Gold and Base Metal Deposits in the Mexican Altiplano, States of Zacatecas and San Luis Potosi, Central Mexico

GUIDEBOOK SERIES Volume 40

GOLD AND BASE METAL DEPOSITS IN THE MEXICAN ALTIPLANO, STATES OF ZACATECAS AND SAN LUIS POTOSI, CENTRAL MEXICO

Guidebook Prepared for the Society of Economic Geologists Field Conference—October 5-9, 2010

Field Trip Leader: Erme Enriquez

SOCIETY OF ECONOMIC GEOLOGISTS

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GUIDEBOOK SERIES

OF THE

SOCIETY OF ECONOMIC GEOLOGISTS, INC.

Guidebook 40

ISBN 978-1-934969-26-7

CD-ROMS of Guidebook 40 May be purchased from

Society of Economic Geologists, Inc. 7811 Shaffer Parkway Littleton, CO 80127 USA

Telephone: 1.720.981.7882 Fax: 1.720.981.7874 Website: www.segweb.org E-mail: [email protected]

Publication Date: September 2010

Cover: Area of central Mexico visited during this field trip.

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Preface………………………………………………………………….…………………….iii Acknowledgments…………………………………………………………………………....v Itinerary………………………………………………………………………………………vii Route Map……………………………………………………………………………………ix List of Participants………………………………………………………………………..….x English-Spanish Geological and Survival Terms……………………………………………xiii FIRST DAY Road Log from San Luis Potosi City to Zacatecas City, The Francisco I. Madero and the Cozamin Mines, San Luis Potosi, and Zacatecas States Erme Enriquez………………………………………………………………….……1 Geology of the Madero Ore Deposit, Zacatecas, Mexico Leopoldo González-V. and Randolfo López-Soto………………………..…………..15 Contribution to the Definition of Superimposed Metallogenic Events in the Francisco I. Madero Ore Deposit, Zacatecas, Mexico Miriam Yta and Raúl Moreno-Tovar………………………………………………...31 Technical Report, Cozamin Mine, Zacatecas, Mexico [Excerpt]…………………………....45 Gordon Doerksen, Jenna Hardy, Robert Sim, and Jeff Woods SECOND DAY Road Log from Zacatecas to Concepción del Oro District, the Peñasquito Mine, and the Camino Rojo Project, Zacatecas State Erme Enriquez……………………………………………………………………….65 Peñasquito Feasibility Study: 100,000 MTPD, NI-43-101 Technical Report [Excerpt] James S. Voorhees, Charlie Ronkos, Jerry Hanks, Tom Drielick, Tom Wythes, Conrad Huss, Michael Pegnam, and Jim Johnson………………………………….77 Technical Report Preliminary Assessment, based on Report, “Technical Assessment of Camino Rojo Project Zacatecas, Mexico” [Excerpt] J. Douglas Blanchflower, Christopher Kaye, and Howard Steidtmann…………….97

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THIRD DAY Road Log from Zacatecas Back to San Luis Potosi and to the Cerro San Pedro Mine, Zacatecas, and San Luis Potosi States Erme Enriquez……………………………………………………………………....127 Geology of the Cerro San Pedro, Precious and Base Metals Mining District, San Luis Potosí, Mexico Mark A. Petersen……………………………………………………………………137 Mesa Central of México: Stratigraphy, Structure, and Cenozoic Tectonic Evolution Ángel Francisco Nieto-Samaniego, Susana Alicia Alaniz-Álvarez, and Antoni Camprubí (Reprinted with permission of the GSA) …………………….155

