GEOSCAN Search Results: Fastlink


TitleYukon's Carlin-Type gold deposits (Rackla Belt, Canada): main characteristics and new insights on alteration styles and geochemistry
AuthorPinet, N; Sack, P; Mercier-Langevin, P; Davis, W JORCID logo; Petts, D CORCID logo; Lavoie, DORCID logo; Percival, J BORCID logo; Dubé, B; Colpron, M; Ardakani, O HORCID logo; Brake, V I
Source; Economic Geology vol. 117, no. 4, 2022 p. 875-904,
Alt SeriesNatural Resources Canada, Contribution Series 20210254
PublisherSociety of Economic Geologists
Mediapaper; digital; on-line
File formatpdf
NTS105K/01; 105K/02; 105K/03; 105K/04
Lat/Long WENS-134.0000 -132.0000 64.2500 64.0000
Subjectsmineralogy; gold; mineral deposits; temperature; pyrite; Carlin
Illustrationslocation maps; schematic models; columnar sections; plans; photographs; geochemical plots; tables; sections; graphs
ProgramTargeted Geoscience Initiative (TGI-5) Gold ore systems
Released2022 02 01
AbstractIn central Yukon, the Neoproterozoic to Carboniferous complexly deformed Rackla belt is along the northern boundary of the Selwyn basin. Toward the eastern end of the Rackla belt, a series of gold deposits in the Nadaleen trend exhibit similarities with Carlin-type deposits of the southwestern United States and may represent some of the best examples of this type of mineralization outside Nevada. These replacement-style gold deposits are hosted in two Neoproterozoic carbonate-dominated intervals and in a Paleozoic siltstone/mudstone unit at the contact with less permeable strata. In Neoproterozoic-hosted deposits, mineralized zones are grossly concordant with bedding. Favorable host rocks (including sedimentary units formed through debris flows) form complexly shaped faulted anticlines that constituted mixed stratigraphic/structural traps for mineralizing fluids. This and the association of gold with arsenic-rich pyrite, the common occurrence of realgar/orpiment, alteration styles dominated by decarbonatization of impure carbonate rocks, late Au-stage calcite characterized by a depleted d18O signature, the very low base metal content and Ag/Au ratio, and enrichment in a series of diagnostic pathfinder elements (Hg, Tl ± Sb, As) are among the key features that are consistent with classification of the eastern Rackla belt as a Carlin-type district. Mineralization style varies significantly at the centimeter to 10-m scale, indicating that mineralizing fluids exploited permeable pathways, regardless of their sedimentary and/or tectonic origin. Alternating finely laminated limestone, siltstone, and floatstone intervals are the dominant host rocks to mineralization in the Conrad, Sunrise, and Osiris deposits. Premineralization fractures acted as feeders for selective bed replacement, and premineralization calcite vein networks, preferentially dissolved by early acidic fluids, acted as conduits to later gold-bearing fluids. Limited evidence suggests that synmineralization deformation was relatively minor and possibly dominated by oblique strike-slip faulting.
Summary(Plain Language Summary, not published)
In central Yukon, a series of gold zones show striking similarities with Carlin-type deposits and can be considered as among the best examples of this type of mineralization outside Nevada. This contribution reviews the main geological characteristics of gold zones and bring new insights on the parameters that controlled mineralization. The contribution has significant impact on the regional metallogeny and ore-forming processes.

Date modified: