Ion-selective electrode determination of iodine in rocks and soils
W. H. Ficklin
1975, Journal of Research of the U.S. Geological Survey (3) 753-755
Use of an iodide-ion-selective electrode permits rapid and fairly accurate determination of iodine (as iodide) in rocks and soils. When a 1-g sample is used, concentrations as small as 0.5 ppm can be determined with a precision of about 25-percent relative standard deviation. When bromine concentration is greater than 5...
Absolute age of disseminated uraninite in Wheeler Basin, Grand County, Colorado
K.R. Ludwig, E. J. Young
1975, Journal of Research of the U.S. Geological Survey (3) 747-751
Uranium and lead isotopic analyses of monazlte and uraninite from the disseminated uraninite occurrence at Wheeler Basin, Grand County, Colo., indicate that these minerals formed 1,446±20 m.y. ago. This time correlates well with intrusion of the Silver Plume Granite. The uraninite and monazite were also affected by a later disturbance...
A late Holocene pollen diagram from near Lake Tahoe, El Dorado County, California
Alojz Sercelj, David P. Adam
1975, Journal of Research of the U.S. Geological Survey (3) 737-745
A 2,500-yr pollen record from an alpine meadow in the central Sierra Nevada shows a general agreement with other more detailed pollen records from the late Holocene of California. Tree roots from the site suggest dry conditions at about 1150 and 1350 radiocarbon yr B.P....
Modern pollen surface samples: An analysis of subsamples
David P. Adam, Peter J. Mehringer
1975, Journal of Research of the U.S. Geological Survey (3) 733-736
Multiple subsamples of pollen samples obtained from the modern soil surface at two sites in southern Arizona were individually collected and analyzed to evaluate the practice of mixing subsamples when collecting modern surface samples. Results suggest that at least five subsamples must be mixed in order to avoid collecting a...
A late Holocene pollen record from Pearson's Pond, Weeks Creek landslide, San Francisco Peninsula, California
1975, Journal of Research of the U.S. Geological Survey (3) 721-731
A 210-cm core from Pearson's Pond yielded a pollen record for the past 3 millenia. Prior to A.D. 1000 the pond biota was particularly sensitive to climatic fluctuations. Two wet intervals occur in the pollen record, between 350 B.C. and A.I). 0 and between A.D. 650 and 900. The pollen...
Stratigraphy, conodont dating, and paleotectonic interpretation of the type Milligen Formation (Devonian), Wood River area, Idaho
Charles Sandberg, Wayne E. Hall, John N. Batchelder, Claus Axelsen
1975, Journal of Research of the U.S. Geological Survey (3) 707-720
The Milligen Formation at and near its type locality in the Wood River area is considerably older than and unrelated to rocks of Early Mississippian age called Milligen Formation in the Lost River Range and other ranges of east-central Idaho. Conodont faunas were found in limestones of a thin upper...
Silurian and Devonian miogeosynclinal and transitional rocks of the Fish Creek Reservoir window, central Idaho
Betty A. Skipp, Charles Sandberg
1975, Journal of Research of the U.S. Geological Survey (3) 691-706
Documentation of Devonian continental-shelf shallow-water carbonate rocks in the core of the Fish Creek Reservoir window shifts the known westernmost limit of the Devonian miogeosyncline 50 km (30 mi) southwest across the structural grain from the well-known miogeosynclinal sequence in the Lost River Range. The miogeosynclinal carbonate sequence in the...
Structure and Paleozoic stratigraphy of a complex of thrust plates in the Fish Creek Reservoir area, south-central Idaho
Betty A. Skipp, Wayne E. Hall
1975, Journal of Research of the U.S. Geological Survey (3) 671-689
Permian, Pennsylvanian, Mississippian, Devonian, and Silurian marine rocks of diverse facies are brought together in a complex of six thrust sheets in the Fish Creek Reservoir area on the north edge of the Snake River Plain, Idaho. The lowest structural element, the parautochthon, is made of more than 450 m...