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Mexico has been an outstanding producer of silver, along with other metals that include gold, copper, zinc, lead, wolframium, and molybdenum. The mining activity accounts for 1 to 3% of the GDP in Mexico. W ith the recent changes in the mining legislation and the Constitution Article 27, exploration companies have given special attention to exploration in Mexico. O ne state with a great amount of continuing activity is Zacatecas. The discovery of Peñasquito and the continued operation of Fresnillo will make these two the largest gold and silver mines in Latin America. San Luis State has also entered in the quest for gold-silver and base metals exploration. Old mine districts like Cerro San Pedro continue producing gold and silver—currently from bulk tonnage mining. Since the mining law changed in 1992, the national gold production has increased from 10.4 tonnes (t) in 1992 t o 68.9 t in 2009, i .e., 662% in only 12 years. G old production is expected to increase by 15% in 2010. Silver production has increased, although not as drastically, by 19% in the same period of time, from 2.317 Mt in 1992 to 2.890 Mt in 2009. The change in the mining law has, therefore, significantly affected the production of silver and gold and the exploration for both. A paper by Leopoldo Gonzalez and Randolfo Lopez clearly explains the steps leading to the discovery of the Madero deposit. A polemic origin has been assigned to the deposit, by which some experts classify it as a S EDEX and others as a skarn deposit. C omplementing the description of the Madero deposit, Miriam Yta describes the superimposed events that led to mineralization and explains the process of alteration in the different types of rocks. NI-43-101 technical reports have been provided for the description of Peñasquito and Camino Rojo. The Peñasquito feasibility study discusses the economic studies prepared by M3 Engineering & Technology Corporation (M3), summarizing the work performed on the property. This report was prepared for Minera Peñasquito, S.A. de C.V., a wholly owned subsidiary of Glamis Gold Ltd. (Glamis). The main scope was given to evaluating the economics of the plant operating at 100,000 M TPD versus the previously envisioned 50,000 MTPD. The orebody is polymetallic, with the precious metals of silver and gold providing over one-half the revenue, and the base metals of lead and zinc providing the remainder. The study sets forth conclusions and recommendations, based on M 3’s experience and professional opinion, that result from their analysis of work done and data collected. Peñasquito hosts a total of 17.8 Moz of gold. Silver

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Downloaded from http://pubs.geoscienceworld.org/books/book/chapter-pdf/3929156/9781934969939_frontmatter.pdf by guest on 29 September 2021 reserves totaled 1,070.1 Moz, and proven and probable lead and zinc reserves total 7.2 and 15.9 M lb, respectively. Annual production over the life of mine (estimated 22 years) is expected to ramp up to approximately 500,000 oz of gold, 28 Moz of silver, and over 450 M lb of zinc. The Camino Rojo gold-silver-lead-zinc occurrence is a new discovery with no evidence of prior exploration. Canplats has carried out aggressive and continuous exploration work on t he property since its discovery in July 2007. During the intervening time, this exploration work has included the following: prospecting, reconnaissance geologic mapping, test pitting with geochemical sampling, trenching with geological mapping and geochemical sampling, induced polarization surveying, and reverse circulation and diamond drilling. The 2007 t o 2008 exploration work focused on the Represa zone, where a large occurrence of gold-, silver-, lead- and zinc-bearing mineralization is hosted by highly altered, silicified and oxidized metasedimentary rocks. The Represa zone has been traced by drilling for more than 1,000 m east- west, 460 m north-south and vertically to a depth of 820 m. Drill hole intercepts (not true widths) with gold and silver values exceeding 0.25 g/t and 5 g/t, respectively, range from 52 to 728 m. Within these drilling intercepts the precious metal-bearing mineralization has good lateral and vertical continuity. Canplats was taken over by Goldcorp Inc. in 2009. The deposit hosts 3.44 Moz of gold and 60.7 Moz of silver. Finally, the description of the Cerro San Pedro, done by Mark Petersen, closes this mining safari. Cerro San Pedro, despite the difficulties of operating due to environmental issues, finally will take advantage of the high gold prices in the market. C erro San Pedro hosts proven and probable reserves estimated as approx. 1.4 Moz of gold and 52 Moz of silver as in 2009. The underground and bulk mining activity in the Mexican Altiplano (Mesa Central) is the main topic of this field trip. The Society of Economic Geologists presents this introduction to the basic geologic concepts for exploration in the Mexican Altiplano in the coming years.

