Oroco Drills 26.48m of 1.18% CuEq in South Zone
Rhea-AI Summary
Oroco Resource (OTCQB: ORRCF; TSX-V: OCO) reported Phase 2 South Zone drilling results at the Santo Tomás copper project, covering holes S027 and S030–S034. Key intercepts include hole S033 with 26.48 m grading 0.90% Cu and 1.18% CuEq from 48 m, within a broader 114.7 m interval at 0.44% Cu and 0.54% CuEq.
Holes S031 and S034 extended mineralization westward beyond the current inferred block model, while holes S027, S030 and S032 defined the southern limit, including mixed oxide-sulphide zones with up to 0.80% CuTot over 49 m. Phase 2 aims to upgrade Inferred to Indicated resources and gather PFS data, with a Pre-Feasibility Study targeted for Q2/Q3 2027. Copper equivalents use updated metal prices and variable recovery curves from the 2024 Technical Report.
Positive
- S033 high-grade intercept: 26.48 m at 0.90% Cu and 1.18% CuEq from 48 m within 114.7 m at 0.44% Cu and 0.54% CuEq
- Western extension of mineralization: S031 and S034 intersected mineralization beyond current inferred block model, supported by surface mineralization up to 330 m west
- Near-surface oxide/transition copper: S030 returned 49 m from 12 m depth at 0.80% CuTot; S032 reported mixed oxide-sulphide with 0.80% CuTot over 36–49 m
- Phase 2 nearing completion in South Zone: program designed to convert Inferred to Indicated resources and collect data required for a Pre-Feasibility Study targeted for Q2/Q3 2027
Negative
- Southern drilling limit defined in South Zone: S027, S030 and S032 results, plus surface oxides, essentially establish a southern boundary to mineralization in this area
News Explained
The program remains in drilling, with no completed resource reclassification or disclosed copper leach-recovery plan yet.
Oroco reports the third assay set from its ongoing Phase 2 South Zone drilling; the results add geological data outside current inferred blocks, but do not themselves change the disclosed resource classification.
The reported CuEq grades use updated metal-price assumptions and variable recovery curves, so the company says they are not directly comparable with earlier CuEq figures calculated under different methodologies.
For mixed oxide-sulphide intervals, the company is not reporting CuEq because no technical report currently incorporates a copper leach recovery circuit.
Resource drilling is described as almost complete, after which the rigs are expected to move to “the Gap”; the next stated milestone is a PFS targeted for
AI-generated analysis. How Rhea-AI works. Not financial advice.
VANCOUVER, British Columbia, Aug. 06, 2026 (GLOBE NEWSWIRE) -- Oroco Resource Corp. (TSX-V: OCO; OTCQB: ORRCF) ("Oroco" or the "Company") is pleased to report the third set of assay results from its Phase 2 resource drilling program focused on the South Zone at its Santo Tomás copper project, Choix, Sinaloa, Mexico. Results are reported for drill holes S027 and S030 through S034. The Company continues drilling with three rigs on site.
Highlights
Westernmost limit of inferred mineralization –central portion of the South Zone
- Holes S031 and S034 confirmed the local westward extension of mineralization beyond the current inferred block model limits in the central western portion of the South Zone.
- Hole S031 is a hole drilled westwards at -65 degrees from the same pad as S029 (previous release). The hole intersected near-surface mineralization and drilled out of inferred material, extending newly identified mineralization westwards. Mineralized outcrops to the west of the intercept suggest a wedge of mineralization extending up to 330m in that direction.
- Hole S033 was drilled at -50 degrees eastwards from a pad located 50m to the east of S034. Intersected mineralization included 26.48m @
0.90% Cu /1.18% CuEq* from a depth of 48.0m. Additional intercepts are included below. - Hole S034 was collared 80m north of S031 and drilled westwards at -60 degrees. The hole displayed mineralization similar to that observed in S031 and, as with S031, intersected mineralization outside the inferred material. Surface mineralization to the west again supports a wedge of additional mineralization to the west.
