Technical Report for the Marimaca Copper Project, Antofagasta Province, Region II, Chile
Report Prepared for:
Coro Mining Corporation
Report Prepared by:
NCL Ingenieria y Construcción SpA
February 2017
Technical Report for the Marimaca Copper Deposit Page 1 Coro Mining Corp NCL SpA
Technical Report for the Marimaca, Copper Project, Antofagasta Province, Region II, Chile
Coro Mining Corporation Address: Suite 1260, 625 Howe St Vancouver, BC, Canada V6C 2T6 E-mail: [email protected] Website: www.coromining.com Tel: +1 604682 5546 Fax: +1 604 682 5542
NCL Construcción SA Adress: General del Canto 235 Santiago, Region Metropolitana, Chile E-mail: [email protected] Website: www.ncl.cl Tel: +56 2 2651 0800 Fax:
NCL Project Number: 1631
Effective date: February 24th 2017 Signature date: February 24th 2017
Authored by: Luis Oviedo, P. Geo. NCL Ingeniería y Construcción SpA (Geology & Resources)
Reviewed by: Ricardo Palma, P. Eng. Consultant NCL
IMPORTANT NOTICE
This report was prepared as a National Instrument 43 Technical Report for Coro Mining Corporation (Coro) by NCL Ingenieria y Construccion SpA (NCL). The quality of information, conclusions, and estimates contained herein are consistent with the quality of effort involved in NCL services. The information, conclusions, and estimates contained herein are based on: i) information available at the time of preparation, ii) data supplied by outside sources, and iii) the assumptions, conditions, and qualifications set forth in this report. This report is intended for use by Coro subject to the terms and conditions of its contract with NCL and relevant securities legislation. The contract permits Coro to file this report as a Technical Report with Canadian securities regulatory authorities pursuant to National Instrument 43-101. Except for the purposes legislated under provincial securities law, any other uses of this report by any third party is at that party’s sole risk. The responsibility for this disclosure remains with Coro. The user of this document should ensure that this is the most recent Technical Report for the property as it is not valid if a new Technical Report has been issued.
This document, as a collective work of content and the coordination, arrangement and any enhancement of said content, is protected by copyright vested in NCL.
Outside the purposes legislated under provincial securities laws and stipulated in NCL’s client contract, this document shall not be reproduced in full or in any edited, abridged or otherwise amended form unless expressly agreed in writing by NCL.
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CERTIFICATE OF QUALIFIED PERSON
I, Luis Oviedo, P.Geo, am consultant as QP with NCLand I have an employment address at 235, General del Canto, Providencia, Santiago de Chile. This certificate applies to the technical report titled “Technical Report for the Marimaca, Copper Project, Antofagasta Province, Region II, Chile” that has an effective date of 24th February 2017 (the “technical report).
I am a registered Professional Geologist (P.Geo.) in Chile. I am registered member of the Comisión Calificadora de Competencias en Recursos y Reservas Mineras (Chilean Mining Conmission: RM, CMC) with the number 013. I graduated with a Geologist degree from the University of Chile in 1977. Postgraduate “Evaluation and Certification of Mining Assets”. Queen’s University Canada and Universidad Católica of Valparaíso, Chile. . I have practiced my profession for 40 years since graduation. I have practiced for more than 40 years. I have been directly involved in resource estimates for all types of mines, audits, half-lives and technical reports of resources for stock exchanges and financial institutions in Canada, Chile, Peru, Ecuador and Colombia. I am a “qualified person” as that term is defined in NI 43-101 - Standards of Disclosure for Mineral Projects (“NI 43-101”), JORC and other stock exchanges in the world.
I visited the Marimaca Project (the “Project”) the second week of December, 2016. I am responsible for the total report..
I am independent of Coro Mining Corp. as independence is described by Section 1.5 of NI 43–101. I have been involved with the Project since November 2016 as part of preparation of the Resources Estimation study.
I have read NI 43–101 and the sections of the technical report for which I am responsible have been prepared in compliance with NI 43–101 .
As of the effective date of the technical report, to the best of my knowledge, information and belief, the sections of the technical report for which I am responsible contain all scientific and technical information that is required to be disclosed to make those sections of the technical report not misleading.
Dated: 24th February 2017
Signed and sealed
Luis Oviedo H. PGeo, QP
0 Executive Summary
The Marimaca Coro Mining Project is an open pit-mineable copper oxide deposit located 45 Km to the north of Antofagasta, Region II of Chile. In anticipation of the report Coro mandated NCL to visit the properties, estimate the Mineral Resources and compile an independent technical report pursuant to Canadian Securities Administrators’ National Instrument 43-101.
In December 2016, a team of independent qualified persons, as the term is defined by National Instrument 43-101, visited operations at Marimaca. This technical report summarizes the technical information that is relevant to support the estimation of Mineral Resources pursuant to Canadian Securities Administrators’ National Instrument 43-101.
0.1 Property Description and Ownership
The Marimaca Project and surrounding tenements are located in Chile’s Antofagasta Province, Region II, approximately 45 kilometres north of the city of Antofagasta, 25 Km to the east of the port of Mejillones and approximately 1,250 kilometres north of Santiago (Figure 0-1). The Cerro Moreno International Airport is located about 44 km south of the Project. Its WGS 85 UTM coordinates (used in the Google EarthTM public base, www.googleearth.com) correspond to 374,800 E and 7,434,900-N. Also is located 14km from the Antofagasta to Tocopilla paved highway. The properties are easily accessed using the public road system. Antofagasta and Mejillones are modern cities with all regular services and a combined population of approximately 560,000. Personnel employed by Coro come primarily from the Antofagasta Region.
Figure 0-1 - Marimaca Project Location
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Antofagasta has a coastal arid climate with mild temperatures year round. Winters are mild with warm temperatures. Annual precipitation averages approximately 2-4 millimetres, the majority of which falls in the winter season. The climate allows for year round mining and exploration activities.
Coro Mining Corp. is an exploration, development & mining company and its 100% owned Chilean subsidiary Minera Cielo Azul Ltda, has the right to acquire a 75% interest in the project by completing a resource estimate, engineering studies and arranging financing. To date, Coro has completed a 54 holes reverse circulation (RC) drilling program for 11.620 m and 6 DDH for 2800.05 m to test outcropping mineralization exposed and in several artisanal miner’s open cuts.
The Marimaca Project is located in an area of approximately 1,300 m (meters), north- south; by 700 m, east-west direction. This land comprises one mining concession containing 23 properties (approximately 115 hectares). The tenements are free of mortgages, encumbrances, prohibitions, injunctions, and litigation. The tenements containing the active and future mining activities are not affected by royalties.
0.2 History
Project site and district exploration programs have been active since the Marimaca deposit discovery in 2016. There is no verifiable history of mining prior to Marimaca 1 to 23 properties.
The area was known since the end of the 19th century as “Mineral de Naguayán”.
In 1962, the first report on the project concluded that a granodiorite hosted mineralization cut by "dark dykes" oriented north-south, and inclined to the east, with copper mineralization occurring within a system of centimetric parallel fractures. Reportedly, 5 tonnes per week grading between 17% and 50% Cu were being mined. Several of the deeper underground adits reached sulphides described as chalcopyrite, bornite and chalcocite.
Between the 70's and 90's there are only reports by geologists of the government institutions such as the Institute of Geological Investigations and ENAMI (Empresa Nacional de Minería).The descriptions mention copper oxide mineralization in north-south oriented fractures and a potential of 200,000 tonnes an average grade of 1.2% of total cooper was estimated.
In 2003 the owners commissioned a geological study that described and sampled a 10° striking narrow veined system and estimated a potential resource of 566,000t of average grade 2.8% Cu. This study recognized an intense fracturing and the key directions for faults and veins.
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At least a couple of companies reviewed the property in the early 2000's, mostly juniors, but none of them reported the possibility of a substantial mining potential.
In May 2008, geologists from Minera Rayrock described the control of the mineralization by a "pseudo-stratification" or a "pseudo-stratified intrusive". The potential for copper oxide mineralization was estimated at 21 Mt of average grade 0.8% Cu. After this, there are no other reports regarding mining activities in the area.
Meanwhile, artisanal miners exploited the properties by developing small open pits and underground workings often with some degree of mechanization. Most of these ores were sold to Michilla, ENAMI and Rayrock.
The small open pits had dimensions that do not exceed 20 by 15 m and depths of up to 20 m. Underground workings reached extensions of no more than 100 m. Minera Cielo Azul (MCAL), a 100% Coro owned subsidiary was the first company to access the property with the idea of exploring for an open pit, leachable, deposit in the Naguayán area.
0.3 Geology, Mineralization and Deposit Types
The Marimaca deposit is located in the Coastal Cordillera in the Antofagasta Region, within a belt of Mesozoic age copper deposits, known as the Coastal Copper Belt, which range in (pre-mining) size from Mantos Blancos, ~500 million tonnes to Ivan with ~50 million tonnes. These types of deposits occur in a variety of host rocks and have different morphologies. However, they have a common Cu-Ag primary mineralogy zoned from bornite outwards to chalcopyrite and pyrite, deep oxidation and frequently, secondary enrichment.
The deposits in the district are located NW of the main branches of the Antofagasta Fault Zone, a subduction-related strike-slip fault system stretching over 1,000 kilometres along the Chilean coast and active at least since the Jurassic.
The copper mineralization at Marimaca is generally referred to as Coastal Copper Belt type of mineralization. The mineralization occurs in intensely parallel fractured monzodiorite, and in detail mineralization occurs in breccias, stockworks, veinlets and disseminations along a “shear zone” (parallel centimeter spaced faulting). Marimaca has become a new exploration model for Coastal Copper Belt deposits displaying close relationships to the plutonic complexes and broadly coeval fault systems.
The Marimaca deposit is a 150-250m thick; gently ESE dipping, portion of strongly fractured Jurassic monzodiorite, formed at the intersection of major N striking Marimaca structure and NE striking feeder zones. The intersection of these structures has produced wide NW-SE oriented zones of eastward dipping mineralization, that have been exploited from a series of open cuts and small underground workings by artisanal miners. Surface
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mapping and drilling has shown that the mineralization is comprised of multiple, thick, higher grade structures bordered by lower grade halos.
The better grades represent the oxidation of a former sulphide enrichment blanket consisting mostly of brochantite and chrysocolla. A large pyrite halo developed in the hanging wall, now oxidised to form limonitic leached cap, containing some low grade copper wad rich irregular zones. Mineralization and concentration of copper are controlled by fracture density. The deposit is cross cut by late, post mineral dykes and sills.
0.4 Exploration Status
Before the drilling that led to the discovery of Marimaca in the first half of 2016, the work carried out was only a few indicative samples of rock and geological reconnaissance. These works were performed as part of the due diligence prior to the option agreement, in late 2014 and part of 2015. In the last year geochemical sampling of rocks on a regular grid of 100 x 100 m, covering the surface of the property and the topographic survey and aerial images taken with UAV / Drone were added.
The exploration was conducted by Coro with the primary purpose of exploring for mineral resources. Work will now be focused on the known mineralization, by improving the quality of the resources and expanding them.
From the first semester of 2016, Coro invested more than US$ 1.5 million in exploration to delineate Mineral Resources, primarily surrounding the Marimaca small open pit, then to the north and south. The information from that program was used to define the current base of measured, indicated and inferred copper oxide resources.
Building on this exploration success, an exploration program is planned for the 2017 period, targeting an infill and the lateral extensions of the investigated areas. The planned exploration program includes around 15,000 metres of core and RC drilling at an estimated total cost of US$ 2 million. The mineral potential targeted by the proposed exploration program is estimated to improve 50% of Indicated resources to Measured resources and 70 % tonnes of Inferred to Indicated resources. The range of tonnage and grades expected from the results of the proposed exploration program are estimated from the recent exploration results. The reader is cautioned that the potential quantity and grade estimates expected from the proposed exploration program are conceptual in nature.
The exploration potential of the Coro properties is good. NCL is of the opinion that aggressive exploration programs must continue to expand and improve the resources.
0.5 Drilling, Sample Preparation, Analyses, and Security
Mineral Resources are derived from the 2016 drill program where Coro drilled 6 core and 54 RC holes in and around the Marimaca old workings. The drilling and sampling
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procedures are consistent with generally recognized industry best practices. NCL concludes that the samples are representative of the source materials and there is no evidence that the sampling process introduced a bias.
Analytical samples for the Marimaca Mineral Resources were prepared and assayed in Geolaquim Laboratory in Copiapo, certified for copper analyses. Conventional preparation and assaying procedures are used. Copper is analyzed by multi acid digestion and atomic absorption spectroscopy (AAS). Specific gravity was systematically measured on 184 core samples of the DDH campaign.
Coro implemented analytical quality control measures, consistent with generally accepted industry best practices. The analytical quality control program includes the use of control samples inserted with all samples submitted. The analytical quality control data was routinely monitored.
In the opinion of NCL, the analytical results are free of apparent bias. The sampling preparation, security, and analytical procedures used are consistent with generally accepted industry best practices and are therefore adequate to support Mineral Resource estimation.
0.6 Mineral Processing and Metallurgical Testing
Coro is carrying out preliminary metallurgical analysis testing to predict its processing performance in terms of metal recovery to SXEW. Four types of leachable copper oxide mineralization were identified in logging and were modelled separately in the resource estimation:
Brochantite/Atacamite Chrysocolla Copper wad and black oxides Mixed oxides and Enriched
At the time of preparing this report, the column tests are in progress. Nevertheless, prior column tests, from open pit samples, returned 75-85% Cu recovery and 20-40 kg/t net acid consumption.
0.7 Mineral Resource Estimates
The Mineral Resources discussed herein are based on information from 60 core and RC drill holes, stored in a secured central database, and were evaluated using a geostatistical block modelling approach. Separate models were prepared for the Marimaca geological estimation units. Only leachable oxides and mixed material are included in the estimation.
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NCL reviewed and audited the different sets of sections and produced 3D solids of each estimation geological unit and in the opinion of NCL the resource evaluation reported herein is a reasonable representation of the Mineral Resources found at Marimaca at the current level of sampling. The Mineral Resources have been estimated in conformity with generally accepted CIM Estimation of Mineral Resource and Mineral Reserves Best Practices Guidelines and are reported in accordance with Canadian Securities Administrators’ National Instrument 43-101. The consolidated Mineral Resource Statement for the Marimaca deposit is presented in Table 0-1.
Table 0-1: Consolidated Mineral Resource Statement, Marimaca, NCL Consulting (January 2017). Metal contained within the boundaries of the Marimaca properties. All figures are rounded to reflect the relative accuracy of the estimates.
0.8 Pit Constrained Resource Estimate
This work is a resource estimate only. According to the standard of the 43-101 instruments, in the case of open pit projects it is necessary to consider an optimized open pit with actual and local parameters. The estimate is included in a Whittle optimized pit, whose technical and economic parameters are shown in Table 0-2:
Table 0-2 - Whittle Input Data and Results
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0.9 Project Infrastructure
At the moment of preparing this report, there is no specific infrastructure developed for Marimaca. The project has a good location and vicinity, and initially is expected to be developed within constraints of existing infrastructure in the surroundings, in particular power and water.
0.10 Conclusion and Recommendations
A team of independent consultants, under the leadership of NCL, was retained by Coro to visit Marimaca the second week of December 2016, inspect the project, review and audit the data and estimate the Mineral Resource. NCL examined the different sources of input information: raw data (QA/QC), exploration, geology and mineral modelling estimation units. The purpose of the investigation was to estimate the Mineral Resource, in compliance with generally recognized industry best practices and report them according to Canadian Institute of Mining, Metallurgy and Petroleum Definition Standards for Mineral Resources and Mineral Reserves (May 2014).
NCL carried out a Resource Estimation of the Marimaca Project, resulting in the estimation of Measured, Indicated and Inferred Resources, plus some potential mineralized rock. For a Cutoff grade of 0.2% CuT, the Resources inside an optimized pit envelope are 21.5 Mt @ 0.68 CuT of Measured + Indicated and 18.8 Mt @ 0.53% CuT Inferred resources. Based on the 2016 Mineral Resources estimation, the project is expected to continue under exploration during 2017.
Since 2016, aggressive exploration in Marimaca has defined oxides mineralization zones amenable to open pit mining and presents very good opportunities to expand the Mineral Resources and extend the life of the project. In this context, NCL recommends to continue the implementation of the exploration program proposed for 2017 (US$2 million). The regional exploration potential of the exploration properties remains good. Regional exploration targeting should be reviewed, including the use of high resolution geophysical data to enhance exploration targeting.
The technical information on Marimaca attests the high overall quality of the exploration and design work completed by site personnel. NCL examined the data, the exploration, and the geology modelling and produced the Mineral Resource estimates of Marimaca. On the basis of this work, NCL concluded that the models, Mineral Resources and Statements for Marimaca January 2017 are appropriately categorized and free of material errors.
Other than disclosed in this technical report, NCL is not aware of any other significant risks and uncertainties that could reasonably be expected to affect the reliability or confidence in the Marimaca Project.
