696 



SUBJECT INDEX 



Organic matter, in clays, 464 



in foundry sands, 478 



in soils, 43, 52, 53 

 Organisms, as agents of transportation, 9 



metabolic processes of, 31 

 Orientation of mineral grains, 571 



relation of, to landslides, 234 

 Oriented water molecules, 98, 110 

 Origin, of carbonate porosity, 623 



of gullies, 417 



of ore deposits, 30, 524-536 



of perennially frozen ground, 254 



of soils, 52 

 Oriskany sandstones, 481 

 Orland irrigation project, 373, 374 

 Orthoclase, 55 

 Orumok, Denmark, 297 

 Osmium, 488 

 Ostracods, 618 

 Ottawa sand, 481 

 Outwash gravel, 12, 13, 120 

 Overburden, 182 

 Overburden pressure, 198 

 Overgrazing, 27, 380, 418 

 Oversaturation, effect of, on precipita- 

 tion, 16 

 Oxalis soil, 48 

 Oxbow lakes, 217 

 Oxidation, 462, 526 

 Oxidation-reduction potential, 5, 16 

 Oxygen content of water in basins, 21 

 Oxyhydroxides, 56 



Packing of sand in relation to porosity, 



607 

 Paleocene, 163 



Paleogeographic distribution, 572 

 Paleozoic, 164, 211 

 Palladium, 488 

 Palms, effect of, on military operations, 



643 

 Panoche soil, 48 

 Parent earth materials, 16, 43 

 Paris, France, 199, 208 

 Park City, Utah, 528, 532 

 Parker Dam, 360, 443 

 Particle size, 240 



relation of, to ceramics, 471 

 Pasco Pumping Plant, Wash., 452 



Pass Christian, 282 



Past climates, 254 



Pasture land in soil erosion, 399 



Pauling's rule, 55 



Pavements, in military warfare, 639 

 in permafrost areas, 261 



Paving gravel, 489 



Payette River, Idaho, 382 



Peak stream flow discharge, 349 



Peat, 48, 121, 141, 236, 491, 495, 640 



Pebbles, 447; see also Gravel 



Pecos River, N. M., 382 



Pediments, 26 



Pedocals, 54 



Pegmatite, 486 



Pemigewasset River, N. H., 190 



Penetration cones, 99 



Penetrometers, 171, 172 



Pennsville Dike, 309 



Pennsylvania, 84, 135, 139, 148, 481, 518, 

 525, 585, 611 



Pennsylvania Geological Survey, 585 



Pennsylvania Turnpike, 133, 139, 142 



Pensauken formation, 475 



Perennially frozen ground, see Perma- 

 frost 



Pergelation, 251 



Permafrost, 139, 145, 247-275, 643 



Permeability, 30, 35, 76, 85, 96, 100, 105, 

 109, 114, 122, 158, 161, 172, 187, 

 204, 224, 232, 235, 237, 240, 478, 

 515, 534, 563, 569, 579-632, 643, 

 659 

 of foundations, 149, 181-192 

 of oil reservoirs, 579-615 

 relation of grain size to, 116 



Permeameters, 589 



Permiam, 148, 518, 569, 611, 627 



Permissible velocities in design of earth 

 canals, 70 



Personnel requirements in foundation 

 studies, 170 



Pervious layers, 108, 181-187, 213, 223 



Petrofabric investigations, 623 



Petrographic analysis, 127, 173, 442, 622 

 of gravel, 444 



Petroleum, 89, 485 



Petroleum geology, 558-632 



Petroleum production, 84 

 engineering of, 84, 90 



Petroleum reservoirs, 579-632 



