Mr. Nicholas Rodway reports
CORE ASSETS PETROGRAPHIC ANALYSIS INDICATES LARGE MULTI-STAGE ZN-PB-AG-CU-BI CARBONATE REPLACEMENT SYSTEM AT THE BLUE PROPERTY; ATLIN, BC
Core Assets Corp. has provided the findings and interpretations of petrographic examinations completed on 17 samples collected within the 6.6- by 1.8-kilometre mineralized trend at the Blue property during the 2021 phase 2 exploration program. The company has also begun drill tendering for the 2022 exploration season at the Blue property located in the Atlin mining district of British Columbia.
- Core Assets' geological approach continues to check boxes that indicate the presence of a large, multistage, world-class carbonate replacement system at the Blue property.
- Massive sulphide composition, intergrowths and replacement textures observed through petrography at the Grizzly, Amp, Jackie and Sulphide City targets show a zonation pattern characteristic of significant world-class zinc-lead-silver-copper-bismuth carbonate replacement deposits (CRDs). This will aid significantly in vectoring toward the porphyry source.
- Reflected light and scanning electron microscopy has confirmed the mineralogy of the system as being hosted in the following sulphide assemblages: sphalerite (Zn), chalcopyrite (Cu), galena (Pb), pyrrhotite and pyrite (Fe-sulphides), crosscut by a later galena-dominated assemblage associated with hessite (Ag telluride) and native bismuth (Bi).
- The presence of Fe-rich sphalerite and local fugitive calcite observed in samples bordering the porphyry hub also indicate a close proximity to the porphyry source.
- The company has begun drill tendering for the upcoming 2022 exploration season.
Core Assets' president and chief executive officer, Nick Rodway, comments: "The recent petrography results further confirm our field observations and the fact that this system is unique for British Columbia's Stikine terrane. The presence of a wide compositional range of volcanic and plutonic rocks spanning from Devonian to Eocene in age, and vast amount of favourable limestone beds observed on the property, suggest the potential for the discovery of an extensive CRD that could produce many millions of tonnes of mineralized material. We eagerly await the final geophysical and channel sampling assay results which should be released in early 2022."
2021 petrographic analysis
In 2021, 17 rock samples consisting of massive sulphide, various intrusive and porphyritic igneous rocks, and calc-silicate gneiss were submitted for petrographic analysis (see associated table, available on-line). The samples were submitted in order to investigate the sulphide composition and textures associated with mineral occurrences at the Blue property, and to interpret these observations with respect to the textural characteristics of significant carbonate replacement deposits (CRDs). As outlined in Megaw (2020): The largest and most economical CRDs are formed over the course of multiple intrusive and hydrothermal stages that resulted in repeated reactions between the products of the individual fluid phases.
The area associated with the Blue property has been subject to a long and protracted tectonomagmatic history spanning from the Devonian to Eocene. Three distinct crustal fragments converge along the Llewellyn fault, which extends from the Tulsequah area (located south of the Blue property, where it crosses into Alaska) to the Tally-Ho shear zone in the Yukon. To date, more than 50 spatially related mineral occurrences including epithermal, mesothermal, porphyry Cu-Mo, and associated skarn and polymetallic vein-type deposits and showings have been identified along the extent of the Llewellyn fault (Ootes, et al., 2017 and references therein).
In large CRD systems, overprinting complexity, repeated depositions of certain sulphide species, intergrowths, recrystallization/pseudomorph textures, the silver content of galena, opaqueness of sphalerite, pyrite replacement of pyrrhotite and the presence of fugitive calcite (Mn-bearing) to name a few, all diminish away from the proximal zone of ore fluid pathways -- therefore, textural complexity alone is and should be used as a first-order exploration vector (Megaw, 2020).
