Montero Mining and Exploration: Lithological and Drill Chip Pile Sampling Confirms Anomalous Copper – Molybdenum Values at the Avispa Property in northern Chile

2022-08-23 06:43:39

TORONTO, Aug. 23, 2022 (GLOBE NEWSWIRE) — Montero Mining and Exploration Ltd. (TSX-V: MON) (“Montero” or the “Corporation”) is reporting the assay results of surface geochemical sampling undertaken within areas of interest on the Avispa property (“Avispa “or “Project”). Company geologists collected lithological samples from the San Salvador River valley and from reverse circulation (RC) drill chip piles from drilling sites completed by BHP and Quantum Pacific Exploration Chile (“Quantum”) on the Avispa property. Some samples returned anomalous copper and molybdenum values which require further investigation and supports Montero’s belief the Avispa project area has been only cursorily explored for potential concealed copper molybdenum porphyry deposits beneath surficial sediments and gravels.

Avispa is located about 40 km to the west of the supergiant Chuquicamata copper porphyry deposit in an area currently being explored by major mining companies. It is situated within the defined north-south trending Palaeocene–Eocene Cu-Mo porphyry belt and 40 km north of BHP’s Spence Cu-Mo mine and KGHM/South32’s Sierra Gorda Cu-Mo mine. Avispa is 20 km east of the extensive north-south trending Caliche Nitrate belt hosting the nearby Maria Elena and Pedro de Valdivia Nitrate-Iodine mines operated by SQM (Figure 1). Avispa project has an extensive cover of sedimentary and evaporite salt deposits underlain by gravel deposits of Miocene age. These sediments overlay and partially cover Cretaceous volcanics and sediments which are intruded by the target Palaeocene monzodiorite and diorite porphyries and Cretaceous andesitic and diorite porphyries that potentially host copper porphyry mineralization.

Dr. Tony Harwood, President and Chief Executive Officer of Montero commented: “Montero is pleased to report that the strategy of increasing our land position has paid off with the results of mapping showing altered intrusive outcrop on the property. Geochemical sampling of these lithologies and samples taken from RC drill chip piles left by previous operators yielded exciting copper and molybdenum anomalies on the property. Copper anomalies of > 100 ppm Cu and between 10-25 ppm Mo were returned from the program. The Company is further evaluating the geochemical results and has engaged a consulting company to undertake propriety algorithmic geochemical analysis of the results with a goal of generating 3-D targets indicating the location of possible copper molybdenum porphyry mineralization.” Avispa is also assessing for its lithium, iodine, and nitrate mineral potential.”

Figure 1: Satellite image of the northern Atacama/Antofagasta region showing the Avispa property relative to major copper molybdenum porphyry mines and Caliche nitrate-iodine mines (amended after Lopez et al, 2019).

The extensive Quaternary and Miocene sedimentary cover at Avispa only allows for geochemistry, structural mapping, remote sensing techniques or, more costly geophysical surveys and drilling to help target Cu-Mo porphyry mineralization in the underlying Cretaceous rocks.

The San Salvador River valley located along the southern boundary of the property provides a window into the Cretaceous geology below the Quaternary and Miocene rocks. The river valley is some 120-160 m below the Miocene plateau and exposes the underlying Cretaceous volcanics and sediments as well as providing information on the thickness of the Miocene sedimentary overburden. Montero conducted detailed mapping and of these rocks along this valley and its tributaries. (Figure 2). A total of 37 grab samples of rock types exposed along a transect were sampled and subjected to 4 acid digest and 48 element ICP-MS assays. Individual analysis, location and sample description for the lithological samples are shown in Table 1.

The results for copper and molybdenum analyses in the San Salvador lithological samples are provided in Figures 3 and 4, respectively. Copper was anomalous in 7 locations returning values of >100 ppm Cu with the highest value of 476 ppm Cu coming from sample of Cretaceous andesite volcanic rock (Figure 3). Molybdenum showed anomalous values of > 5 ppm Mo and in 3 locations highly anomalous values of >10-25 ppm Mo were obtained (Figure 4). The latter values were obtained from altered Cretaceous andesite volcanic rock.

Figure 2: Satellite image with location of Montero’s lithological sampling sites (yellow circles) and RC drill chip pile sampling sites (red circles). BHP drilled widely spaced RC holes while Quantum completed intense drilling.

Figure 3: Geological map of copper (Cu) assay results for lithological grab samples collected along the San Salvador River section. Seven samples returned >100 ppm Cu (red dots) with the highest assay of 476 ppm Cu.

Figure 4: Geological map of the San Salvador valley showing molybdenum assay results of lithological samples collected. Anomalous values of 10-25 ppm Mo were obtained from altered andesite volcanics.