ERME ENRIQUEZ

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The Society of Economic Geologists (SEG) would like to thank all the companies that have given permission to visit their properties. For Peñoles, special thanks to Ing. Armando Sanchez (Mines Director) and Randolfo Lopez (Chief of Geologists) for the tour of the Francisco I. Madero mine. To Darren Pylot (President) and Telesforo Martinez (General Manager) of Capstone Gold, thanks for the opportunity to tour the Cozamin mine. Thanks to Gold Corp., through Salvador Garcia (Vice-President Operations Mexico), Gassaway Brown, and Steve Weiss, for showing their operations at the Peñasquito mine and the Camino Rojo project. Many thanks to Mark Petersen for being the liaison between the SEG and Newgold Inc., and for the great tour of the Cerro San Pedro mine complex. Likewise, the SEG thanks the authors of the papers contained in this publication; thanks for their support in helping with the timely completion of this guidebook. Thanks to Gabriel Arredondo for helping with some of the logistics and road logs. The road logs were put together using all the published information available and tours of the mine sites by the author. Regional maps used for Peñasquito, Camino Rojo, and Cerro San Pedro were taken from the Servicio Geologico Mexicano web page. These show clear, generalized rock units which host the ore deposits mentioned above. Special thanks to Tawn Albinson and Peter Megaw for the description of the geology and the guidelines for the exploration of ore deposits at the Altiplano, in their talk at San Luis Potosí. Thanks to all participants who are directly supporting the SEG. Thanks to all those who helped prepare the material herein.

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ITINERARY

Tuesday, Oct. 5 Depart 14:10 pm DIA Airport, Denver, on American Airlines, flight #1748. Arrive Dallas 17:05 pm. Depart 18:30 pm Dallas on American Airlines Flight #3273. Arrive San Luis Potosí 20:40 pm. Night: Hotel Real de Minas Carretera a México Km. 426.6, 500 m from Distribuidor Juárez San Luis Potosí, SLP Tel: (444)499-8400 www.realdeminasdesanluis.com

Wednesday, Oct. 6 Check out early (6:15 am), breakfast in the Hotel, Depart San Luis Potosí at 7:15 am for Zacatecas. Drive to Francisco I. Madero mine. Underground visit at the Francisco I. Madero mine and mill in the morning. Lunch at the minesite. Drive to Cozamín. Underground and mill visit in the Cozamín mine. Drive to the Zacatecas City. Chance to do laundry. Night: Hotel Parador En Zacatecas Lomas de la Soledad S/N, Col. Lomas de La Soledad Zacatecas, ZAC Tel. (492)922-1790 to 94 www.hotelparadorzac.com Full service four star hotel with restaurant, laundry, bar and awakener.

Thursday, Oct. 7 Don’t check out. Drive to Peñasquito mine. Tour of the open pit, mill and coreshack. Return to Zacatecas City. Stop at Concepción del Oro to look at the core from Camino Rojo. Stop at the Camino Rojo project site. Continue our travel to Zacatecas. Night: Hotel Parador En Zacatecas Lomas de la Soledad S/N, Col. Lomas de La Soledad Zacatecas, ZAC Tel. (492)922-1790 to 94 www.hotelparadorzac.com

Friday, Oct. 8 Check out early (6:20 am) drive to San Luis Potosí. Visit the Cerro San Pedro mine. Tour of the open pit, core shack, and mill. Return to San Luis Potosi. Talk prepared by Tawn Albinson and Peter Megaw. Evening out/free. Night: Hotel Real de Minas Carretera a México Km. 426.6, 500 m from Distribuidor Juárez San Luis Potosí, SLP Tel: (444)499-8400 www.realdeminasdesanluis.com

Saturday, Oct. 9 Check out from the hotel at 13:00 pm. Drive to the San Luis Potosi International Airport and depart in your flight of preference. Bon Voyage!

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Fig. 1. Route map showing the location of mines and projects that are in production and will be visited.

