MEXICO IN THE STATE OF MICHOACAN: THE INGUARAN VALLEY PORPHYRY COPPER-TUNGSTEN PROJECT
INTRODUCTION
Rome Resources Ltd. concentrates its exploration activities in Argentina and Mexico (Fig. 1). Emphasis is on acquisition and development of copper, tungsten, silver and gold properties. The main projects in Mexico are in Michoacan and in Sonora. Focus in Michoacan is on the Inguaran Valley Porphyry Copper-Tungsten Project, which is about 25 kilometers east of La Huacana and 50 kilometers east of the capital Morelia. Porphyry copper prospects in the San Isidro area of Michoacan are also held. Exploration in Sonora includes the: (i) La Colorada Bulk-Mineable Gold Project, about 40 kilometers east of the capital city Hermosillo, (ii) Los Muertos Bulk-Mineable Silver-Gold Project, about 80 kilometers southeast of Hermosillo, and (iii) Don Luis Bulk Tungsten-Gold Greisen-Porphyry Project, about 45 kilometers north of Hermosillo. This article describes the Inguaran Valley Porphyry Copper-Tungsten Project, which is about 25 kilometers east of La Huacana and 50 kilometers east of the capital Morelia in the State of Michoacan, Mexico (about 300 km west-southwest of Mexico City).
General information on exploration of these projects is available in News Releases, etc., that are available on SEDAR (click “Investors”) and at www.RomeResources.com (click “News”). Specifically, the web site gives detailed geological descriptions and assays from the main properties (click “Projects” and select exploration of interest). Additional tables, maps, etc., detailing with property ownership, geology, geophysics, geochemistry and drilling also are available in Rome’s Annual Reports for 2006 and 2007 (click “Annual Reports”).
Figure 1. Rome’s exploration focus includes the: (i) Varvarco Gold Vein and Porphyry Project in Neuquen, Argentina, (ii) Inguaran Valley Porphyry Copper-Tungsten Project in Michoacan, Mexico, (iii) La Colorada Bulk Gold Project in Sonora, Mexico, (iv) Los Muertos Bulk Silver-Gold Project in Sonora, Mexico, and (v) Don Luis Bulk Tungsten-Gold Greisen-Porphyry Project in Sonora, Mexico.
PROPERTIES: INGUARAN
Rome’s Inguaran Valley Porphyry Copper-Tungsten Project in the Inguaran Valley consists of concessions that total 10,209 hectares (Table 1, & Figs. 1 & 2 to 5). All concessions (Table 1) are wholly owned by Roma Recursos de Mexico, S.A. de C.V., a wholly owned subsidiary of Rome Resources Ltd., with the following exceptions that: (i) La Verdosa is subject to a 1.0% net smelter return payable to the Mexican government, and (ii) Concepcion and San Jose are under option.
Rome’s Inguaran Valley Porphyry Copper-Tungsten Project surrounds, but does not include, the Inguaran Copper Mine (Fig. 2). The Inguaran block-caved mine was operated by Asarco from the 1970’s to early 1980’s. Production reported was about 10 million tonnes averaging 1.2% copper.
TABLE 1. Rome’s Properties (Figs. 1 ro 5) in the Inguaran Valley Porphyry Copper-Tungsten Project in Michoacan, Mexico.
| CONCESSION NAME | AREA IN HECTARES |
| ANALI | 150.0 |
| COYOTES | 3,475.0 |
| MANGA | 250.0 |
| POTURO 1 | 672.8 |
| POTURO 2 | 1,158.1 |
| SAN PATRICIO | 1,700.0 |
| SAN PATRICIO II | 291.8 |
| SAN PEDRO | 2,012.8 |
| LA VERDOSA | 378.2 |
| SAN JOSE | 60.0 |
| LA CONCEPCION | 59.9 |
| TOTAL: 11 CONCESSIONS |
10,208.6 HECTARES |
Figure 2. Location of Rome’s Inguaran Valley Porphyry Copper-Tungsten Project in Michoacan, Mexico (Table 1). Properties held by Rome are outlined in black (the small patterned area within the Inguaran Valley Block that surrounds the Inguaran Mine is not included). All properties held are wholly owned, with the exceptions that: (i) La Verdosa is subject to a 1.0% net smelter return payable to the Mexican government, and (ii) Concepcion and San Jose are under option.