South end of the South Zone– Holes containing Oxide and Transition mineralization
- Hole S027 is a vertical hole drilled from the same pad as S030 and S032. The mineralization observed in this hole, combined with results from S032 and S030 and surface expressions of copper oxides, essentially defines the southern limit of the South Zone.
- Holes S030 and S032 have locally defined a southern limit of mineralization in the South Zone.
- Hole S030, located on the same pad as S032, was drilled at -50 degrees towards 280°. A 49m intercept of mixed oxide-sulphides was logged from 12m depth. Total copper assay over the interval returned
0.80% CuTot. Additional sulphide mineralization below this interval is included in Table 2. - Hole S032 is located on the southernmost pad in the South Zone (S027 pad) and was drilled at -45 degrees towards 150°. A mixed oxide-sulphide zone was observed from 0 to 49m depth. The total copper assay over the interval 36 to 49m returned
0.80% CuTot and0.31% CuSol (total and soluble copper respectively). Sulphide mineralization below this interval is reported in Table 2.
“These Phase 2 results support the potential for additional resource outside of the 2024 Technical Report block model and continue to support the approach being taken at Santo Tomás,” said Charles Cryer, Oroco CEO. “Additional drilling to date in the southern half of the South Zone supports the potential for a higher-grade zone as first identified in Phase 1 drill hole S018. Drilling to the west also has the potential for additional tonnage beyond the inferred material classification limits.”
Soluble copper assays for Hole S027 were received and returned a 10.5 m mixed oxide-sulphide intercept from 13.5m depth with
Phase 2 Program Overview
IT IS IMPORTANT TO NOTE that Phase 2 is designed primarily to convert Inferred resources to the Indicated resource classification in the South Zone and to collect geotechnical, hydrogeological, and additional metallurgical data required for Pre-Feasibility Study ("PFS") mine planning. Resource drilling in the South Zone is almost complete. Rigs will thereafter be moved to “the Gap” in the pillar area between the North and South Zones. The PFS is targeted for release in Q2/Q3 2027.
Table 1: Phase 2 Drill Holes S027, S030, S031, S032, S033 and S034
| Hole | East (m) | North (m) | Elev. (m) | Dip (deg.) | Az. (deg.) | Objective / Comment |
| S027 | 779,299 | 2,974,324 | 721 | -90 | 0/360 | Southern most drill pad. Testing southern end of the inferred blocks in the 2024 Block Model |
| S030 | 779,298 | 2,974,325 | 721 | -50 | 280 | Southern most drill pad. Testing southern end of the inferred blocks in the 2024 Block Model |
| S031 | 778,627 | 2,975,566 | 589 | -65 | 270 | Testing western limits of inferred blocks. Mineralization based on drill hole results and surface mineralization 330m to the west suggests the potential for additional tonnage |
| S032 | 779,300 | 2,974,232 | 721 | -45 | 150 | Southern most drill pad. Testing southern end of the inferred blocks in the 2024 Block Model. Drill holes S027, 030 and 032, all intercepted variable copper oxide mineralization in a mixed oxide/sulphide zone. Southern limit now defined |
| S033 | 778,704 | 2,975,645 | 598 | -50 | 100 | Infill hole to the east of S034. Drilling supports the 2024 block model with an additional higher grade near surface intercept of 26.48m @ |
| S034 | 778,656 | 2,975,640 | 587 | -60 | 270 | Testing western limits of inferred blocks. Mineralization based on the drill hole results and surface mineralization 330m to the west also indicating potential for additional tonnage |
