GMEG - Mineral Resources
Project status is complete. Please check the project list for currently active projectsSelected SIMWS publications can be found in U.S. Geological Survey Bulletin-2209 Contributions to Industrial-Minerals Research, a biennial series of chapters, present research strategies, results, and updates of investigations of industrial minerals by USGS scientists and cooperators.
Lacustrine basins are a valued source of industrial minerals (IM). In fact, two IM in lake deposits - borates & diatomite - account for ~64 percent of the high-volume, high-priced IM in the western United States. The US is an important world supplier of diatomite with production in four western states. Diatomite is regionally important & will be considered first in the assessment. Other IM found in lacustrine settings include gypsum, halite, sodium carbonate, zeolites, magnesite, lithium, & clays, as well as sand & gravel in marginal terraces & alluvial fans. Other parts of & other minerals in the lacustrine system may be considered for study, as well as the nature of other products that are environmentally degrading, such as blowing dust. Comparison of lacustrine IM deposits & world-class marine IM deposits in California will identify unique or shared deposit-forming processes.
For this task, a member of the Mineral Information Team (MIT) will examine the lacustrine diatomite industry addressed in the study. MIT will focus on material flow, end use, & development of a GIS layer giving active production sites, prepared so proprietary data are correctly handled.
Subtask: Regional Setting. Identify regional geologic characteristics of late Cenozoic lacustrine deposits in the western US. This information will be used to define the regional parameters of these deposits, including age, tectonic & volcanic setting, nature of depositional system, & climate. This information will help define topical & geographic areas to be addressed in Subtask 4. Analysis to date indicates that deposits formed between about 20 Ma & the present, largely in regions of extension-related volcanism & tectonics, & in response to a general climatic cooling & drying through time.
Subtask: Data compilation. Compile data on global lacustrine deposits to provide additional insight into diatomite geology & genesis; to compare western US & global models; & to compare freshwater & marine deposits. Data to be acquired include: a) Deposit geometry, including location within deposystems of economic diatomite deposits; b) Diatom species & related floral & faunal fossils, paleoecological setting, & probable climatic patterns favorable & unfavorable for deposition; c) Diagenetic industrial minerals (zeolite, clay, chert); d) Effects of post-diatomite sedimentation, tectonics, & diagenesis on deposit characteristics; e) Chemistry (major, trace elements; isotopes) of deposits & both the type & abundance of contaminants (clastics, opal, gypsum, volcanic ash, etc.); f) Age controls; g) Comparative characteristics of freshwater & marine diatomite deposits; h) (MIT) The effect of calcination on diatomite properties & impurity removal; h) extent of lacustrine diatomite industry; & i) (MIT) End uses & associated specification & test procedures used to determine quality of diatomite; compiled tests include those used to determine density, size distribution, surface area, oil absorption, resistivity, & others as identified.
Subtask: GIS data presentation. Incorporate existing & new geologic, geochemical, paleontological, & land ownership data relevant to the task into GIS layers. Identify & acquire relevant data layers pertinent to task but beyond scope of task's data acquisition. Use GIS analysis to identify parameters important for diatomite formation & preservation, such as: a) Effect of highland lithologies on nutrient runoff into lakes, b) Correlation of diatomite- & non-diatomite-bearing lacustrine deposits with tectonic & volcanic setting, & c) Distribution of lacustrine diatomite deposits & occurrences, grade/tonnage of deposits (if available), transportation infrastructure, & processing plants within the primary study area to determine economic feasibility of "undiscovered" diatomite deposits.
Subtask: Through literature search and (budget limited) WA & OR field visits, collect detailed core and sample data on at least 10 producing and past-producing diatomite deposits in the Western US. Compare selected physical and chemical characteristics to like specifications of range of marketed products (specs available through company brochures and web sites). Compare and contrast in situ characteristics with those of processed products to develop improved techniques to determine commercial suitability of diatomite deposits based on limited sample analyses.
