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D.F. Davidson

Publications and source records attributed to D.F. Davidson.

15 recordsLinked to original sources
USGS1985

Undiscovered phosphate resources in the Caribbean region and their potential value for agricultural development

The countries of the world's humid tropical regions lack the soil fertility necessary for high agricultural productivity. A recently developed agricultural technology that increases soil fertility can make tropical agriculture highly productive, but the technique requires large inputs into the soil of phosphorus and other fertilizers and soil amendments. Use of fertilizers derived from phosphate rock is increasing greatly throughout the world, and fertilizer raw materials are being produced more and more frequently from phosphate rock deposits close to the areas of use. An increased understanding of the origin of phosphate rock in ancient oceans has enabled exploration geologists to target areas of potential mineral resource value and to search directly for deposits. However, because of the difficulty of prospecting for mineral deposits in forested tropical regions, phosphate rock deposits are not being explored for in the countries of the humid tropics, including most countries of the Caribbean region. As a result, the countries of the Caribbean must import phosphate rock or phosphorus fertilizer products. In the present trade market, imports of phosphate are too low for the initiation of new agricultural technology in the Caribbean and Central American region. A newly proposed program of discovery and development of undiscovered phosphate rock deposits revolves around reconnaissance studies, prospecting by core drilling, and analysis of bulk samples. The program should increase the chance of discovering economic phosphate rock deposits. The search for and evaluation of phosphate rock resources in the countries of the Caribbean region would take about 5 years and cost an average of $15 million per country. The program is designed to begin with high risk-low cost steps and end with low risk-high cost steps. A successful program could improve the foreign exchange positions of countries in the Caribbean region by adding earnings from agricultural product exports and by substituting domestically produced phosphate rock and fertilizer products for imported phosphate fertilizers. A successful program also could provide enough domestically produced phosphorus fertilizer products to allow initiation of new agricultural technology in the region and thus increase domestic food production. Finally, a new phosphorus fertilizer industry would create new jobs in the mining, chemical, and transportation industries of the Caribbean region.

Circular↗
USGS1963

Tellurium content of marine manganese oxides and other manganese oxides

Tellurium in amounts ranging from 5 to 125 parts per million was present in all of 12 samples of manganese oxide nodules from the floor of the Pacific and Indian oceans. These samples represent the first recognized points of high tellurium concentration in a sedimentary cycle. The analyses may lend support to the theory that the minor-element content of seafloor manganese nodules is derived from volcanic emanations.

Science↗
USGS1953

Stratigraphic sections of the Phosphoria Formation in Idaho, 1949: part II

The U.S. Geological Survey has recently measured and sampled the Phosphoria formation at many localities in Idaho and other western states. These data will not be fully synthesized and analyzed for several years, but segments of the data, accompanied by little or no interpretation, are published as preliminary reports as they are assembled. This is the fifth report of data containing abstracts of sections measured in southeastern Idaho; it includes about half of the data gathered in Idaho in 1949. The field and laboratory procedures adopted in these investigations are described rather fully in a previous report (McKelvey and others, 1953a). Many people have taken part in this investigation, which was organized and supervised by V. E. McKelvey. F. J. Anderson, A. L. Bush, R. S. Jones, K. B. Krauskopf, K. Lutz, M. E. Thompson, R. G. Waring, and M. A. Warner participated in the description of strata and the collection of samples referred to in this report. T. K. Rigby assisted in the preparation of trenches and the collection, crushing, and splitting of samples in the field. The laboratory preparation of samples for chemical analysis was done in Denver, Colo., under the direction of W. P. Huleatt.

Idaho↗
USGS1952

Stratigraphic sections of the Phosphoria formation in Idaho (third Idaho report)

The first of a series of reports giving detailed stratigraphic sections of the Phosphoria formation in the Western phosphate field as measured and described by the Geological Survey will soon be published as Circulars. Because of the needs of industry for many of these data during the 1951 field season, and in view of the unavoidable delays attendant on publication, the tabular data to be included in five of these Circulars have already been placed on open file in simple reproduction form (prepared by Ozalid from photographic negatives) and without explanatory text so that early use could be made of the data. The first four sets of tables, one each for the states of Montana, Idaho, Wyoming, and Utah, were released on open file on August 15, 1951, A second Idaho report was released on October 4, 1951. This report includes data of the same character but of samples from different localities and is the third report on samples from Idaho. The tables include name and location of section measured, brief description of geologic setting, acknowledgments for field and analytical work, abstract data on the sections (bed number, rock name, sample number, and thickness), and analytical data on the samples. The analytical data include reports on P 2 O 5 and acid insoluble for all samples and additional analyses, such as Al 2 O 3 , Fe 2 O 3 , and loss on ignition for selected samples. These reports are placed on open file at the offices of the Geological Survey in Washinton, D. C., Spokane, Washington, Salt Lake City, Utah, and Montpelier, Idaho, and at the offices of the Idaho Bureau of Mines and Geology, Moscow, Idaho, the Montana Bureau of Mines and Geology, Butte, Montana, the Wyoming Geological Survey, Laramie, Wyoming, and the University of Utah, Salt Lake City, Utah.

Idaho↗
USGS1952

Stratigraphic sections of the Phosphoria formation in Idaho, 1947-48, Part I

The Permian Phosphoria formation of the western states contains one of the world's largest reserves of phosphate. Although previous investigations (see especially Mansfield, 1927), including reconnaissance geologic mapping and sampling, established the location of most of the important deposits and their quality of scattered localities, they were not sufficiently detailed to permit a comparison of the merits of individual deposits or an appraisal of the reserves of phosphate rock that might be available under present economic conditions. Because the growing importance of the western phosphate deposits requires a better, more detailed understanding of their distribution and quality, the Geological Survey began in 1947 a comprehensive investigation, including (1) reconnaissance geologic mapping, mostly in Montana, of areas in which the Phosphoria formation could occur but where it had not previously been looked for or found; (2) geologic mapping, mostly in Montana, at a scale no smaller than 1:62,500, of several areas known to contain the Phosphoria formation but not previously mapped except in reconnaissance fashion; (3) geologic and topographic mapping, at a scale of 1:12,000, of some of the richest, thickest, and most accessible deposits; (4) measuring, describing, and sampling all beds of the phosphatic and shaly parts, and in some places the full thickness, of the Phosphoria formation and its stratigraphic equivalents at one or two localities per township over the entire field; (5) chemical and spectrographic analysis of the samples for phosphate, fluorine, minor metals, oil, and rock-forming constituents; and (6) petrologic and geochemical studies of the rocks and minerals of the formation. These studies are designed to define the regional and local geologic structures in which the phosphate bed lie, to provide a basis for the estimation of reserves of the inferred class over the entire region, and to determine the origin of the rocks and the elements contained in them. The data collected are not of the detail required to plan actual mining operations, but it is hoped they will guide industry in the selection of individual deposits worthy of further exploration. Most of the field work contemplated as a part of this investigation is now completed. Although the data will not be compiled or published in final form for some years to come, segments of the data, accompanied by little or no interpretation, will be published as preliminary maps or reports as they are assembled. The present report is the first of a series presenting in abbreviated form the description and analyses of the beds measured and sampled at various localities in southeastern Idaho (pl. 1). Companion reports presenting segments of the data from Montana, Wyoming, and Utah (Swanson and others, 1952, and McKelvey and others, 1952a and 1952b) are being released at the same time as this report, and others are in preparation.

Idaho↗
USGS1952

The geology of the Florida land-pebble phosphate deposits

The land-pebble phosphate district is on the Gulf Coastal Plain of Florida. The phosphate deposits are in the Bone Valley formation, dated Pliocene by most writers. These strata overlie the Miocene Hawthorn formation and are overlain by consolidated sands 3 to 20 feet thick. The minable phosphate deposits, called “matrix” in the district, range from a featheredge to about 50 feet in thickness and consist of phosphatic pellets and nodules, quartz sand, and montmorillonitic clay in about equal proportions. Locally the matrix displays cross-bedding and horizontal laminations, but elsewhere it is structureless. The phosphorite particles, composed largely of carbonate-fluorapatite, range in diameter from less than 0.1 mm to about 60 cm and in P 2 O 5 content from 30 to 36 percent. Coarse-pebble deposits, containing 30 to 34 percent P 2 O 5 are found mainly on basement highs; and fine-pebble deposits, containing 32 to 36 percent P 2 O 5 are, are found in basement lows. Deposits in the northern part of the field contain more phosphate particles and their P 2 O 5 content is higher than those in the southern part. The upper part of the phosphatic strata is leached to an advanced degree and consists of quartz sand and clay-sized particules of pseudowavellite and wavellite. The leached zone ranges in thickness from a featheredge to 60 feet. The origin of the land-pebble deposits is incompletely known. Possible modes of origin are a residuum of Miocene age, or a reworked residuum of Pliocene or Quaternary age.

Florida↗
USGS1951

Stratigraphic sections of the Phosphoria formation in Idaho

The first of a series of reports giving detailed stratigraphic sections of the Phosphoria formation in the Western phosphate field as measured and described by the Geological Survey will be released as Circulars within the next few months. Because of the needs of industry for many of these data during the 1951 field season, and in view of the unavoidable delays attendant on publication, the tabular data to be included in these Circulars are hereby placed on open file in simple reproduction form (prepared by Ozalid from photographic negatives) and without explanatory text so that immediate use may be made of the data. The tables include data on sections in four states: Montana, Idaho, Wyoming, and Utah; and the tables for each of these states are bound together as individual reports. The tables include name and location of section measured, brief description of geologic setting, acknowledgments for field and analytical work, abstract data on the sections (bed number, rock name, sample number, and thickness), and analytical data on the samples. The analytical data include reports on P 2 O 5 and acid insoluble for all samples and additional analyses, such as Al 2 0 3 , Fe 7 0 3 , loss on ignition, F, and V 2 O 5 , for selected samples. Spectrographic analyses for a large number of elements are included samples from selected localities, and special analyses have been made of a few samples. These reports are placed on open file at the offices of the Geological Survey in Washington, D. C., Spokane, Washington, Salt Lake City, Utah, and Montpelier, Idaho, and at the offices of the Idaho Bureau of Mines and Geology, Moscow, Idaho, the Montana Bureau of Mines and Geology, Butte, Montana, and the Wyoming Geological Survey, Laramie, Wyoming, and the University of Utah, Salt Lake City, Utah.

Idaho↗
USGS1951

Stratigraphic sections of the Phosphoria formation in Idaho, 1947-48, Part III

.The U.S. Geological Survey has measured and sampled the Phosphoria formation at many localities in Idaho and other western states. These data will not be fully synthesized and analyzed for several years but segments of the data, accompanied by little or no interpretation, are published as preliminary reports as they are assembled. This report, which contains abstracts of many of the sections in southeastern Idaho (fig. 1), is one of this series and is the third report of data gathered in Idaho during 1947 and 1948. The field and laboratory procedures adopted in these investigations are described rather fully in a companion report (McKelvey and others, 1953). Many people have taken part in this investigation, which was organized and supervised by V. E. McKelvey. D. A. Bostwick, R. M. Campbell, R. A. Gulbrandsen, R. A. Harris, R. L. Parker, R. A. Smart, J. E. Smedley, R. H. Thurston, and R. G. Waring participated in the description of strata and collection of samples referred to in this report. D. B. Dimick, Jack George, W. S. Hunziker, J. E. Jones, H. A. Larsen, and T. K. Rigby assisted in the preparation of trenches and collection, crushing, and splitting of samples in the field. The laboratory preparation of samples for chemical analysis was done in Denver, Colo., under the direction of W. P. Huleatt.

Idaho↗
USGS1950

Value of domestic production of minerals from various classes of rocks

Fluids and sedimentary rocks accounted for 48 and 36 percent, respectively, of the total value of the 1946 domestic mineral production. The epigenetic (vein and replacement) and metamorphic deposits each contributed 6 percent of the total, and residual and igneous deposits accounted for 3 and 1 percent, respectively. Fuels were the most valuable of all the minerals produced--77 percent of the total. Petroleum, natural gas, and similar fluid fuels accounted for 47 percent of the total production and 98 percent of that from fluids; bituminous coal made up 24 percent of the total production and 67 percent of that from sedimentary rocks; anthracite coal was valued at 6 percent of the total production and 92 percent of that from metamorphic rocks. Exclusive of fuels, the bulk of the production of nonmetallics, and of the total mineral production too, was from sedimentary rocks (74 and 50 percent, respectively) and from veins and replacements (8 and 28 percent, respectively). Most of the production of metals, however, was from veins, etc. (62 percent) and residuum (29 percent).

Economic Geology↗