Electron microprobe data for monazite and xenotime used in consideration of gold deposit formation models (ver. 2.0, May 2023)
Dates
Publication Date
2018-02-01
Time Period
2022
Time Period
2017
Revision
2023-05-16
Citation
Taylor, R.D., and Adams, D.T., 2018, Electron microprobe data for monazite and xenotime used in consideration of gold deposit formation models (ver. 2.0, May 2023): U.S. Geological Survey data release, https://doi.org/10.5066/F70Z72G1.
Summary
The genetic origin of many gold deposits, including Pogo in Alaska, remains controversial with questions as to whether they formed due to magmatic-hydrothermal or metamorphic-hydrothermal fluids. Gaining a better understanding of the formation mechanisms for these deposits is critical for defining proper exploration criteria in gold-bearing regions and production within these deposits. Monazite are light rare earth (LREE)-bearing and xenotime are heavy rare earth (HREE)-bearing phosphate minerals that are found as alteration products in many gold deposits. In addition to their importance in geochronological investigations, their minor element chemistry may be used to differentiate between metamorphic, magmatic, diagenetic, and hydrothermal [...]
Summary
The genetic origin of many gold deposits, including Pogo in Alaska, remains controversial with questions as to whether they formed due to magmatic-hydrothermal or metamorphic-hydrothermal fluids. Gaining a better understanding of the formation mechanisms for these deposits is critical for defining proper exploration criteria in gold-bearing regions and production within these deposits. Monazite are light rare earth (LREE)-bearing and xenotime are heavy rare earth (HREE)-bearing phosphate minerals that are found as alteration products in many gold deposits. In addition to their importance in geochronological investigations, their minor element chemistry may be used to differentiate between metamorphic, magmatic, diagenetic, and hydrothermal origin. This data release provides electron microprobe geochemical data that is used to showcase differences in these phosphates when derived from magmatic-hydrothermal systems compared to metamorphic-hydrothermal systems. The electron microprobe data was collected by personnel of the Central Region Minerals Program in Denver, Colorado, for the U.S. Geological Survey (USGS) Mineral Resources Program (MRP). Appreciable differences in chemistry were noted for deposits associated with alkaline magmatic systems (Taurus, AK, and Cripple Creek, CO), calc-alkaline magmatic systems (Pebble, AK, and Butte, MT), and orogenic gold systems derived from metamorphic-hydrothermal systems (systems from Grass Valley, the Mother Lode, and the Klamath Mountains in CA). These characteristics were then applied to the controversially classified Pogo gold deposit, Alaska, in order to provide evidence for how it formed. Following initial study, new electron microprobe geochemical data for this updated data release were collected from reduced intrusion-related gold deposits at the Geology, Geophysics, and Geochemistry Science Center in Denver, Colorado, to add to the database. This new data allows better comparison between gold deposits formed from reduced magmatic-hydrothermal fluids, oxidized magmatic-hydrothermal fluids, and metamorphic-hydrothermal fluids.
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EMPA_results_monazite_xenotime_v2.xml Original FGDC Metadata
View
12.45 KB
application/fgdc+xml
EPMA_DataDictionary_v2.csv
12.18 KB
text/csv
EPMA_results_v2.csv
157.05 KB
text/csv
Version_1.zip
34.42 KB
application/zip
version_history.txt
904 Bytes
text/plain
Purpose
The data serve to address geochemical aspects related to numerous USGS projects. This dataset aims to determine the genetic origins of some controversially classified gold deposits in the Tintina Gold Province of Alaska.
