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Principal Resources Geologist

• Working for a world class Copper operation in a unique location - Ulaanbaatar.
• Great opportunity to work for a global company at the forefront of mining.
• Dynamic work culture and great exposure to multicultural teams.

The opportunity

We are looking for One (1) Principal Resources Geologist in Oyu Tolgoi LLC - Resources & Systems Department based Ulaanbaatar Office with 5 days on and 2 days off.

The purpose of this role is to ensure that the mineral resources of the Oyu Tolgoi deposit are effectively developed, understood, and reported in the context of the global resource strategy. The role is accountable for managing geological and metal resource models that are critical to planning the extraction of the resource, ensuring orebody knowledge is effectively applied, and providing high-quality technical support to Engineering, Processing, Project Execution, Permitting, and other technical teams as the project progresses from Feasibility into Execution and Detailed Design. The role also builds and maintains national technical capability in resource geology, an identified critical gap within OT and the broader Mongolian mining sector.

What the role entails:

• Ensure that the mineral resources of both the open pit and underground mine operations are effectively developed and understood in the context of the global resource strategy.
• Manage (create, update, and review) the geological and metal resource models for the open pit and underground operations. These models are critical to understanding and planning the extraction of the resource.
• Sign off as Competent Person on Mineral Resources across ASX and SEC jurisdictions as well as under the Mongolian classification code. Maintain resource and reserve assurance and governance processes.
• Ensure timely geological input into key decisions, scheduling, production, and reconciliation.
• Reconcile and update geology models with open pit and underground face mapping as provided by the mine geology teams. Assist in the resolution of reconciliation issues (modelled grade and recoveries versus actual grade and recoveries) by working closely with geology, mining, and metallurgical teams.
• Prepare and deliver statutory resource reports, including the Resource Report, in compliance with Mongolian regulatory requirements (MRPAM/MPC) and international reporting codes (JORC, SEC). Liaise with key internal and external stakeholders including Entree LLC, Erdenes OT, and government authorities.
• Accountable for core processing facility operations including core handling, geological logging, and QA/QC programs to ensure data integrity underpinning resource models.
• Collaborate with the broader mining and support services team to ensure appropriate technical input is provided to the project. Ensure work is completed to the required technical standards.
• Participate in all HSEC-related activities by anticipating current and future risks and setting objectives to ensure standards are met.
• Liaise with key stakeholders to evaluate new resource development opportunities through due diligence, and pioneer best-practice approaches to orebody knowledge management.
• Assist the Manager, Resources and Systems in special projects as directed.
• Implement emerging technologies and best-practice techniques to improve resource model accuracy and reduce estimation uncertainty.
• Contribute to strategic decision-making based on an understanding of the mineral resource and production requirements of Oyu Tolgoi.

What you will need for this role

• Degree Geology, Geoscience, or relevant discipline.
• Significant relevant experience in geological modelling and resource estimation, typically achieved through graduate qualifications and a minimum of 10 years of post-graduate experience in resource geology.
• Competitive, academic knowledge of exploration geochemistry/ geophysics and their application in mineral exploration
• Knowledge of international Mineral Resource and Ore Reserve reporting codes and mineral classifications (JORC, NI 43-101, SEC S-K 1300, and Mongolian classification code). Thorough knowledge of geostatistics, structural geology, mineralogy, geochemistry, and geological software packages including Leapfrog Geo, Vulcan, ArcGIS Pro, and equivalent platforms.
• Ability to plan, manage and execute projects and work programs
• Membership of a recognised professional geological or mining society (SME, AusIMM, IMM, AIG, or equivalent) with eligibility to act as a Competent Person under JORC Code, or Qualified Person under NI 43-101 or SEC S-K 1300, is required. Mongolian professional licensing is an advantage.

It is also beneficial if you have:

• Experience in working globally across diverse cultures;
• Previous experience working with multiple stakeholders/management across multiple regions and time-zones.

What we offer:

Be recognized for your contribution, your thinking, and your hard work, and go home knowing you've helped the world progress.

• A work environment where safety is always the number one priority
• Excellent career opportunity one of the world's leading mining organizations
• A competitive base salary reflective of your skills and experience with an annual incentive program
• Private health insurance for employees
• Attractive share ownership plan
• Career development & education assistance to further your technical or leadership ambitions
• Leave for all of life's reasons (vacation/annual, paid parental, sick leave)

About us

Joining the Rio Tinto majority owned Oyu Tolgoi operations is a great opportunity to be part of one of the most exciting developments in copper and gold mining for several decades. The mine contains reserves and resources that make it one of the world's largest copper-gold deposits.

This mega project is expected to be a major contributor to Mongolia's development. As part of the Oyu Tolgoi Operations team, you have the ability to contribute to something significant and learn and develop both personally and professionally. We offer a collaborative, high-performing environment where success is achieved by working together.

Discover more about Mongolia and Oyu Tolgoi

Mongolia is increasingly becoming a destination for tourism and expatriate residents. As a rapidly developing city, Mongolia's capital Ulaanbaatar is seen as a comfortable, yet exciting place to live. With an array of cultural and social activities available and a growing network of international schools, housing options, and leisure facilities, its home to a growing community of international expatriates.

Located in the South Gobi Desert, just 80 kilometers from the Chinese border, the Oyu Tolgoi mine and camp is a large, well-run, and comfortable site with multiple amenities including recreational and sports facilities, a cinema, shops, restaurants, and bars catered to a growing community. For more information about the OT site, please check outthis video.

Where you'll be working

Oyu Tolgoi is an operating Copper / Gold open pit and underground mine. The site is located in the Gobi Desert region of Mongolia.The reserves case for the underground project is in the order of 0.5 billion tonnes of ore to be mined from the 95,000 tonnes per day Hugo North Lift 1 (HNL1) panel cave mine with a 20-year operations life. There is also the potential for 3 further block cave districts to increase mine life beyond 100 years.

Every Voice Matters

At Rio Tinto, we particularly welcome and encourage applications from Indigenous Peoples, women, the LGBTQIA+ community, mature workers, people with disabilities and people from different cultural backgrounds.

We are committed to an inclusive environment where people feel comfortable to be themselves. We want our people to feel that all voices are heard, all cultures respected and that a variety of perspectives are not only welcome - they are essential to our success. We treat each other fairly and with dignity regardless of race, gender, nationality, ethnic origin, religion, age, sexual orientation or anything else that makes us different.

Job application closes on September 11, 2026

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About Rio Tinto

Rio Tinto is a leading global mining and materials company. We operate in 35 countries where we produce iron ore, copper, aluminium, critical minerals, and other materials needed for the global energy transition and for people, communities, and nations to thrive.

We have been mining for 150 years and operate with knowledge built up across generations and continents. Our purpose is finding better ways to provide the materials the world needs - striving for innovation and continuous improvement to produce materials with low emissions and to the right environmental, social and governance standards. But we can't do it on our own, so we're focused on creating partnerships to solve problems, create win-win situations and meet opportunities.

Respect and Inclusion
At Rio Tinto, we particularly welcome and encourage applications from Indigenous Peoples, women, the LGBTQ+ community, mature workers, people with disabilities and people from different cultural backgrounds.
We are committed to an inclusive environment where people feel comfortable to be themselves. We want our people to feel that all voices are heard, all cultures respected and that a variety of perspectives are not only welcome - they are essential to our success. We treat each other fairly and with dignity regardless of race, gender, nationality, ethnic origin, religion, age, sexual orientation or anything else that makes us different.