Applications of trend surface analysis and geologic model building to mineralized districts in Alaska

The Mineral Industry Research Laboratory, University of Alaska, has investigated the application of computers and statistics to mineral deposits in Alaska. Existing programs have been adapted and new ones written for the computers available at the University. The methods tested are trend surface analysis and geologic model making. An existing coeffecient of association program was converted to Fortran IV , but was not applied to an Alaskan problem. A trend surface is a mathematically describable surface that most closely approximates a surface representing observed data. In geologic model making, regression analysis is used to determine what geologic features are significant as ore controls. Coefficient of association compares samples to each other on the basis of a variable being present or absent. Trend surfaces were computed for dips and s t r i k e s of geologic features ( v e i n s , f a u l t s , bedrock) for Southeastern Alaska, the Chichagof district , and the Hyder district . Results for the f i r s t two are presented as maps. Trend surfaces and residual maps were prepared for geochemical data from the Slana district, Alaska. A mineral occurrence model was made for a portion of the Craig Quadrangle, and potential values were computed for c e l l s in the area. Appraisals of potential values by five geologists are compared with those of the model. An IBM 1620 multiple regression program is included

Characterization and evaluation of washability of Alaskan coals

This report is a result of the second part of a continuing study to obtain washability data for Alaskan coals to supplement the efforts of the U.S. Department of Energy in their ongoing studies on washability of U.S. coals.Contract No. U.S.D.O.E. ET-78-G-01-8969 (formerly U.S.B.M. G0166212

Natural resource base of the Fairbanks North Star Borough

This report on the natural resource base of the Fairbanks North Star Borough is one of several continuing research projects related to community planning in Alaska. It represents an interdisciplinary effort of the Mineral Industry Research Laboratory and the Institute of Social, Economic and Government Research at the University of Alaska. The result is a synthesis of the economic development potential of natural resources in the greater Fairbanks region

The effects of placer mining on the environment in Central Alaska

Within the Tolovana Mining District, as a result of placer mining, 800 acres of land have been disturbed (0.25% of the land area) and 4 million cubic yards of much have been transported down the Tolovana River through the subsiding Minto Flats. This has increased the rate of sedimentation of the lakes adjacent to the Tolovana River. Mine tailings are about 50% revegetated by natural species. Approximately 60 million cubic yards of muck must be removed to mine the Livengood deposits. A large area of settling ponds will be needed if the deposit is stripped by hydraulic means, or a large area for stacking overburden if mechanical stripping is required. The Crooked Creek area, mined for 80 years has 1,900 acres disturbed (0.7% of the land area) and 200,000 cubic yards of much has been stripped. No correlation is apparent between mining and the non-anadromous fish population, although sport fishing is considered by some to be not as good as a result of mining. Portions of the stream system observed to be impacted with mud showed evidence of having been periodically flushed out. Slave analysis and trace element analysis were applied in an attempt to trace sediments back to their sources, but were not successful. Mining is the pioneer industry around which much of the State of Alaska developed. The transportation network required by the mining industry benefits sportsmen, the tour industry, and directly increases the value of adjacent land. The profit from mining brought much of the early population to the state, and will be a steady source of revenue in years to come

Current state-of-the-art in drying low-rank coals

Preparing Alaska's coal for marketing -- Drying low-rank coals -- Effect of lignite source -- Acknowledgement -- References.Research on drying of low-rank coals, such as lignites and subbituminous coals, has been conducted for nearly half a century. Although partial drying of Dakota lignite is practiced for freeze-proofing by mixing partially dried coal with run-of-mine coal, full scale drying of low rank coals has never been practiced commercially in this country. The reasons are: ( 1 ) drying of low rank coals by conventional methods results in severe degradation of coal particles; (2) dried coals are thus dusty and difficult to handle; (3) reabsorption of moisture in storage and transit defeats the drying process. In addition the dry coal particles will react with ambient oxygen, and heat up enough to ignite. It appears that large-scale development of Alaskan coals may have to await solutions to these problems. Our Mineral Industry Research Laboratory at the University of Alaska is making a comprehensive literature search seeking solutions to these problems and identifying areas of research that should be undertaken

Engines of Growth in the U.S. Economy

There is good reason to believe that R&D influences on TFP growth in other sectors are indirect.For R&D to spill over, it must first be successful in the home sector.Indeed, observed spillovers conform better to TFP growth than to R&D in the upstream sectors.Sectoral TFP growth rates are thus interrelated.Solving the intersectoral TFP equation resolves overall TFP growth into sources of growth.The solution essentially eliminates the spillovers and amounts to a novel decomposition of TFP growth.The top 10 sectors are designated engines of growt led by computers and office machinery.The results are contrasted to the standard, Domar decomposition of TFP growth.Spillovers;input-output;sources of growth

Copper mineral occurrences in the Wrangell Mountains-Prince William Sound area, Alaska

On January 9, 1970, the U.S. Bureau of Mines entered into an agreement with the University of Alaska based upon a proposal submitted by the Mineral Industry Research Laboratory. Under the terms of this agreement, the Laboratory undertook to compile information on copper occurrences in eight quadrangles covering what are loosely known as the Copper River, White River, and Prince William Sound copper provinces. If time permitted four other quadrangles would be added, and this has been possible. Information was to be obtained by searching published and unpublished records of the Bureau of Mines, the U.S. Geological Survey, the State Division of Geological Survey, the University of Alaska, and the recording offices

Application of hydrocyclones for recovery of fine gold from placer material

Alaska and other gold areas have seen a sharp resurgence of placer mining in the last few years. Mines using sluice boxes usually recover gold down to 100 mesh, but recovery of gold finer than this size is a function of particle shape factor, sluice box design and operating parameters. It is felt that a concentrating device is needed to recover gold finer than 100 mesh that may not be recoverable in a sluice box. The device should be capable of processing a large volume of water and solids discharged from the sluice-box. Compound water cyclones, successfully used in the coal processing industry, seem to offer solutions. A system using these devices could recover a concentrate which would be one twenty fifth the size of the original solids in a two stage process. It is not intended to produce a finished product with cyclones, but to reduce bulk so that the reduced concentrate, free of slimes, could further be treated by flotation, gravity methods, or cyanidation to isolate the gold. This report addresses only the application of hydrocyclones for concentrating gold from placer material.Submitted to Mining and Mineral Resources Research Institute, Office of Surface Mining, U.S. Department of Interior, Washington, D.C. Grant No. G519400