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At least 343 records · Page 19Linked to original sources
USGS1951

Preliminary report on the stratigraphy and structure of the Kiligwa River area, Alaska, 1951

The 1951 field program for Navy Oil Unit party 3 was undertaken with a twofold purpose: (1) to investigate the apparent anticlinorium in the Torok formation (Lower Cretaceous) where exposed along the lower reaches of the Ipnavik, Kiligwa, and Nuna Rivers; and (2) to extend the mapping of the west-central Southern Foothills section initiated in 1950 and determine the relationship of the geology of the foothills to that of the Brooks Range to the south.

Alaska↗
USGS1954

Preliminary report of investigations of springs in the Mogollon Rim region Arizona

The Geological Survey has made a reconnaissance of springs in the Mogollon Rim region in central Arizona. This region is the source of much of the water in the Gila, Salt, and Verde Rivers. The region has not previously been systematically studied with respect to the occurrence of ground water. The Mogollon Rim is an escarpment that extends about 200 miles in a northwest direction from near Clifton and Morenci in southeastern Arizona and gradually disappears north of Prescott. Lumbering, ranching, and in local areas copper mining are the principal industries. Main lines of drainage extend north on the plateau, north of the rim, and south or southwest below the rim. For convenience in discussion and because of structural differences, the region has been separated into western, central, and eastern divisions. Pre-Cambrian to Recent rocks crop out. Pre-Cambrian formations and those of Paleozoic age constitute the thickest sections. Recent basalt flows cap the plateau portion, except in the central part of the region. Large areas in valleys below the rim are occupied by lake-bed deposits. The valleys are aligned northwest, suggesting the possibility that a structural trough extends almost the full length of the rim southwest of the scarp. In some areas, erosion has caused recession of the escarpment for distances of a few miles to 10 or 15 miles from the major rim faults. The origin of late deposits of sodium Sulfate in the Verde basin has not been adequately, explained. As the salts are concentrated near mineralized districts on the southwest side of the basin, a possible genetic relationship between the two should be considered. Pre-Cambrian granite and basalt of probable Tertiary and Quaternary age are the igneous rocks most widely exposed in the region. Diabase dikes and sills are prominent in some areas; they were intruded probably during Late Cambrian time. A thickness of 2,000 feet of volcanic rocks of probable Cretaceous and Tertiary age is exposed in one area along the rim, but these rocks as yet have not been studied in detail. A hypothetical relationship is advanced to explain the coincidence in estimated volumes of rock erupted in the San Franciscan volcanic field and the volumes displaced by subsidence of the Verde basin. Fold structures are relatively uncommon in the region and are of small extent except the Holbrook dome northwest of Snowflake. High-angle faults, for the most part normal, are the most prominent structures identified. Faults parallel to the rim have been mapped in several areas. The inferred relations are shown on three diagrammatic sections. These faults are thought to account for the presence of two rims in the eastern division, and perhaps as many as three near Payson. Major orogeny in the region is believed to have occurred four times, as follows: (1) In the pre-Cambrian; (2) in Miocene(?) time southwest of the Mogollon escarpment; (3) in Pliocene (?) time at least in the Flagstaff area, and; (4) at or near the beginning of Quaternary time. The Laramide structures, prominent elsewhere on the plateau, are reflected only weakly in the rim region, so far as is known. Studies of perennial base flow of major streams draining southward from the rim indicate a sustained yield of about 175 cfs (cubic feet per second) measured at existing gaging stations. Runoff records and partial seepage runs show a loss of water between the upper reaches of the streams and the storage reservoirs. There is a general tendency for the water to become progressively more highly mineralized with increasing distance from headwater springs. Natural lakes, ponds, swamps, and cienagas are common in the eastern and western divisions of the rim. They lose considerable water, and some are fully desiccated each summer. They are of little use in their present condition, but might be developed as natural water catches from which recharge co

Open-File Report↗
USGS1955

Preliminary report on part of the Oat Hill quicksilver mine, Mayacmas district, Napa County, California

Oat Hill quicksilver mine, located in the Mayacmas district of northern California, and credited with having produced more than 160,000 flasks of quicksilver, was sampled cooperatively by the Buray of Mines and Geological Survey during 1944. 28 diamond drill holes totaling 8,120 feet were drilled by the Bureau of Mines in four of the six principal veins to sample virgin low-grade reserves and stope fill, and reserves in the other two veins were estimated from existing underground workings and by inferences from drill holes in nearby veins. The writer estimates a total of 10,220 flasks of quicksilver in indicated and inferred reserves totaling 320,000 tons. Indicated reserves minable under 1943 conditions are estimated at 1,960 flasks of quicksilver in 75,000 tons averaging 3.0 lbs Hg per ton. Inferred reserves minable under 1943 conditions are estimated at 4,640 flasks of quicksilver in 109,920 tons averaging about 3.2 lbs Hg per ton. Inferred reserves believed minable only under economic conditions much more favorable than even those of 1943 are estimated at 2,620 flasks of quicksilver in 135,080 tons averaging a little less than 1.5 lbs Hg per ton. About two-thirds of the indicated reserves are accessible in underground workings. All other reserves are estimated approximately without access underground. Several areas not sampled may possibly contain reserves.