At the Blue property, massive sulphide samples (BTS21-01 through BTS21-06) contain an early sphalerite-chalcopyrite assemblage overlapped with a first phase of galena and/or Fe-sulphides (pyrite, pyrrhotite), that are in turn locally crosscut by a later, galena-dominant phase associated with hessite (Ag telluride) and native Bi. Ag enrichment of this late galena phase is reflected in the assay values obtained in 2021 which returned 481 grams per tonne Ag and is speculated by the lack of well-formed cleavage textures. All massive sulphide samples that were collected in closer proximity to the potential porphyry hub contain opaque sphalerite with deep-red reflections, apart from sample BTS21-07 which is located approximately four kilometres north of the potential hub and is dominated by Fe-sulphide species. This observation, in addition to chalcopyrite replacement (disease) that affects sphalerite grains in all samples, is indicative of a high iron content. Multiple generations of pyrite are present in five out of six massive sulphide samples analyzed. In four of these samples, pyrrhotite is intensely to moderately replaced by pyrite marcasite along internal fractures, as well as colloform pyrite marcasite. The observed intensity of this replacement reaction in massive sulphide samples (early-stage internal facture-controlled veinlets versus late-stage colloform-textured), as well as the complexity and range of sulphide species present, decreases with increasing distance from the inferred porphyry hub. This characteristic is most notably observed in sample BTS21-07 which contains the colloform replacement texture only. Two samples of massive sulphide, BTS21-01 and BTS21-06, collected from the Jackie target exhibit orange-red fluorescence when exposed to ultraviolet (UV) light, indicating the presence of locally moderate amounts of fugitive calcite associated with massive sulphide mineralization.
Abundant carbonate-replacement-style mineralization has affected numerous lithologies within the boundaries of the Blue property. Favourable limestone beds host the majority of massive sulphide on the property; however, a wide range of intermediate-to-felsic volcanic and plutonic rocks and gneissic country rocks are also affected by massive-to-disseminated base metal sulphide mineralization. Petrographic analysis of sulphide-bearing intrusive and porphyritic rocks submitted in 2021 indicates a wide range of compositions ranging from intermediate, amphibole or clinopyroxene-bearing lithologies to more felsic feldspar-quartz-biotite porphyries, determined by the visual abundances in modal mineralogy of primary igneous minerals. The relationships between these prospective units are still largely unclear. Detailed geologic mapping, lithogeochemistry and geochronological studies planned for 2022 will help determine their significance with respect to the tectonomagmatic and mineralization history of the area.
Quality assurance/quality control and sample preparation
All petrography samples were collected in the field using a hammer and chisel. Locations were obtained using a GPS and samples were placed in prelabelled sample bags. Metal tags with the sample numbers scribed into them and flagging tape were left at each sample location. Samples were stored in five-gallon pails in a secure location until ready for shipment. All petrographic samples were shipped by air and ground to Process Mineralogical Consulting (PMC) Ltd. for examination.
Each sample was macroscopically examined, photographed in regular and UV light, and prepared as a thin or polished block section. The section off-cuts were then photographed as well. All prepared petrographic sections were examined with a petrographic microscope in transmitted and reflected light.
National Instrument 43-101 disclosure
Nicholas Rodway, PGeo (licence No. 46541), is president, chief executive officer and director of the company, and qualified person as defined by National Instrument 43-101. Mr. Rodway supervised the preparation of the technical information in this news release.
About Core Assets Corp.
Core Assets is a Canadian mineral exploration company focused on the acquisition and development of mineral projects in British Columbia, Canada. The company currently holds 100-per-cent title ownership in the Blue property, which covers a land area of about 108,337 hectares (about 1,083 square km). The project lies within the Atlin mining district, a well-known gold mining camp. The property hosts a major structural feature known as the Llewellyn fault zone (LFZ). This structure is approximately 140 km in length and runs from the Tally-Ho shear zone in the Yukon, south through the property to the Alaskan Panhandle Juneau ice sheet in the United States. Core Assets believes that the south Atlin Lake area and the LFZ have been neglected since the last major exploration campaigns in the 1980s. The LFZ plays an important role in mineralization of near-surface metal occurrences across the property. The past 50 years have seen substantial advancements in the understanding of porphyry, skarn and carbonate-replacement-type deposits both globally and in B.C.'s Golden Triangle. The company has leveraged this information at the Blue property to tailor an already proven exploration model and believes this could facilitate a major discovery. Core Assets is excited to become one of Atlin mining district's premier explorers where its team believes there are substantial opportunities for new discoveries and development in the area.
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