Pathfinder sampling techniques for locating primary sources of diamond: Recovery of indicator minerals, diamonds and geochemical signatures

• Published in: Journal of geochemical exploration Vol. 53; no. 1; pp. 183 - 204
• Main Author: Muggeridge, M.T.
• Format: Journal Article
• Language: English
• Published: London Elsevier B.V 01.03.1995; Amsterdam Elsevier; New York, NY
• Subjects: Earth sciences; Earth, ocean, space; Exact sciences and technology; Metallic and non-metallic deposits; Useful material except metal geology; diamonds; heavy minerals; exploration; lamproite; geochemical methods; sampling; kimberlite; stream sediments; igneous rocks; loam
• ISSN: 0375-6742; 1879-1689
• DOI: 10.1016/0375-6742(94)00061-F

Pathfinder minerals and elements are important in the search for primary host rocks of diamond as they provide direct evidence of the presence of their source. Tracking down a diamond-bearing source entails detecting and systematically following a weak trail of subtle clues, before a final target for testing is struck. The most successful and broadly applied method in diamond exploration is heavy mineral sampling which, through recovery of indicator minerals and diamonds, has led to the discovery of many mines around the world. This paper reviews critical aspects of heavy mineral sampling techniques, which include sample selection, size, spacing and processing. Special attention is paid to the selection and evaluation of trap sites during drainage sampling. Geochemical and geobotanical exploration methods, which have a more restricted use in diamond exploration programmes, are also discussed. Forethought and meticulous attention to detail are required when planning and conducting each phase of an exploration programme involving any of the pathfinder sampling techniques, in the analysis of samples and in progressive interpretation of results. Effectiveness of each stage of a diamond exploration programme is directly related to the reliability of these results, which in turn are vital to the decision as to whether or not further exploration is warranted.