SUBJECT INDEX 



697 



Petrology, sedimentary, 656 



pH of water, 541 



Phi units, 605 



Philadelphia, Perm., 294, 309 



Philippines, 513 



Phoenix, Ariz., 420 



Phonolite porphyry, 451 



Phosphate, 21, 47, 131, 491, 507, 524 



Photographing sea bottom, 662 



Photometer, flame, in spectrographic 

 work, 622 



Phyllitic rocks as aggregates, 442 



Physical properties, of carbonate sur- 

 faces, 630 

 of sediments, 108, 232, 234 



Physiographic history, effect of, on high- 

 ways, 127 



Physiographic unit, 282 



Physiological effects of compressed air, 

 202 



Piano wire in reservoir surveying, 357 



Piedmont, 114 



Piedmont sediments, ground water in, 

 120 



Piers, 149, 169-180, 659 



Piezometers, 206, 207, 224, 225 



Pile dikes, 326 



Pile-driving formulas, 177 



Pile foundations, 177 



Piles, 82, 170, 177, 243, 269, 332 



Pingos, 256 



Pittsburgh, Penn., 139, 147, 291, 330 



Placer deposits, 267, 488, 495, 496, 507 



Plains, 12, 27, 640 

 outwash, 12 



Plants, as indicators of ore deposits, 542 

 in permafrost, 256 

 relation of, to coal deposits, 27 

 use of, in control of erosion, 6, 416, 431 



Plasticity, 95, 109, 156, 216, 235, 466, 

 624, 645, 652 



Plasticity index, 99-101, 467 



Platinum, 488 



Platoro Dam, Colo., 451 



Platte River, Neb., 121, 332, 445 



Playa deposits, 27, 495 



Plaza Garage Overhead, Visalia, Calif., 

 176 



Pleistocene, 59, 213, 409, 481 



Pleistocene climate, 251 



Pliocene, 123, 409 



Podsol profile, 42, 59, 60 



Point-bar deposits, 214 



Poised river, 214 



Polacca Wash, Ariz., 427 



Polar charges on clays, 234 



Polders, Dutch clay, 44 



Poling boards in tunnels, 200, 202 



Polished surfaces in studies of carbonate 

 rocks, 622 



Polishing sand, 489 



Pollen as source of coal, 28 



Polluted water in permafrost areas, 266 



Polygonal ground in permafrost, 263, 268 



Polyhedra in clay lattices, 55 



Polyhedric fragments in fractured clay, 

 238 



Pondweed in irrigation canals, 366 



Pontotoc, Miss., 467 



Porcelain, production of, 490 



Pore water, 95, 97, 105, 109, 241, 243 



Pore-water pressures, 103, 108, 191, 241 



Porosity, 29, 30, 35, 85, 97, 114, 129, 141, 

 153, 203, 233, 235, 442, 534, 561, 

 569, 579-632, 643, 659 

 in idealized section of spheres, 586 

 of aggregates, 439, 461 

 of oil reservoirs, 585 



Porphyry copper, 529 



Port Hueneme, Calif., 297 



Possum Kingdom Dam, 157, 164 



Postdepositional changes in carbonate 

 rocks, 617 



Postglacial clays, 106 



Potash, 21, 27, 31, 130, 491, 509 



Potassium ions, 233 



Potential differences in electric logging, 

 563 



Pottery, 490 



Powder River, Wyo., 411, 412 



Pozzolan, 492 



Practical applications, of carbonate po- 

 rosity, 620 

 of gully problems, 413 

 of reservoir sedimentation, 360 

 of sedimentation, 33 



Prairie soils, 52 



Pre-Cambrian, 119, 239, 506, 528, 531 



Precipitation, 21, 48-50, 260, 402, 408 

 annual, in west, 420 

 of calcium carbonate, 24, 619 

 of hydroxide from dilute solutions, 542 