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Contents
0 Executive Summary ...... 4 0.1 Property Description and Ownership...... 4 0.2 History ...... 5 0.3 Geology, Mineralization and Deposit Types ...... 6 0.4 Exploration Status ...... 7 0.5 Drilling, Sample Preparation, Analyses, and Security ...... 7 0.6 Mineral Processing and Metallurgical Testing ...... 8 0.7 Mineral Resource Estimates ...... 8 0.8 Pit Constrained Resource Estimate ...... 9 0.9 Project Infrastructure ...... 10 0.10 Conclusion and Recommendations ...... 10 1 Introduction and Terms of Reference ...... 16 1.1 Terms of Reference ...... 16 1.2 Qualification of NCL...... 17 1.3 Basis of Technical Report ...... 18 1.4 Declaration ...... 18 1.5 Units and Currency Definitions ...... 19 2 Reliance on Other Experts ...... 19 3 Property Description and Location ...... 19 3.1 Mineral Tenure and Earn In Agreement ...... 20 3.2 Mineral Rights in Chile ...... 22 3.3 Surface Rights ...... 22 3.4 Water Rights ...... 23 3.5 Environmental Liabilities and Permits ...... 23 4 Accessibility, Climate, Infrastructure and Physiography ...... 23 4.1 Accessibility ...... 24 4.2 Local Resources and Infrastructure ...... 24 4.3 Climate ...... 25 4.4 Physiography ...... 26 5 History ...... 27 6 Geological Setting and Mineralization ...... 28 6.1 Regional Geology ...... 28 6.2 Metallogenic Setting ...... 31 6.3 Local Geology ...... 32 6.4 Property Geology...... 33 6.4.1 Lithology ...... 33 6.4.2 Structure ...... 35 6.4.3 Alteration ...... 36 6.4.4 Mineralization ...... 38 7 Deposit Types ...... 42
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8 Exploration ...... 44 8.1 Surveying, Image and Topographic Base ...... 44 8.2 Surface Sampling ...... 45 8.3 Surface Geologic Mapping ...... 46 8.4 Geochemistry ...... 46 8.5 Geophysics ...... 47 8.6 NCL Comments ...... 48 9 Drilling ...... 48 10 Sample Preparation, Analyses and Security ...... 52 10.1 Drillhole Sampling...... 52 10.2 Sample Rejects and Pulps Storage...... 52 10.3 Specific Gravity Data Sampling ...... 53 10.4 Quality Assurance and Quality Control Programs ...... 53 10.4.1 Standard Sample Analysis ...... 53 10.4.2 Duplicate & Check Sample Analysis ...... 55 10.4.3 Blank Sample Analysis ...... 56 10.5 Sample Security ...... 57 10.6 NCL Comments ...... 57 11 Data Verification ...... 57 11.1 Verifications by Coro ...... 57 11.2 Verifications by NCL ...... 58 12 Mineral Processing and Metallurgical Testing ...... 58 13 Mineral Resource Estimates ...... 59 13.1 Introduction ...... 59 13.2 Resource Estimation Procedures ...... 59 13.3 Database ...... 60 13.3.1 Drilling Database ...... 60 13.3.2 Geological Interpretation ...... 61 13.4 Sample Statistics ...... 63 13.5 Composite Statistics ...... 64 13.6 Contact Analyses...... 65 13.7 Variography – Calculation and Adjustment of Variograms...... 66 13.8 Definition and Generation of the Block Model ...... 69 13.8.1 Geological Model ...... 69 13.8.2 Specific Gravity Model ...... 70 13.9 Kriging Plans and Resource Classification Criteria ...... 70 13.10 Grades Estimation Results ...... 72 13.11 Classification of Resources ...... 74 13.12 Resource Model Validation ...... 74 13.12.1 Visual Validation ...... 75 13.12.2 Statistic Validation ...... 76 13.12.3 Trend Analyses ...... 77 13.13 Reasonable Prospects for Eventual Economic Extraction ...... 79
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13.14 Other considerations and criteria used for the optimization process ...... 79 13.15 Mineral Resource Estimate ...... 80 13.16 Reporting Sensitivity ...... 81 13.17 General Considerations and Other Factors...... 83 14 Mining Method ...... 83 15 Recovery Methods...... 83 16 Project Infrastructure ...... 83 17 Adjacent Properties ...... 83 18 Other Relevant Data and Information...... 84 19 Conclusions and Recommendations ...... 84 20 References ...... 85
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List of Figures
Figure 0-1 - Marimaca Project Location ...... 4 Figure 3-1: - Marimaca Project Location ...... 19 Figure 3-2: - Marimaca Project Mining Property ...... 20 Figure 4-1 - Accessibility ...... 24 Figure 4-2- Key Infrastructure ...... 25 Figure 4-3 - Project location showing relevant physiographic elements. View toward NE...... 27 Figure 6-1- Regional Coastal Cordillera Geology (taken from Ramirez, 2007) ...... 30 Figure 6-2: Coastal Cordillera main Copper Deposits Location (taken from Ramirez, 2007) ...... 31 Figure 6-3- Marimaca Project Geology Summary ...... 33 Figure 6-4 - Feeders, showing hydrothermal alteration and halos of phyllic alteration ...... 36 Figure 6-5 - View of the extent of surface mineralization according to geochemistry and mineral subzones ...... 39 Figure 7-1 - Schematic Section through Marimaca Type Systems ...... 43 Figure 8-1 - Topographic Base and Orthorectification ...... 45 Figure 8-2 - Sampling of road cuts, basic elements of the structure and mineralization from FW to HW ...... 46 Figure 8-3: RPT-processed magnetometry. GeoMagDrone™ flight data ...... 47 Figure 9-1 – Collar locations on the Marimaca Properties ...... 50 Figure 9-2 - Examples of results of orientation measurements of structures by means of BHTV: (a) record of measurements with hole image; (b) stereograms and diagrams of roses ...... 51 Figure 10-1 - SRM Analysis (RC) ...... 54 Figure 10-2 - SRM Analysis (Core) ...... 54 Figure 10-3 - Original vs Check Samples (RC) ...... 55 Figure 10-4 - Original vs Check Samples (RC) ...... 55 Figure 10-5: Original vs PUD Samples (RC) ...... 56 Figure 10-6: - Original vs PUD Samples (Core) ...... 56 Figure 13-1: Geological Interpretation, Section NW 300 viewed to SW) ...... 61 Figure 13-2- Key estimation domains of Marimaca ...... 62 Figure 13-3: Brochantite - Chrysocolla Contact, CuT ...... 65 Figure 13-4: Brochantite - Wad Contact, CuT ...... 65 Figure 13-5: Chrysocolla - Wad Contact, CuT ...... 66 Figure 13-6: Correlogram CuT - Brochantite & Chrysocolla - Hz ...... 68 Figure 13-7: Correlogram CuT - Brochantite & Chrysocolla – Hz – Az=90º - VT 40º ...... 68 Figure 13-8: Correlogram CuT - Brochantite & Chrysocolla – Az = 90º - VT -50º ...... 68 Figure 13-9: Solids - Blocks and Samples - Section NW 300 view to SW ...... 70 Figure 13-10: Log-Probability Plot CuT – Brochantite...... 72 Figure 13-11: Visual Revision of the Model of CuT – Section NE 300 ...... 75 Figure 13-12: Visual Revision of the Model of CuT – Section NE 500 ...... 75 Figure 13-13: Visual Revision of the Model of CuT – Plan view 950 ...... 76 Figure 13-14: Trend Analysis – Brochantite – EW Direction ...... 77 Figure 13-15: Trend Analysis – Brochantite – NS Direction ...... 78 Figure 13-16: Trend Analysis – Brochantite – Elevation ...... 78 Figure 13-17 - Isometric view of the generated Whittle pit and the block model ...... 81
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List of Tables
Table 0-1: Consolidated Mineral Resource Statement, Marimaca, NCL Consulting (January 2017). 9 Table 0-2 - Whittle Input Data and Results ...... 9 Table 1-1 - Responsibility of Report Section ...... 17 Table 1-2: Qualified Person and professionals’ involvement ...... 18 Table 3-1: - List of Concessions in the Surroundings of the Marimaca Project Area ...... 21 Table 9-1: - Summary of Drilling Activities at Marimaca ...... 49 Table 13-1: Database General Information...... 60 Table 13-2: Mineral Zone Codes ...... 61 Table 13-3: Sample Statistic for CuT...... 63 Table 13-4: Sample Statistic, CuS ...... 63 Table 13-5: Sample Statistic for CuT, per Rock Type...... 64 Table 13-6: Sample Statistic for CuS, per Rock Type...... 64 Table 13-7: Types of Contact ...... 66 Table 13-8: Correlograms Preferential Directions ...... 67 Table 13-9: Correlograms, Adjusted Models CuT ...... 67 Table 13-10: Correlograms Adjusted Models CuS ...... 67 Table 13-11: Definition of the Block Model...... 69 Table 13-12: Total Coded Blocks ...... 69 Table 13-13: Specific Gravity per Unit ...... 70 Table 13-14: Kriging Plan Parameters ...... 71 Table 13-15: D85 per Direction and Population (m) ...... 71 Table 13-16: Outliers Limits...... 72 Table 13-17: Estimation Results; Cut and CuS ...... 73 Table 13-18: Kriging Passes and Resource Classification ...... 74 Table 13-19: Statistic Comparison, Blocks vs Composites – CuT ...... 76 Table 13-20: Statistic Comparison, Blocks vs Composites – CuS ...... 77 Table 13-21: Technical – Economical Parameters for Pit Optimization ...... 79 Table 13-22: Consolidated Mineral Resource Statement, Marimaca, NCL Consulting (January 2017)...... 80 Table 13-23: Mineral Resource Estimate for the Marimaca Deposit based on a cutoff grade of 0.20% CuT. January 2017, Luis Oviedo, P. Geo...... 80 Table 13-24: Sensitivity of the mineral resource to changes in CuT cut-off grade (base case cutoff) ...... 82 Table 13-25: Sensitivity of the mineral resource to changes in metal price assumption (US$2.70/lb Cu) ...... 82
ANNEX 1 Lawyers Land Tenure Letter………………………………………………….………………...86 List of Mining and Exploration Concessions ...... 90 Mining and Surface Rights Maps…………………………………………………………...….91
ANNEX 2 MCAL splitting protocols, recovery and sample collection protocols ………………………93
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1 Introduction and Terms of Reference
The Marimaca Project is located near Antofagasta in the Antofagasta Province, Region II of Chile. Coro Mining Corp. (Coro) is a British Columbia company incorporated under the Business Corporations Act of B.C., on September 22, 2004, with a registered office at Suite 1280, 625 Howe Street, Vancouver, British Columbia, Canada, V6C 2T6.
Marimaca is a copper oxide open pit project. Coro’s major shareholder is Greenstone Resources (55.9% of Coro), a private equity group investing in companies with small to medium size projects. Coro is a Canadian public company listed on the Toronto Stock Exchange (symbol COP) which as a result, generates the requirement for Coro to file a technical report to support the disclosure of Mineral Resource memorandum to raise capital to fund the Project.
The Marimaca 1-23 exploitation concessions are owned 100% by Sociedad Contractual Minera Newco Marimaca (SCMNM), whose shareholders are various members of the Carrizo Echanes family of Antofagasta. On November 16th, 2015, all the shareholders signed an Option Agreement with Minera Cielo Azul Limitada (MCAL), a 100% owned subsidiary of Coro, whereby MCAL has the option to acquire up to 75% of the shares of SCMNM and thereby, up to 75% of the Marimaca 1-23 concessions, via a combination of cash payments and earn in.
In 2016, Coro retained the services of NCL Ingenieria y Construccion SpA (NCL) to visit the Coro project and compile a technical report pursuant to National Instrument 43-101 Standards of Disclosure for Mineral Projects and Form 43-101.
This technical report summarizes the technical information that is relevant to support the estimation of Mineral Resources for Marimaca. This technical report is based on an inspection of the property by a team of qualified persons, as this term is defined in National Instrument 43-101, conducted on December 6 and 7, 2016, a review of technical information made available by Coro in electronic format, and discussions with technical personnel. The qualified persons have reviewed such technical information and determined it to be adequate for the purposes of this report. The authors do not disclaim any responsibility for this information.
1.1 Terms of Reference
The scope of work is defined in an engagement letter executed between Coro and NCL. The scope involves mobilizing a team of qualified persons to visit the subject mineral assets to review the technical information relevant to support Mineral Resources estimate. The objective is to provide estimation about the Mineral Resource for Marimaca as of January, 2017, and to compile a technical report pursuant to National Instrument 43-101 to support the disclosure of Mineral Resource by NCL. Responsibilities for each report section are listed in Table 1-1.
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Table 1-1 - Responsibility of Report Section
1.2 Qualification of NCL
NCL includes more than 40 professionals, offering expertise in a wide range of resource estimation and engineering disciplines. The independence of the NCL is ensured by the fact that it holds no equity in any project it investigates and that its ownership rests solely with its staff. These facts allow NCL to provide its clients with conflict-free and objective recommendations. NCL has proven assessments of Mineral Resources, project evaluations and audits, technical reports and autonomous feasibility evaluations to bankable standards on behalf of exploration and mining companies, and financial institutions worldwide. Through its work with a large number of major international mining companies, NCL has established a reputation for providing valuable consultancy services to the global mining industry.
The technical report was compiled by a group of professionals from the NCL Santiago offices. In accordance with National Instrument 43-101 guidelines, qualified persons visited the Marimaca project during December 2016 as shown in Table 1-2.
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Table 1-2: Qualified Person and professionals’ involvement
Company Qualified Person P. Engineer Site Visit Responsibility Overall NCL Luis Oviedo December 2016 responsibility on
behalf of NCL NCL Ricardo Palma December 2016 NCL Cristina Gomez NCL Miguel Vera
1.3 Basis of Technical Report
This technical report is based on information made available to NCL by Coro in electronic files and information collected during the site and office visits. The authors have no reason to doubt the reliability of the information provided by Coro. Other information was obtained from the public domain. This report is based on the following sources of information:
Discussions with Coro, Marimaca, personnel; Site visit to Marimaca conducted in December 2016; Information posted by Coro in an Intralinks; and Additional information from public domain sources.
The qualified persons have reviewed such technical information and do not disclaim any responsibility for the information provided and reviewed.
1.4 Declaration
NCL’s opinion contained herein and effective February 2017 is based on information collected by NCL throughout the course of NCL’s investigation. The information in turn reflects various technical and economic conditions at the time of writing the report. Given the nature of the mining business, these conditions can change significantly over relatively short periods of time. Consequently, actual results may be significantly more or less favourable.
This report may include technical information that requires subsequent calculations to derive subtotals, totals, and weighted averages. Such calculations inherently involve a degree of rounding and consequently introduce a margin of error. Where these occur, NCL does not consider them to be material.
NCL is not an insider, associate or an affiliate of Coro. The results of the report by NCL are not dependent on any prior agreements concerning the conclusions to be reached, nor are there any undisclosed understandings concerning any future business dealings.
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1.5 Units and Currency Definitions
All units in this report are metric, unless specified explicitly in the text. Currency used is dollars of the United States of America.
2 Reliance on Other Experts
NCL has not performed an independent verification of the land titles and tenures of this report. NCL did not verify the legality of any underlying agreements that may exist concerning the permits or other agreements between third parties, but has relied on the information provided by the legal advisors of Coro, Bofill Mir and Alvarez Jana Abogados, (Av. Andrés Bello 2711, piso 8, Las Condes, Santiago, Chile), in an opinion letter sent to Coro on January 2017. This letter is attached as Appendix 1, regarding the ownership status of the Marimaca properties.
Sergio Rivera, Vice President of Exploration, Coro Mining Corp, a geologist with more than 36 years of experience and a member of the Colegio de Geologos de Chile, Society of Economic Geologist and of the Instituto de Ingenieros de Minas de Chile, was responsible for the site visit, the design and execution of the exploration program and some chapters of this report. He is a Qualified Person for the purposes of NI 43-101 instrument.
3 Property Description and Location
The Marimaca Project and surrounding tenements are located in Chile’s Antofagasta Province, Region II, approximately 45 kilometres north of the city of Antofagasta and approximately 1,250 kilometres north of Santiago. The properties are connected to the well-maintained Chilean road system (Figure 3-1). The assets are located at approximately UTM 374820.00 m E and 7435132.00 m S.
Figure 3-1: - Marimaca Project Location
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3.1 Mineral Tenure and Earn In Agreement
The Marimaca 1-23 concession (Figure 3-2) comprised 23 claims of 5 hectares each, for a total of 115 hectares. It is listed in the national mining claims register with the number 02203-0273-3 and is located in the Region and Province of Antofagasta, in the Sierra Naguayán, Commune of Mejillones.
According to its file, it was surveyed in 1981 and registered under the file F 0234, Number 0073 of 1981. According to the Chilean mining legislation, the rights granted to the concession holder do not lapse or expire, provided that the annual claim fees are paid annually.
The concession is in good standing, with the payment of its annual claim fees made up to and including 2016, without interruption. During the term of the Agreement MCAL is obligated to maintain the property in good standing and to pay the annual claim fees, the next of which is due in March 2017. Inspection of the online government mining claims map (http: / / /catastro.sernageomin.cl/) confirms that the Marimaca concession is in good standing, with no third superposition’s of claims, except those placed by MCAL to protect the wider Marimaca area. See Figure 3-2 and Table 3-1.
Figure 3-2: - Marimaca Project Mining Property
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Table 3-1: - List of Concessions in the Surroundings of the Marimaca Project Area PROYECTO MARIMACA MINING CONCESSIONS MINERA CIELO AZUL LTDA Exploitation concesions Concesión Presentación Juzgado Rol Nº Inscripción Fjs Nº Conservador Situación
Miranda II 1/225 08-ago-16 1º Antofagasta V-526 22-ago-16 4712 2840 Antofagasta En trámite Miranda IV 1/150 08-ago-16 2º Antofagasta V-580 22-ago-16 4714 2842 Antofagasta En trámite Miranda III 1/150 08-ago-16 3º Antofagasta V-544 22-ago-16 4713 2841 Antofagasta En trámite Miranda I 1/210 08-ago-16 4º Antofagasta V-567 22-ago-16 4711 2839 Antofagasta En trámite
Exploration Concessions Concesión Presentación Juzgado Rol Nº Inscripción Fjs Nº Conservador Situación Miranda 19 08-ago-16 1º Antofagasta V-524 22-ago-16 4716 2844 Antofagasta En trámite Miranda 22 08-ago-16 1º Antofagasta V-525 22-ago-16 4719 2847 Antofagasta En trámite Chacaya 16 08-ago-16 2º Antofagasta V-578 22-ago-16 4722 2850 Antofagasta En trámite Miranda 20 08-ago-16 2º Antofagasta V-579 22-ago-16 4717 2845 Antofagasta En trámite Chacaya 15 08-ago-16 3º Antofagasta V-542 22-ago-16 4721 2849 Antofagasta En trámite Miranda 23 08-ago-16 3º Antofagasta V-543 22-ago-16 4720 2848 Antofagasta En trámite Miranda 18 08-ago-16 4º Antofagasta V-565 22-ago-16 4715 2843 Antofagasta En trámite Miranda 21 08-ago-16 4º Antofagasta V-566 22-ago-16 4718 2846 Antofagasta En trámite Miranda 2 15-jun-16 1º Antofagasta V-407-2016 01-jul-16 3756 2226 Antofagasta En trámite Miranda 6 15-jun-16 1º Antofagasta V-408-2016 01-jul-16 3764 2230 Antofagasta En trámite Miranda 11 15-jun-16 1º Antofagasta V-409-2016 01-jul-16 3774 2235 Antofagasta En trámite Miranda 15 15-jun-16 1º Antofagasta V-410-2016 01-jul-16 3782 2239 Antofagasta En trámite Miranda 4 15-jun-16 2º Antofagasta V-458-2016 01-jul-16 3760 2228 Antofagasta En trámite Miranda 8 15-jun-16 2º Antofagasta V-459-2016 01-jul-16 3768 2232 Antofagasta En trámite Miranda 12 15-jun-16 2º Antofagasta V-460-2016 01-jul-16 3776 2236 Antofagasta En trámite Miranda 16 15-jun-16 2º Antofagasta V-461-2016 01-jul-16 3784 2240 Antofagasta En trámite Miranda 3 15-jun-16 3º Antofagasta V-420-2016 01-jul-16 3758 2227 Antofagasta En trámite Miranda 7 15-jun-16 3º Antofagasta V-421-2016 01-jul-16 3766 2231 Antofagasta En trámite Miranda 10 15-jun-16 3º Antofagasta V-422-2016 01-jul-16 3772 2234 Antofagasta En trámite Miranda 14 15-jun-16 3º Antofagasta V-423-2016 01-jul-16 3780 2238 Antofagasta En trámite Miranda 1 15-jun-16 4º Antofagasta V-446-2016 01-jul-16 3754 2225 Antofagasta En trámite Miranda 5 15-jun-16 4º Antofagasta V-447-2016 01-jul-16 3762 2229 Antofagasta En trámite Miranda 9 15-jun-16 4º Antofagasta V-448-2016 01-jul-16 3770 2233 Antofagasta En trámite Miranda 13 15-jun-16 4º Antofagasta V-449-2016 01-jul-16 3778 2237 Antofagasta En trámite Miranda 17 15-jun-16 4º Antofagasta V-450-2016 01-jul-16 3786 2241 Antofagasta En trámite Naguayan 1 24-nov-14 2º Antofagasta V-1388 06-ago-15 4374 2514 Antofagasta Constituída Naguayan 2 24-nov-14 2º Antofagasta V-1389 06-ago-15 4376 2515 Antofagasta Constituída Naguayan 3 24-nov-14 2º Antofagasta V-1390 06-ago-15 4379 2516 Antofagasta Constituída Naguayan 5 24-nov-14 2º Antofagasta V-1392 06-ago-15 4384 2518 Antofagasta Constituída Naguayan 6 24-nov-14 2º Antofagasta V-1393 06-ago-15 4386 2519 Antofagasta Constituída Naguayan 9 24-nov-14 2º Antofagasta V-1396 06-ago-15 4392 2522 Antofagasta Constituída Naguayan 10 24-nov-14 2º Antofagasta V-1397 06-ago-15 4394 2523 Antofagasta Constituída Naguayan 11 24-nov-14 2º Antofagasta V-1398 06-ago-15 4397 2524 Antofagasta Constituída Naguayan 12 24-nov-14 2º Antofagasta V-1399 06-ago-15 4399 2525 Antofagasta Constituída Naguayan 13 24-nov-14 2º Antofagasta V-1400 06-ago-15 4401 2526 Antofagasta Constituída Naguayan 14 24-nov-14 2º Antofagasta V-1401 06-ago-15 4403 2527 Antofagasta Constituída Chacaya 1 24-nov-14 2º Antofagasta V-1402 06-ago-15 4346 2500 Antofagasta Constituída Chacaya 2 24-nov-14 2º Antofagasta V-1403 06-ago-15 4348 2501 Antofagasta Constituída Chacaya 3 24-nov-14 2º Antofagasta V-1404 06-ago-15 4350 2502 Antofagasta Constituída Chacaya 4 24-nov-14 2º Antofagasta V-1405 06-ago-15 4352 2503 Antofagasta Constituída Chacaya 5 24-nov-14 2º Antofagasta V-1406 06-ago-15 4354 2504 Antofagasta Constituída Chacaya 6 24-nov-14 2º Antofagasta V-1407 06-ago-15 4356 2505 Antofagasta Constituída Chacaya 7 24-nov-14 2º Antofagasta V-1408 06-ago-15 4358 2506 Antofagasta Constituída Chacaya 8 24-nov-14 2º Antofagasta V-1409 06-ago-15 4360 2507 Antofagasta Constituída Chacaya 9 24-nov-14 2º Antofagasta V-1410 06-ago-15 4362 2508 Antofagasta Constituída Chacaya 10 24-nov-14 2º Antofagasta V-1411 06-ago-15 4364 2509 Antofagasta Constituída Chacaya 11 24-nov-14 2º Antofagasta V-1412 06-ago-15 4366 2510 Antofagasta Constituída Chacaya 12 24-nov-14 2º Antofagasta V-1413 06-ago-15 4368 2511 Antofagasta Constituída Chacaya 13 24-nov-14 2º Antofagasta V-1414 06-ago-15 4370 2512 Antofagasta Constituída Chacaya 14 24-nov-14 2º Antofagasta V-1415 06-ago-15 4372 2513 Antofagasta Constituída Naguayan 4 26-nov-14 2º Antofagasta V-1420 06-ago-15 4382 2517 Antofagasta Constituída Naguayan 7 26-nov-14 2º Antofagasta V-1421 06-ago-15 4388 2520 Antofagasta Constituída Naguayan 8 26-nov-14 2º Antofagasta V-1422 06-ago-15 4390 2521 Antofagasta Constituída
Agreement Terms
The Marimaca 1-23 exploitation concessions are owned 100% by Sociedad Contractual Minera Newco Marimaca (SCMNM), whose shareholders are various members of the Carrizo Echanes family of Antofagasta (Carrizos).
