Date of Award

2026-05-01

Degree Name

Master of Science

Department

Geological Sciences

Advisor(s)

Antonio Arribas

Abstract

The Snip North prospect, part of the Iskut Cu-Au project in the Golden Triangle of northwestern British Columbia, serves as a case study to examine the lithologic, alteration, mineralization, and geochronological factors controlling the distribution of gold and associated Cu-Mo mineralization. The spatial framework for this examination is a representative long section of the prospect. The research combines drill core observations and re-logging of nine drill holes with detailed analysis of 33 selected half-core samples using hand-sample description, optical petrography, micro-X-ray fluorescence (XRF), hyperspectral infrared analysis (TerraSpec), X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), electron probe microanalysis (EMPA), and geochronological methods. The results indicate that Snip North records a multi-stage hydrothermal system characterized by early magnetite-bearing veinlets with secondary biotite alteration, followed by a main quartz-sulfide-carbonate stage in which quartz veinlets containing pyrite and chalcopyrite host most of the copper mineralization, and later pyrite-rich quartz and Mn-bearing carbonate to ankerite-type veining. White mica and secondary biotite define the two main alteration domains recognized in the studied section, with white mica showing the strongest association with gold enrichment. Intervals dominated by white mica, as identified by TerraSpec analysis, correlate with higher gold grades compared to secondary biotite intervals, whereas copper and molybdenum do not show the same degree of alteration selectivity. Electrum was identified as the main observed Au-bearing phase, occurring as micrograins closely associated with pyrite and chalcopyrite, although this mode of occurrence was documented only in a limited number of higher-grade samples. Spatially, gold, copper and molybdenum show overlapping but non-identical distributions: i) gold is preferentially concentrated toward the central to western part of the deposit long section, ii) copper defines a broader central corridor within the white mica domain, and iii) molybdenum occupies a partly overlapping but distinct spatial domain, preferentially concentrated in intervals with lower gold grades. Geochronological data indicate that vein-related mineralization was active during the Early Jurassic, as shown by molybdenite ¹⁸⁷Re/¹⁸⁷Os ages of 196.5 ± 1.1 Ma and 195.1 ± 1.3 Ma, whereas zircon U-Pb ages from monzonite yield 192.3 ± 5.5 Ma, 189.6 ± 5.4 Ma, and 187.4 ± 5.4 Ma, also falling within the same broad Early Jurassic interval. In contrast, the ⁴⁰Ar/³⁹Ar ages of biotite near 50 Ma are interpreted to record a later Eocene thermal overprint or resetting event. These results support a preliminary model in which Snip North represents a multi-stage intrusion-related hydrothermal system in which gold enrichment is most closely associated with white mica alteration and quartz-chalcopyrite-pyrite veining, providing a basis for future exploration and targeting within the prospect. In addition, this study indicates Snip North is part of a porphyry copper system and establishes the first detailed geological and mineralogical framework for this prospect, highlighting its potential as an exploration target within the highly endowed Golden Triangle district.

Language

en

Provenance

Received from ProQuest

File Size

181 p.

File Format

application/pdf

Rights Holder

Daniel Alejandro Castano Madrigal

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