Grand Junction, Colorado, USA

A Center for Uranium Exploration

The arrival of Lieutenant Philip Leahy in 1943 established Grand Junction, Colorado, as a focal point for uranium exploration in the United States. Acting under secret wartime orders, Leahy set up an office near the confluence of the Gunnison and Colorado rivers for the sole purpose of locating uranium for the Manhattan Project. Since that time, the Grand Junction Office—under the U.S. Atomic Energy Commission (AEC) and later the U.S. Department of Energy—has played a central role in uranium mining, milling, exploration, and remediation.

For historical and practical reasons, Grand Junction remains closely associated with uranium exploration, and it is an appropriate home for this web site.

Purpose of This Web Site

This web site is dedicated to uranium exploration geology.

Like gold, uranium is “where you find it.” Its occurrence spans a wide range of geologic environments, ore controls, and deposit types. This site is intended to serve as a go-to resource for uranium exploration, providing access to data, literature, maps, and deposit description that can help lead to future discoveries. While the focus is on the U.S., world-wide uranium deposits are included.

The emphasis here is on: - Uranium ore deposits and mineralization - Geologic controls and exploration tools - Scientific data relevant to discovery - Historical and modern exploration results

This site is not intended to focus on nuclear power generation, uranium economics or pricing, reactor locations, policy debates, radiation hazards, or weapons development. Those topics are well covered elsewhere. The focus here is firmly on exploration geology.

A Brief Note on Uranium History

Uranium was discovered in 1789 by the German chemist Martin Heinrich Klaproth and was later found to emit radiation by Henri Becquerel in 1896. The work of Becquerel and Marie and Pierre Curie laid the foundation for understanding radioactivity.

Uranium exploration accelerated dramatically during World War II and the subsequent Cold War, particularly in the western United States. Beginning in 1944, extensive exploration programs—many centered in Grand Junction—led to the discovery of numerous uranium deposits. Exploration continued intermittently through the 1960s and 1970s and then declined sharply in the late 1980s.

Although uranium exploration has a complex historical legacy, this web site focuses primarily on the scientific and geologic aspects of uranium ore deposits rather than on their political or industrial history.

The Literature Repository

The Literature Repository contains a searchable database of published and unpublished materials related to uranium ore deposits and exploration. These include:

• Government reports including complete sets of:
  • Preliminary Reconnaissance Reports (PRRs)
  • Defense Minerals Exploration Administration (DMEA) Documents
• Grand Junction Office technical reports (e.g., GJBX, GJD, GJO, GJM, PGJ, RME, RMO, TEI, TM)
• U.S. Geological Survey publications
• Selected web-based technical reports

Many thousands of these reports exist, and only a small fraction are readily available online elsewhere.

To our knowledge, this web site is the only location where PRRs (more than 6000 of them) are accessible. PRRs are summaries of visits to uranium-bearing sites made by AEC geologists in the 1950s. DMEA documents also provide descriptive data on uranium deposits and occurrences made during the 1950s. These early descriptions were made at the onset or during the development of many uranium properties - such access is no longer available. Although many new techniques (e.g. isotopes, fluid inclusions) have been established to help understand the formation of uranium concentrations, accurate descripition of the nature and locations of uranium still hold the most valuable clues for discovering new deposits. Also, these old reports describe numerous uranium concentrations that were never developed, and some may still have potential.

The Uranium Deposit and Mapping Repository

The Uranium Deposit Repository contains information about thousands of uranium mines and prospects. Geologic and production data are available for many.

Maps showing the locations of uranium deposits are available and can be searched by various categories.

Uranium Projects

Projects provides web links to on-going uranium projects.

Prospects

The Prospects section is intended to showcase exploration concepts that may point toward undiscovered uranium ore deposits. Prospects emphasize geological reasoning and exploration rationale. This section is populated by experienced explorationists who have developed credible exploration concepts.