinities ranging from 0.2 to 27.2 Wt% NaCl equiv. (avg. 9.0 Wt%), whereas syn-mineralization fluids have salinities ranging from 8.8 to 33.8 Wt% NaCl + CaCl2 (avg. 25.4 Wt%), with NaCl- and CaCl2-rich varieties. The homogenization temperatures (Th) of fluid inclusions from pre-mineralization quartz range from 80 ° to 244 ℃ (avg. 147 ℃), and from syn-mineralization quartz range from 64 ° to 248 ℃ (avg. 128 ℃). Fluid boiling is indicated by the co-development of liquid-dominated and vapor-dominated fluid inclusions within individual fluid inclusion assemblages (FIA) from the syn-mineralization quartz and is related to episodic fluid pressure drops caused by reactivation of basement faults. Our results indicate that composition and P-T conditions of the ore fluids in the PLC are comparable to those of typical URU deposits in the Athabasca Basin, indicating that the uranium deposits in the PLC formed under similar hydrothermal conditions. Episodic reactivation of basement faults was an important driving force to draw uraniferous fluids from the basin and reducing fluids from the basement to the mineralization sites, forming deep basement-hosted deposits.Thematic collection: This article is part of the Uranium Fluid Pathways collection available at: https://www.lyellcollection.org/cc/uranium-fluid-pathwaysSupplementary material:https://doi.org/10.6084/m9.figshare.c.5510179

Stable isotope constraints on the role of graphite in the genesis of unconformity-type uranium deposits

1989 ◽  
Vol 26 (3) ◽  
pp. 490-498 ◽  
Author(s):  
T. K. Kyser ◽  
M. R. Wilson ◽  
G. Ruhrmann
Keyword(s):  
Fluid Flow ◽  
Stable Isotope ◽  
Uranium Deposit ◽  
Shear Zones ◽  
Limited Range ◽  
Hydrothermal Fluids ◽  
Uranium Deposits ◽  
Athabasca Basin ◽  
Ore Zones

The Key Lake unconformity-type uranium deposit occurs in a shear zone where it intersects the unconformity between Archean and Aphebian gneisses and the overlying Proterozoic Athabasca Group sandstones. The roots of the Key Lake and many other unconformity-type uranium deposits in the Athabasca basin are close to gneisses rich in graphite and most deposits have small amounts of carbonaceous materials (bitumen and hydrocarbon buttons) within and around altered basement and sandstone ore zones. In many Athabasca uranium deposits, hydrothermal fluids have destroyed graphite disseminated in the strongly altered gneisses in the vicinity of the deposits, prompting some to suggest that graphite was converted to CH4, which reduced and precipitated the uranium and partially condensed to form bitumen. The δ13C values of graphite collected from unaltered and altered gneisses around the Key Lake deposit have a limited range (−25 ± 5) and are not a function of distance from the mineralization or the intensity of alteration or deformation. The uniformity of these δ13C values suggests that the destruction of graphite was due predominantly to oxidation by basinal fluids from the sandstone and that the graphite near the deposits did not react to form substantial amounts of 12C-rich phases such as CH4. Most of the bitumen samples, which have higher H/C ratios than the graphite, have δ13C values identical to those of the graphite (−25 ± 5). The similarity in the isotopic compositions of carbon in the bitumen and in the graphite indicates that the bitumen formed from degradation of graphite as a result of reactions with no significant isotopic fractionations, such as ones involving radiolysis of graphite. The hydrocarbon buttons and a few samples of bitumen have petrographic relations and 13C/12C ratios (δ13C values less than −30) that are indicative of reduction of graphite by H2 produced from water by radiolysis. Graphite in these deposits did not play a central role as a reducing agent for uranium, rather it represents a critical structural factor by providing shear zones along which fluid flow can be focussed.

Advanced Use of Borehole Acoustic Televiewer (ATV) for Structural Interpretation of Unconformity-Related Uranium Deposits

2021 ◽  
Author(s):  
Antonio Benedicto ◽  
Grant Harrison ◽  
Brandon Eccles ◽  
Patrick Ledru
Keyword(s):  
Fault Reactivation ◽  
Added Value ◽  
Reverse Fault ◽  
Uranium Deposits ◽  
Athabasca Basin ◽  
Structural Interpretation ◽  
Structural Controls ◽  
Core Recovery ◽  
Direct Observations ◽  
Drill Holes

