Riverside Resources and Questcorp Announce Commencement of Drilling at Union Project, Sonora, Mexico
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August 06, 2025 3:15 AM EDT | Source: Riverside Resources Inc.
Vancouver, British Columbia--(Newsfile Corp. - August 6, 2025) - Riverside Resources Inc. (TSXV: RRI) (OTCQB: RVSDF) (FSE: 5YY) ("Riverside" or the "Company") , is pleased to announce that drilling has commenced at the Union Project in northwest Sonora, Mexico. This work is being carried out in partnership with Questcorp Mining Inc. (CSE: QQQ), which is earning into the project through an option agreement from Riverside ( press release, May 6, 2025).
Highlights
- Initial drill program is designed to expand known zones of mineralization, test new targets, and explore areas surrounding multiple historical mine workings within the 25 km² project area.
- Drill program will consist of approximately 1,500m of diamond core drilling across six holes, each averaging 250m in depth.
- Drilling to test the carbonate-hosted replacement deposit (CRD) style of mineralization, with gold associated with mantos, chimneys, and along structural zones.
- Angled drill holes are aimed at cutting perpendicular to stratigraphic targets and some structural targets which is typical in CRD systems
- Structural features may have served as mineralizing conduits and are key targets in the current drill program.
The recent exploration work over the past three months by Riverside has improved the understanding of the structural geology and stratigraphy in the Sierra El Viejo, the mountain range immediately to the west of Union Project. The Union district lies along the flanks of this range, where these updated interpretations help guide current exploration efforts. The exploration target focus is for a large potential gold discovery that expands from previous smaller scale mine operations on the property. The drill program will begin to test the new concepts and expand past previous mining.
John-Mark Staude, CEO, Riverside Resources states, "We are pleased to move forward with initial drilling, which will include one or two holes in each area to begin evaluating the CRD target concepts and potential extensions beyond the limits of historical mining. Ideally, this focused initial program will be followed by a more robust drilling campaign to significantly expand on early results. CRD systems typically require multiple rounds of drilling to identify the most prospective zones, so we're pleased to be getting started now. Riverside has a strong portfolio of over seven projects in Mexico, and it's exciting to see this project advancing with partner-funded drilling. Over the next two quarters, we're hopeful that additional districts within our portfolio will also move toward drill testing."
The Drill Program Targets include more than four different areas, beginning with this early-stage stratigraphic and orientation phase of drilling exploration aimed at evaluating scale of alteration and indications of mineralized system. This will be the first drilling ever conducted on most of the targets, despite past mining having occurred in the majority of these areas. The initial program will consist of just one to three holes per area, primarily for orientation purposes. Follow-up drilling is planned and can be expanded based on initial results, which will help verify the stratigraphy, lithologies, and structural features allowing for improved modeling and next-stage discovery targeting. The four areas are listed below:
- Union Main Mine Area - The program will use angled drill holes to test limestone and other carbonate stratigraphic hosts within the Clemente Formation, with the potential to reach the underlying Caborca Formation. These units are considered the primary hosts for replacement-style mineralization.
- North Union Mine Area - The initial focus of the program will be on testing structural interpretations. Additional drilling is anticipated following this first phase, as results will help guide future drill testing of areas with past mining activity and various structural orientations.
- Cobre Mine Area - The Clemente Formation is the primary host unit, and structural features combined with areas of past mining provide multiple target zones. Drilling will begin with an initial stratigraphic test hole to help orient around the thickness of the host unit and extend into the lower Caborca Formation, which is also a favorable host for CRD-style mineralization.
- Central Union Area - Structural targets, as possible mineralization feeder zones, are a key focus in this past mining manto area. There are extensive additional target zones in the area, and this initial orientation drilling will provide vectoring for the next stage of drilling and further study of the Clemente Formation, and possibly into the Caborca Formation as currently interpreted.
General Overview of La Union Project
The Project is summarized in a recently published NI 43-101 Technical Report and more briefly on the Riverside website. Riverside initially acquired the Project and subsequently consolidated additional inlier mineral claims, building a strong land position. The company then advanced the Project through surface access agreements and drill permitting, making it a turn-key exploration opportunity for the Optionee.
The Project was originally identified through Riverside's exploration work in the western Sonora Gold Belt, conducted in collaboration with AngloGold Ashanti Limited, Centerra Gold Inc., and Hochschild Mining Plc. Earlier PhD research by Riverside Founder John-Mark Staude also contributed to recognizing the district's potential. Initial work by members of the Riverside team, drawing on more than two decades of geological compilation and analysis, further confirmed the region as highly prospective.
