Journal Publications

Hits:

Impact Factor:5.109

Journal:Mineralium Deposita

Key Words:Midcontinent Rift . Coldwell Complex . Syn-magmatic sill . PGEmineralization . Marathon deposit

Abstract:The W Horizon is a thin continuous zone of low sulfide-high-grade platinum group element (PGE) mineralization in the Two Duck Lake gabbro at theMarathon Cu-PGE deposit, Coldwell Complex, Canada, that resembles reef-type PGE deposits found in much larger intrusions. The Marathon deposit was previously shown to have grown by accretion of syn-magmatic, sulfide- bearing sill-like intrusions that formed each of the W Horizon, Main Zone, and Lower Zone mineralization. Each zone can be distinguished by features such as sulfide mineral or platinum group mineral assemblages, or by Cu/Pd, Pd/Se, and Pd/Au values. For example, the WHorizon is defined by the presence ofbornite, very high PGE values, low Cu/Pd (< 1000), and high Pd/Au (34 ± 32), whereas the Main Zone and Lower Zone types are characterized by mantle-like Cu/Pd (1000 to 10,000), and Pd/Au of 10.3 ± 4.7. Model calculations based onKerr-Leitch multistage dissolution upgrading show that PGE enrichment and decoupling ofPGE from Au and chalcophile elements in the W Horizon can be related to progressive upgrading and recycling of sulfide liquid by successive pulses ofsilicate magma. For the WHorizon, extreme PGE enrichment can be explained by the interaction ofa sulfide liquid with up to 25 pulses ofmagma and simultaneous sulfide liquid dissolution resulting in a loss of> 95% ofthe original sulfide liquid. In some samples, metal and S abundances indicate that PGEwere transported as TABS-PGE phases. This work describes an example of thin PGE-rich sill-like injections that could be ofimportance to PGE exploration elsewhere.

Co-author:Iain Samson, Robert Linnen, David Good

First Author:Yonghua Cao

Indexed by:Journal paper

Discipline:Natural Science

First-Level Discipline:Geology

Document Type:J

Volume:56

Issue:6

Page Number:1151-1176

Translation or Not:no

Date of Publication:2021-01-05

Included Journals:SCI

Links to published journals:https://doi.org/10.1007/s00126-020-01033-0

Attachments: