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H. W. Lakin

Publications and source records attributed to H. W. Lakin.

15 recordsLinked to original sources
USGS1977

Tellurium, a guide to mineral deposits

Te dispersion patterns are useful in exploring for different types of mineral deposits and in providing additional information about known ore deposits. The Te content of rocks is given for five mining districts in the western United States: Coeur d'Alene, Idaho; Robinson, near Ely, Nevada; Montezuma, Colorado; Crater Creek area, Colorado; Cripple Creek, Colorado. Many of the analyses were obtained by use of a new analytical method sensitive to 0.001 ppm Te. The principal ore deposits in the Coeur d'Alene district, Idaho, are Pb-Zn-Ag replacement veins in Precambrian rocks of the Belt Supergroup. Te dispersion patterns show the outlines of the original mineral belts, the effects of intrusive events, the location of ore deposits, the displacements caused by post-ore faulting, and the borders of the 780-km 2 district. The disseminated porphyry Cu deposits of the Robinson mining district, Nevada, are associated with Cretaceous quartz monzonite stocks that have intruded Palaeozoic carbonate rocks. Te is present in rock samples in concentrations as high as 10,000 ppm and forms a halo around the areas containing the Cu deposits. The alteration zones in the porphyry Mo district near Montezuma, Colorado, are developed around several small Tertiary intrusions occurring along a regional shear zone. Te haloes reflect the locations of porphyry intrusives, individual deposits and their ore shoots, and the pattern and intensity of adjacent alteration. The Te content of soils over the Montezuma stock is higher than, and varies independently from, the Te content of adjacent outcrops. Soils generally contain more Te than adjacent outcropping rocks. Soil may collect gaseous Te compounds from mineral deposits. The Crater Creek area is a northwestern extension of the Summitville mining district, Colorado. Te dispersion patterns radiate out from exposed Cu-Pb-Zn veins, from an outcrop of molybdenite stockwork veins and from associated iron-stained altered rock. Te haloes intensify exponentially with proximity to known ore and suggest the presence of Summitville-type chimney deposits. Most of the gold- and silver-telluride ore in the Cripple Creek district, Colorado, is found in fracture fillings within a volcanic subsidence basin. Haloes of Au, Ag and Te all define the mineralized portions of the fissure veins.

Journal of Geochemical Exploration↗
USGS1974

Statistical summary of geochemical data furnished by 85 laboratories for for six geochemical exploration reference samples

Evaluation of the methods of analysis used in geochemical exploration is the concern of both the chemists producing the geochemical data and the geologists interpreting the data. This mutual concern resulted in the formation of the Committee on Geochemical Analysis of the Association of Exploration Geochemists. This committee recommended the preparation of several reference samples to be used in evaluating methods of analysis useful in geochemical exploration. Six reference samples--three soil samples and three rock samples--were distributed to 176 participating laboratories around the world. This report summarizes data, on fifteen elements (table 1), which have been furnished by 85 laboratories. The amount of data furnished by an individual laboratory varies from one element analyzed by one method to twelve elements, some analyzed by several methods. Fourteen variables for each element were taken from the reports of analyses submitted by individual laboratories. This report only considers four variables--geochemical reference samples, method of analysis, element, and concentration; that is, the report summarizes the variation in concentration for 15 elements by method of analysis for each of the six geochemical exploration reference samples. There are no restrictions on the remaining variables.

Open-File Report↗
USGS1968

Utilization of humus-rich forest soil (mull) in geochemical exploration for gold

Distribution of gold in humus-rich forest soil (mull) reflects the known distribution of gold deposits in bedrock in the Empire district, Colorado. Gold from the bedrock is accumulated by pine and aspen trees and is concentrated in the mull by the decay of organic litter from the trees. Anomalies in mull which do not coincide with known gold deposits merit further exploration. The gold anomalies in soil (6- to 12-inch depth) and in float pebbles and cobbles poorly reflect the known distribution of gold deposits in bedrock beneath the extensive cover of colluvium and glacial drift.

Circular↗
USGS1965

A field method for the determination of silver in soils and rocks

A rapid, sensitive, and specific field method useful in geochemical exploration has been developed for the determination of silver in geologic materials. In this method the sample is digested with nitric acid and the silver is extracted with triisooctyl thiophosphate (TOTP) in benzene and stripped from the organic phase with dilute hydrochloric acid. Silver is then measured indirectly by its catalytic action on the persulfate oxidation of manganous ion to permanganate. The lower limit of sensitivity of the method is 0.01 ppm. Soils, rocks, oxides and sulfide ores have been analyzed, and the results agree favorably with assay and spectrographic analyses. About 80 determinations can be made per man-day.

