Oroco Continues Its Drilling Success

VANCOUVER, British Columbia – (April 20, 2022) Oroco Resource Corp. (TSX-V: OCO, OTC: ORRCF) (“Oroco” or “the Company”) is pleased to announce the receipt of additional assay results from its drilling campaign at the Santo Tomas property (the “Property”) in northwestern Mexico, having received the assay results from Holes N009 through N012 in the North Zone deposit.  Assay results through the first twelve drill holes (8,633 m of drilling) have now been received (see Table 1 below and Figure 1, attached, or at the Company’s website www.orocoresourcecorp.com). The drill program in the North Zone is proceeding very well with the targeted mineralization intersected at the anticipated depths and with noteworthy intervals in all holes.  In addition, drilling in the Brasiles Zone continues at Hole B005 with the assays from Holes B001 to B003 pending.

The 2021-2022 drill program in the North Zone has now spanned 900 m of strike length along the core of the mineral deposit.  Notably, Drill Hole N010 returned 311.0 m of 0.42 Copper Equivalent.  Drill Hole N010 lies south of Hole N008, which produced the best intersection to date in the 2021-2022 drill program.  Hole N008 yielded a true-thickness of 328.3 m of 0.45% Copper Equivalent.

"Management is very pleased to see the targeted mineralization intersected at the anticipated depths in the North Zone, with significant intervals existing in all holes.  Drilling results have established wide, near-surface intersections of good grade Cu-Mo-Au mineralization, confirming the primary target of this drill program.  With the mineralized structure taking shape, the Company will now target down-dip extensions in areas of the North Zone previously untested by historical drilling” commented Craig Dalziel, Oroco’s Executive Chairman.  "Oroco's opportunity at Santo Tomas continues to gain strength," Mr. Dalziel concluded.


  • In summary, Drill Holes N001 to N012 were drilled to test the North Zone deposit at angles almost perpendicular to its structural attitude.  As a result, core intervals for those holes are within approximately 10% of true thicknesses, except for Hole N004.
  • Hole N004 was drilled to test a geophysical target and did not test the North Zone deposit.  Core intervals are not representative of true thickness for that hole.
  • Hole N005 was ended early, in unstable ground at 38 m depth.  Hole N006 was collared adjacent to N005 and was drilled to completion.
  • Holes N013 to N016 in the North Zone and B001 to B004 in the Brasiles Zone are completed and constitute an additional 6,205 m of drilling from which assays have yet to be generated.
  • To date, the 20 drill holes that have been completed at Santo Tomas (16 in the North Zone) total 14,838 m of diamond drilling, mainly in HQ core size.
  • The Company has now received the approvals necessary to begin drilling the western extension of the North Zone 3D IP model, thereby targeting a deeper tier of potential mineralization 300-400 m below the 2009 Gradeshell model of Cu > 0.3% (the “2009 Gradeshell Model”) contained in the current Technical Report (the “Technical Report”) (Bridge, 2019: See the Company website www.orocoresourcecorp.com/projects/technical-reports/ or SEDAR).

Table 1: Significant Assay Intervals in the Santo Tomas 2021-2022 Program, Holes N001 to N012:

Cu Equivalent (CuEq) % = Cu % + (Mo %*3.75) + (Au ppm*0.752).  The commodity prices (3-year Average) used are in $US: Cu $3.20 /lb, Mo $12.00 /lb, and Au $1,650.00 /troy oz.  * Ag values are not used in the CuEq calculations.