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MCAL can earn a 51% interest in SCMNM on payment of $125,000 together with completion of an NI 43-101 compliant resource estimate and an engineering study that demonstrates the technical and economic feasibility of producing a minimum of 1,500tpy Cu as cathode by August 6th 2018 at MCAL's cost.
An additional 24% interest in SCMNM can be earned by MCAL on obtaining financing for the project construction.
The Carrizos interest will comprise a 15% interest free carried to commencement of commercial production and a 10% participating interest subject to dilution. The owners at their election may request MCAL to loan them the equity portion corresponding to their 10% interest, if any. This loan plus applicable interest would be recoverable by MCAL from 100% of the project's free cash flow after debt repayments.
Coro has a first right of refusal over Carrizos interest.
The Agreement establishes an area of influence within which the Carrizo family, but not MCAL, is required to deliver to SCMNM any new concessions acquired or staked by them for the benefit of SCMNM. MCAL has staked, and is achieving, exploration and exploitation claims in its own right to cover prospective ground, and areas for dumps, pads and mining installations.
Based on the current information, the mineralization is largely contained within the confines of the Marimaca 1-23 concession, but may extend to adjacent ground held by third parties. The Chilean mining regulations provide for the extraction of a concession holder, with the granting of a access through any possible adjoining property.
The Marimaca 1-23 concession is not subject to any royalties, contracts or liens of any kind.
3.2 Mineral Rights in Chile
Excluding liquid or gaseous hydrocarbons and lithium, the mining concessioner can exploit and benefit from all other minerals within the boundaries of the relevant concessions, without additional administrative concessions or operation agreements.
In the event that the surface property owner does not voluntarily agree to the granting of the easement, the titleholder of the mining concession may request such easement before the Courts of Justice, which shall grant the same upon determination of due compensation for losses.
3.3 Surface Rights
SCMNM has no existing surface rights over the area covered by the concession Marimaca 1 to 23. It has no access prohibitions. The mere fact of being a mining concessionaire gives
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the right to dispose of the surface for the mining works. MCAL has not applied for surface rights in the area, with SCMNM being the preferential right.
3.4 Water Rights
The area lacks of water resources in the form of surface flows and no exploration for underground resources has been carried out on or near the property. The deeper mining workings, of about 100 m and the drill holes of MCAL that reached up to 350 m of depth did not encounter water. Consequently there are no water rights that could affect mining development in the area.
3.5 Environmental Liabilities and Permits
The magnitude or intervention of the mining works executed in the property Marimaca 1 to 23 does not qualify to be submitted to the environmental norm. There are no permits or commitments in force resulting from the application of Chilean environmental regulations. The work of small miners is regulated by the mining safety regulations, whose implementation is monitored by the National Service of Geology and Mining (SERNAGEOMIN).
For purposes of future work carried out on the property, it will be the responsibility of the owner to evaluate the respective pertinence and to apply for any permissions from the authorities. In the immediate future, exploration work and drilling projects, do not require environmental permits due to the low impact that they have on the environmental conditions of the area.
The location of Marimaca property 1 to 23 does not indicate conditions of risk that have affected or may affect future exploration and mining developments. There are no climatic or other hazards that need to be specially considered.
An environmental baseline study has been completed for the Marimaca copper leach development-stage project. The work was carried out by an independent consultant, BORDOLI & Consultores Asociados EIRL of Antofagasta, Chile between November 2016 and January 2017. The consultant concluded that there were no material environmental issues that would impede the development of the Marimaca project, and the information gathered will form part of the feasibility study for the project that is in progress.
4 Accessibility, Climate, Infrastructure and Physiography
The project is located in the Antofagasta Province, Region II of northern Chile at an elevation of 800 to 1.100 metres above sea level and approximately 45 kilometres north of the City of Antofagasta and 25 kilometres east of the port of Mejillones, see Figure 4-1.
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4.1 Accessibility
Marimaca is accessible by maintained dirt roads, one coming from the Cerro Moreno Airport and the other branching off of Route Antofagasta -Tocopilla. Antofagasta regional airport is serviced by regional and international flights from Santiago and other destinations on a daily basis. The regional Cerro Moreno airport is located 44 Km to the Project. Antofagasta and Mejillones are strategically located on the coast through a well-maintained multi- lane highway. High voltage lines that transport energy from the power stations located in Mejillones to the interconnected system of the north are also close to the road.
Figure 4-1 - Accessibility
4.2 Local Resources and Infrastructure
Antofagasta and Mejillones are modern cities with all regular services, serving a combined population of approximately 570,000. Numerous mining-related businesses are located in the cities. Personnel employed by Coro mainly come from the Antofagasta region. Power lines and water desalination plants are at near distance of the property. See Figure 4-2 with the image of resources and infrastructure around the project.
There are 3 thermoelectric plants installed in Mejillones and power lines are located within 12km of the project.
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While Mejillones is an industrial port and most of the labour force is specialized in this type of jobs, Antofagasta has the largest labour force dedicated to mining in northern Chile. Their level of knowledge in the matter is high and participate both in the work of large and medium mining. The city is a “mining cluster", where research, education, technical training centers and the largest suppliers of equipment and services for mining in the country operate.
Figure 4-2- Key Infrastructure
4.3 Climate
The Project is located about 39 km north of the Tropic of Capricorn. The minimum temperatures vary between 10 to 15 ° C and the maximum temperatures between 20 to 29 ° C, while the average relative humidity oscillates between 67 to 70%. The climate is dry and the average annual rainfall is 2-3 mm as an annual average of 24 hours.
In the region, rainfall is very rare and decade’s events of rains, which can reach up to 12 to 30 mm in a few hours, can occur. In the Resource area, however, they have no major impact
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because they do not have high slope drainage from the coastal cliff, a feature that develops both to the south and north of the Mejillones Peninsula.
To the east extends the central depression zone, characterized by vast areas of low slope, the "pampas", where the weather conditions are extremely arid and with notable variations in temperature between day and night. These, in general, vary between 28º C (day) and 2 ° C (night).
4.4 Physiography
The Marimaca Project is located in the Cordillera de la Costa, a relevant physiographic unit in the northern territory of Chile. The project area is mountainous with a relief varying between 0 and 1,000 metres. Vegetation is minimal outside of inhabited valleys where irrigation and the “Camanchaca” sea mist that comes from the nearby ocean, support vegetation that is capable of withstanding the desert environment.
The Project is located in an active seismic zone. The sector is not limited to the west by the characteristic steep coastal cliff that can reach differences of average height of 700 m; whereas the Mejillones Peninsula, the cliff is moved about 37 km to the west, permitting the intermediate space to be occupied by a vast "pampa" (flat land) about 20 km wide (Figure 4- 2).
Controlled by faults of north-south to north-northeast orientation the relief of the area consists of mountain ranges that reach up to 1,500 meters above sea level (Cerro Naguayán) rising to the E on pampas of an average altitude of 700 m.o.s.l. The main one is the pampa that is aligned in the northeast direction bordering the Mititus Fault. It extends for more than 30 km and its width varies from 1 to 2 km along the course of the Quebrada Naguayán..
The drainage system of the Mejillones and Naguayán drains the area from east to west and south to north, respectively. They contribute the main gulch almost east-west in the northern part of the area, and tributaries from the Marimaca area in the northwest and the Quebrada Naguayán almost north-south.
The watershed divides two physiographic domains: to the west the topographic differences and steep drainage to the basin of Quebrada Mejillones, below 1,000 m.a.s.l; and to the east a morphology of gentle hills that descend to the east and form the eastern limit of the intermediate depression where the relief ascends over 1,000 m.a.s.l. Figure 4-3 shows these aspects with vertical exaggeration (3 in Google Earth):
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Figure 4-3 - Project location showing relevant physiographic elements. View toward NE.
5 History
Project site and district’s exploration programs have been active since the Marimaca deposit discovery in 2016. There is no verifiable history of mining prior to Marimaca 1 to 23.
The area was known since the end of the 19th century as “Mineral de Naguayán”. The Mining Bulletin of 1928 (Kuntz, 1928) reports that several mines (Atahualpa, Leonor, Mala Noche) existed but at that time they were inactive.
More detailed information in 1962 recognized the granodiorite intrusions by "dark dikes" oriented north-south, inclined to the east, stated that the copper mineralization occurs within the same system of parallel planes and commented on the extraction of small quantities of direct smelting ores with very high copper grade (5 tonnes per week between 17% and 50% Cu). Several of the deeper underground adits have reached sulphides described as chalcopyrite, bornite and chalcocite.
Between the 70's and 90's there are only reports of reviews by geologists of the government’s Institute of Geological Investigations (IIG) and ENAMI (Empresa Nacional de Minería).
A study by ENAMI (Ilabaca, 2004), which included some short bore holes; refers to the Marimaca 1 to 4 and 10 to 23 concessions in the central-west part of the property. The description mentioned copper oxide mineralization in north-south oriented fractures and an estimated resource potential of 200,000t at an average grade of 1.2% CuT.
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The owners commissioned a geological study in 2003 (Alvarado, 2003) who described and sampled a 10° oriented narrow veined system. The estimation of a potential resource resulted in 566,000t at an average grade 2.8% Cu. Alvarado recognized an intense fracturing and the three key directions of fractures and veins, azimuth 10 °, 40 ° and 270 °.
At least a couple of companies reviewed the property in the early 2000's, mostly juniors, but none of them reported substantial mining potential. In May 2008, Minera Rayrock geologists described the control of mineralization by a "pseudo-stratification" or a "pseudo-stratified intrusive". The potential for copper oxide mineralization was estimated at 21 Mt of average grade 0.8% Cu. After this memorandum (Hinostroza and Medina, 2008) there are no other reports regarding the mining activities of the area.
In the meantime, new tenants developed small scale underground workings and others with a higher degree of mechanization exploited the properties. Most of these ores were sold to Michilla, ENAMI and Rayrock processing plants.
Before the exploration by MCAL, the property had only been exploited by small miners, generating small pits whose dimensions do not exceed 20 by 15 m and depths of up to 20 m. Underground workings reach extensions of no more than 100 m. No organized exploration work was carried out to discover and evaluate a mining resource with potential interest for mid-level operations. MCAL was the first company to access the property with the idea of explore an open pit, leachable deposit.
The area in general did not attract the interest of medium-sized mining companies that thrived in the vicinity (within 60km) between the early 80s and early 2000s. The lack of interest in the Naguayán sector is due to the fact that the area was considered with no potential to become a major producer, even when ore from Marimaca, was sold for a long time to Michilla and Rayrock (Ivan plant).
6 Geological Setting and Mineralization 6.1 Regional Geology
Geological setting is largely based on the Mejillones and Peninsula of Mejillones 1: 100,000 geology charts by SERNAGEOMIN (Cortes, et al, 2007). This is complemented by structural and petroleum studies carried out in the Mejillones Peninsula (Lucassen et al., 2000, Herve et al., 2007, Casquet et al., 2014) and the Naguayán and Fortuna areas mapped by Cortes et al., 2007. Economic geology studies of have been carried out by geology graduates of the Universidad Católica del Norte (Vergara, 1985; Veliz, 1994; Gonzales, 2002).
The oldest exposed rocks are late Palaeozoic and Triassic age and correlate with metasedimentary and intermediate intrusions basement rock of the Coastal Cordillera. The area is characterized by intrusive bodies from early Jurassic to lower Cretaceous. The intrusive units correspond to diorites, monzonites and monzodiorites with variations to
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gabbro and, to a lesser extent, to quartz monzonites and metadiorites, dated 155-154 Ma. This last unit hosts the mineralization in Marimaca .The mines of the Naguayán District are located along the western contact (see Figure 6-1). The other important unit is the volcanoclastic rocks of La Negra formation which extend to the north, south and east of the area. Also below the pampa to the west where they are partly covered by conglomerates and red sandstones of the Coloso Formation, assigned to the Cretaceous.
The Tertiary units correspond to marine sediments, which mark the paleo-coastal lines in the Mejillones Peninsula and also to the south. Closer to the Project area, there are important levels of alluvial gravels, interbedded with somewhat reworked ash levels. These are dated from 12 to 20 Ma, coinciding with the catastrophic eruptions of ignimbrites that make up much of the Altiplano and are located about 200 km east (Cortes et al, 2007).
An andesitic dyke swarm, with variations to diorites or even more acidic, that follow the structural control north south to northeast, are observed throughout the area and are also exposed in the sector of the Project. Their ages would be in the 146 to 147 Ma range (Gonzales, 1996; Cortes, et al, 2007).
The project is located to the northwest of the Atacama Fault System Zone (ZFA), which extends over hundred kilometres along the Chilean coast. The Antofagasta fault zone is a subduction-related arc-parallel strike-slip Fault System that has been active at least since the Jurassic, whose main trace has a curvature towards the west, as a disturbance of the north-south general strike. The product of this curvature (Figure 6-1) predominate the northeast trend. Parallel to this, other fault systems of regional importance neighboring the project area control the morphology of the peninsula. In the Sierra Fortuna are exposed milonites and sheared rocks cut by andesitic dykes from north to south to northeast. The studies have shown that movements are essentially strike parallel, originated by Jurassic- Cretaceous Transtensional events (Scheuber and Andriessen, 1992; Gonzales, et al., 2006; Cortes, et al, 2007).
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Figure 6-1- Regional Coastal Cordillera Geology (taken from Ramirez, 2007)
A shear zone of at least 3 km wide and extending for more than 15 km, north-south to north- northeast oriented and inclined between 40 and 60° to the east and southeast, is a very important feature, both in the geological setting and in the mineralization controls in Marimaca and surroundings. In this report this zone will be denominated Naguayan Shear Zone (ZFCN). The rock affected by the shear zone is the Naguayán intrusive and its extension, and it’s easily observable in the field. The andesitic or more acidic Jurassic dyke swarms follow this fracturing zone, generating systems of parallel dykes and sills, following the inclination to the east of the fracture planes.
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6.2 Metallogenic Setting
The area comprises “manto-type” copper deposits hosted in volcanites of the La Negra Formation, as well as some IOCG-affiliated vein districts, hosted by Jurassic intrusives (Espinoza et al., 1997; Maksaev and Zentilli, 2002). Towards the eastern border there are some porphyry-type copper systems of late Jurassic to lower Cretaceous age (Figure 6-2).
Figure 6-2: Coastal Cordillera main Copper Deposits Location (taken from Ramirez, 2007)
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The “manto-type” copper deposits typically correspond to sulfides and copper oxides hosted in volcanic sequences, especially in the brecciated and vesicular upper portions of lava flows. The variations are due to the relative predominance of structural control by local fault systems.
The size of the individual manto deposits varies between 15 and 40 Mt of grade near 1% CuT. Exceptionally, Mantos Blancos has resources for more than 200 Mt of grade near 1% CuT. The by-product in concentration of minerals is Ag, which can reach grade of 10 to 20 g/tAg. Their location and good metallurgical and mining conditions have made these types of deposits and their districts attractive for mining since the 1980's (Michilla, Mantos de la Luna, Buena Esperanza, Ivan).
Vein deposits, with chalcopyrite-bornite and presence of magnetite, form districts hosted in intrusive rocks, following east-west structural directions, perpendicular to the ZFA-dominated system. They are related to the late Jurassic intrusive and have calco-sodic alteration halos. Iron vein deposits exist in the area of Naguayán (Vergara, 1985, Venegas and Vergara, 1985). At present, the district is known as Cáprica and was exploited in the years 2010 to 2014. These deposits are very similar to the deposits of Fe of the III Region.
The copper porphyries of Jurassic upper and lower Cretaceous are located on the eastern edge of the Cordillera de la Costa (Figure 6-2). These systems form clusters with low-grade oxidized copper mineralization. None of these porphyries reaches the resource levels of the large Tertiary systems located further east.
A key aspect of regional metalogenesis is the post-Cretaceous geomorphological and climatic evolution that has allowed the generation of deep columns of supergene enrichment and oxidation. In Michilla the oxidized and mixed minerals extend up to 200 to 250 m depth, in Mantos Blancos the thickness of the oxides is of 100 to 150 m and in Marimaca of more than 200 m. Despite the deficiency of pyrite in the systems, chalcopyrite and scarce pyrite (equal to or less than 1% by volume) have been sufficient to give the required acid to leach the sulphides and form the secondary enrichment zones and then continue the process of leaching, to produce oxides or to oxidize primary sulphides generating in-situ chalcocite/covellite. It is estimated that these phenomena have had a long duration since the rise and contraction of the Jurassic-Cretaceous and especially since the Tertiary.
It is estimated that the rise of the Cordillera de la Costa was generated in the Lower Tertiary, changing the climate due to the development of the Humboldt cold current (Bissig and Riquelme, 2010). In this way the morphological evolution and the climatic control of the rains has allowed the supergene zones to be generated and preserved from the Cretaceous.
6.3 Local Geology
The Marimaca Project is located in the Naguayán District in the Mesozoic Coastal Copper Belt, where Mantos Blancos ~500 million tonnes and Ivan ~50 million tonnes, illustrate the
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range of size and morphologies of copper deposits that occur. See Figure 6-3. They are sited in a variety of host rocks and have differing morphologies; they have a common Cu-Ag primary mineralogy zoned from bornite outwards to chalcopyrite and pyrite, with deep oxidation and secondary enrichment.
The Marimaca property contains a number of NNE-SSW trending, ~60º E dipping, broad shear zones, cross cut by later NE-SW oriented sub vertical feeder structures, all hosted by Jurassic age intrusive rocks. The intersection of these structures has produced wide NW-SE oriented highly fractured parallel zones of eastward dipping mineralization, that have been exploited from a series of open cuts and small underground workings by small miners. Surface mapping and drilling has shown that the mineralization is comprised of multiple, thick, high grade structures bordered by lower grade halos.
Figure 6-3- Marimaca Project Geology Summary
6.4 Property Geology
6.4.1 Lithology
Marimaca, is hosted in Monzonites (MON) and Monzodiorites (MZD) of equigranular texture and coarse grain, this lithology is cut by dykes mainly of andesitic composition and variations to aplitic, diorite and rhyolite (AND, APL, DIO, Figure 6-4).
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The package exhibits remarkable fracturing by centimetric subparallel structural planes, extending throughout the property. The intrusive shows a "pseudo-stratification" product of the fracturing, which is also reflected in the control of the dykes system (also sub-parallel). These are described as sills. This structural system is named as Banded Rock Structural Zone (ZEB) or Shear Zone (ZDC) and forms an integral part with the Naguayán Shear Fault Zone (ZFCN).