The Company completed sampling of rock chips piles from previous RC drilling site at Avispa (Figure 2). The origin of the RC drill chips piles is unknown and it assumed they are mixed and originated from an unknown depth at each drill site. A total of 48 grab samples from drill chip piles were submitted for 48-element analysis by 4 acid digestion followed by ICP-MS analysis. The results for copper and molybdenum analysis are provided in Figures 5. The highest copper concentrations of >100 ppm Cu were obtained from the area of intense drilling. In contrast the highest molybdenum anomalies of 10-25 ppm Mo were collected from 3 BHP RC drill hole sites. Individual analysis for the drill chip samples are shown in Table 1.

The lithological sampling in the San Salvador area and the drill chip sampling confirmed the occurrence of altered, intrusive rock as part of the underlying geology, from which several grab samples returned anomalous copper and highly anomalous molybdenum concentrations. For reference, exploration geochemical results during the exploration of BHP’s Spence deposit south of Avispa reported anomalies up to 100 ppm Cu and 5 ppm Mo (Cameron and others 2004, 2009) in surface gravels. Similarly, EMSA/Codelco reported anomalies of up to 43 ppm Cu and 7 ppm Mo in gravels at their Pampa las Torres property east of the Chug Chug prospect. (Expatriate Resources, 2001).

Figure 5: Satellite image showing the location of RC drill chip sampling sites with Cu results in Cu ppm (left image) and Mo results in Mo ppm (right image).

Table 1: Location, lithology and results for Cu, Mo, Pb and Zn analysis by 4 acid digestion ICP-MS of samples obtained from lithological grab samples from the San Salvador River valley and surrounds.

























Sample ID Rock Type Cu ppm Mo ppm Pb ppm Zn ppm Sample ID Rock Type Cu ppm Mo ppm Pb ppm Zn ppm
612060 Tuff 78 2 9 79 612141 Andesite 37 4 11 46
612061 Tuff 50 <2 2 68 612142 Andesite 74 9 58 261
612062 Tuff 61 <2 8 72 612143 Altered volcanic 58 12 623 340
612063 Tuff 49 <2 2 47 612144 Altered volcanic 41 13 193 24
612064 Andesite 35 3 9 53 612145 Volcanic? 99 2 3 59
612065 Andesite 57 <2 4 81 612146 Intrusive 27 11 47 605
612066 Intrusive 36 6 62 55 612147 Andesite faulted 112 4 42 231
612067 Intrusive 63 4 14 85 612148 Altered volcanic 76 3 7 100
612068 Intrusive 107 <2 12 80 612149 Igneous Breccia 68 4 7 53
612069 Volcanic 32 3 5 13 612150 White carbonate 15 <2 6 33
612070 Conglomerate 99 <2 <2 64 612151 Altered volcanic 29 7 12 36
612071 Conglomerate 476 <2 6 69 612152 Intrusive 119 <2 8 62
612072 Conglomerate 121 <2 8 73 612153 Intrusive 117 <2 <2 35
612073 Gravel 45 2 11 35 612280 Andesite 68 9 7 51
612074 Conglomerate 54 <2 3 71 612281 Altered volcanic 59 6 8 84
612075 Conglomerate 89 <2 4 76 612282 Andesite 93 <2 7 63
612136 Intrusive 40 4 14 109 612283 Altered volcanic 76 8 10 58
612137 Intrusive 68 3 3 77 612284 Andesite 53 <2 5 118
612138 Andesite 46 <2 6 15 612285 Andesite 28 <2 <2 93
612139 Intrusive 66 <2 5 42 612286 Intrusive 34 3 13 55
612140 Intrusive 143 2 13 118 612287 Intrusive 56 3 25 58

Table 2: Location, lithology and results for Cu, Mo, Pb and Zn analysis by 4 acid digestion ICP-MS of samples obtained from previous drill holes sites.




