Description of the geoelectric section, Rattlesnake Hills unit 1 well, Washington
Dallas B. Jackson
1975, Journal of Research of the U.S. Geological Survey (3) 665-669
A complex 64-in. normal log from the 3,249-m-deep Rattlesnake Hills well was digitized and reduced to a form resembling a simple resistance log. The simplified form of the log made it possible to recognize three major geoelectric intervals in the well that were not apparent on the original log. The...
Phosphate fertilizer materials in Colombia; imports, uses, and domestic supplies
James B. Cathcart
1975, Journal of Research of the U.S. Geological Survey (3) 659-663
The distribution of potentially economic phosphate deposits and the locations of major users of phosphate products in Colombia are some of the economic factors that indicate the capability of the deposits to supply domestic demands. Much research is required to determine the types of processing plants needed and to outline...
Progressive metamorphism of schists recovered from a deep drill hole near Fairbanks, Alaska
Robert B. Forbes, Florence R. Weber
1975, Journal of Research of the U.S. Geological Survey (3) 647-657
In 1965, a deep test hole drilled near Eielson Air Force Base, Fairbanks district, Alaska, penetrated 9,774 ft (2,979.1 m) into schists of the metamorphic complex of the Yukon-Tanana Upland. Cores recovered from the test hole show that the section is dominated by calc-magnesian rocks with subordinate pelitic schists. Pelitic...
Evaluation of stochastic models describing movement of sediment particles on riverbeds
Petar Todorovic, Carl F. Nordin Jr.
1975, Journal of Research of the U.S. Geological Survey (3) 513-517
Various stochastic models have been proposed to describe the movement of sediment particles on the riverbed. Here it is attempted to summarize in an integrated form and to generalize the most important theoretical results in this field. The approach adopted in this paper is based on the fact that most...
Fossil fishes from the Pliocene or Pleistocene Cache Formation, Lake County, California
Richard W. Casteel, Michael J. Rymer
1975, Journal of Research of the U.S. Geological Survey (3) 619-622
The remains of fossil fishes comprising three species were found in the Cache Formation in Lake County, Calif. The rocks containing the fossils are considered to be late Pliocene or early Pleistocene. The species are all freshwater and primarily quiet-water types that now live in Clear Lake and the waters...
Lower Keweenawan volcanic rocks of Michigan and Wisconsin
Harold A. Hubbard
1975, Journal of Research of the U.S. Geological Survey (3) 541
Unconformable sequences of Keweenawan volcanic rocks occur in Michigan and adjacent Wisconsin. The sequences differ in types of rocks, magnetic properties, metamorphic grade, and pattern of structural deformation; they had different vent areas and were deposited in basins that were only partly overlapping. The older sequence includes the Bessemer Quartzite...
A typical cross section based on magnetic data of lower and middle Keweenawan volcanic rocks, Ironwood area, Michigan
Elizabeth R. King
1975, Journal of Research of the U.S. Geological Survey (3) 543-546
A north-trending aeromagnetic profile of a sequence of east-striking Keweenawan volcanic rocks near Ironwood, Mich., can be matched to a calculated profile over a model consisting of a series of dipping layers. (The dips were those measured by H. A. Hubbard along the north-trending valley of the Black River.) Remanent...
Replacement barite deposit, southern Independence Mountains, Nevada
Keith B. Ketner
1975, Journal of Research of the U.S. Geological Survey (3) 547-551
Allochthonous Devonian chert, metaquartzite, and greenstone in the Blue Basin quadrangle,, southern Independence Mountains, Nevada, are mineralized with barite forming a deposit of possible commercial grade and size. Textural evidence indicates that the barite was deposited in the host rocks principally by replacement, to a lesser extent by a process...