The objective of the task is to develop models that give insight to IM geology and economic development. The primary focus is aggregate. Preparing models help will result in a better understanding of explore the geologic, economic, and societal issues that related to development of large quarries within a national and international context. There are two general classes of large quarries currently being developed. Those found in carbonate rocks produce not only aggregate but also a multitude of other commodities including material suitable for cement, agricultural lime, and filler. These multiple commodity quarries offer producers opportunities to maximize revenues where the waste associated with one type of product is a primary feedstock for a second. One quarry in British Columbia is currently gearing up (planned production of 10 million tons per year) and may control aggregate supply for the Northwest United States and perhaps the west coast. The second type of large quarry can be located in several possible rock types and predominantly produces aggregate. The possibility of comparable production sites in sand and gravel deposits also needs to be investigated given the very large sedimentary deposits generated by catastrophic floods related to past glacial outbursts particularly in the Northwest US.
In order to assess probable development of large quarries in the western region and elsewhere of the US (including SE Alaska) we need to examine and model their geology, geography and economics. We will acquire basic data and develop 1) occurrence and deposit characteristic models of megaquarries, 2) data on areas permissive and most importantly, areas not permissive for their development and 3) distribution models of primary transportation systems, points of consumption and use. Assessment will include hypothetical development and economic scenarios by area.
Subtask: Economic & other issues in large quarries & aggregate development: This subtask will develop quantitative & other models using economic and other metrics to characterize the situation & societal attitudes that will affect the timing &, within the limits of geologic & other controls, the regional location of the development of large quarries. Task work continues in the focuses on the interpretations of temporal production & cost trends of domestic aggregate production including the numbers of companies & numbers of production sites for the US as a whole, with a focus on the western US & elsewhere as needed. Analysis will also include determining the relationship of production of sand & gravel to the production of crushed stone in quantity & cost. Trends in aggregate import & export will be evaluated. Work will make use of statistical & other mineral economic-related techniques to evaluate the production trends as related to a constant Gross Domestic Product & other metrics. The results of the work are expected to be completed in a report underway and to be completed in this fiscal year.
A new effort addressing development of large production sites in catastrophic flood deposits will begin.
Subtask: Carbonate rocks & large quarries: The subtask objective is to determination location & geologic characteristics of carbonate rocks that may be suitable for developing large quarries in carbonate in the Southwestern US. The study is expected to identify areas where detailed studies are justified & to begin such detailed studies, as possible. We hypothesize that the successful large quarries in carbonate in the future that supplies the aggregate demands of Southern Calif. & Ariz. Sunbelt will follow, when possible, the model of similar operations in British Columbia in terms of their geology & geography. Future carbonaterock-based large quarries are expected to produce multiple products wherein waste rock for one product might be feedstock for another. Regardless of the eventual source of aggregate, cement will be an essential product needed by the still-rapid growth in this region as well as demanded in continued infrastructure maintenance & replacement. Therefore, it is expected further hypothesize that high-calcium limestone for cement manufacture would also be a requirement for a successful large quarries in carbonate rocks. Access to inexpensive transportation would be a clear advantage. And clearly, if a site is to centralize production, yet another requirement is that there be a large reserve of multiple-product rock, or that existing reserves be expansible within existing land-use constraints.
This task addresses selected industrial minerals, rocks and specialty metals found in hydrothermal systems as well as in pegmatites and in skarns. Priority is given to minerals and specialty metals that are high value, which include feldspar, quartz, kaolin, talc, and gallium (Ga). The current problem addressed by the task is our lack of understanding of the distribution and genesis of high concentrations of gallium (Ga) recently discovered in clays associated with hydrothermal systems at the McDermitt mercury deposit, Nevada. How and where the Ga is located affects its recoverability and viability of extraction from the mineralized horizons. Large hydrothermal alteration zones are localized within this and other volcanic centers where deposits of clay have been developed and mined. These alteration zones potentially host significant resources of gallium either as a primary product or a byproduct of clay extraction.