The Monzonites and Monzodiorites contain plagioclase, amphibole and less pyroxene, with aggregates of feldspar and quartz in the more acidic variants (Figure 6-5). In the property, local textural variations have been observed to more porphyritic or fine grained. Different degrees of alteration can influence rock type classification towards more acidic variants (eg granodiorites). Considering the different degrees of pervasiveness of alteration, there are no significant textural changes, except for a subtle increase in grain size (Figure 6-4).
Figure 6-4- Main Rock Types (a) Wall Rock Monzonite (b) Andesitic Dyke
The andesitic dykes (sills) correspond to tabular bodies of hundreds of meters in length, parallel to the structural banding, with widths between 2 to 4 m up to 50 m long, aligned for several kilometers, oriented north to north-northeast and inclined between 40º and 70° to the
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east. The widths vary from 30-50 cm to 5-10 m, being 1-2 m on average. The textures are of fine grain, equigranular to slightly porphyritic of plagioclase and hornblende. The study of thin sections under the microscope has shown that some dykes have quartz and feldspar but in an amount that is not enough to classify them as dacites. It is common for andesitic dykes to show vesicles, filled with quartz.
6.4.2 Structure
The development of the “Banded Structural Zone” (ZEB) or Shear Zone (ZDC) is the most important structural feature in the project area. The system of parallel planar centimetric structures is oriented north-south to north-east with dips to the east and controls the dykes system. These dykes are cut and displaced by a system of faults oriented 40° dipping to the southeast and by other faults, probably the youngest, striking-west to northwest (Figure 6-5).
Figure 6-5 - Parallel planar structures oriented north-south to north-east with east dips and dykes system
The ZEB or ZDC is the most ubiquitous structure of the project. Examining satellite imagery it stands out easily as a marked system of lineaments, which are organized following generally the north to north-northeast directions. This structural anomaly can be followed continuously for about 15 km long and 3 to 4 km wide, with a more persistent central portion of fracturing of 1 km wide. This is well exposed in the Marimaca area and in the Cerro Naguayán area (Figures 6-5 and 6-6).
Figure 6-6 - Banded Structural Zone (ZEB) or Cizalle Zone (ZDC)
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The average frequency of dykes, measured approximately in satellite images, is 40-50 m. In the Marimaca zone this frequency is reduced to 10 to 5 m spacing. Nevertheless it maintains the north-northeast general course, with some variations to the east and to north-east.
The sub-vertical northeast faults have been denominated "feeders", due to their direct relation with the copper oxide mineralization in the more shallow parts of the deposit. This relationship has not been proven with certainty in the drilling. These structures are faults, with 0,2 to 0,5 m of width of gouge and fracturing zones between 1 to 5 m persistent over 300 to 400 m. Eight of these structures have been exposed in the pit walls and in underground workings. A good part of old and more modern workings tried to follow these faults as guides to high grade oxide mineralization. Their nature is accentuated to the east, when reaching or breaching the hanging wall (HW) alteration / mineralization limit, showing halos of phyllic alteration. In addition there are high contents of limonite derived from oxidation of pyrite (Figure 6-8). Towards the central part, near the surface, their geometry as veins is not so evident, because the evidence has been obliterated by the intense and pervasive supergene alteration and the mineralization of copper oxides. In some diamond drilling, deeper sections have been observed and they look like vein-faults, with abundant copper mineralization.
Figure 6-4 - Feeders, showing hydrothermal alteration and halos of phyllic alteration
The interaction of the three systems of structures, in a very poorly reactive rock with the generation of open spaces capable of being used by the migration of fluids, has been considered as the key to understanding the geometry of the oxides bodies of Marimaca.
6.4.3 Alteration
The Marimaca alteration consists of metasomatism with very little evidence of destructive hydrothermal alteration (Carten, 1986; Putnis and John, 2010). The calco-sodic metasomatism is manifested by the replacement of mafics by actinolite, magnetite and of plagioclase by albite. Sometimes the occurrence of tourmaline and chlorite is quite common replacing mafics in the interstices. Epidote in some spots and veinlets is observed in the margins, outside the best mineralized zone. The Ca-Na metasomatism extends to a considerable distance from the mineralized body. However, in the property it is possible to
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observe the alteration associations that allow zoning in the hanging-wall (HW) and footwall (FW). The footwall alteration contains more actinolite and magnetite, with variable degrees of albitization, chlorite replacement. The hanging-wall alteration shows a more intense albitization and development of more hematite than magnetite, a relative increase of chloritization and the occurrence of disseminated pyrite whose surface oxidation leads to the development of a weak "leach cap" and a strong argillic alteration.
The zone between the HW and FW hosts the mineralization, the alteration is intense and consists of an increase in the replacement of albite-chlorite- (feldspar K) -actinolite- magnetite. The albitization is very intense and in cases it produces changes in texture by reducing the size of the grains and produce changes in the definition of rock types. This is a “belt” between 250 and 300 m thick, which can be followed in the north-northeast orientation with the average dip of the ZDC, near 50 ° to the east, and hosts most of the mineralization discovered at Marimaca. See Figure 6-9.
Figure 6-9 - Main Rock Types (a) Wall Rock Monzonite (b) Andesitic Dyke
The andesitic dykes also show alteration by Ca-Na metasomatism. The alteration is as intense as those that affect the MZD-MON, so that it appears that the dykes predate the alteration event related to the mineralization, which is not very evident in the zone of oxides.
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6.4.4 Mineralization
Marimaca is a copper mineralization closely related a parallel fracture of the ZDC. This control generates "stratiform" bodies’ defined in a purely geometric descriptive aspect without a genetic component involved (Figures 6-10a and 6-10b).
Figure 6-10 a and b - Views of stratiform mineralization and base boundaries of north south (b) view of stratiform mineralization and distribution of Rajos 1 and 2, looking NE
Copper oxides and sulphides occur not only in structural discontinuities, but also following transverse fracture patterns and some brecciated zones and as disseminations in the rock. Its nature is not fully concordant with the main structural control, however, its 3D geometric occurrence in zones of alteration-mineralization within a volume that has a foot wall and a hanging wall is very well defined.
The copper oxides start from the surface, as confirmed by mining workings, surface exposures, drill holes and surface geochemical samples (> 200 ppm Cu) for more than 700 x 300 m. The stratiform body of Cu oxides is oriented northwest. It measures 900 m long by 700 wide and extends in depth up to 400 m. Measured in the direction of the main control 10° / 50° the body reaches dimensions of 900 m wide, 900 m of extension in the dip direction and 300 m of real width, perpendicular to the fracturing (Figure 6-11). Deeper mineral areas of primary sulphides have not been considered for this work.
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Figure 6-5 - View of the extent of surface mineralization according to geochemistry and mineral subzones
The deposit consists of a zone of Cu oxides, underlain by remnants of a mixed zone, supergene sulfides and primary sulfides mixed with Cu oxides. Most of the body drilled to date is in oxides. In the oxides, some remains of Cu sulphides have been observed showing that the body was formed by a superimposed oxidation of primary sulphides.
The mineralization in the upper zone is of “green” and “black” copper oxides, which occur as disseminations, coatings, fracture filling and following the structural fabric of the intrusive country rock. The chief mineralogy is atacamite, brochantite and chrysocolla, together with malachite and other varieties of Cu sulfates.
The “black” copper oxides are mostly wad and also some tenorite, copper bearing limonites, and relicts of native Cu. They are usually observed surrounding the green oxides zones.
Based on the information of the mineralogy obtained from the logging, it is possible to establish mineral subzones within the copper oxide body, based on dominant oxides:
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chrysocolla, brochantite or wad. The chrysocolla and brochantite dominant subzones make up the zone of green oxides and the wad are the black oxides. Even though they are usually intercalated, the subzones show a broad zonation with chrysocolla dominant in the most superficial portion and those of brochantite in the deep central part of the body, close to relics of chalcocite and covellite. See Figure 6-12.
The wad subzone is located in the margins and extends several meters towards the edges of the body, characterized by low CuT and CuS grades (0.2 up to 0.5 %Cu).
The base of the oxides is a surface that has been interpreted as a "top of sulphide" and has been modeled in 3D, located at depths between 200 and 300 m. Its contour is irregular and the hills and valleys show the control of the structures.
Figure 6-12 - Mineral subzones within the body of oxides based on dominant oxides: chrysocolla, brochantite and wad
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The volumes with mixed mineralization are more continuous in the central-north part of the mineralized body and are recognized from 150 m depth. Under the central part, they have been interpreted as isolated bodies at depths of 300 m.
The secondary sulphide mineralization is quite restricted and consists of thin bodies with chalcocite, covellite that replace in variable grade, chalcopyrite. Nevertheless at least part of the covellite mineralization seems to be primary in origin.
The deepest drill holes have intercepted irregular columns of primary sulphides that consist of massive chalcopyrite, accompanied by scarce pyrite and magnetite. In some diamond drills the massive chalcopyrite follows the structural fabrics displaying different widths ranging from 10-15 cm to 30 cm. Also occurs in some breccia characterized by red fragments of country rock, magnetite and chalcopyrite cement. The breccias also follow the control of ZDC-type fracturing.
It is interpreted that the zones of primary sulphides must be the natural continuation of the oxide body following its stratiform geometry, which cannot be fully assured due to lack of deep enough drilling. However, one core of primary mineralization has been identified below the center of best Cu grade, located toward the center-east of the body. This has been intercepted by RC holes and the cuttings show massive chalcopyrite mineralization. On the other hand, the extension in the dip has been verified by the holes located towards the east end, which, in depth, show increases in the contents of Cu, in relation to the pyrite and chalcopyrite disseminations.
The pyrite contents are persistent but of very low abundance (1% or less in volume). In general they form a halo around the mineralized body. Several drill holes intersect disseminated and fracture filling pyrite mainly in the FW, towards the west of the body. The halo of pyrite is more intense towards the HW as evidenced by the intersections of the drills carried out in the east sector. Pyrite accompanies chalcopyrite in the Cu high primary zone.
The common gangue in the oxide zone is limonite, especially goethite-hematite with very little jarosite. The limonite is related to the feeders, denoting a supergene action following the subvertical fractures. Actinolite and chlorite are common gangue in the primary zone, rare in the superficial parts, due to intense supergene alteration. Fractures with calcite are more common in contacts with andesitic dykes. However, fine calcite, probably as product of albitization, is related to the copper mineralization. The superimposed alteration associated with the oxidation zone does not generate high amounts of clays that could negatively affect the proposed leaching process.
The mineralization of oxides is quite uniformly occupying the volume of fractured and altered rock. The existence of low-grade intercalations is a smaller amount and this is confirmed by the grades of Cu in drills. Low grades are related to intense fracturing and leaching, and to andesitic dykes. Nevertheless in their contacts, oxides and Cu usually increase. The continuity of the mineralization and the definition in subzones are considered to be in
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keeping with the data and the natural, structural and physicochemical controls of the mineralization. A schematic distribution of the mineralization and structural controls, in addition to the tentative positions of the FW and HW and the deep potential, is shown in the scheme of Figure 6-13.
Figure 6-13 - Scheme of mineralization and main controls over the block model
7 Deposit Types
The Marimaca copper deposit is located in an IOCG district of vein deposits (Venegas and Vergara, 1985). The district context, however, is combined with Fe bearing structures (Caprica) and the typical "manto-type" deposits in volcanic rocks (El Desesperado, Ivan). The IOCG type brings together a very broad spectrum of occurrences with genetic associations not yet resolved. Mineral occurrences in the Naguayán area can be considered as part of the variety. Common factors are the regional metamorphism / metasomatism enviroment, the Ca-Na alteration, the presence of magnetite and hematite, the dominant chalcopyrite sulphide and a low overall content of sulphides (Sillitoe, 2003; Richards and Mumin, 2013). Although the Au contents are low, the presence of Co, U, REE and Ag is unknown. The proportion of magnetite is rather low, without a significant content of Fe in the mineralization.
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In the coastal range, where manto (Cu-Ag, feldspar-chlorite-albite) and IOCG (Cu-Fe-Au, actinolite-albite-magnetite) vein type deposits have traditionally been found together, the mineralization discovered in Marimaca does not fit well in either type. Although its shape in purely geometrical sense is stratiform, its mineralized rock is an intrusive monzodioritc rock and so far no other copper mineral occurrences of this type have been identified. Without exception, all have form and genesis related with volcanic piles (Espinoza, et al, 1997). The mineralogy of the sulphides and alteration resemble IOCG systems; however the lack of Fe oxides and Au and the occurrence of hypogene chalcocite and covellite are not common in IOCG deposits (Richards and Mumin, 2013). These features appear to be more frequent in the “manto-type” deposits.
The variation from the FW-to-HW alteration has been reported in some manto deposits of the size of Mantos Blancos and El Soldado (Maksaev and Zentilli, 2002; Ramírez, 2007), but no cases are documented in the more typical IOCG (eg Manto Verde or Candelaria). In summary, the mode of occurrence in a peculiar fracturing system in intrusive rocks, highlights them as a type of deposit from which no analogies are known in Chile from recent literature. On the other hand, the alteration and mineralization put it closer to the manto type, such as El Soldado or Mantos Blancos. . Finally, a factor that also makes the occurrence of Marimaca different is the phenomena of enrichment and oxidation, which extended for a long period of time, and contributed to concentrate the deposit. The existence of moderate amounts of pyrite in the HW, available to generate free acid and the condition of low reactivity country rock, are ideal to generate a good supergene profile (Blanchard, 1968; Chavez, 2000). This set of events generated several stages of cumulative secondary enrichment and oxidation. See Figure 7-1.
Figure 7-1 - Schematic Section through Marimaca Type Systems
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Despite the genetic scenario, the district extension of intrusives, fracturing and of alteration, in addition to the occurrence of mineralization, provides an attractive potential for the exploration and discovery of other ore bodies of copper, in addition to the exploration of the extensions of the known mineralization. All this forms the basis for future plans of exploration of Marimaca and its surroundings.
8 Exploration
Marimaca is an active exploration project. The exploration strategy is focused on an infill program to improve the quality of the resources and targeting potential extensions of currently known mineralization.
From the first semester of 2016, MCAL invested more than US$ 1.5 million in exploration to identify mineral resources, primarily below the Marimaca small open pit, to the north and south and then to the east and west, totaling 13,628 meters. A total of 6 holes were diamond drilled and 54 were RC and the information from that program was used to define Measured, Indicated and Inferred Resources.
Based on this exploration success, an exploration program is planned by MCAL for the 2017 period, targeting infill and the lateral extensions of the areas investigated.
The objective of this exploration program is to improve and define additional resources. Based on the results of the exploration program implemented since 2016, the mineral potential targeted by the proposed 2017 exploration program is estimated to upgrade between 50% of the Indicated resources to Measured and 70% of the Inferred to Indicated resources of oxide mineralization. The range of tonnage and grades expected from the results of the proposed exploration program are estimated from the recent exploration results. The range of quantity and grade estimates is derived from the surface areas of the Mineral Resources projected over the areas that will be infilled by the 2017exploration drilling programs. The reader is cautioned that the potential quantity and grade estimates expected from the proposed 2017 to 2018 exploration program are conceptual in nature. It is uncertain if the implementation of the proposed exploration program will result in the delineation of new Mineral Resources
8.1 Surveying, Image and Topographic Base
A photographic and photogrammetric survey, using UAV technology and digital camera, covering ~ 2 km2, was used as the topographic basis of the Project. The flight resolution was 8-13 cms per pixel, and a digital elevation model (DEM) was generated with interpolated curves at 1 m for use at the 1: 1000 scale (Figure 8-1). The topographical support was made by conventional topography, which from official bases generated a sufficient network of points to balance and orthorectify the image and DEM.
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Figure 8-1 - Topographic Base and Orthorectification
8.2 Surface Sampling
During the due diligence period, prior to the signing of the MCAL option agreement, superficial geological reconnaissance and orientation surveys were carried out. These activities were restricted to the western part of the property, which has the largest amount of mineralized exposures.
In a road cut at the northern part of the property, which crosses the entire mineralized profile, a continuous sample of rock chips was collected along 150 meters, with samples every 2 meters. The results confirmed the extension of the mineralization between the structures of high grade, exploited by small miners. The average of 150 m of the sample delivered 0.36% CuT and 0.24% CuS that included 85 m with an average of 0.48% CuT and 0.32% CuS. A second road cut sample over 30 meters averaged 0.53% CuT and 0.43% CuS. Other results in cuts of the central-west part of the property are shown in Figure 8-2.
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Figure 8-2 - Sampling of road cuts, basic elements of the structure and mineralization from FW to HW
The samples were collected by MCAL personnel and prepared and tested (only with laboratory quality controls based on the indicative nature of the samples) in the laboratories of Andes Analytical Assay (AAA) in Santiago, Chile.
8.3 Surface Geologic Mapping
The first geological mappings were made by direct observations in old workings and road cuts, sufficient to generate concepts regarding the type, controls and distribution of mineralization and to outline an attractive potential for Coro.
Based on geochemistry and surface observations, the geological observations were focused on the distribution of copper oxides and the ZDC “shear” zone that is the main control for the continuity and intensity of mineralization. The structures 40° orientation or “feeders” were also recognized. The basis for organizing this information was a mixture of aerial images of the Drone at 1: 2000 scale, filters and rock geochemistry. Based on these elements the sections with the interpreted distribution of the oxide mineralization were generated and the drilling campaign was planned to test these projections in depth.
8.4 Geochemistry
Considering the quality of the outcrops and that the mineralization of oxides reaches surface, it was considered necessary to explore the total surface of the mining property through a geochemical rock sampling grid. Due to the size of the mineralized zones, the chosen grid was 100 x 100 m. The material collected was rock chips in outcrops around the sampling point. The locations were obtained with GPS adjusted to UTM coordinates PSAD 56. A total of 83 samples of 5-6 kg of average weight were collected and sent to chemical analysis.
Samples were collected by MCAL staff and prepared and analyzed by Cu in AAA. The quality controls were the laboratory's own, considering the indicative character of the sampling and that the value of the data is only complementary for the decision making and subsequent evaluation of the property.
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In relation to the results, the first aspect of interest is the high Cu background of the area. The average of all samples is 574 ppm Cu. The range of the anomaly containing the main mineralized body exposed on the west side of the property is > 200 ppm Cu. The contents > 1,000 ppm (> 0.1% Cu) confirm the extensions of surface mineralization. The anomalies of the same range in the eastern part are restricted to smaller structures, and a frequency increase is noted to the west (Figure 6-10).
8.5 Geophysics
Geophysics was not used as a tool for exploration for the initial discovery of Marimaca. However, to verify the relationship of the mineralization - in depth - with high magnetite contents - a high resolution aeromagnetic survey was carried out using GeoMagDrone™ technology (GfDashttp://www.geomagdrone.cl/).
The survey was conducted in 2016 and its results with Reduction To Pole (RTP) process and a 3D interpretation are summarized in Figure 8-3. The possibility of using this tool in the district exploration is under review, through the feedback of the interpretation with measurements of surface magnetic susceptibility.
Figure 8-3: RPT-processed magnetometry. GeoMagDrone™ flight data
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8.6 NCL Comments
The Marimaca project is, at present, primarily considered as an open pit project. Exploration drilling completed by MCAL demonstrates potential for extending the oxide and sulphide and for new discoveries amenable for mining. The infill program and the exploration potential of MCAL properties remain good. NCL is of the opinion that the aggressive exploration programs as envisioned by the company will continue to expand and improve the quality of the mineral resources.
9 Drilling
In 2016 MCAL completed 60 boreholes in the Marimaca project. Six of these holes were diamond drill holes (DDH), and the remainder reverse circulation (RC). All core boreholes 5 were drilled using HQ barrels. RC holes (5¾” to 5 /8” diameter) were completed by Perfochile Ltda. and core drilling by Superex SA. The majority of the boreholes were drilled with an azimuth of 310 degrees and alternatively 220 degrees, with inclinations between - 55° and -60°. Borehole lengths average 334.68m for DDH and 215.19m for RC. Boreholes were surveyed by Wellfield Services Ltda., personnel.
To test the continuity of the mineralization a 100 x 100 m grid was drawn, oriented NE and NW. Two sets of vertical sections were interpreted. These sections were numbered at 100 m intervals, between NE 100 to NE 1000 and NW 100 to NW 800.