Open-File Report↗
USGS1955

Preliminary report on the potential waterpower of Grant, Ptarmigan, Cooper and Crescent lakes on the Kenai Peninsula, near Seward, Alaska

Grant, Ptarmigan, Cooper, and Crescent Lakes, located in the Kenai Mountains in the upper portion of the Kenai River Basin, approximately 25 miles to the north of Seward, present favorable opportunities for the development of waterpower. Grant and Ptarmigan Lakes can be made readily accessible by roads from the Seward-Anchorage Highway which in this area practically parallels the Alaska Railroad; and Cooper and Crescent Lakes by access roads from the Sterling Highway. Geologic conditions are favorable for the construction of the various elements of a power development although some special problems may be encountered. The power sites are located in areas of severe winter temperatures, -30° to -40° or less in most winters. This climatic feature must be given due consideration in the design of the various structures required for a power development. Streamflow records are available for a 7-year period for Grant and Ptarmigan Creeks and for a 5-year period for Cooper and Crescent Creeks. Only short and incomplete records of precipitation are available in the area of the power sites but records have been kept at Seward for 30 years. The precipitation at Seward during the periods for which streamflow records are available was, in general, less than average. It seems reasonable that similar conditions would prevail over the upper Kenai Basin. Consequently, the available stream-flow records cover a period of less than average precipitation and estimates of potential power based on these figures probably are on the conservative side. Only regulated flow is considered in this report. Each of the four lakes is a favorable storage site. Adequate capacity for complete regulation of the flow on a year-to-year basis or over a period of several years can be obtained by the construction of dams ranging in height from 20 to 50 feet. Water from the reservoirs can be conveyed to the powerhouses through conduits, tunnels, or pipelines of reasonable length. The total estimated potential power for the four lakes is 11,000 kilowatts for 90 percent of the time and 14,000 kilowatts for 50 percent of the time. Transmission line distances to Seward range from 22 miles for the Ptarmigan Lake power site to as much as 50 miles for the Cooper Lake power site that would be located on the Kenai River. The transmission line distance to Anchorage will approximate 100 miles, depending on the route selected.

Alaska↗
USGS1956

Preliminary report on waterpower resources of Cascade Creek, Scenery Creek, and Delta Creek near Petersburg, Alaska

The heavy precipitation and runoff, suitable storage sites near tidewater, and steep stream gradients are favorable to the development of hydroelectric power on the streams considered in this report. A geologic examination of the sites indicates that their development would not be hindered by any unusual geologic conditions. On the basis of the 18 years of available stream-flow records for Cascade Creek, it is estimated that 20,800 kilowatts of power could have been generated continuously on Cascade Creek; 13,300 kilowatts on Scenery Creek, and 7,900 kilowatts on Delta Creek. Conditions for power development on Delta Creek are not as favorable as on Cascade Creek or Scenery Creek in view of the size of the structures required in relation to the potential power. The development of a substantial part of this power would depend upon the creation of new industries as the present power market is very limited. There is a heavy growth of timber near tidewater throughout this part of Alaska, and the utilization of this timber in the manufacture of wood pulp is the most likely industrial possibility. The Cascade Creek, Scenery Creek, and Delta Creek drainage basins are in rugged mountainous terrain. There is little land in the immediate vicinity suitable for the location of industrial developments and the supporting communities, and the power would have to be transmitted to a more favorable area. A considerable area is available near Point Agassiz on Frederick Sound about 10 air-line miles from the mouth of Scenery Creek and 5 airline miles from the mouth of Delta Creek.

Alaska↗
USGS1956

Preliminary report on the geology and deposits of monazite, thorite, and niobium-bearing rutile of the Mineral Hill district, Lemhi County, Idaho

Deposits of minerals containing niobium (columbium), thorium, and rare earths occur in the Mineral Hill district, 30 miles northwest of Salmon, Lemhi County, Idaho. Monazite, thorite, allanite, and niobium-bearing rutile form deposits in metamorphic limestone layers less than 8 feet thick. The known deposits are small, irregular, and typically located in or near small folds. Minor faults are common. Monazite generally is coarsely crystalline and contains less than one percent thorium. Rutile forms massive lumps up to 3 inches across; it contains between 5 and 10 percent niobium. Rutile occurs in the northwestern half of the district, thorite in the central and southeastern parts. Monazite occurs in all deposits. Allanite is locally abundant and contains several percent thorium. Magnetite and ilmenite are also locally abundant. A major thrust fault trending northwest across the map-area separates moderately folded quartzite and phyllitic rocks of Belt age, on the northeast, from more intensely metamorphosed and folded rocks on the southwest. The more metamorphosed rocks include amphibolite, porphyroblastic feldspar gneiss, quartzite, and limestone, all probably of sedimentary origin, and probably also of Belt (late Precambrian) age. The only rocks of definite igneous origin are rhyolite dikes of probable Tertiary age. The more metamorphosed rocks were formed by metasomatic metamorphism acting on clastic sediments, probably of Belt age, although they may be older than Belt. Metamorphism doubtless was part of the episode of emplacement of the Idaho batholith, but the history of that episode is not well understood. The rare-element deposits show no evidence of fracture-controlled hydrothermal introduction, such as special fracture systems, veining, and gangue material. They may, however, be of hydrothermal type. More likely they are metamorphic segregations or secretions, deposited in favorable stratigraphic and structural positions during regional metamorphism.

Idaho↗