Table 2: Significant Assay Results**
| Hole | From (m) | To (m) | Length (m) | CuT (%) | Mo (%) | Au (g/t) | Ag (g/t) | CuEq (%) |
S027 | 13.5 | 41.82 | 28.32 | 0.47 | 0.011 | 0.015 | 3.22 | n/a Ox |
| 48 | 70 | 22 | 0.49 | 0.023 | 0.014 | 3.41 | 0.63 | |
| 76 | 95 | 19 | 0.25 | 0.015 | 0.007 | 1.86 | 0.34 | |
| 96 | 110.5 | 14.5 | 0.33 | 0.011 | 0.019 | 2.32 | 0.41 | |
| 172.5 | 202 | 29.5 | 0.28 | 0.007 | 0.023 | 4.10 | 0.38 | |
S030 | 12 | 61 | 49 | 0.80 | 0.023 | 0.032 | 0.79 | n/a Ox |
| 129 | 147 | 18 | 0.18 | 0.018 | 0.021 | 1.44 | 0.29 | |
| 153 | 177 | 24 | 0.27 | 0.031 | 0.013 | 2.55 | 0.44 | |
| 182 | 201 | 19.1 | 0.17 | 0.049 | 0.015 | 1.00 | 0.40 | |
| S031 | 26.7 | 103 | 76.3 | 0.28 | 0.012 | 0.008 | 2.49 | 0.37 |
S032 | 32 | 49 | 17 | 0.67 | 0.010 | 0.013 | 2.98 | n/a Ox |
| 49 | 76 | 27 | 0.32 | 0.009 | 0.007 | 2.16 | 0.38 | |
| 82 | 109.5 | 27.5 | 0.32 | 0.005 | 0.007 | 1.55 | 0.35 | |
| S033 | 35.3 | 150 | 114.7 | 0.44 | 0.004 | 0.045 | 2.49 | 0.54 |
| incl. incl. | 73.7 26.48 | 0.55 0.90 | 0.002 0.001 | 0.064 0.141 | 3.02 4.62 | 0.66 1.18 | ||
| S034 | 42 | 145 | 103 | 0.31 | 0.011 | 0.011 | 2.789 | 0.39 |
* CuEq (%) = [(Cu% × Cu recovery (variable) × Cu price) + (Mo% × Mo recovery (variable) × Mo price) + (Au g/t × Au recovery (variable) × Au price) + (Ag g/t × Ag recovery (variable) × Ag price)] ÷ (Cu price × Cu recovery (variable)). Metal prices are in US$/lb (Cu, Mo) and US$/oz (Au, Ag). See Table 3. Metal recoveries are grade-based by individual assay in the reported intervals and vary accordingly. In these intervals, Cu recovery ranges from 82
Drill hole intervals reporting sulphide and non-sulphide copper (oxide) results are not reported with a copper equivalent.
**Significant Intervals comprise intervals ≥ 10m of ≥
+CuTot is the total contained copper % via ME-ICP62, four-acid digest.
++CuSol is the soluble copper assay via Cu-AA05 using a sulphuric acid leach conducted on intervals exhibiting oxidation.
All intervals are downhole drill core lengths. True widths will be confirmed when Phase 2 results are incorporated into the updated geological and resource models. Where holes are drilled approximately perpendicular to the interpreted structural attitude of the mineralization, core intervals are expected to approximate true thickness.
Copper Equivalent (CuEq) Reporting
CuEq grades in this release are calculated using the variable metal recovery curves from Chapter 13 of the Company’s 2024 Technical Report (“Santo Tomás Copper Project, Sinaloa, Mexico — Technical Report on a Preliminary Economic Assessment” (the “PEA”), filed on SEDAR+ August 2024) and the metal price deck in Table 3, reflecting 12-month actual trailing average prices to April 30, 2026. This price deck differs from that used in the PEA.
Copper equivalent grades in this release are not directly comparable to CuEq grades reported in the Company’s 2024 Indicated and Inferred Resource Summary Table or in earlier drill-result news releases prior to 2024, which used different metal price assumptions and CuEq methodologies. The Company has recalculated the significant-intercept database for the full drill-hole dataset using the updated CuEq calculation: the historical drilling results and the results for holes S022 to S034 have been updated in the VRIFY drill-hole viewer and are available at VRIFY and via the Company’s website. Intervals that include soluble copper assays do not have CuEq values calculated.