For the orientation, a geometric criterion was used, based on the idea of the genetic control by the intersection of the orientations of the north-south structure and the 40° orientation of the feeders, assuming a perpendicular flow of the fluids from these. In this way it was determined that the optimal orientations of the grid were 310° for NW sections and 40° for NE sections. The drill holes were located in both sections following 310° / -55° and 210° / - 55° orientations (Figure 9-1). The angle of -60° was used as operationally more suitable for RC equipment and more perpendicular according to the inclination 50° east of the parallel fracturing. Table 9-1 summarizes the drilling information for Marimaca.
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Table 9-1: - Summary of Drilling Activities at Marimaca
The Holes were surveyed by Wellfield Services Ltda., with the exception of three, one core and two RC boreholes, which haven’t been surveyed at the moment of preparing this report. Moreover, the coordinate locations of Marimaca holes were compared to associated proposed locations, topography, and GPS coordinates, to evaluate accuracy and identify errors. There were no significant errors documented. All the time MCAL had the control of
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the operation, but especially of the sampling intervals (regular to 2 m), the processes of measurement the weight of the sample, and the split of the samples according to the MCAL splitting protocols (Annex 2).
RC drilling samples were collected by MCAL and operational reports on each campaign were issued. Drillhole locations, depths and sampling were coordinated on a daily basis between contractor’s shift boss and MCAL’s field assistant. MCAL recovery and sample collection protocols are in Annex 2.
Core recovery typically exceeded 90%. Borehole spacing in the resource areas is approximately 100 metres and wider along the edges of the resource areas and beyond (Figure 9-1).
Figure 9-1 – Collar locations on the Marimaca Properties
Table 9-1 shows the information of the collars of all drilled holes. They include data on campaign, name, east and north coordinates (UTM PSAD 56), azimuth, inclination (both in the collar) and depth. Figure 9-1 shows the distribution of the drill holes in the area.
The logged data are: rock, structure, alteration (basis of relative abundance and occurrence of minerals), mineralization (same as alteration on the basis of individual minerals) on the basis of drilling intervals, recoveries and analytical results. Only after validation are defined the mineral and alteration zones, according to the geological criteria of the project. The result is entered in the database as a table with all mapped data. A consolidated log of the drill is prepared as a strip log at the end, to review the consistencies in graphic form.
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The core was geologically logged capturing data of rock types, structure and mineralization- alteration in the same way as in the logging of RC. The natural contact intervals were added to the controls, leaving 2 m regularization for sampling. A first log was also made with the complete core and the consistency of grades with mineralization was reviewed and the mapping was adjusted when necessary. Stored data in tables were integrated into databases and their consistency revised in the form of columns summaries or strip logs.
In addition to measuring deviations, most of the holes were surveyed using an optical viewfinder probe (OPTV), with structures and orientation measurements, which continuously and thoroughly records holes’ walls and measured structures. The structures were measured in ranks according to their width and the results reported and plotted on stereographic networks and roses diagrams (Figure 9-2).
Figure 9-2 - Examples of results of orientation measurements of structures by means of BHTV: (a) record of measurements with hole image; (b) stereograms and diagrams of roses
NCL is of the opinion that the drilling and sampling procedures adopted by MCAL are consistent with generally recognized industry best practices. The resultant drilling pattern is sufficiently dense to interpret the geometry and the boundaries of the copper mineralization. The core samples were collected by competent personnel using procedures meeting generally accepted industry best practices. The process was undertaken or supervised by suitably qualified personnel. NCL concludes that the samples are representative of the source materials and there is no evidence that the sampling process introduced any bias.
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10 Sample Preparation, Analyses and Security
10.1 Drillhole Sampling
Analytical samples informing the Marimaca Mineral Resources were prepared at the project site and assayed at the Geolaquim Ltda. laboratory in Copiapo, certified in 2004 to ISO 9001:2000 by the DNV, and then updated to its 2005 and 2008 versions, for commercialization, mechanical preparation and chemical analysis of mineral samples. Compliance to the ISO standard is verified yearly.
The umpire laboratory was Andes Analytical Assay Ltda. in Santiago, certified in 2015 to ISO 9001:2008 by the IQNET. MCAL only worked with AAA during the first RC drilling campaign, and didn’t employ an umpire laboratory for the rest of campaigns.
The samples were transferred by the laboratory personnel from the project to Copiapo, and then the preparation pulps were returned to generate the analysis batches with inserts for the QA/QC program.
Upon reception, sample details are logged and insertion points for quality control samples in the sample flow are determined. MCAL RC holes were sampled on a 2 m continuous basis, with dry samples riffle split on site and one quarter sent to the laboratory by Coro personnel, for preparation and assaying. A second quarter was stored on site for reference. DDH samples were prepared using the following standard protocol: drying, crushing to better than 80% passing -10#, homogenizing, splitting and pulverizing a 400 g subsample to 95% passing -150#. All holes were assayed for CuT (total copper) and CuS (acid soluble copper) by AAS. A QA/QC program, involving insertion of appropriate standards and duplicates was employed with acceptable results.
Assay data were loaded directly from digital assay result files into the final database in order to minimize sources of error.
10.2 Sample Rejects and Pulps Storage
RC boreholes chips are stored, at appropriate places in the field (old adits), as are samples’ coarse rejects of about 8-9 kg weight, obtained from the third riffle pass. The laboratory was requested to store in appropriate places of the project, all the crushed rejects of DDH samples (-1/4 ") Trays with half of DDH control, cutting boxes and backing bags of 1 kg of RC samples From the core extracted for metallurgical tests, a representative 10 cm core is left. All pulps of the total samples collected in the project: sampling of cuts, geochemistry and drilling are stored in paper envelopes and cardboard boxes in an orderly way in the project.
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10.3 Specific Gravity Data Sampling
Specific gravity was measured systematically on core fragments taken from the deposit for density and geotechnical issues. Specific gravity is determined using a water displacement method with paraffin coating. The 184 fragments sampled are 7 to 26 centimetres long, with an average specific gravity of 2.67 gr/cm3.
In order to obtain density measurements characterizing the Marimaca mineralized rocks, test-samples were taken from core samples. The sample selection criteria and laboratory tests are as follows: Each selected piece was logged in detail and photographed. They were then sent to Calama's Rock Tests certified laboratories, for the corresponding unit weights. The method was the weight-volume ratio, with previously kerosene waterproofed and weighted in air and then, weighed submerged in water.
The variability of the weights is considered acceptable. The total of samples sent to density characterization was 184. The first 22 were collected with criteria of rock-mineralization units and correspond to pieces of about 20 cm of average length. The base was completed by sending specimens corresponding to the remaining half of samples, collected almost systematically. For this study another 162 samples were collected and measured in the laboratories of Rocktest in Calama. For measurements of geomechanical parameters, 46 point load tests were performed in the rock-test laboratory in Calama. The samples were selected by a geomechanical consultant. The information from the mappings was incorporated into the databases in the relate tables.
10.4 Quality Assurance and Quality Control Programs
The analytical quality control program implemented at Marimaca includes the use of control samples, such as preparation and pulp duplicate, reference material and check samples inserted within all samples submitted for assaying. The samples were distributed among three different drilling campaigns:
First RC drilling campaign (MAR-1 to MAR-16): Only check samples, sent to AAA, the umpire laboratory. Second RC drilling campaign (MAR-17 to MAR-54): Preparation duplicate samples, pulp duplicate samples and reference materials. Core drilling campaign (MAD-01 to MAD-06): Pulp duplicate samples and reference materials.
10.4.1 Standard Sample Analysis
Geostats Pty Ltd. provided 360 standard reference materials (SRM’s) of 9 different types for use at Marimaca, with grades ranging from 0.103 to 2.185 percent copper. These were inserted at an approximate rate of one every 16 samples for the second RC drilling campaign (MAR-17 to MAR-54), totalling 275 samples, and at an approximate rate of one
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every 12 samples for the core drilling campaign (MAD-01 to MAD-06), adding up to 85 samples. Figures 10-1 and 10-2 summarize the time sequenced analytical results of the SRM’s used in the RC and core drilling campaigns, respectively.
Figure 10-1 - SRM Analysis (RC)
Figure 10-2 - SRM Analysis (Core)
The upper and lower acceptable limits shown outline boundaries of +/- 5% relative to each certified SRM grade. Even though these limits are rather strict and could be further improved by using confidence intervals provided by Geostats, it can be concluded that the core drilling campaign (Figure 10-1) shows good SRM’s analytical results with only a few outliers, while the RC drilling campaign (Figure 10-2) shows a greater number of outliers,
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especially at the lower grades. This is to be expected given that lower grades are closer to the detection limit and depend increasingly on the instrument’s numerical accuracy at the decimal and centesimal scales. MCAL has protocols in place for handling analytical results on standards that exceed acceptable limits, which ultimately can trigger a re-assay of portions or of an entire sample batch.
10.4.2 Duplicate & Check Sample Analysis
This involves 270 preparation duplicate (PRD), 370 pulp duplicate (PUD) and 239 check samples (CHD). As mentioned previously, CHD samples were used as the sole quality control measure for the first RC drilling campaign (MAR-1 to MAR-16), and were taken at an approximate rate of one every 6 samples. PRD samples were inserted exclusively for the second RC drilling campaign (MAR-17 to MAR-54), at an approximate rate of one every 16 samples. A batch of 275 PUD samples was also inserted during this campaign, at the same rate. The core drilling campaign (MAD-01 to MAD-06) contains 95 PUD samples, inserted at an approximate rate of one every 12 samples. Figures 10-3; 10-4; 10-5 and 10-6 summarize the results of PRD and PRU samples in the RC and core drilling campaigns, respectively.
Figure 10-3 - Original vs Check Samples (RC)
Figure 10-4 - Original vs Check Samples (RC)
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Figure 10-5: Original vs PUD Samples (RC)
Figure 10-6: - Original vs PUD Samples (Core)
Even though the quality control measures used for the first RC drilling campaign aren’t as reliable as the ones put in place for the other campaigns, and that a more comprehensive analysis would be preferred, it can be concluded that the analytical results on all batches of check and duplicate samples processed and analyzed indicate very good reproducibility, as expressed by the R2 coefficient present in the previous figures. These results indicate the sampling process is not introducing bias, and that samples are representative.
10.4.3 Blank Sample Analysis
Information received by NCL did not include a database of blank samples, and upon questioning, Coro confirmed that they did not use this type of control during their campaigns. This omission is not irrelevant, but it can be partially mitigated by reviewing the quality controls performed and reported by the laboratory. NCL had access to the QA/QC protocols of Geolaquim, the primary laboratory, and to the reports of AAA, the umpire laboratory, and both seem to have well-structured quality control measures in place, including the insertion of blank samples.
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Adding this to the fact that the SRM’s and duplicate samples analyses are acceptable, NCL considers that there’s low probability for contamination in the different assays performed. Nevertheless, for a future quality control analysis, NCL recommends the preparation of check sample batches with control samples, including blank samples, to verify this assertion.
10.5 Sample Security
All drilling assay samples are collected by company personnel or under the direct supervision by company personnel. Samples from Marimaca were processed at the project site and shipped directly from the property to the Geolaquim laboratory.
Assay samples are collected by appropriately qualified staff at the laboratories. Sample security involved two aspects: maintaining the chain of custody of samples to prevent unnoticed contamination or mixing of samples and rendering active tampering as difficult as possible.
During the site visit, NCL found no evidence of active tampering or in adverted contamination of assay samples collected on the Marimaca properties.
10.6 NCL Comments
NCL reviewed the field procedures and performed their own extensive analytical quality control with data provided by Coro. In the opinion of NCL, company personnel used care in the collection and management of the field and assaying exploration data. Based on reports and data available, NCL has no reason to doubt the reliability of exploration and production information provided by Coro. The reports and analytical results projected by NCL suggest that, even though there are minor concerns regarding some of the SRM’s assayed values and the absence of blank samples, analytical results delivered by the laboratories used by Coro are free of apparent bias.
NCL considers that the sampling preparation, security and analytical procedures used by Coro are consistent with generally accepted industry best practices, and recommendations were made to further improve them. Therefore, it’s in the opinion of NCL that these are adequate to support the Project’s Resource estimation.
11 Data Verification
11.1 Verifications by Coro
The exploration and production work completed by Coro is conducted using documented procedures and involved verification and validation of exploration and production data, prior to consideration for geological modelling and Mineral Resource estimation. During drilling, experienced geologists implemented industry standard measures designed to ensure the consistency and reliability of the exploration data.
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Quality control failures are investigated and appropriate actions are taken when necessary, including requesting re-assaying of certain batches of samples.
11.2 Verifications by NCL
In accordance with National Instrument 43-101, professionals under the supervision of NCL visited the Marimaca properties from 6 to 7 of December 2016, accompanied by Sergio Rivera Exploration Vice president of Coro. The team included Ricardo Palma, P. Ing. and Luis Oviedo P. Geo. qualified to National Instrument 43-101.
Site visit took place and all aspects that could impact materially the integrity of the borehole databases (core logging, sampling, and database management) were reviewed with Coro staff. NCL was able to interview staff to ascertain exploration procedures and protocols.
NCL examined core from a number of boreholes and found that the logging information accurately reflects actual core. The lithology and grade contacts checked by NCL match the information reported in the core logs.
NCL toured the Marimaca area and observed diamond and RC drill sites, collars and maintenance.
NCL reviewed the borehole databases, for the preparation of this technical report, NCL was able to produce the block models, tonnage and grade evaluations to a satisfactory degree.
NCL also completed statistical comparison of the global block models grade against the informing drilling data and visually compared on plans and sections the block models against the informing samples to confirm that the various models are generally an adequate representation of the distribution of the copper mineralization.
12 Mineral Processing and Metallurgical Testing
Third party column test work had been carried out on material extracted from the Marimaca surface workings prior to Coro’s involvement in the project, and this indicated 75-85% CuT recoveries and 20-40kg/t net acid consumption.
Four types of leachable copper oxide mineralization were identified in logging and were modelled separately in the resource estimation: Acid solubilities in the oxide zones are good at 76% for all assays greater than 0.1% CuT and rising to 81% for all samples greater than 0.3% CuT. This is consistent with previous preliminary column test work carried out from surface samples noted above.
Column test work is in progress at the moment of preparing his report.
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13 Mineral Resource Estimates
13.1 Introduction
Mineral Resources were estimated for the Marimaca deposit, which most likely will be mined by open pit methods. The Marimaca open pit Mineral Resource model was generated by NCL
NCL reviewed and audited the models generated by Coro. This section outlines the Mineral Resource estimation methodology and summarizes the key assumptions adopted for the generation of the Mineral Resource models.
In the opinion of NCL, the resource evaluation reported herein is a reasonable representation of the Mineral Resources found at Marimaca at the current level of sampling. The Mineral Resources have been estimated in conformity with generally accepted CIM Estimation of Mineral Resource and Mineral Reserves Best Practices Guidelines and are reported in accordance with Canadian Securities Administrators’ National Instrument 43- 101.
Mineral Resources are not Mineral Reserves and have not demonstrated economic viability. There is no certainty that all or any part of the Mineral Resource will be converted into Mineral Reserve.
13.2 Resource Estimation Procedures
The main objective of this chapter was to build the resources model of the Marimaca deposit and produce the first resource estimates.
Main stages of the study were:
Analysis of exploration data and definition of the estimation populations. Generation and Validation of composites. Validation of three-dimensional solids to the defined population. Statistical analyses of the composites of the different variables in each population. Variography and anisotropy analyses. Definition of preferential directions, calculation and adjustment of variograms per population and elements to be estimated. Detection and treatment of outliers. Definition of the Block Model. Definition of the estimation strategy and Kriging plans per element and population. Estimation of grades for each element of each population. Categorization of resources. Validation of the Model through:
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o Comparative statistics between composites and estimated blocks. o Analyses of smoothing of grades. o Moving window analyses of composites and blocks estimated in different directions. o On screen validation. Final Report of the geological resources by category.
Programs from the GSLIB library were used for the geostatistical analyses and the block model was generated using Gems software. The final model and database are available in Gems and ASCII format, to be loaded using software that Coro determines.
13.3 Database
The basic information for this study has been provided by MCAL and corresponds to:
Drilling database, with the following major information: o Identification of 60 drill holes with: UTM coordinates of collars, total length, Interval, Dip and Azimuth. o Samples with: intervals from and to, analyses of total (CuT %), Cu sequential (CuS, CuCN. y Cu Residual), Au and type of mineralization (Oxide, Enriched and Primary). o 22 sections NEast and NWest, each 100 m apart, with the interpretation of mineralized zones (Oxide, Enriched and Primary). Results of 184 specific gravity measurements.
Details of available information are presented below.
13.3.1 Drilling Database
The drilling database comprehends Diamond Drills (DDH) as well as Reverse Circulation (RC) holes. Table 13-1 presents the information contained in the database.
Table 13-1: Database General Information.
Total DDH RC # Drillholes 60 6 54 Drilled mts 13,628 2,008 11,620 Total Samples 6,763 1,003 5,760
Total DDH RC # Samples Meters # Samples Meters # Samples Meters Samples with CuT>0 6,763 13,561 1,003 2,005 5,760 11,556 Samples with CuS>0 6,763 13,561 1,003 2,005 5,760 11,556
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All samples without any grade value in the database were eliminated previous to the resource modeling, also values labeled <0.001% were changed to 0.001% for both CuT and CuS.
13.3.2 Geological Interpretation
MCAL produced NE and NW sections following the 100x100m drilling grid, with outlines of estimation domains. These units were interpreted based on the different lithologies, alterations and minerals mapped in surface and sub-surface, as well as anisotropies identified in structural analyses, and were created for estimation purposes.
The four zones of interest for Resource estimation purposes are Brochantite; Chrysocolla; Wad and Mixed and were coded in the block model using the solids of the geological model described previously as shown in Table 13-2.
Table 13-2: Mineral Zone Codes
Code Description 1 Brochantite 2 Chrysocolla 3 Wad 4 Mixed
As an example, Figure 13-1 presents a section with the geological interpretation of the major units. Figure 13-1: Geological Interpretation, Section NW 300 viewed to SW)
Brochantite Chrysocolla Wad Mixed
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Using the digitized outlines (polylines) of these sections, NCL built Leapfrog 3D volumes of the four key estimation domains: Chrysocolla (CRIS), Brochantite (BROC), Wad (WAD), and Mixed (MX), as shown in Figure 13-2.
According to MCAL, the NE sections provide the most reliable interpretation of the geological units, so this set of sections is the one controlling the volumes. The NW sections were outlined following the NE set, and provided a secondary control of the interpolations, as did the drilling intervals for each unit, which were expected to be contained inside its corresponding volume.
In addition to the main geological controls, NCL applied a set of structural trend parameters which gave the volumes uniformity and continuity in between sections and, finally, added some polylines to give further consistency to the model, where the original interpretation was insufficient or where the interpolations didn’t deliver expected results.
Figure 13-2- Key estimation domains of Marimaca
After comparing the Marimaca Mineral Resource model against the informing composites and the statistics of the model, NCL concludes that the modeling approach produced a reasonable and reliable model.
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13.4 Sample Statistics
Based on the generated solids codes, each sample from the database has been coded, according to the solid that contains the sample centroid. Tables 13-3 and 13-4 show the basic statistic per population, according to the original database codes and the new codes obtained from the 3D solids.
Table 13-3: Sample Statistic for CuT.
Brochantite Chrysocolla Wad Mixed Original Raw Data CuT N° Samples 870 977 397 1364 Min (%) 0.028 0.02 0.088 0.001 Max (%) 10.48 6.06 2.46 0.55 Average (%) 1.03 0.71 0.40 0.06 STD 1.03 0.62 0.26 0.06 CV 1.00 0.87 0.65 0.87 Solid Coded Data CuT N° Samples 1054 1381 909 253 Min (%) 0.002 0.001 0.002 0.006 Max (%) 10.5 9.8 2.4 4.5 Average (%) 0.82 0.59 0.22 0.46 STD 1.03 0.70 0.26 0.66 CV 1.3 1.2 1.2 1.4
Table 13-4: Sample Statistic, CuS
Brochantite Chrysocolla Wad Mixed Original Raw Data CuS N° Samples 870 977 397 1364 Min (%) 0.008 0.01 0.011 0.001 Max (%) 10.47 5.24 2.22 0.51 Average (%) 0.84 0.57 0.24 0.03 STD 0.93 0.52 0.21 0.04 CV 1.10 0.91 0.85 1.24 Solid Coded Data CuS N° Samples 1054 1381 909 253 Min (%) 0.001 0.001 0.034 0.001 Max (%) 10.5 6.3 1.0 4.1 Average (%) 0.62 0.45 0.13 0.19 STD 0.85 0.55 0.23 0.34 CV 1.4 1.2 0.5 1.8
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The differences in the figures of raw data and re-coded, are a function of the deposit’s mineralization and the smoothing of the solid model, which is particularly noted in the Mixed population.