Subtask: The key parts of this subtask are to define the spatial geologic position, morphology, geochemical, & mineralogical aspects of Ga mineralization in clays within volcanic centers where NURE sediment data show significant Ga geochemical anomalies associated with known epithermal mineralization. Methods & procedures include: 1) Compilation map of Ga and associated elements (Ce, La, and other metals) distribution in volcanic centers in the Western United States. 2) Analysis of principal mineral assemblages in which Ga occurs from newly collected samples in these volcanic centers.
Subtask: This subtask determines the speciation (oxidation state, local coordination, & mineralogic residence) of Ga in: (a) in newly collected Ga-rich clay alteration from volcanic centers in the western U.S. The objective is to characterize Ga speciation & phase and to correlate these to temporal, spatial, & chemical trends resulting from Ga-bearing hydrothermal fluids. Methods & procedures include: 1) Adding to the reference library of Ga phases for XAFS spectra that have already been obtained & for which "average" Ga speciation in the model mineral phases is determined using powdered specimen mineral samples with Ga concentrations of 50 ppm or higher, or synthetic Ga substituted analogs of aluminosilicate minerals and aluminum hydroxide phases; 2) Resolve the other Ga phase species present in core samples from the McDermitt deposit using XAFS spectroscopic techniques.
Subtask: This subtask synthesizes in the laboratory Ga enriched iron & aluminum sulfate phases in the alunite-jarosite solid solution series. These synthesis studies will determine the maximum amount of Ga that can occur in these sulfate minerals & XAFS analysis of the synthetic Ga enriched phases will establish how Ga occurs in the chemical structure of these compounds. These laboratory studies provide a basis for understanding how Ga may occur in clay deposits enriched in sulfate minerals.
The objective of this task is to develop a better understanding of those resources supplying energy-related materials in the US and elsewhere & determine what are the key characteristics that will influence their availability & suitability for use. The expectation is that activities within the task will lead to a better understanding of the known distribution of these minerals resulting in better genetic & exploration models and the development of evaluation models to help recognize where additional resources might be found. The initial focus of the task are on those commodities addressed in the following subtasks.
Subtask: Bedded barite resources in the U.S.: A modern analogs approach: The goals of the investigation are threefold. The first goal is to understand how tectonic settings & geochemical processes affect the physical & compositional attributes of bedded barite deposits. Barite deposits forming in a variety of modern marine environments will serve as the primary data source. The second goal is to better understand the distribution, occurrence, composition & origin of bedded barite deposits in the western U.S. & elsewhere in North America at individual deposit, district, & regional scales. These two goals may be achieved by reference to modern analogs. An attempt will be made to differentiate among subtypes of bedded barite deposits in western North America. A third goal is to better characterize & interpret the trace-element content of bedded barite deposits with emphasis on elements (e.g., Hg, Cd, As, Se, Pb.) of environmental concern.
In support of these activities the following will be initiated this fiscal year:
Subtask: Garnet geology, genetics, models & assessment: Garnet deposits are not equal in quality or potential value. It is important to understand what geologic factors can be used to relate deposits to end-use characteristics before garnet assessments are attempted. In addition, to have a sufficient size & grade (that will need to be modeled), viable garnet deposits must contain garnets of a preferred mineralogy & stones of desirable sizes & angularity. Garnets must have specific properties for use in abrasives and filtration, and to qualify as gemstones. While the world resources of industrial garnets may be large, the magnitude of these resources is uncertain if classified in terms of stone-size distributions & other characteristics set forth in end-use specifications. For example, the American National Standards Institute (ASNI) specification B74.18-1977 provides grading guides for abrasive grains used on coated abrasive products, ANSI specification B74.12-1976 dictates grain size distribution for use in various industrial tools, & American Water Works Association specification B100-89 indicates properties needed for use in filtration (Harben, 1995). Demand for mineral specimens also create a demand for a relatively small part of garnets production be it commercial or as individual mineral collectors on public or private land. There is also a small percent of garnets that will be of gem quality either as collectables or for jewelry fabrication &, if recovered as part of garnet extraction, may provide additional revenues. Possible byproducts are mica, quartz, & gold.
