President and Chief Executive Officer, Director
Darren Hall has over 30 years of experience in the mining industry with a track record of increasing production, reducing costs, improving capital effectiveness, and promoting health, safety and business excellence. Since August 2017, he has been Principal at Hall Mining Services, a provider of operating and technical assessments, among other things, to the international mining industry. Mr Hall previously he served as Chief Operating Officer of Kirkland Lake Gold, which acquired Newmarket Gold, where Mr. Hall served as the Chief Operating Officer throughout 2016. Prior to Newmarket Gold, Mr. Hall worked for Newmont Mining Corporation where he held roles of increasing responsibility throughout the organization for almost 30 years. Mr. Hall graduated with a Bachelor of Mining Engineering (Hons) from the Western Australia School of Mines in Kalgoorlie
Senior VP and Chief Financial Officer
John Seaberg has held a number of roles within the mining industry throughout his career. Since June 2018, he has been the Executive Chairman of Paramount Gold Nevada Corp. Mr Seaberg was previously Senior Vice President of Strategic Relations at Klondex Mines Ltd. In this role Mr. Seaberg was responsible for global investor relations and corporate development initiatives as an acting member of the senior executive team. Prior to Klondex, Mr. Seaberg was employed for more than 10 years by Newmont Mining Corporation where he last held the position of Vice President, Investor Relations. Mr. Seaberg has an MBA from the University of Denver.
VP, Corporate Development and Investor Relations
Ryan King brings an established approach to business in the natural resource sector, with specific and targeted applications for delivering shareholder value in the mining industry. Ryan has over 15 years of experience in increasingly senior capacities in capital markets in the resource sector and was responsible for leading the investor relations activities for Newmarket Gold, as the company completed a $2 billion transformational merger with Kirkland Lake Gold. Before joining Newmarket Gold, Ryan was involved in starting Terrane Metals which owned the Mount Milligan Copper-Gold Project in British Columbia, Canada. From 2006 through to 2010, Mr. King was involved in financing, corporate development, and investor relations for Terrane Metals as well as providing assistance with the acquisition of Terrane Metals in 2010 by Thompson Creek for $800 million. During his career, Ryan has assisted in raising $250 million for previous companies. Ryan holds a Bachelor of Commerce from Royal Roads University in British Columbia, Canada. Mr King currently sits on the Board of Newcore Gold and Edgewater Exploration Ltd.
Mark has more than 30 years of experience in the mining sector, including the past 10 years as Vice President of Exploration for New Gold Inc. His background includes key contributions and leadership to new deposit discoveries, fast track resource development through feasibility and commercial start-up, reserves growth at operating mine sites, evaluations and corporate development. Prior to joining New Gold, he spent thirteen years at Metallica Resources in progressive management roles before joining the executive team as Vice Presdient of Exploration. Mark is a member of Professional Geoscientists Ontario (PGeo) and Registered Member of the Society for Mining, Metallurgy and Exploration.
VP, Technical Services
Mr. Patterson was appointed Vice President, Technical Services of Calibre in September, 2019. Mr. Patterson is a Civil Engineer with global mining exposure in all phases of the mine life cycle including strategic planning, advanced exploration, early stage studies, project engineering, environmental management, permitting, construction, start-up, operations, and closure. Mr. Patterson has a strong cross-functional technical background with specific expertise in managing geographically-dispersed, cross-functional teams. Prior to joining Calibre, he was an executive at Goldcorp Inc. for 5 years and had previously worked with Newmont Mining for 12 years. He has worked in many countries around the globe including the U.S., Canada, Indonesia, Australia, New Zealand, Peru, Suriname, Bolivia, Mexico, Ghana, Argentina, and Chile. He is a registered Professional Engineer and holds a Master’s Degree in Civil Engineering and a Masters of Business Administration.
Dustin VanDoorselaere is a Canadian Mining Engineer with over 25 years of experience in operational and technical roles in Underground and Open Pit mines, as well as exploration projects around the world. Mr. VanDoorselaere has a proven track record in optimizing mine efficiency through increased production, reduced costs, fleet optimization, operational excellence and promoting health, safety, and environmental stewardship. Prior to joining Calibre in March 2020, Mr. VanDoorselaere worked as an independent mining consultant, specializing in operational / organizational efficiency. Previously he served as Chief Operating Officer at First Majestic Silver Corp from November 2016 to May 2019, General / Country Manager for Nyrstar, overseeing the El Mochito mine in Honduras and the Campo Morado mine in Mexico from October 2014 to October 2016 as well as various positions of increasing responsibility in companies including Goldgroup Mining, Aurico Gold, Redback Mining, Norilsk Nickel, Inco, Placer Dome and Orica. Mr. VanDoorselaere graduated with a Bachelor of Mining Engineering (Hons) from Laurentian University in Sudbury ON.
Juan Carlos Becerra
VP, SCM and Commercial
Juan Becerra joined Thyssenkrupp Industrials Solutions, USA in September 2013, as VP of Supply Chain Management, and in January 1, 2015 was appointed CEO and Managing Director of Thyssenkrupp Industrial Solutions, Chile. He served as CEO and Managing Director of Chile and Peru from January 2015 to October 2019. Prior to joining Thyssenkrupp Industrial Solutions, Mr. Becerra served as Senior Director, Global Supply Chain Management of Newmont Mining Corp. Over his 7 years with Newmont, Mr. Becerra worked in global supply chain management appointed in various roles. Prior to Newmont, Mr. Becerra was a senior project manager with Outotec, in Englewood, Colorado. Mr. Becerra worked for Washington Group International/Morrison Kundsen starting his career as a staff structural engineer in 1991 on various global engineering, procurement, and construction projects. Mr. Becerra graduated from the University of Nevada, Las Vegas with a Bachelors in Civil/Structural Engineering.