13.5 Composite Statistics
An analysis of the samples’ length was done in order to check if regularization was required (compositing). Practically all the samples are 2 meters long, only one sample inside the modeled solids has 1 meter long and the rest are 2 meters long, so it was concluded that no further action in this regard was needed.
Therefore, the samples to be used in the grade modeling process are the raw samples from the drillhole database, coded according to the solid that contain their centroid.
Tables 13-5 and 13-6 show the statistics of the final populations used in the grade modeling process.
Table 13-5: Sample Statistic for CuT, per Rock Type.
Total Copper (CuT) Domain N°Data Min % Max % Average % STD % CV Brochantite 1054 0.002 10.48 0.82 1.03 1.25 Chrysocolla 1381 0.001 9.85 0.59 0.70 1.20 Wad 909 0.002 2.42 0.22 0.26 1.18 Mixed 253 0.006 4.53 0.46 0.66 1.45
Total 3597 0.001 10.48 0.55 0.77 1.39
Table 13-6: Sample Statistic for CuS, per Rock Type.
Soluble Copper (CuS) Domain N°Comp Min % Max % Average % STD % CV Brochantite 1054 0.001 10.47 0.62 0.85 1.37 Chrysocolla 1381 0.001 6.32 0.45 0.55 1.22 Wad 909 0.034 1.00 0.13 0.23 1.68 Mixed 253 0.001 4.06 0.19 0.34 1.80
Total 3597 0.001 10.47 0.40 0.62 1.54
It can be noted from the above given tables, that all the samples with CuT grade has a CuS value. A check for eventual CuS values greater than CuT grades was done and no contradictions were found.
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13.6 Contact Analyses
The contact characteristics between the units to estimate have been reviewed according to the mean grade of the samples, in relation to their distance to the contact defined in the solids model. Figures 13-3, 13-4 and 13-5 show the behavior of the grades along the border of the contact between the units.
Figure 13-3: Brochantite - Chrysocolla Contact, CuT
Figure 13-4: Brochantite - Wad Contact, CuT
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Figure 13-5: Chrysocolla - Wad Contact, CuT
As can be noted in the above figures, the contact between both green oxides seems gradual, and the contact between green and black oxides looks hard. Based on these observations, it has been decided to estimate both green oxides together and the Wad independently. Table 13-7 summarizes the conclusions of the contact analysis:
Table 13-7: Types of Contact
Brochantite Chrysocolla Wad Brochantite - Soft Hard Chrysocolla Soft - Wad Hard Hard -
13.7 Variography – Calculation and Adjustment of Variograms
The variography of CuT and CuS has been developed using the samples of the populations derived from the Contact Analysis: Brochantite + Chrysocolla and Wad. Correlograms were calculated, instead of conventional variograms, as they are more stable.
Correlograms in distinct directions were calculated, according to visual tendencies and discussions with Coro’s technical team. A range of directions were tested, selecting those with better results. The determination of the nugget for each population was done using the down-the-hole correlograms.
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Finally, for each population, the Correlograms have been calculated and adjusted, according to the preferential directions defined and shown in Table 13-8:
Table 13-8: Correlograms Preferential Directions
Brochantite Chrysocolla Wad Eje Azimuth Dip Azimuth Dip Azimuth Dip X' 90 -50 90 -50 90 -50 Y' 0 0 0 0 0 0 Z' 90 40 90 40 90 40
Tables 13-9 and 13-10 show the parameters of the adjusted Correlograms. For the Mixed population, no adequate correlograms were found, so it was decided to use Inverse Distance Square (ID2) for the grade interpolation.
Table 13-9: Correlograms, Adjusted Models CuT
1st Structure 2nd Structure 3rd Structure Domain Nugget Sill 1 Range (m) Sill 2 Range (m) Sill 3 Range (m) X' Y' Z' X' Y' Z' X' Y' Z' Brochantite 0.25 0.2 10 5 1 0.15 10 55 30 0.4 48 55 30 Chrysocolla 0.25 0.2 10 5 1 0.15 10 55 30 0.4 48 55 30 Wad 0.25 0.52 10 15 5 0.23 15 10 35
Table 13-10: Correlograms Adjusted Models CuS 1st Structure 2nd Structure Domain Nugget Sill 1 Range (m) Sill 2 Range (m) X' Y' Z' X' Y' Z'
Brochantite 0.35 0.15 5 10 5 0.5 50 60 55 Chrysocolla 0.35 0.15 5 10 5 0.5 50 60 55
Wad 0.4 0.35 5 10 10 0.25 15 40 40
The experimental Correlograms and the adjusted models of each population and preferential direction were calculated.
As an example, obtained correlograms for Brochantite & Chrysocolla are presented in Figures 13-6, 13-7 and 13-8.
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Figure 13-6: Correlogram CuT - Brochantite & Chrysocolla - Hz
Figure 13-7: Correlogram CuT - Brochantite & Chrysocolla – Hz – Az=90º - VT 40º
Figure 13-8: Correlogram CuT - Brochantite & Chrysocolla – Az = 90º - VT -50º
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13.8 Definition and Generation of the Block Model
For the final estimation of the grades, it has been decided to utilize a block model of 5m*5m*5m, rotated N 40º E, in order to match with the geological sections. Table 13-11 presents the geometric parameters of the model.
Table 13-11: Definition of the Block Model.
Axis Origin N° of Blocks Block Size Extension (m) X 375,250 210 5 1,050 Y 7,434,600 252 5 1,260 Z 700 100 5 500 Rotation N40E
Using the interpretation of the Oxide, Enriched and Primary, the respective models were generated, assigning the codes defined per each block of the model, using the intersection of the blocks and the respective solids. According to the blocks and the definition of the populations, a final model has been generated with a unique code per each block of the model. Table 13-12 and Figure 13-9 present a summary of the codification used.
Table 13-12: Total Coded Blocks
Domain N°Blocks Volume m3 Brochantite 97,329 12,166 Chrysocolla 93,109 11,639 Wad 137,526 17,191 Mixed 20,614 2,577
Total 348,578 43,572
13.8.1 Geological Model
The remaining blocks below surface topography were coded as waste. A validation of the correctness of the rock coding was done, checking some sections and plans on screen. Figure 13-9 shows Section NW 300, with the solid’s contour, the coded boreholes and the block model.
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Figure 13-9: Solids - Blocks and Samples - Section NW 300 view to SW
13.8.2 Specific Gravity Model
The average specific gravity of each estimation unit was calculated using a set of 184 measures, divided according to each mineral zone. Three outliers were eliminated, one coded Broc = 3.37 t/m3 and two coded LXF, one very high = 3.46 t/m3 and another too low = 1.91 t/m3. Table 13-13 shows the density per population.
Table 13-13: Specific Gravity per Unit
Count 184 55 58 10 Mean (t/m3) 2.65 2.62 2.65 2.71 Max (t /m3) 3.46 2.74 2.87 2.91 Min (t /m3) 0.00 2.15 2.25 2.51 Std 0.239 0.120 0.111 0.113
13.9 Kriging Plans and Resource Classification Criteria
Once the correlograms were calculated and adjusted for each population, grade values for CuT and CuS in each population were estimated. The grade interpolation method selected was Ordinary Kriging, attending to the nature of the deposit and the data availability. The kriging was done using the software Gems.
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Four kriging plans were defined, to be executed in sequential order. The general concept is to “fill” the grades model, starting with a restrictive estimation plan which considers only interpolation between drill holes, separated distances below the equivalent of 85% of the variogram sill. Then, the following plans increase the search distance and release other restriction gradually, until the estimation is complete.
The distance, where the correlogram reaches the value equivalent to 85% of the sill, is called D85, and is used as a referential value to the different kriging plans.
The geometric parameters of the estimation of each kriging plan are shown in Table 13-14.
Table 13-14: Kriging Plan Parameters
Estimation Plan 1 2 3 4 Max N° Composite per Octant 5 5 5 5 Min N° of Octants with inf. 3 3 1 1 Min N° of Composites 8 6 4 4 Max N° of Composites 12 12 12 12
Search Range D85 2 x D85 4 xD85 1,000
Each population of blocks is estimated with samples of the same population.
The utilized D85 for each population are shown in Table 13-15. It can be noted that anisotropic search was used for all estimation units:
Table 13-15: D85 per Direction and Population (m)
D85 - X D85 - Y D85 - Z CuT - Broch + Chry 25 30 15 CuT - Wad 6 7 12 CuS - Broch + Chry 25 30 15 CuS - Wad 6 7 12
Outliers
An analysis of the existence of outliers in the estimation populations was done using the log-probability curves for each samples’ population, looking for some singularities in the curves that may signal the presence of an outlier limit.
Figure 13-10 shows, an example, the log-probability plot of brochantite:
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Figure 13-10: Log-Probability Plot CuT – Brochantite
Based on the shape of the curves, the outliers’ limits were defined for each population, as shown in Table 13-16.
Table 13-16: Outliers Limits. CuT (%) CuS (%) Capping Capping Brochantite 4.5 4 Chrysocolla 3.5 3.2 Wad 1.6 1.3 Mixed 1.8 1.5
Values greater than the above, defined limits were made equal to the limit for grade estimation purposes.
13.10 Grades Estimation Results
Upon completion of grades estimation, Table 13-17 summarizes the number of blocks estimated in each kriging pass per kriging domain.
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Table 13-17: Estimation Results; Cut and CuS Total N° Blocks Total N° Blocks Total N° Blocks Total N° Blocks Total N° Blocks Total N° Total N° Estimated in 1st Pass Estimated in 2nd Pass Estimated in 3rd Pass Estimated in 4th Pass Total Domain Blocks Blocks Number Number Estimated Number % of Total of % of Total of % of Total Number % of Total Number % of Total of Blocks Estimated Blocks Estimated Blocks Estimated of Blocks Estimated of Blocks Estimated Brochantite 97,329 97,329 7,080 7% 22,519 23% 48,211 50% 19,519 20% 97,329 100% Chrysocolla 93,109 93,109 9,987 11% 29,275 31% 44,262 48% 9,585 10% 93,109 100% Wad 137,526 137,526 251 0% 2,169 2% 20,779 15% 114,327 83% 137,526 100% Mixed 20,614 20,614 102 0% 659 3% 6,226 30% 13,627 66% 20,614 100%
Total 348,578 348,578 17,420 5% 54,622 16% 119,478 34% 157,058 45% 348,578 100%
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13.11 Classification of Resources
Resource Classification has been done according to the conditions defined by the number and location of samples in the neighborhood of each block. This criterion attends the requirements established at the CIM code.
The 1st pass generates block estimates with a minimum of two drill intercepts, both within distances shorter than the D85 (distance corresponding to the point where the correlogram reaches 85% of the sill); The 2nd pass maintains the restriction of the number of drill intercepts, but enlarges the search range by twice the D85. These two passes generate the rd demonstrated resources. The 3 pass increment the search radius to 4 times the D85 and reduces the number of drillholes within this range to one, generating Inferred Resource. A fourth pass was added using a very large search radio, in order to ensure that all the blocks inside the geological model are estimated. This fourth pass generates Potential Resource.
Taking these criteria into account, the categorization of resources has been done according to Table 13-18.
Table 13-18: Kriging Passes and Resource Classification N° Kriging Search Range N° Intercepts Classification
1 D85 2 Measured
2 2 x D85 2 Indicated
3 4 xD85 1 Inferred Potentially 4 1,000 m 1 mineralized
A classification code was added to the block model. The codes utilized to this model are: 1, Measured; 2 Indicated; 3 Inferred and 4 Potentially mineralized rock.
13.12 Resource Model Validation
Three validation exercises were done in order to ensure the quality of the generated block model, as discussed in this chapter.
Visual Validation Statistic Validation Moving window Analysis
The results of these validations are presented below.
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13.12.1 Visual Validation
A visual inspection on screen of several plan views and vertical sections of the block model was done and the grades of the blocks and the drill holes have been compared. Also the resource classification was analyzed comparing the existing information. As an example, the results of this validation are presented in Figures 13-11, 13-12 and 13-13.
Figure 13-11: Visual Revision of the Model of CuT – Section NE 300
Figure 13-12: Visual Revision of the Model of CuT – Section NE 500
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Figure 13-13: Visual Revision of the Model of CuT – Plan view 950
13.12.2 Statistic Validation
The grades of composites and blocks have been compared statistically. Tables 13-19 and 13-20 present a comparison of the basic statistic of composites and blocks per population. Also included in the comparative table are the declustered grades, obtained through the technique of nearest neighbors.
Table 13-19: Statistic Comparison, Blocks vs Composites – CuT
N° Samples Minimum (%) Maximum (%) Average (%) STD C.V. Kriging Blocks 97,329 0.017 3.18 0.66 0.34 0.52 Brochan NN Blocks 97,329 0.000 4.50 0.61 0.64 1.05 Samples 2,435 0.001 4.50 0.67 0.75 1.12 Kriging Blocks 93,109 0.017 2.55 0.50 0.29 0.57 Cris NN Blocks 93,109 0.001 3.50 0.47 0.58 1.23 Samples 2,435 0.001 3.50 0.66 0.70 1.06 Kriging Blocks 137,526 0.003 1.04 0.19 0.08 0.43 Wad NN Blocks 137,526 0.002 1.60 0.16 0.19 1.20 Samples 909 0.002 1.60 0.22 0.25 1.14 Kriging Blocks 20,614 0.019 1.70 0.42 0.24 0.58 Mixed NN Blocks 20,614 0.006 1.80 0.39 0.45 1.16 Samples 253 0.006 1.80 0.41 0.47853 1.16
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Table 13-20: Statistic Comparison, Blocks vs Composites – CuS
N° Samples Minimum (%) Maximum (%) Average (%) STD C.V. Kriging Blocks 97,329 0.003 2.81 0.48 0.28 0.59 Brochan NN Blocks 97,329 0.001 4.00 0.45 0.52 1.16 Samples 2,435 0.001 4.00 0.51 0.63 1.22 Kriging Blocks 93,109 0.003 2.25 0.38 0.24 0.64 Cris NN Blocks 93,109 0.001 3.20 0.35 0.47 1.37 Samples 2,435 0.001 3.20 0.51 0.60 1.18 Kriging Blocks 137,526 0.001 0.83 0.11 0.07 0.62 Wad NN Blocks 137,526 0.001 1.30 0.09 0.15 1.68 Samples 909 0.001 1.30 0.13 0.21 1.57 Kriging Blocks 20,614 0.004 1.04 0.20 0.15 0.79 Mixed NN Blocks 20,614 0.001 1.50 0.19 0.26 1.38 Samples 253 0.001 1.50 0.18 0.25 1.40
From the tables it is concluded that the estimation generates robust results, from a statistical point of view.
13.12.3 Trend Analyses
For trend analyses of the block model, the mean and the declustered mean of the samples has been compared with the block results. In order to decluster the composites, the method of nearest neighbor has been used, introducing a third figure in the analysis. The comparison of mean grades of blocks versus direct mean and declustered mean of composites for each estimation domain, are presented in the following pages. Graphs include the number of composites per slice as a graph bar. As an example, the results of this validation for Brochantite are presented in the next figures (13-14, 13-15 and 13-16):
Figure 13-14: Trend Analysis – Brochantite – EW Direction
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Figure 13-15: Trend Analysis – Brochantite – NS Direction
Figure 13-16: Trend Analysis – Brochantite – Elevation
Same analysis was made for Chrysocolla and Wad and, in general, the estimated mean behaves in a satisfactory way, similarly with the declustered mean. An excessive smoothing is not observed. Generally, the declustered grades are lower than the mean samples, when the differences between them are higher. Moreover, declustered grades are normally situated between them and closer to the declustered mean. From moving window and tendencies of presented grades, it is concluded that the model of estimated grades, preserves the characteristic of the mean grade, global variability and tendencies of the original samples.
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13.13 Reasonable Prospects for Eventual Economic Extraction
The CIM Definition Standards for Mineral Resources and Mineral Reserves (May 2014) establish a Mineral Resource as:
“A Mineral Resource is a concentration or occurrence of solid material of economic interest in or on the Earth’s crust in such form, grade or quality and quantity that there are reasonable prospects for eventual economic extraction. The location, quantity, grade or quality, continuity and other geological characteristics of a Mineral Resource are known, estimated or interpreted from specific geological evidence and knowledge, including sampling.”
The above definition normally implies that there exists some quantity of material that meets a defined economic threshold and that the Mineral Resources are reported at an adequate Cutoff Grade (COG) that considers the defined technical-economic scenario assumed for the project. It must be clarified that Mineral resources are not Mineral Reserves, as they haven’t demonstrated their economic viability yet. Table 13-21 shows the technical-economical parameters used to determine the Resource inside a pit generated using the Lerchs & Grossmann algorithm inside the software Whittle:
Table 13-21: Technical – Economical Parameters for Pit Optimization Value Cu Price 3.20 US$/pound Base Mining Cost 2.8 US$/t Mining Cost Increment going up 0.01 US$/t per bench Mining Cost Increment going down 0.01 US$/t per bench Slope angle 45° Processing cost Oxides 10,5 US$/t ROM sbl: 4,6 US$/t Selling Cost Oxides 0,07 US$/pound ROM sbl: 0,07 US$/pound Metallurgical Recovery Oxides 76% ROM sbl: 38%
13.14 Other considerations and criteria used for the optimization process
All material outside the property is considered as waste, at zero grade. The pit walls are not constrained by the property boundaries, as allowed by the Chilean regulations, in case the material within the property justifies the mining. Measured, Indicated and Inferred categories were considered as valuable.
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13.15 Mineral Resource Estimate
The consolidated Mineral Resource Statement for the Marimaca deposit is presented in Table 13-22.
Table 13-22: Consolidated Mineral Resource Statement, Marimaca, NCL Consulting (January 2017). Metal contained within the boundaries of the Marimaca properties. All figures are rounded to reflect the relative accuracy of the estimates.
Mineral resources were tabulated within the generated pit (Figure 13-17), using a cutoff grade of 0.20 % CuT, above the marginal value which covers processing, tailings, selling and G&A costs. Table 13-22 shows the estimated mineral resource per category, for a COG = 0.20 % CuT.
Table 13-23: Mineral Resource Estimate for the Marimaca Deposit based on a cutoff grade of 0.20% CuT. January 2017, Luis Oviedo, P. Geo. Contained Metal Quantity Grade CuT CuS Classification Tonnes CuT CuS Tonnes Tonnes (000s) (%) (%) (000s) (000s) Measured Brochantite 2,165 0.88 0.68 41,960 32,460 Chrysocolla 3,093 0.65 0.52 44,590 35,726 Wad 30 0.33 0.22 221 143 Mixed 13 0.46 0.19 133 54 Total Measured 5,301 0.74 0.59 86,904 68,384 Indicated Brochantite 6,776 0.74 0.55 110,538 82,605 Chrysocolla 9,045 0.60 0.46 120,242 90,730 Wad 297 0.32 0.21 2,102 1,375 Mixed 80 0.50 0.19 887 338 Total Indicated 16,198 0.65 0.49 233,769 175,048
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Measured and Indicated Brochantite 8,941 0.77 0.58 152,498 115,065 Chrysocolla 12,138 0.62 0.47 164,832 126,456 Wad 327 0.32 0.21 2,323 1,518 Mixed 93 0.49 0.19 1,020 393 Total Measured and Indicated 21,499 0.68 0.51 320,673 243,432 Inferred Brochantite 6,873 0.61 0.45 92,279 68,338 Chrysocolla 8,576 0.53 0.41 99,635 76,947 Wad 2,596 0.32 0.21 18,541 12,132 Mixed 724 0.53 0.20 8,446 3,241 Total Inferred 18,769 0.53 0.39 218,901 160,659 Notes: 1. Mineral resources are reported within a constraining pit shell developed using Whittle™ software. Assumptions include a metal price of US$3.20/lb for Cu and process recoveries of 76% for CuT leaching and 38% for Cu ROM leaching US$ 2.80/t of mining plus US$0.01/bench downward and US$0.01/bench upward. US$10.0/tonne for leach processing, and US$0.50/tonne for G&A. 2. Assumptions include 100% mining recovery. 3. An external dilution factor was not considered during this resource estimation. Internal dilution within a 5 m x 5 m x 5 m is considered and the use of small loading equipment is foreseen for adequate selectivity. 4. Quantities and grades in a mineral resource estimate are rounded to an appropriate number of significant figures to reflect that they are approximations.
