Kieran Iles: Geochemistry of subalkaline volcanic rocks, Abitibi Greenstone Belt: VMS fertility

Value of the Information & Strength of the Argument

The presentation provides valuable insights into the geochemical diversity of volcanic rocks in the Abitibi Greenstone Belt and links this diversity to VMS fertility. The argumentation is solid, based on a large dataset and systematic modeling. The use of multiple classification diagrams and modeling scenarios strengthens the interpretation. The comparison between fertile and infertile assemblages is particularly informative, highlighting specific geochemical groups associated with VMS mineralization. The step-by-step modeling approach effectively explains the observed trends, and the final synthesis linking fertility to mid-upper crustal magmatic processing is compelling.

Scientific Rigor, Source Quality, Title Accuracy

The scientific rigor is high, with a clear methodology and use of established geochemical tools. The sources are primarily the author’s own work and that of colleagues, as indicated by references to previous studies. The title accurately reflects the content. The presentation is well-structured and data-driven, though it lacks explicit citations to external literature, which is common in conference talks. The adequacy between title and content is excellent.

The title accurately reflects the content, which focuses on the geochemistry of subalkaline volcanic rocks in the Abitibi Greenstone Belt and their VMS fertility.

8/10

The presentation is based on a large dataset (12,000+ samples) and uses established geochemical classification and modeling techniques. The methodology is clearly outlined, and the results are presented with appropriate caveats. However, the talk is a conference presentation and lacks peer-reviewed publication details, which slightly reduces the score.

Markers derived by PSI from the transcript: the creator did not define chapters.

• 00:00Introduction to the study and the Abitibi Greenstone Belt assemblage map.
• 02:00Overview of the dataset: over 12,000 geochemical samples, classification into 12 groups.
• 04:00Classification diagrams: Jensen diagram and Th/Yb vs. Nb/Yb plot.
• 06:00Spider diagrams illustrating geochemical characteristics of each group.
• 08:00Introduction to petrogenetic modeling: fractional crystallization, recharge, AFC, and mixing.
• 10:00Modeling results for major elements and trace elements, including new models for HREE-enriched basalts and tholeiitic felsic rocks.
• 12:00AFC models with basaltic wall rock at different pressures, explaining transitional and calc-alkaline series.
• 14:00Comparison of assemblages: proportions of rock types and magmatic affinities.
• 16:00Radial diagrams showing normalized proportions of geochemical groups per assemblage.
• 18:00Fertile vs. infertile assemblage comparison and synthesis linking VMS fertility to mid-upper crustal processing.

• Metal Earth scientific meetings — Presentation venue and context for the research.

• Previous studies by the author and colleagues on Blake River and Stoughton-Roquemaure assemblages — Referenced in the talk as prior work that this study builds upon.