Bulletin, Issue 959U.S. Government Printing Office, 1949 - Geology |
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Acad aeromagnetic survey alternating current amplifier analysis anomalies apparatus applied assignor circuit Claims allowed coil component comprising computed condensed by V. S. core corporation of Delaware curves deposits depth detector determination direct current discussed drilling earth earthquakes elastic electrical logging electrical resistivity electrode electromagnetic elements equation formation frequency geochemical geoid Geol geomagnetic Geophys Geophysical Abstracts given gradient gravimeter gravity ground horizontal hypocenters indicate Inst instrument intensity investigations issued kilometers layer magnetic airborne detector magnetic field magnetometer maps means measurements ments meters method milligal minerals Moscow observations Observatory obtained Okla oscillator pendulum Petroleum potential problems prospecting radio radioactive Rayleigh waves records reflection region Rept resistivity rocks Røros rotating Russian samples seismic waves seismograph seismological seismometer signal soil stations structure surface temperature terrestrial theory tion torsion balance Tulsa U. S. patent values variation velocity vertical vibrations voltage Washington
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Page 135 - The purpose was to determine the extent of the pitchblende lenses occasionally encountered in the silver-bearing fissures. Adjustments made in the counter to equip it for field use are indicated, the field technique is outlined, and suggestions are offered on the general precautions to be observed in exploration. The results of the survey show that the instrument is capable of detecting not only a pitchblende ore shoot in a shear zone but also the mildly radioactive host rock at a considerable distance...
Page 344 - NY, assignor to Radio Corporation of America, a corporation of Delaware : US patent 2,268,643, issued January 6, 1942.
Page 244 - ... earthquake. Surveys made in 1947 give positive evidence of a slow continuous movement of the area west of the San Andreas fault, relative to the area east of the fault. The outer coastal area is moving northwestward at an annual rate of about 5 centimeters per year and has a total displacement of 3 meters since 1880, the date of the first precise surveys.— Author's abstract. 10417. World Oil.
Page 197 - crochets" (ultraviolet solar radiation effect) has been studied over 11 years, in conjunction with data of solar flares and radio fade-outs. The trace movements in H, D and V of 23 examples are reproduced, in addition to tabulated data for these and for 32 other cases of less certain identification. The general synchronization of flare, fade-out, and crochet (when present) is noteworthy. Comparison is made of the amplitude AH and direction AD of the crochets with the normal diurnal inequality of...
Page 249 - Mass., assignor to General Electric Co., a corporation of New York : US patent 2,438,372, issued Mar.
Page 296 - ... interpretation is given of pressure waves generated in shallow water by explosions of charges of TNT ranging from 0.5 to 300 Ibs., and recorded by Ewing and Worzel. (See accompanying paper, Explosion sounds in shallow water.) The normal mode theory of propagation of sound in layered media, which was developed by the writer in 1941, was extended to cover the case of explosive sound, and the predictions of the theory about the shape and variation of amplitude in the received pressure pulse were...
Page 105 - Electr., vol. 52, no. 4, pp. 497-503, Baltimore, Md., 1947. Geomagnetic activity — the frequency and intensity of magnetic disturbance — is supposed to indicate the influence of solar corpuscular radiation on the earth. Magnetic disturbance also has associations with other terrestrial phenomena similarly correlated with solar changes, and notably with auroras, earth currents, and disturbances of the ionosphere such as those measured by radio methods. Two schemes for magnetic characterization,...
Page 197 - D at about ioh-7 apparent solar time, in conformity with the diurnal inequality in D. The correlation with the diurnal inequality in H is less obvious, but AH is of the correct sign (negative) over the range of daylight hours in which crochets occurred. There are indications of other diurnal and seasonal factors (other than a simple dependence upon the Sun's zenith distance) in the occurrence of crochets at Abinger. Some crochets in 1946 have synchronized with reported bursts of
Page 129 - The authors point out tliat the existence or nonexistence of a maximum may be correlated with the Hall effect curve of the sample. It is shown that the position of the maximum, when it occurs, may also be predicted from Hall effect data. 10083. Jones, WA Experience with some electrical and magnetic methods of prospecting : Canadian Min. Met. Bull. 426, Trans, sec., pp. 537-557, Montreal, Quebec, 1947. To aid mining engineers and geologists in understanding the principles of geophysical exploration...
Page 98 - The magnetometer was found suitable for delineating the location and trend of significant structures in this area. It is indicated that local magnetic anomalies probably bear an Inverse relationship to structural elevation and that structures exist which might be favorable for the localization of lead and zinc deposits. Therefore, exploratory drilling for the purpose of locating ore bodies would be justified, especially along minor structural highs inferred from the magnetic survey.