Sample ID Rock Type Cu ppm Mo ppm Pb ppm Zn ppm Sample ID Rock Type Cu ppm Mo ppm Pb ppm Zn ppm
506504 Volcanic 44 4 13 58 506528 Gravel 38 5 17 58
506505 Andesite 31 3 13 63 506529 Gravel 37 25 14 92
506506 Andesite 30 6 14 63 506530 Gravel 32 5 12 70
506507 Andesite 40 3 14 80 506531 Andesite/Intrusive 84 5 7 82
506508 Andesite 33 9 14 71 506532 Andesite/Tuff 68 3 13 70
506509 Andesite/Intrusive 16 5 21 75 506533 Andesite 99 7 13 76
506510 Dacite 22 6 12 49 506534 Andesite 137 4 12 76
506511 Gravel 32 2 16 75 506535 Andesite 84 9 17 99
506512 Gravel 41 8 22 89 506536 Andesite 58 2 16 105
506513 Gravel 33 11 18 79 506537 Andesite/Intrusive 60 9 11 76
506514 Gravel/Andesite 21 2 8 57 506538 Andesite 93 5 14 82
506515 Gravel 12 7 12 53 506539 Andesite/Intrusive 84 6 14 74
506516 Gravel 38 4 37 122 506540 Andesite/Intrusive 80 3 9 83
506517 Andesite/Intrusive 34 9 12 70 506541 Andesite/Intrusive 56 8 12 58
506518 Andesite 18 4 19 95 506542 Gravel/Andesite 64 3 11 66
506519 Andesite 55 3 8 81 506543 Andesite 73 7 7 80
506520 Gravel 34 8 18 80 506544 Andesite/Intrusive 137 5 12 71
506521 Gravel 37 6 17 86 506545 Gravel/Andesite 64 6 11 78
506522 Gravel 43 9 23 110 506546 Gravel/Andesite 59 2 8 69
506523 Andesite 25 5 13 83 506547 Gravel 60 4 9 79
506524 Gravel/Andesite 45 4 10 67 506548 Intrusive 102 9 13 70
506525 Gravel 29 14 13 66 506549 Gravel 214 5 47 126
506526 Gravel 25 5 13 48 506550 Gravel/Andesite 55 7 12 83
506527 Gravel 41 5 14 103 506551 Gravel 30 6 12 70

To assist the Company in defining potential porphyry drill targets, management has engaged Fathom Geophysics to evaluate all current project data with the objective of identifying potential vectors to buried porphyry-type Cu-Mo deposits. The results of this work are expected in Quarter 3 2022 and will be integrated into the targeting program for an eventual initial drilling program at Avispa.

Montero has also undertaken initial geological mapping and sampling to evaluate Avispa’s potential to host lithium, iodine, and nitrate (fertilizer) mineralization. The target lithologies are Quaternary to Miocene in age and consist of lacustrine sediments and evaporite deposits that have previous reported anomalous values of these elements and minerals (PR February 26, 2019). The Company has conducted remote sense data interpretation and field mapping can confirm that these lithologies are exposed over an area of more than 100 km2 at Avispa. The Company has outlined 44 locations on the and complete a detailed mapping and sampling and the results of this work are expected in Quarter 3, 2022.

Qualified Person’s Statement

This press release was reviewed and approved by Mr. Mike Evans, M.Sc. Pr.Sci.Nat. and Sr. Marcial Vergara B.Sc. Geology who are qualified persons for the purpose of National Instrument 43-101. Sr Vergara is based in Santiago and has more than 30 years’ experience in copper exploration experience in Chile.

About Montero

Montero is a junior exploration company focused on finding, exploring, and advancing globally significant gold, silver, and base metal deposits in Chile. Montero’s board of directors and management have an impressive track record of successfully discovering and advancing precious metal and copper projects. Montero trades on the TSX Venture Exchange under the symbol MON and has 38,647,485 shares outstanding.

For more information, contact:
Montero Mining and Exploration Ltd.
Dr. Tony Harwood, President and Chief Executive Officer
E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Tel: +1 416 840 9197 | Fax: +1 866 688 4671
www.monteromining.com

Neither 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.

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING INFORMATION

This news release includes certain “forward-looking information” within the meaning of applicable Canadian securities laws. Forward looking information includes, but is not limited to, statements, projections and estimates with respect to the Share Consolidation. Generally, forward-looking information can be identified by the use of forward-looking terminology such as “plans”, “expects” or “does not expect”, “is expected”, “budget”, “scheduled”, “estimates”, “forecasts”, “intends”, “anticipates” or “does not anticipate”, or “believes”, or variations of such words and phrases or state that certain actions, events or results “may”, “could”, “would”, “might” or “will be taken”, “occur” or “be achieved”. Such information is based on information currently available to Montero and Montero provides no assurance that actual results will meet management’s expectations. Forward-looking information by its very nature involves inherent risks and uncertainties that may cause the actual results, level of activity, performance, or achievements of Montero to be materially different from those expressed or implied by such forward-looking information. Actual results relating to, among other things, completion of the agreement, results of exploration, project development, reclamation and capital costs of Montero’s mineral properties, and financial condition and prospects, could differ materially from those currently anticipated in such statements for many reasons such as: an inability to complete the agreement on the terms as announced or at all; changes in general economic conditions and conditions in the financial markets; changes in demand and prices for minerals; litigation, legislative, environmental and other judicial, regulatory, political and competitive developments; technological and operational difficulties encountered in connection with Montero’s activities; and other matters discussed in this news release and in filings made with securities regulators. This list is not exhaustive of the factors that may affect any of Montero’s forward-looking statements. These and other factors should be considered carefully and accordingly, readers should not place undue reliance on forward-looking information. Montero does not undertake to update any forward-looking information, except in accordance with applicable securities laws.

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