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The iron ores of Minas Gerais, Brazil, fall into two categories: (1) hypogene hematite ore averaging 66 percent or more Fe, and (2) lower-grade supergene ores. Most ore now extracted is high-grade hypogene ore; lower-grade supergene ores will be of much future value. All supergene ores formed by weathering of itabirite, a metamorphosed oxide-facies iron formation averaging about 38 percent Fe and 44 percent Si02. The Caue Itabirite crops out for...

Rigid plastic collars of one to three colors proved useful for recognition of individual Canada geese (Branta canadensis). The collars did not seem to affect the behavior of the geese, and there was little mortality caused by their use. In good light, bright colors are visible through a 20-power spotting...

Larger Foraminifera from the middle Eocene of Florida and southern Georgia are discussed, including 2 new species, and their geographic and stratigraphic distribution, not only in the U. S., but also at selected localities in the Caribbean region, is analyzed. Several species not previously reported from the U. S. are...

Work toward establishing a program of international cooperative studies in scientific hydrology began about 4 years ago, and the IHD (International Hydrological Decade) will begin under international auspices in January 1965. This program will be highly important for hydrology and hydrologists, and it should contribute greatly to human welfare in the future. Fortuitously, the opening year...

The biblical Jordan River Valley, which extends from Lake Tiberias (the Sea of Galilee) to the Dead Sea, is decidedly similar to the Jordan River Valley of Utah, which joins Lake Utah and Great Salt Lake. Both Jordan Rivers drain relatively large fresh-water lakes and also are major sources of discharge into large salty lakes that have no outlets to the ocean.The...

No abstract available....

The fugacity of sulfur along the curve representing the univariant equilibrium assemblage, chalcopyrite + bornite + pyrite + vapor, has been determined by the electrum tarnish method (1). The conditions of the equilibrium may be expressed by the equation (TP) - /°s 2 (T, 1 atm) = -50,730 + 56.95T (cal.) (350 - 500° C) (T in °K). With gentle curvature, the line...

Officer's Cave is the uppermost of four rapidly eroding cave levels constituting a cavern complex about 700 feet long developed chiefly in clay and silt. Its outer room is 35 feet by 43.5 feet by 100 feet and slopes about 45° east into the western end of a narrow linear hill called Officer's Cave Ridge. Dry valleys, blind valleys, hanging valleys, sinkholes, pipes,...

Pre-Tertiary rocks of the Blue Mountain region of central and northeastern Oregon comprise three major sedimentary and volcanic sequences and two distinct intrusive magma series. The ages of the sedimentary-volcanic sequences are Paleozoic, Late Triassic-Late Jurassic, and middle Cretaceous (Albian to Cenomanian), respectively. The earlier intrusive magma series ranges in composition from peridotite to albite granite and was emplaced during the major...

Profiles of the basement surface in western Kansas and Nebraska were constructed by drawing smooth curves through the shallowest depths estimated from aeromagnetic anomalies along six widely spaced traverses. Ratios of inferred-depth-to-basement to true depth along the traverses ranges from 0.7 to 1.0. Clusters of shallow depth estimates commonly yield an average estimate within 15 percent of the true depth....

THIS note reports measurements made in an attempt to determine: (1) the possible effect of xenoliths on whole-rock basalt age determinations; (2) whether or not potassium-argon age determinations on xenoliths in basalt might approximate the age of the basalt flow. The field location is in the...

THROUGH a fortunate circumstance, a recording magnetometer was operating in the city of Kodiak, 30 km north-west of the surface trace of a fault zone along which movement occurred at the time when the earthquake occurred in Alaska on March 27, 1964. Fortunately, too, the instrument...

Characteristic minerals are psilomelane, hollandite, cryptomelane, and coronadite, more rarely ramsdellite and pyrolusite. Host rocks are Mn-deficient; 80 percent of examples are middle to late Tertiary layered volcanics. Though deposits are shallow, mostly mined to only 100-200 feet (maximum 500 feet), a hypogene origin is...

The ratio of cation to hydrogen-ion concentration is used as a basis for coordinating many observed varieties of silicate rock alteration. Low ratios drive alteration from feldspar through sericite, montmorillonite, or paragonite, toward kaolinite or pyrophyllite. Principal controls of ratio are reactions with wall rock,...

Deposits of ferruginous nickeliferous lateritic soils formed by weathering in place of ultramafic rocks occur at several places in northwestern California and southwestern Oregon, mostly in the Klamath Mountains province. Most of the deposits have been derived from relatively fresh peridotite, although at least one...

A well drilled for geothermal power near Salton Sea in Imperial Valley, Calif., is 5,232 feet deep; it is the deepest well in the world (1962) in a high-temperature hot spring area. In the lower half of the hole temperatures are too high to measure with available equipment, but are...

Right-lateral separation of about 120 miles along Chatham Strait Fault is suggested by apparent displacement of major geologic features on opposite sides of the fault....

Strongly oriented lineaments, defined by lake shores and stream and vegetation alignments, are distributed throughout more than 45,000 square miles of the Beni basin in northeastern Bolivia. The area in which these features occur is a flat, poorly drained, lake-studded plain. It is underlain by flat-lying, poorly consolidated, continental clastic...

Potassium-argon dates of 90,000 ± 90,000 years and 60,000 ± 50,000 years on the basalt in Sawmill Canyon of the Sierra Nevada, California, that underlies a moraine correlated with the Tahoe Glaciation and overlies pre-Tahoe till show that the Tahoe is probably less than 100,000...

The movement of 47 barchan dunes on the west side of Salton Sea, California, ranged from 325 to 925 feet over the 7 years between 1956 and 1963, an average of 82 feet per year. During the 15 years between 1941 and 1956, the movement...

Colored plastic adhesive tape wrapped around the tarsus has been used successfully for color-marking birds and has proved to be easy to put on, adaptable, permanent, and colorfast....

No abstract available....

Geologic interest in Thorne Cave stems from its link with valley alluvium along Cliff Creek, which accumulated to a height of 48 ft., continued to build up another 13 ft. while men lived here, and then reached 30 ft. higher-sealing in the signs of man. Mineralogic study shows that ground water then circulated...

No abstract available....

No abstract available....