VP, Human Capital
Jason Gregg has more than 20 years of experience as a human resources professional and joined the Calibre Mining team on November 1, 2019. Mr. Gregg was most recently Executive Vice President, Human Resources for Alio Gold. He holds a BBA (1995) and a MBA (2000) from Simon Fraser University. Before Alio Gold, he was the Vice President of HR, Safety and Environment for Newmarket Gold. Before joining Newmarket, he provided HR consulting services to various mining organizations as well as other industries including forestry and technology. Prior to developing his consulting practice, he worked as a Human Resources executive in the mining industry with Farallon Mining and Nyrstar. Mr. Gregg has also held senior level human resource roles with HDI, International Forest Products, Canadian Forest Products, and Teck.
Mr. Dagsaan is a Chartered Professional Accountant (CPA, CA) with over ten years of experience in financial reporting, auditing, equity financings, and regulatory compliance. Mr. Dagsaan articled with PricewaterhouseCoopers LLP from 2005 to 2007 where he worked primarily in the firm’s mining practice. Mr. Dagsaan has an undergraduate business degree from Vancouver Island University.
VP & Country Manager
Omar Vega has 36 years of working in the Nicaraguan mining industry. He has a degree in mining engineering (Mexico, 1983) and also has a master’s degree in mining engineering with a major in mining company administration (Mexico, 1990). In addition, he is a graduate of the INCAE Senior Management Program (Costa Rica, 2013), among other studies.
In 2009, he led the technological reconversion of the largest mine in Nicaragua, Mina La Libertad. He is a leading professional with extensive capacity and knowledge of Nicaraguan mining, having worked in the three main gold mining districts of Nicaragua.
Senior Manager, Corporate Affairs
Thomas Lee has been working in the mining industry in Nicaragua for over ten years. Originally from California, Thomas has lived in Nicaragua for over thirty years and has a strong understanding of the country’s sociopolitical and cultural characteristics, enabling him to engage successfully with national and external stakeholders. As Senior Manager, Corporate Affairs for Calibre Mining, Thomas oversees the areas of Human Resources, Community Development, Community Relations, and Communications.
Thomas has a Bachelor of Arts degree in Political Science from Stanford University and a Master’s degree from Fitchburg State University. Since 2014, Thomas has also served on the Board of Directors of the Association of Nicaraguan Producers and Exporters (APEN).
Senior Finance Manager
Ezequiel Sirotinsky has almost 25 years of experience in finance and accounting roles in the mining industry, including leadership roles with Red Eagle Mining (Director of Finance Colombia), Petaquilla Minerals (CFO), Silver Standard Resources (Director of Finance Argentina), and AngloGold Ashanti (Director Administration and Finance Argentina). Ezequiel has a degree of Certified Public Accountant obtained at Buenos Aires University (Argentina) and a Post-graduate Diploma in Management obtained at the Graduate School of Business of the University of Cape Town, South Africa. During his career, Ezequiel has worked closely to operations and mine sites enabling him to acquire a comprehensive understanding of the mining business and its operational drivers.
Carlos David Castillo M.
Carlos Castillo has over 21 years’ experience as a Lawyer and Public Notary, of which 13 years has been in the mining sector. Initially serving as a Counsel and Managing Partner of a Nicaraguan law firm until joining B2Gold Corp in 2009 responsible for all its subsidiaries in Nicaragua specializing in Corporate Governance, working closely with Law Firms in Vancouver, Minneapolis and New York. He has an Executive Global MBA from the University of Miami (2014), has completed courses in Mining Laws: Domestic and International Issues taught by Rocky Mountain Mineral Law Foundation, Colorado, U.S.A. (2014) and U.S. Legal Methods: Introduction to U.S. Law, at the Institute for U.S. Law of George Washington University, Washington D.C., USA. (2019).
During his work for B2Gold he was responsible in securing require local guarantees in Nicaragua for ISDA Agreement with MacQuarie Bank Limited for up to US$200 Million and other Credit Agreements with HSBC Bank USA, National Association for amounts up to US$800 Million. He also was in charge on behalf of B2Gold for Due Diligence in its intent to acquire a local company for US$95 Million. He represented B2Gold in Nicaragua in the Share Purchase Agreement with Calibre Mining Corp. for US$100 Million.
General Manager, El Limón Mine
He has 35 years of working in the mining industry, inside and outside Nicaragua. He is Nicaraguan, graduated as a Mining Engineer from the National Autonomous University of Mexico. He has higher studies in Investment Project Management (INCAE) and has received several specialization courses in project formulation and evaluation, among other topics.
During his mining career, he has held positions ranging from mine supervision, mining project management, technical services management and general management. In addition to working successfully in the three main mining districts of Nicaragua, he has also worked in the mining industry of Honduras, Mexico, Canada and United States.
Néstor Concha Cruz
General Manager, La Libertad Mine
Néstor Concha Cruz joined Calibre mining on July 27, 2020, as the General Manager, La Libertad mining complex. He graduated with a Civil Engineering degree in Mining, Masters, in Business Administration (MBA), Diploma in Environmental Management, and Diploma in Six Sigma Management (Black Belt level), all from the University of Chile.
Mr. Cruz has more than 27 years of experience in the gold, silver and copper mining industry, including both open pit and underground mining.
Mr. Cruz has previously held executive positions in Chile and Argentina which focused on the areas of mining operations, planning and engineering, contract control and administration, project development from initial construction including environmental management and processing, process re-engineering, and international consulting in continuous process improvement and operational excellence.