Abstract The structural controls on unconformity-related uranium deposits of the Athabasca basin, Saskatchewan, Canada, are a matter of debate regarding the role of inherited fault systems and their reactivation. This can be related to the lack of outcrops allowing for direct observations, the strong clay alteration halos wrapping deposits that often obliterate structures, and the poor core recovery related to drilling strongly altered and mineralized intervals, which limits observation of structures and reliable oriented measurements. Borehole imaging technology is an invaluable alternative for obtaining oriented data through challenging drilling intervals. The use of borehole Acoustic Televiewer (ATV) has been integrated in recent exploratory campaigns in the Athabasca basin by Orano Canada. Here, we present the inputs and benefits of the use of the ATV in the exploration of unconformity-related uranium deposits and the structural analysis of oriented data from seven inclined diamond drill holes completed in 2016 during the McClean project (Sue deposits). The main objectives were to precisely identify the structural controls of the basement-hosted mineralization, and to test the tool in a well-known site. This work shows the applicability and added value of using televiewer probes to provide reliable oriented data in zones where there is much less information available. The ATV data structural interpretation supports the concept of mineralization of dilational jogs opening during preexisting shear-related foliation under right-lateral reverse fault reactivation. The ATV provides robust oriented data, allowing for a better understanding of the meaning of flat-lying mineralized structures along the Sue trend.

scholarly journals Structural Controls of Uranium Mineralization in the Basement of the Athabasca Basin, Saskatchewan, Canada

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-30
Author(s):  
Antonio Benedicto ◽  
Maher Abdelrazek ◽  
Patrick Ledru ◽  
Cameron MacKay ◽  
Dwayne Kinar
Keyword(s):  
Regional Scale ◽  
Structural Data ◽  
Shear Zones ◽  
Uranium Mineralization ◽  
Uranium Deposits ◽  
Athabasca Basin ◽  
Structural Controls ◽  
The Right ◽  
Drill Holes

The occurrence of unconformity-related uranium mineralization requires the combination of three components: fluids with the right composition, geochemical traps with the right agents that produce precipitation, and structural traps with the right geometry. In the Athabasca Basin unconformity-related uranium deposits, while basinal brines are commonly accepted as the principal mineralized fluids and graphite and gases (CH4, CO2, and H2S) are well known as the reductants, only few case studies describing structural traps are published. A number of recent works, including numerical modelling, have improved the understanding of the role of inherited shear zones on fluid flow and the development of uranium deposits at a micro- and regional-scale. Nevertheless, there is still a lack of knowledge about the meso- or deposit-scale structural controls that lead to the present (and potentially predictive) localization of uranium deposits along a given shear zone. The present work examines new structural data from drill holes and deals with (i) the identification of mesoscale structural traps that lead to the formation of the Athabasca unconformity-related uranium deposits hosted within the basement and (ii) with the understanding of the role and mode of reactivation of the inherited shear zones. The Sue deposits (McClean Project), the Tri-Island showing (Martin Lake Project) in the Eastern Athabasca, and the Spitfire prospect (Hook Lake Project) in the Western Athabasca have been selected for a detailed analysis of structures and related uranium mineralization. The structural analysis performed brings new insights about the mesoscale structural controls, the role the inherited ductile fabric had on the mode of brittle reactivation and to trap mineralization, and the tectonic regime to which basement-hosted uranium deposits may be associated in the Athabasca Basin.

NUMERICAL MODELING OF NON-NEWTONIAN FLUID FLOW BETWEEN POROUS DISKS IN THE PRESENCE OF NANOPARTICLES

2017 ◽  
Vol 8 (1) ◽  
pp. 67-83
Author(s):  
M. Zubair Akbar Qureshi ◽  
Kashif Ali ◽  
Muhammad Farooq Iqbal ◽  
Muhammad Ashraf
Keyword(s):  
Numerical Modeling ◽  
Fluid Flow ◽  
Newtonian Fluid

Hydrothermal Rare Earth Element (Xenotime) Mineralization at Maw Zone, Athabasca Basin, Canada, and Its Relationship to Unconformity-Related Uranium Deposits—A Reply

2018 ◽  
Vol 113 (4) ◽  
pp. 998-999 ◽  
Author(s):  
Guoxiang Chi ◽  
Nigel J.F. Blamey ◽  
Morteza Rabiei ◽  
Charles Normand
Keyword(s):  
Rare Earth ◽  
Rare Earth Element ◽  
Earth Element ◽  
Uranium Deposits ◽  
Athabasca Basin
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