Figure 13-17 - Isometric view of the generated Whittle pit and the block model
13.16 Reporting Sensitivity
Table 13-23 shows the sensitivity of the Marimaca Mineral Resource Estimate to variations in the CuT cutoff grade, highlighting in bold text the base case COG.
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Table 13-24: Sensitivity of the mineral resource to changes in CuT cut-off grade (base case cutoff)
Measured Cutoff Tonnage Grade Contained Metal CuT % kt CuT% CuS% CuT (Mlb) CuS (Mlb) 0.7 2,326 1.10 0.86 56,409 44,277 0.5 3,606 0.92 0.72 73,171 57,607 0.3 4,889 0.78 0.62 84,520 66,568 0.2 5,301 0.74 0.59 86,904 68,384
Indicated Cutoff Tonnage Grade Contained Metal CuT % kt CuT% CuS% CuT (Mlb) CuS (Mlb) 0.7 6,063 0.99 0.73 132,152 97,346 0.5 9,987 0.83 0.62 183,517 136,907 0.3 14,773 0.69 0.52 225,675 169,422 0.2 16,198 0.65 0.49 233,769 175,048
Measured and Indicated
Cutoff Tonnage Grade Contained Metal CuT % kt CuT% CuS% CuT (Mlb) CuS (Mlb) 0.7 8,389 1.02 0.77 188,561 141,623 0.5 13,593 0.86 0.65 256,688 194,514 0.3 19,662 0.72 0.54 310,195 235,990 0.2 21,499 0.68 0.51 320,673 243,432
Inferred Cutoff Tonnage Grade Contained Metal CuT % kt CuT% CuS% CuT (Mlb) CuS (Mlb) 0.7 3,859 0.93 0.66 78,970 56,090 0.5 8,625 0.74 0.55 140,642 104,675 0.3 15,541 0.59 0.43 200,863 148,863 0.2 18,769 0.53 0.39 218,901 160,659
Additional to the sensitivity showed above, a smaller pit was evaluated, this time using a copper price of 2.70 US$/lb and maintaining the rest of the parameters fixed. Table 13-24 shows the sensitivity values for this new pit.
Table 13-25: Sensitivity of the mineral resource to changes in metal price assumption (US$2.70/lb Cu)
Measured Cutoff Tonnage Grade Contained Metal CuT % kt CuT% CuS% CuT (Mlb) CuS (Mlb) 0.7 2,323 1.10 0.86 56,363 44,219 0.5 3,593 0.92 0.73 72,986 57,477 0.3 4,858 0.79 0.62 84,223 66,378 0.2 5,259 0.75 0.59 86,479 68,096
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Indicated Cutoff Tonnage Grade Contained Metal CuT % kt CuT% CuS% CuT (Mlb) CuS (Mlb) 0.7 6,006 0.99 0.73 131,026 96,469 0.5 9,872 0.83 0.62 181,451 135,587 0.3 14,500 0.70 0.52 222,495 167,264 0.2 15,848 0.66 0.49 230,147 172,713
Measured and Indicated
Cutoff Tonnage Grade Contained Metal CuT % kt CuT% CuS% CuT (Mlb) CuS (Mlb) 0.7 8,330 1.02 0.77 187,389 140,688 0.5 13,465 0.86 0.65 254,437 193,064 0.3 19,358 0.72 0.55 306,717 233,642 0.2 21,108 0.68 0.52 316,625 240,809
Inferred Cutoff Tonnage Grade Contained Metal CuT % kt CuT% CuS% CuT (Mlb) CuS (Mlb) 0.7 3,588 0.93 0.66 73,397 52,085 0.5 8,025 0.74 0.55 130,845 97,613 0.3 14,138 0.59 0.44 184,203 137,158 0.2 16,820 0.54 0.40 199,113 146,881
13.17 General Considerations and Other Factors
Apart from the conditions identified in this report, and according to the available information, NCL is not aware of other environmental, permitting, legal title, taxation, socio- economic or political factors that could affect materially the Mineral Resource estimate.
14 Mining Method
The Marimaca deposit would be mineable by open pit methods
15 Recovery Methods
The Marimaca deposit would be exploited using heap leach methods to produce copper cathode via SXEW (solvent extraction and electrowinning).
16 Project Infrastructure
The project is located in an area of good existing infrastructure
17 Adjacent Properties
There are no adjacent properties of relevance
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18 Other Relevant Data and Information
Coro has signed a letter of intent to acquire Minera Rayrock, a subsidiary of Compañía Minera Milpo, which owns the Ivan SXEW plant, located ~20km to the south of Marimaca. Completion of this acquisition would allow for the Marimaca project to be operated in conjunction with Ivan
19 Conclusions and Recommendations
A team of independent consultants, under the leadership of NCL, was retained by Coro to visit Marimaca the second week of December 2016, inspect the project, review and audit the data and estimate the Mineral Resource. NCL examined the different sources of input information: raw data (QA/QC), exploration, geology and mineral modelling estimation units. The purpose of the investigation was to estimate the Mineral Resource, in compliance with generally recognized industry best practices and report them according to Canadian Institute of Mining, Metallurgy and Petroleum Definition Standards for Mineral Resources and Mineral Reserves (May 2014).
NCL carried out a Resource Estimation of the Marimaca Project, resulting in the estimation of Measured, Indicated and Inferred Resources, plus some potential mineralized rock. For a Cutoff grade of 0.2% CuT, the Resources inside an optimized pit envelope are 21.5 Mt @ 0.68 CuT of Measured + Indicated and 18.8 Mt @ 0.53% CuT Inferred resources. Based on the 2016 Mineral Resources estimation, the project is expected to continue under exploration during 2017.
Since 2016, aggressive exploration in Marimaca has defined oxides mineralization zones amenable to open pit mining and presents very good opportunities to expand the Mineral Resources and extend the life of the project. In this context, NCL recommends to continue the implementation of the exploration program proposed for 2017 (US$2 million). The regional exploration potential of the exploration properties remains good. Regional exploration targeting should be reviewed, including the use of high resolution geophysical data to enhance exploration targeting.
The technical information on Marimaca attests the high overall quality of the exploration and design work completed by site personnel. NCL examined the data, the exploration, and the geology modelling and produced the Mineral Resource estimates of Marimaca. On the basis of this work, NCL concluded that the models, Mineral Resources and Statements for Marimaca January 2017 are appropriately categorized and free of material errors.
Other than disclosed in this technical report, NCL is not aware of any other significant risks and uncertainties that could reasonably be expected to affect the reliability or confidence in the Marimaca Project.
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20 References
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Bissig y Riquelme, 2010, Contrasting landscape evolution and development of supergene enrichment in the El Salvador porphyry Cu and Potrerillos-El Hueso Cu–Au districts, Northern Chile. In: Titley, S. (Ed.), Society of Economic Geologists Special Publication No. 14, Supergene Environments, Processes and Products, pp. 59–68.
Blanchard, 1968; Interpretation of leached outcrops: Reno, Nevada Bur. Mines Bull. 66, 196 p
Carten, R.B., 1986, Sodium-Calcium metasomatism: chemical, temporal and spatial relationships at the Yerington, Nevada, porphyry copper deposit. Econ. Geol. Vol. 81, pp. 1495-1519
Casquet, C., Herve, F., Pankhurst, R.J., Baldo, E., Calderon, M., Fanning, C.M., Rapela, C.W., y Dahlquist, J., 2014, The Mejillonia suspect terrane (Northern Chile): Late Triassic fast burial and metamorphism of sediments in a magmatic arc environment extending into the Early Jurassic, Gondwana Research, 25, p. 1271-1286.
Chavez, W. X., 2000, Supergene oxidation of copper deposits: zoning and distribution of copper minerals. SEG Newsletter, N° 41
Cortes, J., Marquardt, C., Gonzales, G., Wilke, H.G., y Marinovic, N., 2007, Cartas Mejillones y Península de Mejillones, Región de Antofagasta, Serv. Nac. de Geol. y Min. Carta Geológica de Chile Nos 103 y 104, 63 p.
Espinoza, S., Véliz, H., Esquivel, J., Arias, J., y Moraga, A., 1996. The Cupriferous Province of the Coastal Range, Northern Chile. In: Camus, F., Sillitoe, R.H., and Petersen, R., eds. Andean Copper Deposits: New Discoveries, Depósitos Estratoligados de Cu -(Ag) Chilenos 11 Mineralization, Styles and Metallogeny. Society of Economic Geologists, Special Publication Number 5, pp. 19-32
González, G.; Dunai, T.; Carrizo, D.; Allmendinger, R., 2006. Young displacements on the Atacama Fault System, northern Chile from field observations and cosmogenic 21Ne concentrations. Tectonics.25
Gonzales, R., 2002, Geología de la Cordillera de la Costa de Mejillones, entre los 23°00’00’’ – 23°08’11,5’’ Sur y los 70°12’01,3’’ – 70°20’46,9’’ Oeste. Región de Antofagasta. Chile. Memoria Titulo de Geólogo. Univ Cat del Norte. Inédito. 129 p.
Gonzales, G., 1996, Evolución tectónica de la Cordillera de la Costa de Antofagasta (Chile). Con especial referencia a las deformaciones sinmagmáticas del Jurásico-Cretácico Inferior. Berl. Geowiss. Abh, Rethe A, 181, 1-111.
Hinostroza, J., y Medina, J., 2008, Evaluación geológica del prospecto Marimaca. Memorando, Minera Rayrock, Inédito, 7 p.
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Hervé, F., Faundez, V., Caldern, M., Massonne, H.-J. & Willner, A.P., 2007, Metamorphic and plutonic basement complexes, in The Geology of Chile, pp. 231–261, eds Moreno, T. & Gibbons, W., Geological Society of London.
Ilabaca, P., 2004, Resultados de los sondajes en la Mina Marimaca 1 al 23 (Distrito Minero Naguayan – II Región), ENAMI, Informe Inédito, 73 p.
Kuntz, J., 1928. Monografía minera de la provincia de Antofagasta, Boletin Minero, XL, N° 348, p. 190-209.
Lucassen, F., Becchio, R., Wilke, H.G., Franz, G., Thirlwall, M.F., Viramonte, J., Wemmer, K., 2000. Proterozoic–Paleozoic development of the basement of the Central Andes (18–26°). A mobile belt of the South American craton. Journal of South American Earth Sciences 13, 697–715
Maksaev, V., y Zentilli, M., 2002. Chilean strata-bound Cu- (Ag) deposits: An Overview. In - Porter, T.M. (Editor), 2002 - Hydrothermal Iron Oxide Copper-Gold & Related Deposits: A Global Perspective, volume 2; PGC Publishing, Adelaide, Australia, pp. 185-205
Putnis, A., y John, T., 2010, Replacement process in the Earth’s crust. Elements, vol.6, pp.159-164.
Ramírez, 2007, L., Metalogénesis, petrogénesis y tectónica del Distrito Minero de Mantos Blancos, Cordillera de la Costa, Norte de Chile, Tesis Doctorado en Ciencias, Univ. De Chile, Inédito, 178 p.
Richards, J.P., y Mumin, H., 2013, Magmatic-hydrothermal process within an evolving Earth: iron oxide-copper-gold and porphyry Cu-Mo-Au deposits, Geology, v.41, n°7, p.767-770.
Scheuber, E., y Andriessen, A.M., 1990, The kinematics and geodynamic significance of the Atacama Fault Zone, northern Chile. JSG,,12, 243-257.
Sillitoe, R.H., 2003, Iron Oxide-copper-gold deposits: an Andean view. Mineralium Deposita, 38, 787-812
Veliz, H., 1994; Antecedentes geológicos, deformación frágil e implicancias metalogénicas del sistema de Falla Atacama, entre las Quebradas El Desesperado y La Chimba. Cordillera de la Costa, Segunda Región de Antofagasta, Chile. Memoria Titulo de Geólogo. Univ Cat del Norte. Inédito. 137 p.
Venegas, R., y Vergara, M., 1985, Yacimientos de Fe-Cu-(Au) ligados a rocas intrusivas y volcánicas jurásicas de la Cordillera de la Costa a la latitud de Mejillones. II Región de Antofagasta. IV Congr. Geol. Chileno, Actas 3, 3/730-3/751
Vergara, M., 1985, Geología de los Distritos cupríferos Naguayán; Desesperado y Chacaya. II Región de Antofagasta. Tesis de Grado. Univ. Cat. Del Norte. Inédito, 80p.
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ANNEX 1
Lawyers Land Tenure Letter
Santiago, February 21st, 2017
Sergio Rivera
Legal Representative
Compañía Minera Cielo Azul Limitada
Via email
Ref.: Sociedad Contractual Minera Compañía Minera
Newco Marimaca Option Agreement
Dear Sergio,
As Chilean counsel to Compañía Minera Cielo Azul Limitada (“MCAL”), we have been asked to
advise on the status and legal condition of the Option Agreement over shares (the “Option Agreement”) of Sociedad Contractual Minera Compañía Minera Newco Marimaca (“Newco Marimaca”), a contractual mining company owner of the mining properties that form the mining project named “Marimaca”, located in the borough of Mejillones, province of Antofagasta, II Region, Chile (“Project”).
For the purposes of this opinion, we have examined originals or copies, certified or identified to our satisfaction, of the documents related to the Option Agreement (as defined herein below) and of such official public records, certificates of public officials and such other documents and have considered such questions of law and made such other investigations as we have deemed relevant or necessary as a basis for the opinion expressed herein.
We have assumed the genuineness of all signatures, the legal capacity of all individuals (other than Chilean individuals), the authenticity of all documents submitted to us as originals and the conformity to authentic original documents of all documents submitted to us as certified, conformed or photostatic copies or facsimiles thereof. We have also assumed the completeness, truth and accuracy of all facts set forth in the official public records, certificates and documents supplied by public officials or otherwise conveyed to us by public officials.
We are solicitors qualified to carry on the practice of law in Chile only and we express no opinion as to any laws or matters governed by any laws other than the laws of Chile.
In relation to the aforementioned, we can inform the following: a. Terms detailed in the Option Agreement for up to 75% of Newco Marimaca
On November 16, 2015, MCAL and the shareholders of Newco Marimaca (the “Owners”) entered into an option agreement for the said shares. Therefore, MCAL is the beneficiary of 2 options under the terms of Section 169 of the Chilean Mining Code, with the character of irrevocable and direct, to
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acquire the number of shares that are jointly equivalent to 75% of the total of the shares of Newco Marimaca, according to the following terms:
1) First Option: 51% of the total shares for a price of USD $ 185,000, whose term for exercising the said option expires on August 6th, 2018.
2) Second Option: 24% of the total shares for a price of USD $ 1,000, whose term for exercising the said option expires 24 months after the acquisition date of 51% of the total shares as a result of having exercised the abovementioned First Option.
Consequently, if both options are exercised, the Owners will only jointly own the remaining 25% of the shares of Newco Marimaca, being released from the obligation of concurrence for any expense, investment or quota determined by the Shareholders Meeting, until the beginning of the commercial production and up to 15% of the share capital, being obliged to compete only with respect to the remaining 10%, subject to the fact that - if they do not concur in that percentage - they may be subject to dilution. In the event that the Owners so wish, MCAL will be able to lend the amount corresponding to the concurrence in the expenses up to that indicated 10%, with current interest rate for non-adjusting operations in force to date, credit that will be solved preferably to any distribution of any nature to be made to the partners.
In the event that MCAL exercises the First Option and acquires 51% of the total shares of Newco Marimaca, a Shareholders Agreement will be subscribed to regulate certain aspects of its relationship as partners and the management of the company. With regard to the transfer of shares, the said Agreement will establish the right of preferential option of the other partners. b. Incorporation of Newco Marimaca and participation of the partners
By public deed dated September 23rd, 2015 Mrs. María Aura del Carmen Echanes Morgado, Mr. Mario Carrizo Darlington, Mr. Max Salomón Carrizo Echanes and Mr. Mario Carrizo Echanes incorporated Newco Marimaca. The said company is registered on page 2097 number 528 of the Property Registry and its shares on page 4271 number 80 of the Shareholders Registry, both corresponding to the year 2015 of the Mining Registrar of Antofagasta.
The social capital amounts to $ 25,000,000 Chilean pesos and comprise the exploitation mining concessions "MARIMACA 1 AL 23", located in the borough of Mejillones, province of Antofagasta, II Region, whose judicial award and measurement minute are registered on page 234 number 73 of the Property Registry of the Mining Registrar of Antofagasta, corresponding to the year 1981, and the money that is detailed below and that the constituent partners contribute to the company. The social interest is divided into 100 shares, which are subscribed and paid as follows:
1) 25 shares, which Mario Carrizo Darlington subscribed by means of contributing to the company the exploitation mining concessions named "MARIMACA 1 to 4", "MARIMACA 10 to 14" and "MARIMACA 17 to 23", whose title in favor of the contributor Mario Carrizo Darlington is registered on page 338 number 199 of the Property Registry of the Mining Registrar of Antofagasta, corresponding to the year 1988, which the partners agree to value in the sum of $ 5,000,000 Chilean pesos;
2) 25 shares, subscribed by María Aura del Carmen Echanes Morgado through the contribution of the exploitation mining concessions named "MARIMACA 5 to 9", whose title in favor of the contributor María Aura Echanes Morgado is registered on page 617 number 125 of the Property Registry of the Mining Registrar of Antofagasta, corresponding to the year 1991, which the partners agree to value in the sum of $ 5,000,000 Chilean pesos;
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3) 25 shares, subscribed by Max Salomón Carrizo Echanes through the contribution of the exploitation mining concessions named "MARIMACA 15" and "MARIMACA 16", whose title in favor of the contributor Max Salomón Carrizo Echanes is registered on page 1041 number 220 of the Property Registry of the Mining Registrar of Antofagasta, corresponding to the year 2013, which the partners agree to value in the sum of $ 5,000,000 Chilean pesos; and
4) 25 shares, subscribed by Mr. Mario Alfonso Carrizo Echanes in the incorporation act and that he will pay by means of the contribution in money of the sum of $ 5,000,000 Chilean pesos within the term of one year counted from the date of the incorporation public deed.
All previously identified mining concessions were contributed to Newco Marimaca according to registrations on page 2099 number 530 and page 2100 number 531, both in year 2015, and on page 3100 number 1122 of year 2016, all of the Property Registry of the Mining Registrar of Antofagasta. c. Current status of the registration of the Option Agreement in the Mining Registrar of Antofagasta
Both the First and the Second Option of the irrevocable Option Agreement for the Newco Marimaca shares are registered on page 69 number 1 and page 70 number 2 of the Encumbrances and Prohibitions Register of the Shareholders’ Book of the Mining Registrar of Antofagasta corresponding to year 2016.
The prohibition of encumbering and disposing of Newco Marimaca shares is registered on page 71 number 3 of the Encumbrances and Prohibitions Register of the Shareholders’ Book of the Mining Registrar of Antofagasta corresponding to year 2016.
The prohibition of encumbering and disposing of the mining concessions contributed by María Aura del Carmen Echanes Morgado ("MARIMACA 5 AL 9") and Max Salomón Carrizo Echanes ("MARIMACA 15" and "MARIMACA 16") are registered on page 75 number 8 of the Prohibitions and Interdictions Registry of the Mining Registrar of Antofagasta corresponding to year 2016. The registration of the prohibition of encumbering and disposing of the mining concessions contributed by Mario Carrizo Darlington ("MARIMACA 1 AL 4", "MARIMACA 10 AL 14" and "MARIMACA 17 AL 23") is pending at the Mining Registrar of Antofagasta. d. Deadlines and conditions that must be complied with to exercise the First and Second Option for the 51% and then 75% of the shares respectively (future conditions) for owning the shares and mining property.
