SUBJECT INDEX 



1191 



Refraction {see also Refracted wave), 650, 

 663-665 



critical angle of incidence, 665, 666 



law of, 674 



of longitudinal waves, 641, 650-652, 750 



of traverse waves, 652 



Snell's law of, 664, 665 

 Refraction method (seismic), 750-779 



application to salt dome exploration, 775-779 

 bore-hole method, 778, 779 

 fan shooting, 755-778 



basic assumptions, 765, 766 



comparison to reflection method, 650 



correlation of refractions, 769-774 



delay-times determinations, 766-769 



depth determination, 751-755 



dip determination, 758-764 



field application, 855 



history of, 12, 13 



limitations, 764, 765 



marker horizon, mapping of, 766-769 



operating principle, 650 



refracted ray path {see Refracted ray path) 



seismograms, 721, 722, 770-778 



velocity determination, 751-764 

 Regional gradient, 499 

 Reservoir sites, 59 

 Residual deposits, 54 



Resistance logging measurements, 1018-1024 

 Resistance thermometer, 1064 

 Resistivity: 



apparent, 491, 493, 494, 496, 498, 499, 501, 

 503, 505, 506, 515, 546 



longitudinal, 515 



magnitude of, 440 



methods {see Resistivity methods) 



of igneous and metomorphic rocks, 441 



of minerals and ores, 442 



of sedimentary rocks, 441 



seismic-electric effect, 554 



transverse, 515 

 Resistivity cell, 1070, 1072 

 Resistivity departure curve, 1037 

 Resistivity methods, 465-554 



A. C. methods, 539-541 



anisotropic media, influence on, 514, 515 



anomalies, 498-505, 511, 512 



application of, 557, 559, 562, 572, 574-579 



current (ground) elimination, 537-539 

 by auxiliary circuit, 547 



current penetration variations, 514 



curve correlation, interpretation by, 509 



depth of measurement, 513, 514 



dip determination, 506 



electrodes in {see Electrodes) 



equipotential bowl theory, 508 



investigations: 

 double depth, 503 

 lateral, 498-501 



of asymmetrical inhomogeneties, 501, 502 

 vertical, 501 



Laplace's equation, 469-471 

 solutions by, 471-483 



Resistivity methods (continued) 



lateral exploration, 503, 504 



low velocity layer, measurement of, 718 



mapping of, 574, 575 



Ohm's law, 467, 468, 469 



operating principle, 460, 467 



potential gradient method, 545 

 instruments for, 546 



potential method, 535-537 



ratio E/I, measurement of, 541-545 



ratiometer methods, 545, 546 



recording apparatus for, 548, 549 



Tagg's graphical method, 491-496 



transient method, 549-554 



two-layer problem, mathematical solution of, 

 483-489 



vertical exploration, 504-506 



visual interpretations in, 507-509 



volt-ammeter method, 533-535 



Wenner electrode configuration in, 489-491, 

 517, 518 



wires and reels for, 529-533 

 Rhenium, 992, 993 

 Ring shooting, 774 

 Rotary drill, 872 

 Rotary method of coring, 1083 

 Ruska magnetometer, 119 



Saline deposits, 53 



Salt domes, 267, 286, 294 



gravimeter survey of, 427, 428, 429 



seismic refraction survey of, 775-779 



seismic survey of, 742, 743 



torsion balance survey of, 286-288, 361-363 

 Samarium isotope, 992 

 Sandstone: 



density of, 266 



magnetic susceptibility of, 165 



radio activity intensity range, 1102 



velocity of, 660 

 Scaling circuit, 1005, 1006 

 Schist, 225 



density of, 264 



magnetic susceptibility of, 165, 166 

 Schlumberger sample taker, 1084 

 Schmidt-type magnetometer, {see 



Magnetometers) 

 Schwedar seismometer, 805-807 

 Scintillation counters, 1005 

 Search coil, 443, 587, 593, 595, 625-627 

 Section gauge, 1087 



field operation with, 1089 



log, 1088, 1089 



operation of, 1087, 1088 

 Sedimentary rocks, 51, 53 



density of, 266 



magnetic susceptibility of, 165 



resistivity of, 441 

 Seismic amplifier unit, 810, 811, 812 



amplification control, 808, 809 



filtering, 808 



shielding, 813 