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Antony (Tony) Makuch Eric Kallio President and CEO Vice President Exploration, Lake Shore Gold Corp. Lake Shore Gold Corp, 181 University Ave, Suite 2000, 181 University Ave, Suite 2000, Toronto, ON Canada L4N7E6 Toronto, ON Canada L4N7E6 Phone: (416) 703-2026 Phone: (416) 703-2026 E-Mail: [email protected] Cel: (416) 407-2026 Email: [email protected] Aristeo Nuñez Othón José Carmelo # 116 Col. Balderrama Erme Enriquez Hermosillo, 83180, Sonora Director Exploration and Development Mexico Minera Canasil, S.A. de C.V. Tel: 52-(662) 214-9640 Alheli No. 142, Fracc. Jardines de Dgo [email protected] Durango, DGO 34200 Mexico Bernardo Alvarez Tel: +52 (618)129-6082 Colque Exploraciones, S.A. Cel: (618)134-3074 Gabriel Puló 102 E-Mail: [email protected] Salta, Argentina Tel: +54 (387) 4010911 Gassaway Brown E-Mail: [email protected] Exploration Manager Minera Penasquito, Goldcorp Mexico Chad Wells Zacatecas, Zacatecas, Mexico Altius Resources Inc. Tel: (842) 424-2772 (Mazapil, Zac) Mailing: P.O. Box 8263, Station "A" St. Cel: (492) 103-2643 John's, NL, A1B 3N4 Civic: Suite 202, Kenmount Business Henry Marsden Center, 66 Kenmount Road, St. John's, NL, 1417 Windsor Cr A1B 3V7 Delta, BC, Canada, V4M3C3 Telephone: +1 (709)579-8278 Tel: (604) 512 6407 E-Mail: [email protected] E-Mail: [email protected]

Chris Bell Hugh Samson 1201 - 1238 Richards St Serengeti Resources Inc. Vancouver BC V6B 6M6 #500 602 West Hastings Street Canada Vancouver, BC V6B 1P2 Tel: (604) 727-466 Canada E-Mail: [email protected] Tel: (604) 605-1300 E-Mail: [email protected] Daria Bukhanova Kamehatka State University Kamchatsky, Kamchatkiy-Kari Russia E-Mail: [email protected]

Downloaded from http://pubs.geoscienceworld.org/books/book/chapter-pdf/3929156/9781934969939_frontmatter.pdf by guest on 29 September 2021 Jaime Cisneros Linus Keating, DSc. Kinross Gold Corp. PO Box 16301 Guadalajara, Jalisco Tucson, AZ 85732 USA Mexico Tel: (520) 235-3660 E-Mail: [email protected] E-Mail: [email protected]

John-Mark Staude Miguel Heredia President Exploration Manager, Mexico Riverside Resources Inc. Riverside Resources Mexico S.A. de C.V. Suite 701 - 744 West Hastings Street Fray Anton de Montesinos # 330 Vancouver, British Columbia Fraccionamiento Quintas del Marques V6C 1A5 Queretaro, Queretaro CP 76047 Canada Mexico Tel: (778) 327-6671 Tel: +52 (442) 248-3710 and 223-7094 E-Mail: [email protected] E-Mail: [email protected]

Jorge Cirett Galán Manuel Tovar Mancera Retorno 103 # 21 Col. Modelo Geologist Hermosillo, 83190, Sonora Riverside Resources Mexico S.A. de C.V Tel: 52-(662) 214-2908 Esteros # 1 Esq.con Tepoca Col. Sonacer E-Mail: [email protected] Hermosillo Sonora C.P. 83174 Mexico Jose Natividad Rosales Ortiz Tel: +52 (662) 216-6920 Distritct Manager E-Mail: [email protected] Minera Hecla S.A. de C.V. Av. 20 de Noviembre # 519 Ote. Mariano Poodts Durango, Dgo. 34000 Geologist Mexico Colque Exploraciones SA Tel. +52 (618) 818 41 83 ext. 109 Gabriel Puló 102 Cel. (618) 840 58 60 Salta, Argentina E-Mail: [email protected] Tel: +54 (387) 4010911 Cel: 0387 155108500 Lawrence Winter, Ph.D., P.Geo. Vice President Exploration Martin Moscosa Altius Resources Inc. Kinross Gold Corp. Mailing: P.O. Box 8263, Station "A" St. Guadalajara, Jalisco John's, NL, A1B 3N4 Mexico Civic: Suite 202, Kenmount Business E-Mail: [email protected] Center, 66 Kenmount Road, St. John's, NL, A1B 3V7 Martin Spivey Toll Free: 1-877-576-2209 Extract Resources Telephone: +1 (709)579-8278 South Perth E-Mail: [email protected] Washington, USA E-Mail: [email protected]

