The United States Geological Survey (USGS) is a scientific organization created in 1879, and is part of the U.S. government. Their scientists explore our environment and ecosystems, to determine the natural dangers we are facing. The agency has over 10,000 employees that collect, monitor, and analyze data so that they have a better understanding of our problems. The USGS is dedicated to provide reliable, investigated information to enhance and protect our quality of life. This is one of their bulletins.

Prepared on behalf of the U.S. Atomic Energy Commission and published with permission of the Commission.

Prepared on behalf of the U.S. Atomic Energy Commission and published with the permission of the Commission.

Significant refinements of biogeochemical methods applied to mineral exploration have been made during more than twenty years since the last major publication on this technique. This innovative, practical and comprehensive text is designed as a field handbook and an office reference volume. It outlines the historical development of biogeochemical methods applied to mineral exploration, and provides details of what, how, why and when to collect samples from all major climatic environments with examples from around the world. Recent commercialization of sophisticated analytical technology permits immensely more insight into the multi-element composition of plants. In particular, precise determination of ultra-trace levels of 'pathfinder' elements in dry tissues and recognition of element distribution patterns with respect to concealed mineralization. Data handling and interpretation are discussed in context of a wealth of previously unpublished information, including a section on plant mineralogy, much of which has been classified as confidential until recently. Data are provided on the biogeochemistry of more than 60 elements and, by case history examples, their roles discussed in assisting in the discovery of concealed mineral deposits. A look to the future includes the potential role of bacteria to provide new focus for mineral exploration. - Describes the practical aspects of plant selection and collection in different environments around the world, and how to process and analyze them - Discusses more than 60 elements in plants, with data interpretation and case history results that include exploration for Au, PGEs, U, base metals and kimberlites

1919/28 cumulation includes material previously issued in the 1919/20-1935/36 issues and also material not published separately for 1927/28. 1929/39 cumulation includes material previously issued in the 1929/30-1935/36 issues and also material for 1937-39 not published separately.