Table 3: Metal Prices Used for Phase 2 CuEq Calculations
| Metal | Cu | Mo | Au | Ag |
| Price (rounded) | US | US | US | US |
| Actual trailing average | US | US | US | US |
Quality Assurance / Quality Control
Historical drilling data used in the resource estimate and design of the current exploration program were subject to the data verification procedures described in the Company’s current Technical Report. Drill collar locations are verified by differential GPS with checks against LiDAR data. Geological logging, core sampling, sample preparation, analysis, and chain of custody are governed by QA/QC protocols that include the insertion of certified reference standards, blanks, and duplicates. Samples are submitted to ALS Chemex (Hermosillo, Mexico) for sample preparation; pulps are sent to ALS Canada Ltd. (Vancouver) for analysis. Total copper, molybdenum, and silver are determined by ALS method ME-ICP61 (four-acid ICP-AES); over-limit results use ore-grade assay method Cu-OG62, and non-sulphide copper is determined by method Cu-AA05. Gold is determined by ALS method Au-AA23 (30 g fire assay with AAS finish).
Qualified Person
Andrew Ware, RM-SME, a Qualified Person as defined in NI 43-101 — Standards of Disclosure for Mineral Projects, and a senior consulting geoscientist to the Company, has reviewed and approved the technical disclosures in this news release. The Company adheres to CIM Best Practices Guidelines in conducting, documenting, and reporting exploration activities.
About Santo Tomás
Santo Tomás is an advanced-stage porphyry copper project in Choix, Sinaloa, Mexico. Oroco holds a net
The August 2024 MRE, prepared by SRK Consulting (U.S.), Inc., outlined an Indicated Resource of 540.6 Mt at
About Oroco Resource Corp.
Oroco Resource Corp. is a Vancouver-based mineral exploration and development company advancing the Santo Tomás copper project in Sinaloa, Mexico.
For further information:
Charles (Charlie) Cryer, CEO
Oroco Resource Corp.
Tel: 604-688-6200 | info@orocoresourcecorp.com | www.orocoresourcecorp.com
Cautionary Note Regarding Forward-Looking Information
This news release contains forward-looking information within the meaning of applicable Canadian securities legislation, including statements regarding: the Phase 2 drilling program and its objectives; the consistency of drilling results with the 2024 Technical Report block model; the anticipated advancement of the Santo Tomás Project toward a Pre-Feasibility Study and its targeted release in Q2/Q3 2027; planned and ongoing drilling, access and pad development; pending assays and the anticipated release of additional drilling data; the Company’s intention to update VRIFY with additional drill results; and the anticipated conversion of Inferred resources to the Indicated category. Forward-looking information is based on management’s current expectations and assumptions, including assumptions regarding continued access to the project, contractor availability, assay laboratory turnaround times, geological continuity and commodity prices. Such information is subject to known and unknown risks, uncertainties, and other factors that may cause actual results to differ materially from those expressed or implied, including drilling results, geological and resource estimation uncertainty, commodity price fluctuations, regulatory and permitting risks, and general economic conditions. A Preliminary Economic Assessment is preliminary in nature, includes Inferred Mineral Resources considered too speculative geologically to be categorized as Mineral Reserves, and there is no certainty that results of the PEA will be realized.
There is no certainty that any Inferred Mineral Resource will be converted to the Indicated category, or that any mineral resource will be converted to a mineral reserve. Mineral resources that are not mineral reserves do not have demonstrated economic viability. Inferred Mineral Resources are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorized as mineral reserves.
Forward-looking information is made as of the date of this news release and is qualified in its entirety by the foregoing cautionary statements. Readers are cautioned not to place undue reliance on forward-looking information. The Company does not undertake to update forward-looking information, whether as a result of new information, future events or otherwise, except as required by applicable securities law.
Neither the TSX Venture Exchange nor its Regulation Services Provider accepts responsibility for the adequacy or accuracy of this news release.