Downloaded from http://pubs.geoscienceworld.org/books/book/chapter-pdf/3929156/9781934969939_frontmatter.pdf by guest on 29 September 2021 Mary Little Sik Lap Chan President and CEO 3/F, Hang Lai Garden, 387 Tuen Tsz Wai, Mirasol Resources Ltd. Tuen Mun, N.T., Hong Kong 1510-789 West Pender Street Phone: +852 98774721 Vancouver, BC V6C 1H2 Canada Email: [email protected] Tel: 1-604-602-9989 Cel: 1-604-808-9206 Canada Steven I. Weiss Cel: 1-303-809-6513 US Regional Geologist E-Mail: [email protected] Goldcorp - Mexico Tel: +52 (842) 424-0741 Michael Hocking Goldcorp Inc. 77 Charlotte St. 5190 Neil Rd., # 310 Ottawa, ON, K1N 8J9 Reno, NV 89502 USA Canada E-Mail: [email protected] Tel: (613)241-5464 E-mail: [email protected] Tawn Albinson Sinaloa No. 106, Desp. 302 Peter Drobeck Colonia Roma Senior VP Exploration and Development 06700 Mexico, D.F. Gammon Gold Inc. Tel: +52 (555) 514-5638 ext. 106 17768 W 59th Pl E-Mail: [email protected] Golden, CO 80403 USA Timothy Kingsley Tel: (3030) 277-9085 Crdero Resources Group Cel: (303) 681-7782 Lone Pine E-Mail: [email protected] California, USA E-Mail: [email protected] Peter Megaw President Vernon Arseneau Imdex Inc. VP Exploration P.O. Box 65538 Zincore Metals Inc Tucson, AZ Manuel de Falla 297, Piso 2 USA 85728 San Borja, Lima Tel: (520) 529-2231 Perú E-Mail: [email protected] Tel: (511) 224-0900 E-mail: [email protected] Segundo Carrasco Colque Exploraciones, S.A. Gabriel Puló 102 Salta, Argentina Tel: +54 (387) 4010911 E-Mail: [email protected]

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October 6–9, 2010

English-Spanish Geological and Survival Words and Phrases

gold oro ore mena smelter fundición mill molino hill cerro eggs huevos tailings dam presa de jales coffee cafe silver plata spicy picante copper cobre chicken pollo lead plomo meat carne zinc cinc fish pescado limestone caliza beans frijoles sandstone arenisca milk leche fold pliegue flour tortillas tortillas de harina thrust fault cabalgadura bread pan granite granito juice jugo rhyolite riolita orange juice jugo de naranja andesite andesita beer cerveza shear cizalla dessert postre clay arcillas vegetables verduras fault falla french fries papas fritas silicification silicificación potatoes papas underground subterráneo sugar azúcar open pit tajo abierto salt sal refinery refineria black pepper pimienta gangue ganga bench banco

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Downloaded from http://pubs.geoscienceworld.org/books/book/chapter-pdf/3929156/9781934969939_frontmatter.pdf by guest on 29 September 2021 Where is the bathroom?...... Donde esta el baño? What is the gold grade?...... Cuál es la ley de oro? Bartender, more beer, please ……...……….....Mesero, mas cerveza, por favor. Nine shots of tequila for my new friends!...... Nueve copas de tequila para mis amigos! I'm sorry, Officer ………………………………Lo siento, Official… Help, my friend is in jail! ...... Ayudenme! Mi amigo está en la cárcel! Do you have any aspirin? .…………………….Tienes una aspirina?. How much for this gold ring? ...... Cuánto cuesta este anillo de oro?

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