The contract in question is an irrevocable option to purchase shares of a contractual mining company, to which the mining concessions of the Project were contributed. Therefore, MCAL will not acquire ownership of these concessions, but shares in a company that owns the said mining concessions.
However, under the Option Agreement, the Owners of the shares of Newco Maricama encumbered their shares and the mining concessions of the Project that were contributed to the said company with a prohibition in favor of MCAL, forcing them not to encumber or alienate them or celebrate contracts of any kind with respect to them, which shall remain in force for the term of the Second Option and, as the case may be, until the granting and registration of the deed of exercise or acceptance of the Second Option. During the validity of the options, Newco Marimaca will not be able to assign or transfer to third parties, in any capacity, royalties or rights to extract minerals from the mining concessions of the Project.
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The terms and conditions to exercise the irrevocable options over the Newco Marimaca shares are as follows:
1) First Option: 51% of the total of the shares for a price of USD $185,000, whose term for exercising the said option expires on August 6th, 2018. The price will be paid in installments (USD $10,000 on August 7th, 2014; USD $50,000 on April 6th, 2015; USD $125,000 at the time of accepting the offer and exercising the option). As a condition for exercising this option: a) MCAL shall carry out at its cost a Project Feasibility Study, i.e. execute a set of studies and necessary reports to determine the technical and economic feasibility of commercially exploiting the minerals contained in one or more of the Project's mining properties, considering a minimum production of 1,500 tons of copper per year. This Feasibility Study should comply with the standards and requirements imposed by National Instrument 43-101 of Canada, should contain all the information, analysis and recommendations that are usually required by international financial institutions for the purpose of deciding whether or not to concur, and if they decide to do so, in what conditions, to the financing of all or part of the Project's funding requirements, and must pronounce, positively or negatively, on the feasibility and desirability of constructing the Project. b) The Owners may not require MCAL to comply with the preceding condition if, within 90 days from the signing of the Option Agreement, they do not raise all liens, mortgages and prohibitions affecting the mining properties and if they do not register them under the domain of Newco Marimaca in the respective Mining Registrar.
2) Second Option: 24% of the total shares for a price of USD $ 1,000, whose term for exercising the said option expires 24 months after the acquisition date of 51% of the total shares as a result of having exercised the abovementioned First Option. As a condition for exercising this option: a) MCAL must have obtained the necessary financing for the construction of the Project, in accordance with the conclusions of the Feasibility Study.
If you require any further information or clarification, please let me know.
Yours sincerely,
Technical Report for the Marimaca Copper Deposit Page 90 Coro Mining Corp NCL SpA
List of Mining and Exploration Concessions
PROYECTO MARIMACA CONCESIONES MINERAS MINERA CIELO AZUL LTDA
Concesiones de Explotación
Concesión Presentación Juzgado Rol Nº Inscripción Fjs Nº Conservador Situación
Miranda II 1/225 08-ago-16 1º Antofagasta V-526 22-ago-16 4712 2840 Antofagasta En trámite Miranda IV 1/150 08-ago-16 2º Antofagasta V-580 22-ago-16 4714 2842 Antofagasta En trámite Miranda III 1/150 08-ago-16 3º Antofagasta V-544 22-ago-16 4713 2841 Antofagasta En trámite Miranda I 1/210 08-ago-16 4º Antofagasta V-567 22-ago-16 4711 2839 Antofagasta En trámite Concesiones de Exploración
Concesión Presentación Juzgado Rol Nº Inscripción Fjs Nº Conservador Situación
Miranda 19 08-ago-16 1º Antofagasta V-524 22-ago-16 4716 2844 Antofagasta En trámite Miranda 22 08-ago-16 1º Antofagasta V-525 22-ago-16 4719 2847 Antofagasta En trámite Chacaya 16 08-ago-16 2º Antofagasta V-578 22-ago-16 4722 2850 Antofagasta En trámite Miranda 20 08-ago-16 2º Antofagasta V-579 22-ago-16 4717 2845 Antofagasta En trámite Chacaya 15 08-ago-16 3º Antofagasta V-542 22-ago-16 4721 2849 Antofagasta En trámite Miranda 23 08-ago-16 3º Antofagasta V-543 22-ago-16 4720 2848 Antofagasta En trámite Miranda 18 08-ago-16 4º Antofagasta V-565 22-ago-16 4715 2843 Antofagasta En trámite Miranda 21 08-ago-16 4º Antofagasta V-566 22-ago-16 4718 2846 Antofagasta En trámite Miranda 2 15-jun-16 1º Antofagasta V-407-2016 01-jul-16 3756 2226 Antofagasta En trámite Miranda 6 15-jun-16 1º Antofagasta V-408-2016 01-jul-16 3764 2230 Antofagasta En trámite Miranda 11 15-jun-16 1º Antofagasta V-409-2016 01-jul-16 3774 2235 Antofagasta En trámite Miranda 15 15-jun-16 1º Antofagasta V-410-2016 01-jul-16 3782 2239 Antofagasta En trámite
Miranda 4 15-jun-16 2º Antofagasta V-458-2016 01-jul-16 3760 2228 Antofagasta En trámite Miranda 8 15-jun-16 2º Antofagasta V-459-2016 01-jul-16 3768 2232 Antofagasta En trámite Miranda 12 15-jun-16 2º Antofagasta V-460-2016 01-jul-16 3776 2236 Antofagasta En trámite Miranda 16 15-jun-16 2º Antofagasta V-461-2016 01-jul-16 3784 2240 Antofagasta En trámite Miranda 3 15-jun-16 3º Antofagasta V-420-2016 01-jul-16 3758 2227 Antofagasta En trámite Miranda 7 15-jun-16 3º Antofagasta V-421-2016 01-jul-16 3766 2231 Antofagasta En trámite Miranda 10 15-jun-16 3º Antofagasta V-422-2016 01-jul-16 3772 2234 Antofagasta En trámite Miranda 14 15-jun-16 3º Antofagasta V-423-2016 01-jul-16 3780 2238 Antofagasta En trámite Miranda 1 15-jun-16 4º Antofagasta V-446-2016 01-jul-16 3754 2225 Antofagasta En trámite Miranda 5 15-jun-16 4º Antofagasta V-447-2016 01-jul-16 3762 2229 Antofagasta En trámite Miranda 9 15-jun-16 4º Antofagasta V-448-2016 01-jul-16 3770 2233 Antofagasta En trámite Miranda 13 15-jun-16 4º Antofagasta V-449-2016 01-jul-16 3778 2237 Antofagasta En trámite Miranda 17 15-jun-16 4º Antofagasta V-450-2016 01-jul-16 3786 2241 Antofagasta En trámite Naguayan 1 24-nov-14 2º Antofagasta V-1388 06-ago-15 4374 2514 Antofagasta Constituída Naguayan 2 24-nov-14 2º Antofagasta V-1389 06-ago-15 4376 2515 Antofagasta Constituída Naguayan 3 24-nov-14 2º Antofagasta V-1390 06-ago-15 4379 2516 Antofagasta Constituída Naguayan 5 24-nov-14 2º Antofagasta V-1392 06-ago-15 4384 2518 Antofagasta Constituída Naguayan 6 24-nov-14 2º Antofagasta V-1393 06-ago-15 4386 2519 Antofagasta Constituída Naguayan 9 24-nov-14 2º Antofagasta V-1396 06-ago-15 4392 2522 Antofagasta Constituída Naguayan 10 24-nov-14 2º Antofagasta V-1397 06-ago-15 4394 2523 Antofagasta Constituída Naguayan 11 24-nov-14 2º Antofagasta V-1398 06-ago-15 4397 2524 Antofagasta Constituída Naguayan 12 24-nov-14 2º Antofagasta V-1399 06-ago-15 4399 2525 Antofagasta Constituída Naguayan 13 24-nov-14 2º Antofagasta V-1400 06-ago-15 4401 2526 Antofagasta Constituída Naguayan 14 24-nov-14 2º Antofagasta V-1401 06-ago-15 4403 2527 Antofagasta Constituída
Chacaya 1 24-nov-14 2º Antofagasta V-1402 06-ago-15 4346 2500 Antofagasta Constituída Chacaya 2 24-nov-14 2º Antofagasta V-1403 06-ago-15 4348 2501 Antofagasta Constituída Chacaya 3 24-nov-14 2º Antofagasta V-1404 06-ago-15 4350 2502 Antofagasta Constituída Chacaya 4 24-nov-14 2º Antofagasta V-1405 06-ago-15 4352 2503 Antofagasta Constituída Chacaya 5 24-nov-14 2º Antofagasta V-1406 06-ago-15 4354 2504 Antofagasta Constituída Chacaya 6 24-nov-14 2º Antofagasta V-1407 06-ago-15 4356 2505 Antofagasta Constituída Chacaya 7 24-nov-14 2º Antofagasta V-1408 06-ago-15 4358 2506 Antofagasta Constituída Chacaya 8 24-nov-14 2º Antofagasta V-1409 06-ago-15 4360 2507 Antofagasta Constituída Chacaya 9 24-nov-14 2º Antofagasta V-1410 06-ago-15 4362 2508 Antofagasta Constituída Chacaya 10 24-nov-14 2º Antofagasta V-1411 06-ago-15 4364 2509 Antofagasta Constituída Chacaya 11 24-nov-14 2º Antofagasta V-1412 06-ago-15 4366 2510 Antofagasta Constituída Chacaya 12 24-nov-14 2º Antofagasta V-1413 06-ago-15 4368 2511 Antofagasta Constituída Chacaya 13 24-nov-14 2º Antofagasta V-1414 06-ago-15 4370 2512 Antofagasta Constituída Chacaya 14 24-nov-14 2º Antofagasta V-1415 06-ago-15 4372 2513 Antofagasta Constituída Naguayan 4 26-nov-14 2º Antofagasta V-1420 06-ago-15 4382 2517 Antofagasta Constituída Naguayan 7 26-nov-14 2º Antofagasta V-1421 06-ago-15 4388 2520 Antofagasta Constituída Naguayan 8 26-nov-14 2º Antofagasta V-1422 06-ago-15 4390 2521 Antofagasta Constituída
Technical Report for the Marimaca Copper Deposit Page 91 Coro Mining Corp NCL SpA
Detailed Mining and Surface Rights Maps
Technical Report for the Marimaca Copper Deposit Page 92 Coro Mining Corp NCL SpA
Technical Report for the Marimaca Copper Deposit Page 93 Coro Mining Corp NCL SpA
ANNEX 2 MCAL splitting protocols, recovery and sample collection protocols
RC DRILLHOLES PROTOCOLS Field
Location of field recommendations with GPS in corrected Table of recommendations in excel PSAD56 coordinates Construction of platform and staking of the recommendation Control shift equipment with lime mark in azimuth Verification of equipment installation with compass and inclinometer Drilling bit diameter register Report scanned drill holes Database with serial numbers and identification of control Registration in excel and serial cards samples (B), reference materials and duplicates Preparation of materials: bags; Labels, cutting boxes Serial Sample Cards Report of shift, log diameter and other operational Report scanned drill holes Continuous sampling every 2 m Report scanned drill holes Collection and quartet in riffles Controller observation Control of mass in situ shows total and in 1st and 3rd quartet Record in notebook / report Samples A and B are pocketed in plastic bags 40x60 labeled with probing, interval, series with bracket ticket Sample of cutting, plastic box 20 divisions thick and thin, back Physical backing bag of approx 1 kg Sample B is stored in the site Physical backing Guide (1) preparation request, pulps in Sample A is sent to mechanical preparation three envelopes, rejection is eliminated Transportation of samples by truck from project to laboratory Guide (1) preparation request Identification of the collar using PVC pipe and metal plate with Physical location the name of the well Measurement of deflection and orientation of structures Meter Report Measurement of collar location with topography Definitive certificate of coordinates Laboratory
Data to lab control system. Mass control Lab receiving and mass control report in excel + physical table and particle size control every xxx samples Mechanical Preparation Preparation Protocols Drying 105 ° C Preparation Protocols Sieving and crushing 85% low # 10 Preparation Protocols Rotary divider split Preparation Protocols Spray 500-700 g 95% low # 150 Preparation Protocols Obtain three envelopes of pulps 2 of 125g and 1 of 250 g Preparation Protocols Send the envelopes to MCAL to generate lots of analysis
MCAL receiving pulps Received in physical Standard revision according to shipping guides to preparation Revision against shipping guides (1) Insertion of control samples, reference materials and duplicates of 2 ° on Test request guide (2) with attached detail Shipping to chemical analysis of samples sent (according to master table)
Technical Report for the Marimaca Copper Deposit Page 94 Coro Mining Corp NCL SpA
Chemical analysis
Reception of batches of pulps
CuT: 1 g digestion with 10 ml mixture HNO3 + 4 ml HClO4 + 1 Chemical analysis protocols ml H2SO4 in 20 ml dilution of 50% HCl for a 100 ml gauge flask Quantification with AAS limit of detection of 0.01% for CuT Chemical analysis protocols CuS: 1 g leaching with 50 ml H2SO4 in 250 ml gauge flask, Chemical analysis protocols shaking at 130 RPM for 1 hour Quantification with AAS limit of detection of 0.01% for CuT Chemical analysis protocols Laboratory reports in excel sheet by lots of MCAL receiving results and Qa-Qc approx 50 samples Input of results to database Excel table Review of control samples according to Qa-Qc system Excel chart charts and statistics Under Qa-Qc re-analysis is requested (new reception circuit- Excel table review results) Validated results are sent to users Excel table Excel table with backs of physical Official database certificates of laboratory Chemical Results Master Chart
Table with masses - recoveries
Operating time chart
Tables of Qa-Qc
Excel tables with lab results - digital files
Physical backups
Samples B (MAR 17 to 54)
Cutting boxes and backing
Pulps
DDH PROTOCOLS Field
Location of field recommendations with GPS in corrected Table of recommendations in excel PSAD56 coordinates Construction of platform, settling pool, and staked Control shift equipment recommendation with lime mark on azimuth Verification of equipment installation with compass and inclinometer Drilling diameter registration
Obtaining the control sample according to drilling races
Sample is available in aluminum trays, runs provided by wooden blocks (white color) Record drilling depths and recoveries Report scanned drill holes Transfer of tray to sample and first geological revision
Race review, recoveries and regularization at intervals of 2 m Registration of careers and regularized marked with wooden blocks (yellow) sections with their recovery measures Geotechnical mapping and identification of PU specimens and Logging in geotechnical tests Photograph of trays of witnesses (in natural light) Photographic record Weighing of each tray Weight record of trays with full control Geological mapping Log
Technical Report for the Marimaca Copper Deposit Page 95 Coro Mining Corp NCL SpA
Database with serial numbers and identification of control Registration in excel and serial cards samples (B), reference materials and duplicates Preparation of materials: bags; Labels. Serial Sample Cards Sampling by hydraulic guillotine break at intervals of 2 m and shelf in plastic bags 40x60 labeled with probing, interval, series
with clasped ticket Weighing of each sample Weight register Tray Weighing (sample quality check) Tray weight register with half control Photo of trays with half of witnesses (in natural light) Photo Registration Tray storage
Transportation of samples by truck from project to laboratory
Identification of the collar using PVC pipe and metal plate with Physical location the name of the well Measurement of deviation Meter Report Measurement of collar location with topography Definitive certificate of coordinates Data to lab control system. Mass control Lab receiving and mass control report in excel + physical table and granulometric control every xxx samples Mechanical preparation Preparation Protocols Drying 105 ° C Preparation Protocols Sieving and crushing at 1/4 "
Sieving and crushing 85% low # 10 Preparation Protocols Rotary divider split Preparation Protocols Spray 500-700 g 95% low # 150 Preparation Protocols Obtain three envelopes of pulps 2 of 125g and 1 of 250 g Preparation Protocols Sending the envelopes to MCAL to generate lots of analysis
Pulp reception Physical reception Serial revision according to shipping guides to preparation Revision against shipping guides (1) Insertion of control samples, reference materials and duplicates of 2 ° on Analysis request guide (2) with attached Shipping to chemical analysis detail of submitted samples (according to master table) Reception of batches of pulps
CuT: 1 g digestion with 10 ml mixture HNO3 + 4 ml HClO4 + 1 ml H2SO4 in 20 ml diluent of 50% HCl for a 100 m capacity Chemical analysis protocols flask l Quantification with AAS limit of detection of 0.01% for CuT Chemical analysis protocols CuS: 1 g leaching with 50 ml H2SO4 in 250 ml gauge flask, Chemical analysis protocols shaking at 130 RPM for 1 hour Quantification with AAS limit of detection of 0.01% for CuT Chemical analysis protocols Laboratory reports in excel sheet by lots of Reception of results and Qa-Qc approx 50 samples Input of results to database Excel table Review of control samples according to Qa-Qc system Excel chart graphs and statistics Under Qa-Qc re-analysis is requested (new circuit of reception- Excel table revision of results) Validated results are sent to users Excel table
Technical Report for the Marimaca Copper Deposit Page 96 Coro Mining Corp NCL SpA
Excel table with backs of physical Official database certificates of laboratory Chemical Results Master Chart
Table with recoveries of races and regularization
Table with masses of trays and samples
Operating time chart
Tables of Qa-Qc
Excel tables with lab results - digital files
Physical backups
Preparation reject at -10 #
Half Wit Trays
Pulps
OTHER PROCEDURES PU Test Tubes Serial identification Photography Geological description (Rx-ZAL-ZMIN) Uniaxial Loading Probes ID Photography Serial identification PU samples made on full-length and full-length test specimens Pre and post test photo lab registration Metallurgical samples Interval selection table Tray Extraction Record of weights sub-samples of 2 m Bags, sample number, bag number Shipping to lab
Technical Report for the Marimaca Copper Deposit Page 97 Coro Mining Corp NCL SpA
Signature Page: Technical Report for the Marimaca Copper Project, Antofagasta Province, Region III, Chile
Prepared for: Coro Mining Corporation
Prepared by: NCL Ingenieria y Construccion SpA
NCL Project Number: 1631 Effective date: January 27th 2017 Signature date: January 27th 2017
Authored by: Luis Oviedo, P. Geo.
CERTIFICATE OF QUALIFIED PERSON
I, Luis Oviedo, P.Geo, am consultant as QP with NCLand I have an employment address at 235, General del Canto, Providencia, Santiago de Chile- This certificate applies to the technical report titled “Technical Report for the Marimaca, Copper Project, Antofagasta Province, Region II, Chile” that has an effective date of 24th February 2017 (the “technical report).
I am a registered Professional Geologist (P.Geo.) in Chile. I am registered member of the Comisión Calificadora de Competencias en Recursos y Reservas Mineras (Chilean Mining Conmission: RM, CMC) with the number 013. I graduated with a Geologist degree from the University of Chile in 1977. Postgraduate “Evaluation and Certification of Mining Assets”. Queen’s University Canada and Universidad Católica of Valparaíso, Chile. . I have practiced my profession for 40 years since graduation. I have practiced for more than 40 years. I have been directly involved in resource estimates for all types of mines, audits, half-lives and technical reports of resources for stock exchanges and financial institutions in Canada, Chile, Peru, Ecuador and Colombia. I am a “qualified person” as that term is defined in NI 43-101 - Standards of Disclosure for Mineral Projects (“NI 43-101”), JORC and other stock exchanges in the world.
I visited the Marimaca Project (the “Project”) the second week of December, 2016. I am responsible for the total report..
I am independent of Coro Mining Corp. as independence is described by Section 1.5 of NI 43–101. I have been involved with the Project since November 2016 as part of preparation of the Resources Estimation study.
I have read NI 43–101 and the sections of the technical report for which I am responsible have been prepared in compliance with NI 43–101 .
As of the effective date of the technical report, to the best of my knowledge, information and belief, the sections of the technical report for which I am responsible contain all scientific and technical information that is required to be disclosed to make those sections of the technical report not misleading.
Dated: 24th February 2017
Signed and sealed
Luis Oviedo H. PGeo, QP
Technical Report for the Marimaca Copper Deposit Page 98 Coro Mining Corp NCL SpA
Technical Report for the Marimaca Copper Deposit Page 99 Coro Mining Corp NCL SpA