Open-File Report↗
USGS1963

The precipitation of aluminum, iron and manganese at the junction of Deer Creek with the Snake River in Summit County, Colorado

The oxidation of disseminated pyrite in relatively acid schists and gneisses of the Snake River drainage basin provides abundant iron sulfate and sulfuric acid to ground and surface water. This acid water dissolves large quantities of many elements, particularly aluminum and surprisingly large quantities of elements, such as magnesium and zinc, not expected to be abundant in the drainage basin. The adjoining drainage to the west, Deer Creek, is underlain by basic rocks, from which the water inherits a high pH. Despite the presence of base- and precious- metal veins in the drainage basin of Deer Creek, it carries less metal than the Snake River. The principal precipitate on the bed of the Snake River is hydrated iron oxide with small quantities of the other metals. In Deer Creek manganese oxide is precipitated with iron oxide and large quantities of other metals are carried down with this precipitate. Below the junction of these streams the pH stabilizes at a near-neutral value. Iron is removed from the Snake River water at the junction, and aluminum is precipitated for some distance downstream. The aluminum precipitate carries down other metals in concentrations slightly less than that in the manganese precipitate on Deer Creek. The natural processes observed in this junction if carried to a larger scale could provide the mechanism described by Ansheles (1927) for the formation of bauxite. In the environment described, geochemical exploration by either water or stream sediment techniques is difficult because of (1) the extreme pH differential between the streams above their junction and (2) the difference in the precipitates formed on the streambeds.

Colorado↗
USGS1963

Tellurium: A new sensitive test

A new, extremely sensitive method for the quantitative determination of tellurium is based on the induced precipitation of elemental gold from a 6N HCl solution containing gold chloride, cupric chloride, and hypophosphorous acid; the amount of gold reduced is proportional to the amount of tellurium present. As little as 1 nanogram (1 X 10 -9 g) of tellurium gives a measurable reaction with 1 mg of gold in 50 ml of solution.

Science↗
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↗
USGS1961

A comparison of analytical methods used in geochemical prospecting for copper

Analytical methods used in geochemical prospecting for copper were compared by analysis of samples of residual soil collected in duplicate near a copper -bearing vein at the Malachite mine, Jefferson County, Colo. In this area barren or "background" samples have a mean copper content of 58 ppm (parts per million) and anomalous samples containing copper derived from the vein have a mean copper content of 216 ppm. Most anomalous samples are above 100 ppm and most barren samples are below. Geochemical prospecting tests, such as the spectrographic, biquinoline, dithizone and chromograph tests for copper and the citrate soluble and acid-soluble tests for total heavy metal, are almost as sensitive but are less precise and less accurate than standard quantitative trace analysis. Statistical techniques based chiefly upon the coefficient of variation show that the geochemical prospecting tests differ considerably among themselves in sensitivity, precision, and accuracy. This study indicates that the dithizone and the biquinoline tests for copper are the best for geochemical prospecting in this area.

Colorado↗
USGS1947

The zinc content of plants on the Freidensville zinc slime ponds in relation to biogeochemical prospecting

The zinc content of thirty different kinds of plants growing on slime ponds containing on the average 12.5 per cent zinc were determined by the dithizone method. The zinc content ranged from 39 p.p.m. in the fruit of the false solomon's seal (Smilacina racemosa) to 5,400 in the horsetail (Equiseteum arvense}. This latter plant varied considerably in zinc at different places on the slime ponds. The zinc contents of the aspen (Populus grandidentata}, ragweed {Ambrosia artemisiifolia), and horsetail grown on normal soils are compared to those on the slime ponds and it is recommended that the poplar and ragweed be studied further as indicators of zinc ore bodies.

Pennsylvania↗
USGS1944

The relation of selenium to western duck sickness

In 1936 Twomey and Twomey reported that 20-50 parts per million of selenium as sodium selenite in the drinking water produced poisoning in ducks in which the syndrome was identical with that produced by Clostridium botulinum type C, which had been considered the principal causative agent in western duck sickness (Kalmbach and Gunderson, 1934). In a more recent paper, Twomey, Twomey and Williams (1939) reported the analyses of a number of duck livers collected at various points near Great Salt Lake where the sickness is prevalent. These analyses show the presence of 7-148 p. p. m. of selenium, based on the oven-dried weight of the livers. In contrast, no selenium was found in duck livers obtained in Pennsylvania, where sickness has not been reported. As a result of these findings, a thorough investigation of the significance of selenium in outbreaks of western duck sickness was undertaken in the summer of 1940.

The Auk↗