GEOLOGY, GEOCHEMISTRY, GEOPHYSICS & DIAMOND DRILL RESULTS: INGUARAN
Figure 3. Regional geology of the Tertiary San Isidro and Inguaran batholiths and location of a postulated “abyssal fault”. Copper showings are marked; the major ones are La Verde, San Isidro, Inguaran and Anali. Rome holds concessions in the general areas marked by green ovals. Significant exploration features related to Rome properties here are: (i) the “abyssal fault” that might be a major control on porphyry deposit emplacement [as it is for a number of famous porphyry deposits along the West Fissure Fault in Chile], and (ii) the zoning in the Inguaran batholiths from granodiorite-rim to granite-core-hosted porphyry deposits [similar to the zonation related to the world-class Valley Copper Mine in the Guichon batholith, British Columbia].
Mineralization in Rome’s properties have been explored along three northwest trending zones called: (i) Anali, (ii) Dos Cerritos (on the southwestern and northeastern side of the valley, respectively), and (iii) El Toro (eastern extension of Dos Cerritos). This property is prospective for one or more important low-grade porphyry copper deposits in the fifty to hundred million tonne category. The following analysis is a compilation and overview of all geophysical and geochemical exploration data collected on the Inguaran Valley Porphyry Copper Project since exploration commenced in 2003. Included are results of two diamond drill programs in 2004, and 2006 to 2007. Drill holes for these programs are located in Figures 4 and 5.
The diamond drilling program in December 2004 of 12 holes, totaled 2,681 meters (Table 3), and eleven trenches totaled 350 meters (black dots in Figs. 4 & 5). The best hole in the Anali Zone (ING04DD12) intersected 34.0 meters with a weighted average of 0.91% copper, and the best trench in the Anali zone intersected 58.0 meters of 0.91% copper and 58 meters of 0.73% copper. The best hole in the Dos Cerritos Zone (ING04DD11) intersected 42.0 meters with a weighted average of 1.18% and the best trench in the Dos Cerritos Zone (ING04TR12) intersected 20.0 meters (open at both ends) of 1.10% copper. Weighted average copper intersections and grades in diamond drill holes and trenches are 422.0 meters at 0.82% copper. Average of diamond drill hole check samples, mainly from the Anali and Dos Cerritos Zones, above a cut-off of 0.4 percent copper was: 284 meters of copper mineralization averaging 0.83% copper, 0.0004 percent molybdenum, 0.113 g/t gold, 3.63 g/t silver and 3.73 g/t tungsten.
A 3,000 meter diamond drilling program from November 2006 to January 2007 has been completed (Table 4, and green dots in Figs. 4 & 5). This program mainly tested geochemical and geophysical anomalies in the El Toro and Esmeralda Zones in the northeastern portions of the area held by Rome. Results indicated mainly strong copper veins in the El Toro Zone; these are characteristic of mineralization peripheral to major porphyry mineralization.
Figure 4. Soil copper geochemistry in Rome’s Inguaran Valley Porphyry Copper-Tungsten Project in Michoacan, Mexico. Red contours are greater than 200 ppm copper. Drill holes from 2004, and 2006 to 2007 are marked black and green, respectively.
Figure 5. Induced polarization, Frazer filtered, over Rome’s Inguaran Valley Porphyry Copper-Tungsten Project in Michoacan, Mexico. Red contours are chargeability greater than 6. Drill holes from 2004, and 2006 to 2007 are marked black and green, respectively.
