Crustal Imaging and Characterization Team
Stable isotopes when combined with geologic and other geochemical studies are exceptionally powerful tools in understanding the processes during the life cycle of ore deposits. Our objective is to conduct mutlidisciplinary stable isotope-based studies that are designed to answer specific questions about critial gaps in knowldege of processes that occur of the life cycle of mineral resources. The topics selected for study are closely coordinated with the goals of several major projects in the Mineral Resources Program and the new knowledge gained is expected to impact the direction of these and future projects. Another objective of the task is to facilitate a cohesive approach to ore genesis studies using stable isotope, active gas and noble gas isotope, and solute chemistry techniques.
A manuscript will be written on the magmatic steam environment using Alunite Ridge, Marysvale District, Utah as a natural laboratory. This paper will explore the significance of magmatic steam alunite as an indicator of mineralization.
Alunite has proven to be an exceptionally valuable mineral for the identification of porphyry and high sulfidation type mineralization. Indeed some of the largest discoveries of Cu-Au deposits in the last 15 years have been related to identification and understanding of the genetic implications of various types of alunites. Most of this previous work has been stable isotope based. This next year we will expand efforts of correlating the stable isotope geochemistry with new data on the trace element geochemistry to see what more potential alunite may have as an assessment tool. The same will done with hydrothermal jarosite.
Work will continue on the banded hydrothermal jarosite from Gilbert district with comparisons to magmatic steam alunite and its significance as an indicator of mineralization in the area. This jarosite has many of the same characteristics of magmatic steam alunite.
A manuscript based on LA-ICP-MS study of single fluid inclusions in quartz from the Summitville, Colorado high sulfidation gold deposit will be written with Rich Fifarek.
A paper on the Copiapo jarosite deposit of New Mexico will be written with Virgil Lueth.
Efforts to develop capability to develop laboratories capable of analyzing chemistry, stable isotopes, active gases and noble gas isotopes of single or small groups of inclusions in a variety of minerals will continue.
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Mineral Resources |
Eastern / Central / Western / Alaska / Minerals Information |
| Crustal Imaging & Characterization / Spatial Data |
U.S. Department of the Interior |
U.S. Geological Survey
URL: http://crustal.usgs.gov
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