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Indicator Mineralogy

  • Indicator mineralogy is one of the most definitive exploration methods for detecting covered mineral deposits.

  • ODM has broad indicator mineral expertise with many deposit types and can detect a wide variety of deposits from a single survey.

  • ODM’s indicator mineral services include much extra value:

    • ​​Simultaneous recovery of gold grains, kimberlite indicators and MMSIMs® saving time and money.

    • Indicator mineral logging by seasoned exploration geologists with full reporting of any unexpected indicators.

    • Resolution of questionable indicator minerals by SEM analysis, reducing downstream analytical costs.

    • Research-grade data at practical, exploration prices.

    • Comprehensive data reports with interpretive summary.

Gold Grains

ODM is a world leader in the recovery and classification of fine gold grains. ODM proposed the widely used industry-standard classification system used for variably transported grains (pristine, modified, reshaped).

Every day, the ODM team recovers, counts, measures and classifies hundreds of gold grains from glacial till and alluvial and beach sand and gravel samples. Gold grains are also extracted from soil (even from humus samples) to explain geochemical anomalies found in soil surveys.

The wear processes of gold grains in different sedimentary environments produce distinct end-products. For example, the wear rate for gold grains in till is steady and can be used to estimate the distance gold grains have travelled from the source mineralization.

 

Bedrock sources can be fingerprinted by examining transported gold grains by scanning electron microscopy and using crystal morphology, gold fineness and diagnostic mineral inclusions. New deposits can be identified in the dispersal shadows of known deposits. Lode sources can be identified from active gold placers.

Magmatic or Metamorphosed Massive Sulphide Indicator Minerals (MMSIMs®)

ODMs trade-marked MMSIMs® technique was developed in the early 1990’s during Canada’s first diamond rush. Our exploration geologists, who exclusively perform the indicator mineral logging, used their knowledge of deposit models and mineral chemistry to associate key minerals to alteration systems.

This technique allows us to search for mineral deposits in under-explored terrains obscured by high-grade metamorphism.

We provide customized suites of indicator minerals for magmatic or metamorphically recrystallized mineral deposits of the following types:

  • Ni-Cu-PGE including mineral subsuites indicating melt fertility, melt contamination and sulphide separation

  • Cu-Zn and Zn-Pb

  • Carbonatite (Cu and rare earths)

  • IOCG, skarn and greisen

Porphyry Copper Indicator Minerals (PCIMs®)

Since 2002, our PCIM® technique has emerged as a significant exploration tool in arid, tropical and arctic regions, as well as the Cordillera of British Columbia.

PCIMs® derived from specific alteration zones (propylitic, potassic, sericitic, advanced argillic) can be used to focus in on the best-mineralized sectors of porphyry systems.

PCIMs® can also be used to explore for high-sulphidation epithermal Au deposits peripheral to porphyry Cu deposits and for porphyry Mo deposits.

Our specialized processing reduces the need for large samples. In arid regions, 1 kg samples are sufficient, thereby reducing shipping costs from remote areas.

Stu Averill discusses ODM’s porphyry Cu indicator mineral (PCIM®) technology with the Arizona Mining Review. To watch Stu’s interview click HERE

Kimberlite Indicator Minerals (KIMs)

Indicator mineralogy is the best diagnostic tool for identifying diamond-bearing kimberlite.

During the Canadian diamond rush of the 1990s and early 2000s, ODM contributed to many kimberlite discoveries by processing and logging more than 50,000 samples.

We continue to be a key KIM laboratory used by diamond explorers in all parts of Canada and the world.