Tectonic History and Metallogeny of Mexico with Focus on Epithermal Deposits of Copper Canyon, Chihuahua
Michael Feinstein
Mexico has a young geologic history, the oldest basement (Grenvillian) near the Gulf of Mexico has been rapidly accreted along the western margin since Mesozoic time. The accreted island arcs and the related subduction, magmatism, and tectonism created an ideal regime for the emplacement of world-class metals deposits.
Mexico has about 7 Metallogenic provinces, wherein the different metal deposits share chemical and structural characteristics. The world’s largest primary silver mine in Fresnillo is at the heart of the Altiplano Silver Province. Running along the western half of Mexico for nearly 1,300 kilometers, exists the largest tertiary volcanic province in the world. More than 250 calderas have been identified in the province that is characterized by a 1,000+m thick rhyolite series which overlies intermediate volcanics. Rapid extensional opening of the Gulf of California (only 8 Ma) served to dissect this terrain into extreme canyons (called barrancas).
In southwest Chihuahua State, there is an extensional juncture that created a “super barranca” which is known as the Cuenca de Oro (CDO), due to the occurrence of gold and silver along its margins. This region is federally known as Copper Canyon (CC) and it rivals the Grand Canyon (GC). The CC is much steeper than the GC and vegetation ranges from pine trees on the high plateau to tropical brush in the valleys, often more than a kilometer below.
El Sauzal, along the northern margin of the CDO, was the largest gold mine in Mexico when constructed in 1998 and was successfully decommissioned in 2015 after producing more than 2 million ounces gold. Batopilas, 20 km east of Sauzal, was discovered by the Spanish in 1632 and has produced more than 250 million ounces silver.
Several projects along the southern margin of the CDO are in early exploration stages. The Cerro Cascaron Project is being drilled by Harvest Gold currently. The Don Chano Project is located 40 km South of El Sauzal & Batopilas, the land position consists of a federal mineral claim, covering 1,413 hectares (3,492 acres) in the Municipality and Ejido of Morelos, Chihuahua.
Mineoro has collected approximately 600 measured-width bedrock samples over the Don Chano Project. High-Grade vein targets and large disseminated bodies of precious metal mineralization have been identified; maximum Gold value of 167 ppm Au w/ 132 ppm Ag encountered at Pacheco; maximum Silver value of 2,130 ppm Ag w/ 18.4 ppm Au sampled at Guadalupe. Visible gold has been confirmed from 2 locations (600m of strike) along the Tres Mujeres Vein Swarm.
Biography
Mike started performing geologic work in Mexico about 12 years ago. As an economic geologist he has primarily focused on the early stage exploration of metallic and hydrocarbon deposits. He has operated as a consultant for numerous public and private mineral exploration companies in Mexico and the western USA. Also served as a Geologist, Petrophysicist, and Database Administrator for Oil & Gas E&P Companies operating in the Midland and Anadarko Basins of Texas and Oklahoma.
Born and raised in Houston, TX he caught the “gold bug” while completing his BS at Sam Houston State University in Huntsville, TX. West Texas was calling and his passion for mineral specimens and hard-rock geology were cultivated at the University of Texas at El Paso, where he focused on Economic Geology under the tutelage of Dr. Kenneth Clark and Dr. Philip Goodell.
His MS thesis presented a geologic traverse from Upper Volcanic Series (Bolivar Mine, DiaBras) through Lower Volcanic Series (El Sauzal, successfully decommissioned by Goldcorp in 2015) and into Batholith (Choix, Sinaloa). The Cuenca de Oro (Basin of Gold) is an extensional basin with numerous precious metal deposits exposed along the periphery, this study provided context for the Western half of the CDO.
Networking in the mining industry led to securing funding for a Doctoral Study on a historic gold mining district that was being re-evaluated and drilled. A project-specific deposit model was created for the district from the integration of: field mapping (stratigraphy, structure, alteration, and quartz textures), geochemistry, fluid inclusions, stable isotopes, and age dating. The High Grade District in Northeast California was drilled as the “Golden Ridge Project” and highlights of the 3,500m drill program include a 5' high grade (120 ppm Au) zone and a 30' interval grading 25 ppm Au.
MineOro Explorations is an operating entity that provides: mapping (geology, alteration, under-ground), geochemistry (prospecting/grid), technical reports, due diligence reviews, native relations, permitting, drilling, 3D modeling, and project management services. We have successfully operated in some of the rougher locales, where native engagement and relationships are paramount to any advancement. Mike uses a strong network of contacts and actively explores gambusino leads. Mineoro has also operated with a prospect generator business model, in which mineral projects are vended to explorers that will fund drilling and development. The Chloride Gold Project in NW Arizona has been vended and drilling should commence in short order.
A notable current work is the boot-strapped discovery of the Don Chano Precious Metal Prospect in SW Chihuahua (along the southeastern rim of the Cuenca de Oro). More than 5 bonanza grade structures have been defined by bedrock sampling within the 4 x 1 km footprint. This stratiform deposit has never been drilled and nearly 600 measured width chip samples show strong precious metal activity across the footprint. The project is drill-ready and shares numerous characteristics with other world-class deposits.