Mike O’Brien – Red Pennant Geoscience Director and Principal Consultant

Mike O’Brien, Director and Principal Consultant, Red Pennant Geoscience

Mike O’Brien – Principal Consultant

Mike is an independent Geoscience professional with decades of experience in 3D Geological Modelling, Mineral Resource Estimation and problem-solving.

For 38 years he has been making a difference to Mineral Resources and mines. On the technical front, he has extensive experience in Mineral Resource estimation and geological modelling. He has managed technical teams to achieve results in mining companies and in consultancies.

While the majority of his experience has been in gold deposits, he has expertise in the uranium, base metals and multi-product environment.

A qualified geologist and geostatistician, he has been a team member and reviewer of due diligence and feasibility exercises in South Africa, Brazil, Ghana, Namibia, the DRC, Russia, Kazakhstan, Uzbekistan, Colombia, Peru and the United States.

His areas of specialization include Mineral Resource estimation, geostatistics, Mineral Resource classification, and Mineral Resource reporting codes, e.g. SAMREC, JORC.

As Director and Principal Consultant of Red Pennant Geoscience, he writes the Red Pennant Geoscience Blog.

“I aim to bring new insights and new practical applications of best-of-breed solutions to problems and enhance opportunities in a challenging era for mineral resources and mines.”

Mike O’Brien, P.Geo.


Mobile (604) 652 3781
Skype: mike.mob

Professional record

  • Red Pennant Communications Corp.
    Principal Consultant & Director – Geoscience Division
    April 2019 to present
  • Minerva Intelligence Inc., Vancouver, BC
    Technical Advisor – Mineral Resources and Spatial Statistics
    Oct. 2020 onwards (information below retrieved oct. 27, 2021)
  • Ausenco
    Technical Director, Geology & Resources
    May 2018 – April 2019
  • Seequent
    Senior Principal Consultant
    Nov 2014 – Apr 2018
  • AMEC
    Principal Technical Specialist
    Oct 2013 – Nov 2014
  • Tetra Tech Inc., Mining & Minerals
    Chief Geologist
    Jun 2011 – Oct 2013
  • AngloGold Ashanti
    Manager: Mineral Resources & Mine Geology
    Nov 1998 – Jun 2011
    Technical leader for Resource Estimation and Mine Geology, initially in South Africa, and at various times in Ghana, Australia and North & South America. Due diligence and M&A team technical member and reviewer.
  • Anglo American (Ore Evaluation Department)
    Divisional Ore Evaluation Analyst
    Oct 1991 – 1998
  • Anglo American Corp.
    Resident Geologist
    1990 – 1991
    President Brand Gold Mining Company, Welkom
  • Anglo American Corp. 
    Technical Assistant
    Company Name Anglo American Corporation
    1988 – 1990
  • Vaal Reefs Exploration & Mining
    Section Geologist
    1986 – 1988

Licenses & Certifications

Issued Jan 2015
Credential ID 41338
Pr.Sci.Nat. (Geological Scientist)
The South African Council for Natural Scientific Professions (SACNASP)
Issued Jul 1987
Credential ID 400295/87
Pilot Certificate – Basic Operations (Remotely Piloted Aircraft Systems)
Transport Canada
Apr 2019
Credential ID PC19112134x


University of the Witwatersrand
M.Sc. (Eng.) Mineral Economics, Mining Geology
1995 – 1999
University of South Africa (UNISA)
Diploma in Data, Statistics, Computer Science
1985 – 1988
University of KwaZulu-Natal
B.Sc. (Hons.) Geology
1975 – 1978


“Mike O’Brien is the best Mineral Resources Geologist with the best knowledge of mineral resources reporting codes in the industry. To work for him is an opportunity to learn a lot in several fields and also about his culture.”

Alessandro Silva, Senior Manager at AngloGold Ashanti: Resource Evaluation & Mine Geology

“Mike is an incredible, down-to-earth type of Manager, who was instrumental in laying down solid foundations for me to build my career further on. He mentored me, and I have the world’s respect for the way that he interacts with people; always quick with a joke or two and then down to serious business. Mike is a real asset to the Mining industry and his accolades and achievements over the years bear testimony to this.”

Johan De Bruin, M.Eng, Pr.Sci.Nat. (SACNASP), FSAIMM, Group Technical Services/Mineral Resources Manager, Thriveni EarthMovers Pvt. Ltd.