The Anali Zone (Table 3, Figs. 14 & 15) was drilled in the program of 2004. The zone is characterized by intense phyllic alteration characteristic of porphyry style mineralization, which is similar to the mineralization in the Dos Cerritos Zone (Tables 3 & 4, & Figs. 14 & 15). There are a number of important copper intersections in this zone, as detailed in Table 3. Copper grades in several holes in this zone are significant. Consequently, a compilation of data from this zone is in progress.
The Dos Cerritos Zone (Tables 3 & 4, and Figs. 14 & 15) was initially drilled in the program of 2004. One hole was drilled in 2006. The zone is characterized by intense phyllic alteration characteristic of porphyry style mineralization, which is similar to the mineralization in the Anali Zone (Table 4, Figs. 14 & 15). Copper grades in several holes in this zone are significant. Consequently, a compilation of data from this zone is in progress.
The El Toro Zone is characterized by intense induced polarization chargeability anomalies (Tables 3 & 4, & Figs. 14 & 15) and is marked by a number of old pits and an old adit at the El Toro Mine. A trench near this adit, reported in the 2004 program, yielded 0.46% copper over 6 meters. Mineralization encountered in the current drilling program was mainly in wide veins mineralized with chalcopyrite, pyrrhotite, and locally, sphalerite. Traces of pyrite, arsenopyrite and galena were also noted. Such veins can be economic in their own right, as indicated in the assays of up to 2.82% copper in Table 4. However, this type of vein is characteristic of mineralization peripheral to porphyry systems. The proximity of the El Toro zone to porphyry systems is further indicated by the intersection in some holes of hydrothermal breccias, albeit these breccias are weakly mineralized with copper. This El Toro Zone, and some of the hydrothermal breccias encountered in the drilling, flanks a circular geological feature, which merits further attention.
The Esmeralda Zone (Table 4, & Figs. 14 & 15) hosts several high-grade copper bearing veins and breccias bodies explored and mined by old workings. Drilling was designed to determine whether or not large tonnage, porphyry style phyllic alteration and copper mineralization occurred on the property. One drill hole encountered 0.36% copper over 24 meters that was mainly within a hydrothermal breccia. Although this intersection is interesting, the grades in the other holes on the property were not encouraging. Consequently, Rome’s option on the Esmeralda property was dropped.
TABLE 2. Assay results from the 2004 diamond drill holes (black dots in Figs. 14 & 15) on the Inguaran Valley Porphyry Copper-Tungsten Property in Michoacan, Mexico. Intersections (true widths undetermined) with 0.4 and 0.8 percent cut-off copper are listed. Overall interval and grade in hole, at or above cut-off 0.4% copper, are in bold face. Red marks intervals with greater than 1.0% copper.
| DRILL HOLE | INTERVAL (METERS) | COPPER (%) |
| ANALI ZONE: ING04DD01 | 96.5 | 0.51 |
| ANALI ZONE:ING04DD02 | 38.0 | 0.94 |
| ANALI ZONE:ING04DD03 | 35.5 | 1.12 |
| ANALI ZONE: ING04DD05 | 2.0 | 0.46 |
| ANALI ZONE: ING04DD06 | 4.0 | 0.60 |
| DOS CERRITOS ZONE: ING04DD07 | 14.0 | 0.64 |
| EL TORO: ING04DD08 | 6.0 | 2.63 |
| EL TORO: ING04DD09 | 2.0 | 0.63 |
| DOS CERRITOS ZONE: ING04DD11 | 42.0 | 1.18 |
| ANALI ZONE: ING04DD12 | 34.0 | 0.91 |
TABLE 3. Assay results from the 2006 to 2007 diamond drill holes (green dots in Figs. 14 & 15) on the Inguaran Porphyry Copper-Tungsten Property in Michoacan, Mexico. Intervals highlighted in red are equal to or greater than 1.0% copper. Calculations are based on: (i) minimum and edge grades of 0.2% copper, (ii) minimum lengths of 6 meters, and (iii) allowed internal dilution of 8 meters at 0.1% copper.
