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Browse more than 65,000 articles authored by our scientists over the past 100+ year history of the USGS and refine search by topic, location, year, and advanced search.

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Properties of synthetic triclinic KFeSi3O8, iron-microcline, with some observations on the iron-microcline⇌iron-sanidine transition

Triclinic KFeSi 3 O 8 , iron-microcline, has been synthesized from oxide mixes and by complete conversion of monoclinic KFeSi 3 O 8 , iron-sanidine. Iron-microcline is triclinic, C ī, a =8·68±0·01 Å, b =13·10±0·01, c =7·34±0·01, α =90° 45′±10′, β =116° 03′±10′, γ=86°14′±10′. The optical properties (Na light) are: α =1·585±0·002, β =1·596±0·002, γ=1·605±0·002, 2 V α =85° (calc.), X≈ b , Z ∧ c =20°±
Authors
David R. Wones, Daniel E. Appleman

Some aspects of sampling salty ground water in coastal aquifers

Investigations of the fluctuations of chloride content in wells that tap the zone of diffusion between fresh and salt water show that the salty well water behaves erratically when the well is pumped. Frequently, a static distribution of chloride content that ranges from less than 1,000 ppm at the top to more than 10,000 ppm at the bottom is present in the open‐hole part of a well. When the well is
Authors
F. A. Kohout, N.D. Hoy

Observations on archaeological remains in northeastern Bolivia

In the Department of Beni, northeastern Bolivia, there are remnants of cultivated fields, roadways, and canals that are distributed over an area of 15,000 square miles. These features are interpreted as indicating the former existence of a highly organized, populous, agrarian society that antedates the culture of the Indian tribes now in the area. 
Authors
G. Plafker

The atomic ratios of natural ferruginous biotites with reference to 'the stability relations of the ferruginous biotite, annite'

The atomic ratios given by Eugster and Wones (1962) for analyses of high FeO-low MgO micas cited by Foster (1960) are in error. The recalculated atomic ratios herein presented show that only three of the thirteen have low (OH+F), and only one has characteristics that may possibly be due to loss of water during determination. None of the analyses exhibit characteristics suggestive of oxidation of i
Authors
Margaret D. Foster, David R. Wones, H.P. Eugster

Glaucophane-bearing metamorphic rock types of the Cazadero area, California

A detailed field and laboratory study has been made of a well-exposed glaucophane schist sequence within the Jurassic and Cretaceous Franciscan Formation of northern California. Three types of glaucophane-bearing metamorphic rocks have been distinguished in and around the area of the detailed study. Each is characterized by distinctive textures and mineral assemblages that are interpreted to repre
Authors
R. G. Coleman, D. E. Lee

Garnet types from the Cazadero area, California

This is the third in a series of papers on glaucophane schists from the Franciscan Formation near Cazadero, California. Previous papers describe three distinct types of glaucophane-bearing Franciscan metamorphic rocks near Cazadero.The purpose of this study is to investigate the garnets present in metamorphic types III (bedrock schists) and IV (tectonic blocks) as defined by Coleman & Lee (1963).
Authors
D. E. Lee, R. G. Coleman, Richard C. Erd

The peg claims spodumene pegmatites, Maine

The Peg Claims pegmatites are located southwest of Rockland in the towns of Warren and Cushing, Knox County, Maine. These pegmatites are representative of a group of zoned, granitic, lithium-bearing pegmatites in which spodumene is present nearly from wall to wall. The pegmatites are discordant, steeply dipping, tabular bodies in the Penobscot quartz-mica schist near the Waldoboro granite. A narro
Authors
H. W. Sundelius

A new geographic and host record for infectious pancreatic necrosis

The occurrence of infectious pancreatic necrosis in rainbow trout (Salmo gairdneri), brook trout (Salvelinus fontinalis), and cutthroat trout (Salmo clarki) has been experimentally authenticated for the first time in the western United States. The cutthroat trout represents a new host. Brook trout fin tissue culture inoculated with bacteria-free filtrate from the diseased fish tissue showed marked
Authors
T. J. Parisot, W. T. Yasutake, V. Bressler

A method for live-trapping dusky grouse

A drive trap, used to capture dusky grouse (Dendragapus obscurus obscurus) females and their broods for transplantation, is described. The trap consists of two 75-foot wings, leading to a netting-covered enclosure with a smaller wooden catch box at the rear. A four-man crew finds a brood in open cover and, while one or two men keep the brood under observation, the others rig the trap along the bir
Authors
R. E. Tomlinson

A modification of the line intercept method of sampling understory vegetation

No abstract available.
Authors
T.H. Ripley, F.M. Johnson, W.H. Moore