Drill Hole
Cu % Mo % Au g/t Ag g/t* CuEQ %
N001 272.6 299.6 27.0 0.18 0.012 0.018 0.82 0.24
" 310.0 565.0 255.0 0.39 0.010 0.045 2.20 0.46
" 571.0 620.0 49.0 0.17 0.003 0.008 1.31 0.18
N002 349.9 630.0 280.1 0.38 0.012 0.025 2.85 0.44
N003 295.0 306.8 11.8 0.31 0.009 0.014 2.85 0.36
" 315.3 333.0 17.7 0.33 0.008 0.017 1.49 0.37
" 339.0 364.5 25.5 0.29 0.015 0.020 2.81 0.36
" 370.0 384.3 14.3 0.50 0.008 0.026 3.33 0.56
" 390.0 597.7 207.7 0.39 0.014 0.019 2.82 0.45
" 601.8 678.0 76.2 0.18 0.002 0.007 2.53 0.20
N004 434.3 498.0 63.7 0.38 0.012 0.017 2.12 0.44
N006 31.0 219.5 188.5 0.39 0.004 0.051 2.29 0.44
" 223.4 277.0 53.7 0.17 0.005 0.011 1.55 0.20
N007 213.9 405.2 191.3 0.32 0.005 0.029 2.93 0.37
" 408.1 518.0 109.9 0.32 0.012 0.018 3.06 0.38
N008 159.8 488.0 328.3 0.38 0.010 0.038 2.60 0.45
N009 438.0 470.0 32.0 0.76 0.011 0.021 4.90 0.82
" 516.2 538.0 21.9 0.31 0.027 0.013 2.00 0.42
" 542.0 665.6 123.6 0.29 0.014 0.011 1.76 0.35
" 671.4 686.6 15.2 0.45 0.016 0.022 2.61 0.53
" 692.1 752.0 59.9 0.27 0.010 0.020 2.70 0.32
N010 137.0 448.0 311.0 0.36 0.011 0.029 2.33 0.42
" 454.0 476.0 22.0 0.21 0.002 0.005 1.59 0.22
N011 48.2 279.0 230.8 0.39 0.007 0.039 2.84 0.45
N012 309.1 606.0 296.9 0.35 0.015 0.025 2.58 0.42

Cu Equivalent (CuEq) % = Cu % + (Mo %*3.75) + (Au ppm*0.752).  The commodity prices (3-year Average) used are in $US: Cu $3.20 /lb, Mo $12.00 /lb, and Au $1,650.00 /troy oz.  * Ag values are not used in the CuEq calculations.


The Company advises that the 2012-2022 drilling results continue to confirm the following:

  • Copper grades in holes N009 through N012 are comparable to the historical drilling reported on each related cross-section (Figures 1-5, attached, or on the Company website: www.orocoresourcecorp.com)  Results to date continue to confirm the geological conclusions and the 2009 Gradeshell Model contained in the Technical Report.
  • Importantly, in the southern area of the North Zone, drilling (N008 and N010) has intersected increasing widths of mineralization.  The Dias Geo 3D IP modelling shows broader chargeability responses on the western side of the deposit.  Recent drilling has begun to test these extensions, and assays are pending.  Also, copper grades are higher in the footwall alteration zone on the eastern flank of the North Zone in the area of N008 and N010 than in the area immediately north of hole N008 (holes N001, 002 and 003).
  • The 16 drill holes completed to date test the North Zone deposit and the 2009 Gradeshell Model to a depth of 300 to 400 m below the surface.  Notably, geological and geophysical modelling support a westward targeting at a significantly greater depth below surface. 

The Santo Tomas Cu-Mo-Au porphyry deposit is an example of the geologic style of Laramide-age porphyry copper deposits in the southwestern United States and northwestern Mexico.  Historical Pre-Feasibility Studies, recent 3D modelling of historical drilling, and several new programs of geophysical surveying have defined drill targets both for confirmation of historical mineral resource estimates and for additional resource exploration.

  • Geological logging indicates that copper is present as chalcopyrite, with significant covellite, chalcocite, and bornite disseminations and vein fillings.  Pyrite is relatively sparse in the main drill intersections.  The best mineralization in the central portions of the North Zone is hosted in strongly potassic-altered volcanic and intrusive rocks with an overprint of phyllic alteration.
  • Molybdenum, gold, and silver are elevated in the core across the width of the North Zone and provide an approximate 15% contribution to the copper equivalent grade without factoring for metallurgical recoveries.  Silver is not used in Oroco’s copper equivalent grade calculations.
  • Fracturing, mylonite zones, Laramide intrusive dikes, veining and sulphide mineralization are controlled by faulting co-eval with the formation of the North Zone deposit.  Drilling confirms a strike of N20°E and a dip of 50-55°W, as reported in the Technical Report.

Historical drilling from 1968 to 1994 in the North Zone was primarily vertical and unsuited to defining the full width and depth of the deposit, especially on the southern extremity that is concealed under a blanket of limestone.  The 2021-2022 program is better suited to the orientation of the deposit by utilizing angled drill holes more perpendicular to the re-modelled strike and dip of the deposit.  This is the first program that features drill holes that pass from the hanging wall of the North Zone deposit into the footwall, and which also features a full suite of assay information that includes copper, molybdenum, gold, and silver.

Drilling confirms that the North Zone comprises intensely fractured, potassic- and phyllic-altered andesite volcanics and Laramide-age porphyritic intrusive dikes.  Elevated Mo, Au and Ag accompany copper assays along the central axis of the North Zone.  Pyrite is relatively low in the core of the North Zone, explaining the IP response that is in the mid-range of the Chargeability High responses on the Property.  In contrast, drilling into the footwall of the North Zone has consistently intersected propylitic-altered andesite.  The footwall contains abundantly disseminated and vein pyrite, explaining the pronounced Chargeability High and a corresponding Resistivity Low in the 3D IP modelling.


Appropriate QA/QC protocols governed geological logging, core sampling, sample preparation, analyses, and security during the current program, including quality controls with duplicates, standards, and blanks.  Samples were submitted to the Mexican division of ALS Limited in Hermosillo, Mexico, for sample preparation to pulps.  Sample pulps are then sent to ALS Canada Ltd. in Vancouver, Canada, for analysis. Total copper and molybdenum contents are determined by four-acid digestion with an AAS finish.  Gold was determined by fire assay of a 50-gram charge, or alternately, for a 30-gram charge (1 Assay ton).

The historical drilling data employed in this current exploration program was the subject of Data Verification procedures cited in the current Technical Report.  Additional drill collar verifications are being performed in the current program.


Mr. Paul McGuigan, P. Geo., of Cambria Geosciences Inc., a “Qualified Person” (as defined in NI 43-101 -Standards for 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 holds a net 73.2% interest in the collective 1,172.9 ha Core Concessions of the Santo Tomas Project in NW Mexico and may increase that majority interest up to an 85.5% interest with a project investment of up to CAD$30 million.  The Company also holds a 77.5% interest in 7,807.9 ha of mineral concessions surrounding and adjacent to the Core Concessions (for a total project area of 22,192 acres).  The Project is situated within the Santo Tomas District, which extends from Santo Tomas up to the Jinchuan Group’s Bahuerachi project, approximately 14 km to the northeast.  Santo Tomas hosts a significant copper porphyry deposit defined by prior exploration spanning the period from 1968 to 1994. During that time, the property was tested by over 100 diamond and reverse circulation drill holes, totalling approximately 30,000 meters. Based on data generated by these drill programs, a historical Prefeasibility Study was completed by Bateman Engineering Inc. in 1994.

The Santo Tomas Project is located within 160 km of the Pacific deep-water port at Topolobampo and is serviced via highway and proximal rail (and parallel corridors of trunk grid power lines and natural gas) through the city of Los Mochis to the northern city of Choix. The property is reached by a 32 km access road originally built to service Goldcorp’s El Sauzal Mine in Chihuahua State.

For further information, please contact:

Mr. Craig Dalziel, Executive Chairman
Oroco Resource Corp.
Tel: 604-688-6200


Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accept responsibility for the adequacy or accuracy of this release.

Cautionary Note Regarding Forward-Looking Information

This news release includes certain “forward-looking information” and “forward-looking statements” (collectively “forward-looking statements”) within the meaning of applicable Canadian securities legislation.  All statements, other than statements of historical fact included herein, including without limitation, statements relating to future events or achievements of the Company, are forward-looking statements. There can be no assurance that such forward-looking statements will prove to be accurate, and actual results and future events could differ materially from those anticipated or implied in such statements.  Many factors, both known and unknown, could cause actual results, performance or achievements to be materially different from the results, performance or achievements that are or may be expressed or implied by such forward-looking statements.  Readers should not place undue reliance on the forward-looking statements and information contained in this news release concerning these matters.  Oroco does not assume any obligation to update the forward-looking statements should they change, except as required by law.

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These historical resource estimate models are based upon historical resource estimates prepared by John Thornton in 2011. While, in the opinion of Dane A. Bridge, author of the revised NI 43-101 standard technical report, Geology, Mineralization and Exploration of the Santo Tomas Cu-(Mo-Au-Ag) Porphyry Deposit, Sinaloa, Mexico dated April 21, 2020 (the “Report”), reliable estimation practices were used, in order to upgrade or verify the historical estimations, resampling and assay of historical drill samples, twinning of historical drill holes, and a new program of regularly spaced drilling is required. No qualified person has undertaken sufficient work to classify the current mineral resources or mineral reserves upon which these models are based and the Company is not treating the estimates as current estimates of the mineral resources. The Company gives no assurance that either these models or the historical resource estimates upon which they are based are accurate, and does not undertake any obligation to update the models or to release publicly any update or revisions of the resource estimates except as required by applicable securities law. The reader is cautioned not to rely upon these models or the historical resource estimates upon which they are based.

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