THE ROLE OF FLUID INCLUSIONS IN ORE GENESIS RESEARCH: YESTERDAY, TODAY AND TOMORROW

Today fluid inclusions represent a valuable source of information concerning ore-forming processes. According to Lemmlein, the first description of fluid inclusions was in the 11th century by Abu Reykhan al-Biruni. Other descriptions of inclusions followed, including the first in English by Robert Boyle in 1672. The earliest reported suggestion that fluid inclusions could be used as geothermometers came from Sorby in 1858, who noted that bubbles contained in fluid inclusions were the result of differential shrinkage of the fluid and host mineral during cooling.

Fluid inclusions have been used to study ore-forming process for at least 100 years. It is worth noting that in the same year that the inaugural issue of Economic Geology was published (1905), Lindgren reported “They [halite-bearing inclusions] prove, I think conclusively, that the acid porphyry magma [at Morenci] was accompanied by notable quantities of aqueous solutions containing a large quantity of salt which probably was NaCl.” Lindgren further emphasized “It is perhaps a significant fact that these inclusions are absent in the diorite porphyries, which as a rule have no connection to the copper deposits.” During the first half of the 20th century fluid inclusions were used only occasionally in ore deposits research in the U.S., but were an important tool in economic geology in the former Soviet Union. Soviet researchers made many major advances during that time. The use of fluid inclusions in North America expanded in the 1950s as improved microscopes were developed and researchers began to build homemade heating and cooling stages to study inclusions. While many workers contributed to this effort, Roedder emerged as the leading proponent of fluid inclusions and helped to establish fluid inclusions as a valuable tool for quantitative studies of ore-forming processes.

Much progress has been made during the past 100 years and the future of fluid inclusion research remains bright. The entrance of enthusiastic young researchers into the field, combined with major advances in technology that now permit analysis of major and trace elements in individual inclusions, are proof that fluid inclusions will continue to contribute to our understanding of ore-forming processes during the next century.