At the Project, historical mining by the Penoles Mining Company targeted chimney and manto-style replacement bodies within the upper oxide zones. As a result, the underlying sulfide zones represent immediate and compelling drill targets for further exploration.
The Project features favorable limestone host rocks, an extensive alteration footprint, and multiple small-scale historical workings, with mineralization styles similar to those at the Hermosa Project in southern Arizona. At Hermosa, South32 is advancing mine development following its acquisition of the project from Arizona Mining. On 15 February 2024, South32's board approved a US?$2.16?billion capital investment to develop the Taylor zinc-lead-silver deposit, representing the largest private mining investment in Southern Arizona's history. The project is now considered one of the most significant undeveloped base-metal assets in the United States.
At the Union Project, immediate drill targets offer the potential for significant-scale discoveries. La Union is well positioned for near-term exploration success, with targets that include both oxide and deeper sulfide mineralization.
Figure 1. Geologic map with the tenure of the Union internal concession shown in pink. Manto and chimney type CRD targets are shown as red polygons. Riverside now controls all mineral tenures on this map. The drill program will focus on the Union Mine and areas north of the Union Mine with the initial drill work.
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Figure 2. Cross section looking west with conceptual drill targets and schematic drillhole traces. Assays from Riverside's sampling of rock dump materials from the two mine areas are labeled in black. Red areas are interpreted as manto and chimney target bodies that are now well defined and drill ready. Assays shown on figures 1 and 2 have been previously released and disclosed as summarized below the geochemical QA/QC and in published NI 43-101 Report that Questcorp published 2025 on Sedar+.
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Overview of the Option Agreement:
On May 5, 2025, Riverside's wholly owned subsidiary, RRM Exploracion, S.A.P.I. DE C.V. (the "Vendor") entered into a definitive option agreement (the "Option Agreement") with Questcorp (the "Optionee") for the La Union project. As part of the agreement, Questcorp issued shares to Riverside, making Riverside a 9.9% shareholder and aligning both parties' interests in the project's success. With funding provided by Questcorp, an initial C$1,000,000 exploration program is now underway. This marks the first phase of a larger, C$5,500,000 work commitment, contingent on exploration results and Questcorp's continued participation.
Qualified Person & QA/QC:
The scientific and technical data contained in this news release pertaining to the Project was reviewed and approved by Freeman Smith, P.Geo, a non-independent qualified person to Riverside Resources Inc., who is responsible for ensuring that the information provided in this news release is accurate and who acts as a "qualified person" under National Instrument 43-101 Standards of Disclosure for Mineral Projects.
Rock samples from previous exploration programs discussed above at the Project were taken to the Bureau Veritas Laboratories in Hermosillo, Mexico for fire assaying for gold. The rejects remained with Bureau Veritas in Mexico while the pulps were transported to Bureau Veritas laboratory in Vancouver, BC, Canada for 45 element ICP/ES-MS analysis using 4-acid digestion methods. A QA/QC program was implemented as part of the sampling procedures for the exploration program. Standards were randomly inserted into the sample stream prior to being sent to the laboratory.
About Riverside Resources Inc.:
Riverside is a well-funded exploration company driven by value generation and discovery. The Company has a solid balance sheet with no debt and less than 75M shares outstanding with a strong portfolio of gold-silver and copper assets and royalties in North America. Riverside has extensive experience and knowledge operating in Mexico and Canada and leverages its large database to generate a portfolio of prospective mineral properties. Riverside has properties available for option, with information available on the Company's website at www.rivres.com.
ON BEHALF OF RIVERSIDE RESOURCES INC.
"John-Mark Staude"
Dr. John-Mark Staude, President & CEO
For additional information, contact:
Certain statements in this press release may be considered forward-looking information. These statements can be identified by the use of forward-looking terminology (e.g., "expect"," estimates", "intends", "anticipates", "believes", "plans"). Such information involves known and unknown risks -- including the risk that the Transaction will not be completed as contemplates, or at all, availability of funds, the results of financing and exploration activities, the interpretation of exploration results and other geological data, or unanticipated costs and expenses and other risks identified by Riverside in its public securities filings that may cause actual events to differ materially from current expectations. Readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this press release.
Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.
 SOURCE: Riverside Resources Inc. |