| DRILL HOLE | INTERVAL (METERS) | COPPER (%) |
| EL TORO: ING06DD01 | 6.0 | 0.62 |
| DOS CERRITOS: ING06DD05 | 60.0 | 0.61 |
| ESMERALDA: ING06DD09 | 24.0 | 0.36 |
| EL TORO: ING07DD01 | 6.0 | 2.82 |
| EL TORO: ING07DD01 | 10.0 | 0.66 |
| EL TORO: ING07DD02 | 6.0 | 0.98 |
| EL TORO: ING074DD02 | 20.0 | 1.76 |
Positive geological features of the Inguaran Valley Porphyry Copper-Tungsten Project, include:
1. Location Rome’s properties within the Michoacan Copper Belt.
2. Association of Rome’s concession with several mines or significant deposits with important potential (e.g. La Verde, San Isidro, Inguaran and Anali).
3. Proximity of Rome’s properties to an “abyssal fault”—comparable to the famous West Fissure in Chile—that passes through the center of the Inguaran batholith and the property.
4. Central location of Rome’s concessions within the Inguaran batholiths, which is zoned from a granodiorite rim to a granite core—similar to the world-class Valley Copper Mine in south-central British Columbia.
5. A number of major copper occurrences (with significant tungsten) within Rome’s concessions that have geological, alteration, geophysical, geochemical, characteristics common to major porphyry copper deposits.
6. Ownership by Rome of the Anali Porphyry Copper Deposit or Zone that is ready for drill-testing for development of reserves.
7. Potential new discoveries to be found within a central-valley induced polarization chargeability anomaly and coincident anomalous soil copper geochemistry—an anomalous area about seven kilometers long (northwest – southeast) by three kilometers wide (northeast – southwest); in other words there are numerous geophysical and geochemical anomalies that remain to be drill tested.
8. Encouraging drill intersections of both porphyry copper style and vein mineralization that indicate that formal reserves can be established by additional drilling.
Rome’s Inguaran Valley Porphyry Copper-Tungsten Project in the Inguaran Valley has many features comparable to major calc-alkaline porphyry copper deposits in Chile and British Columbia. Mineralization encountered in drilling to date generally consists of the copper minerals bornite and chalcopyrite with trace pyrite and minor quartz in veins and microveins with phyllic envelopes. The near absence of pyrite is notable, because relatively minor chargeability anomalies could be highly prospective. In addition, several types of copper-mineralized breccia occur in the property. Wide, steeply dipping copper-rich veins also have been intersected. Detailed geophysical and geochemical profiles will facilitate the sophisticated targeting of additional drill holes. These profiling techniques will specifically enhance the evaluation of lower magnitude anomalies due to the lack of pyrite and/or a greater depth to sources.
FUTURE DEVELOPMENT ON THE INGUARAN VALLEY PORPHYRY COPPER-TUNGSTEN PROJECT
Ongoing exploration on the Inguaran Copper-Tungsten Porphyry Project involves, first of all, detailed evaluation of all data collected to date. Following this a program that will attempt to define reserves on the property will be proposed. Detailed diamond drilling on at least the Anali and Dos Cerritos Zones will be required.
QUALIFIED PERSON & CAUTIONARY NOTE
Colin I. Godwin, PhD, PEng, PGeo, is a Professor Emeritus of the Department of Earth and Ocean Sciences. He is President and Director of the Rome Resources Ltd., and is a qualified person as defined in National Instrument 43-101. He has verified the technical data disclosed in this description of the Inguaran Copper-Tungsten Porphyry Project in Michoacan, Mexico.
Rome Resources Ltd. is in the process of exploring its resource properties and has not yet determined whether the properties contain minerals or mineral reserves that are economically recoverable. The recoverability of the amounts shown for resource properties and any related deferred costs is dependent on the existence of economically recoverable mineral reserves, and the ability of Rome to obtain the necessary financing to complete the development and future profitable production from the properties or proceeds from the disposition thereof.