This study will explore geological setting & geomorphological factors important to determine the key geological controls in the development of major garnet placer deposits (e.g., Emerald Creek, Idaho) initially focusing on those deposits found in the northwest U.S. These deposits represent an important end-member where the placers are both relatively young & near the bedrock sources of the garnets. The primary objective is to develop exploration models that will help to identify extensions of existing deposits & geological factors, & their associated assessment models, that help suggest the location & quality of deposits not yet identified. The models & information developed during the study will be used in a preliminary evaluation of garnet resources. A second effort on bedrock garnets may follow later in the study.
An over arching issue in the evaluation of industrial minerals is the development of ways to evaluate resources that commonly are low in-place commodities, as typified by aggregate. This task also supports those activities necessary to educate project members and others on the diverse and complex issues and topics involving industrial minerals, as well as promote development of new ideas for future research on this project and about industrial minerals in general.
A national evaluation of most industrial minerals will be difficult due to this problem. Development of methods, including economic filters is one direction that research will need to continue in the future. Patterns toward large quarry size develop (addressed elsewhere in this project) will only be developed given a set of geologic conditions in certain locations, but will allow a certain type of regional evaluation to be executed. A successful evaluation of aggregate, regional or national will require the assistance of others who have expertise not found in the USGS. This includes geologists, material and civil engineers, and others concerned with issues of aggregate primarily for roads, the biggest end user of aggregate in the nation. The objective of this task is to identify and work with these collaborators who can provide technical assistance in future national aggregate evaluation, as well as help to identify needs and issues that can be used to set Bureau research directions. Another part of this task is the release of related data that will be usable by federal and other land managers in the present as well as in future evaluations.
The purpose of this task is to develop a national framework to identify and prioritize regional IM activities and issues to be addressed over a 5-year plan with other IM chiefs who make up the IM Advisory Team (IMCAT). The objective is to provide an avenue for timely scientific coordination & discourse of cooperative studies among the three regions & to identify and promote new and novel, future scientific directions to be undertaken in the IM arena. This will be accomplished by:
Earlier preliminary work by the principal investigators has indicated that perchlorate (ClO4-) can naturally occur in some minerals & materials other than Chilean nitrate ores. Perchlorate has been detected in the mineral hanksite, in sylvinite ore (largely composed of halite & sylvite), & in a variety of playa crust materials. While both marine & continental styles of deposition are represented, all of these materials formed under evaporitic conditions in arid areas. However, the distribution of perchlorate within these materials is erratic & the form in which perchlorate occurs in these, or even the Chilean nitrate ores, remains unclear. We do not know if the perchlorate occurs as a potassium or sodium perchlorate salt, if it is an impurity in the crystal structure of another mineral, or if the perchlorate is trapped as an anion within fluid inclusions in the minerals composing these materials.
Contrary to public expectations, some low-grade perchlorate contamination cannot be linked to military or industrial point sources. Because the mineral sylvite (KCl) is a commonly used to produce fertilizer, there is a possibility that perchlorate could be dispersed in agricultural processes. Alternatively, large areas of the US are underlain by evaporitic rock sequences that could contain perchlorate-enriched rocks. For instance, the distribution of perchlorate detection in shallow wells in west Texas closely mirrors the boundaries of the Permian Salado Basin. While the evaporates lie at depth, under some hydrologic regimes, it is possible that an extremely mobile anion such as perchlorate could be transported closer to the surface. Our lack of understanding of the form of perchlorate occurrence in natural minerals & materials makes it difficult to evaluate such occurrences. In addition, knowledge of the form of occurrence of the perchlorate would allow us to better isolate sufficient quantities of naturally occurring perchlorate for isotope characterization. Isotopes offer the tantalizing possibility of being distinctive for man-made versus natural perchlorates.
The project is envisioned to last for one year from funding date. All samples will be submitted for analysis by the sixth month. Verbal progress reports will be made to a designated Air Force representative at quarterly intervals. An administrative report on the results of the project with data tables will be submitted within 30 days of the completion of the project. In addition, assuming coherent results, a journal paper will be produced.
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