New USGS Alaska Geochemical Atlas Tells Rich Tales About the Last Frontier
The U.S. Geological Survey has produced a new compilation of landscape-scale sediment and soil geochemical data for Alaska. This was last completed nearly 40 years ago in 1978, but the new effort uses modern modeling and analysis techniques to map 68 elements across a newly developed and updated geochemical atlas of Alaska.
This new publication enables users to see the distribution of geochemical elements across the entire state.
A rich legacy of geochemical data produced since the early 1960s covers the great expanse of Alaska, providing significant opportunities for applying this information. The new geochemical maps could be useful for landscape geochemistry, mineral resource exploration, geo-environmental investigations, agriculture, forestry, land-use planning and water quality evaluation.
“The geochemical maps in the atlas provide a wealth of knowledge that can be useful for assessing the mineral resource potential of Alaska” said retired USGS scientist Greg Lee, the first author of the report. “However, the maps also show very clearly what we don’t know, and because the majority of the samples that were analyzed have sub-samples that are stored by the USGS, there is a huge opportunity for future workers to use these samples to collect invaluable data about the distribution of strategic and critical minerals in Alaska.”
Important and valuable regional geochemical knowledge may be gained by comparing results from the geochemical atlas with other earth science, digital datasets and databases, such as the newly published USGS geologic map of Alaska.
The USGS compiled and integrated analyses of more than 175,000 sediment and soil samples to produce the atlas maps. These samples originated from three major, separate sources: the USGS, the National Uranium Resource Evaluation program, and the Alaska Division of Geological & Geophysical Surveys geochemical databases, and were analyzed using many different methods over a 50-year time period. Over this duration, many changes in analytical techniques were developed and applied. Various data types presented challenges in building consistent and integrated datasets for modeling and mapping of element distributions, but the final maps indicate that legacy data can be used to build coherent and informative products.