Diagenesis of Miocene siliceous shales, Temblor Range, California
K. J. Murata, R.R. Larson
1975, Journal of Research of the U.S. Geological Survey (3) 553-566
Siliceous Monterey Shale and related shales of the Temblor Range, Calif., are subdivided into three depth-controlled zones characterized by different forms of silica. These are, in descending stratigraphic order: (1) Biogenic opal zone, with remains of diatoms and other siliceous organisms, (2) diagenetic cristobalite zone, and (3) diagenetic quartz zone....
Tectonic setting of the Tertiary volcanic rocks of the Olympic Peninsula, Washington
Wallace M. Cady
1975, Journal of Research of the U.S. Geological Survey (3) 573-582
Lower and middle Eocene abyssal and Hawaiian type tholeiitic basalts form two accumulations that apparently were once far out on the east flank of the Juan de Fuca Ridge, within the Juan de Fuca plate. One of these (more than 15 km thick) is near the eastern and southeastern periphery...
Tectonics of the western Valley and Ridge foldbelt, Pendleton County, West Virginia - a summary report
William J. Perry Jr.
1975, Journal of Research of the U.S. Geological Survey (3) 583-588
A belt of high anticlines, the Nittany anticlinorium, occupies the western Valley and Ridge foldbelt in the central Appalachians. It extends southwestward from the Nittany arch of central Pennsylvania into the Virginias. An investigation of the tectonics of this anticlinorium in Pendleton County, W. Va., rules out active basement involvement...
Quaternary faults at San Diego Bay, California
George W. Moore, Michael P. Kennedy
1975, Journal of Research of the U.S. Geological Survey (3) 589-595
Acoustic-reflection profiles of subbottom strata reveal numerous faults that cut Quaternary deposits within and directly outside of San Diego Bay. These faults, together with previously mapped onshore faults, constitute the Rose Canyon fault zone that forms the local west boundary of the Santa Ana tectonic block, which is bounded on...
Age of volcanism, intrusion, and mineralization in the Thomas Range, Keg Mountain, and Desert Mountain, western Utah
David A. Lindsey, Charles W. Naeser, Daniel R. Shawe
1975, Journal of Research of the U.S. Geological Survey (3) 597-604
Twenty-six new age determinations by the fission-track method establish a chronology for volcanism, intrusion, and mineralization in the Thomas Range, Keg Mountain, and Desert Mountain, in western Utah. The fission-track ages confirm D. R. Shawe's three-fold classification of igneous rocks. The oldest group of rocks consists of flows, agglomerates, and...
Geomorphic evidence for late Holocene tilting in southern San Mateo County, California
David P. Adam
1975, Journal of Research of the U.S. Geological Survey (3) 613-617
Relations between the stream channels and the alluvial deposits along Bradley Creek and the lower part of Butano Creek suggest that the area has been tilted very recently, and localized swampy conditions supply additional supporting evidence. Radiocarbon dates show that some of the valley alluvium along Butano Creek was deposited...
Spectrochemical determination of trace elements in galena
E. L. Mosier, J.C. Antweiler, J. M. Nishi
1975, Journal of Research of the U.S. Geological Survey (3) 625-631
A semiquantitative spectrochemical method is described by means of which 10-mg samples of galena can be analyzed for their trace element content. Results on 40 elements are reported as six logarithmically spaced intervals per order of magnitude and obtained by visual comparison with standards prepared in spectrographically pure lead sulfide....
Revised value for the O18 fractionation between CO2 and H2O at 25°C
James R. O’Neil, Lanford H. Adami, Samuel Epstein
1975, Journal of Research of the U.S. Geological Survey (3) 623-624
A new value of 1.0412 for the fractionation factor a between CO2 and H2O at 25°C is recommended on the basis of new data and a reevaluation of earlier published data....
Silica mineralogy and structure of the Monterey Shale, Temblor Range, California
K. J. Murata, R.G. Randall
1975, Journal of Research of the U.S. Geological Survey (3) 567-572
The d(101) spacing of diagenetic cristobalite decreases regularly with depth of burial in the siliceous Monterey Shale of the Temblor Range. This relation has been used to delineate the folded structure of the Monterey Shale at a locality near Taft....
