INDEX. 



505 



Page. 



Peridotite, relations of 249, 250 



relations to gabbro 246, 260, 261, 265 



(^eeWebrlite.) 



Perlitic parting in aporbyolite 87 



plate of 274,276 



in basalt tuff, plate of 294 



Pertbite In biotite-granite 41,42 



Pesbalcumme Falls, iron ore at 375 



Peshakumme Kiver 14, 15 



Pewabic mine 69 



Pbenocryata of granite-porphyry, orientation of 45 



Phillips. H.F., indebtedness to 331 



referred to 22 



Pbyllite. of Mansfield formation 411,439 



described 57-62 



Phlogopite of dolomite 410 



iPhysiography of district 13. 29-37, 329-335 



Pichler, A., on alteration of ataurolite 196 



Pickings, Mather & Co. (See Hemlock mine.) 



Picotite of picrite-porpbyry 217 



of olivine 252 



Picrite-porpbyry described 212-221 



Pilite from augite 211 



from olivine 211.217 



of metabasalt 211 



of metadolerite 201 



of picrite-porphyry 218 



pseodpmorphs after olivine 202 



pseudomorpbs after pyroxene 218 



Pilotasitic texture in metabasalt 98,99,104,212 



Pine. (See Timber.) 



Pinnite, including rutile 410 



of dolomite 410 



Plagioclase included in hornblende 235,241 



including biotite 193, 484 



including hornblende 484 



of acid lavas 89 



of amphibolite 296 



of aoiphibole-scbist 466 



of biotite-granite 41, 42, 191 



of bioti te-schist 468, 469 



of diorite 223,224 



of gabbro and norito 233,234 



of greenstone 483, 484 



of hornblende-gabbro 240,241 



of metabasalt 101 



of mica-diorite 227, 232 



plate of 308 



of mica-schist 414 



of muscovite-biotite-granlte 193 



of pyroclastics 146 



of rbyolite-porphyry 82 



of tuffs 138 



^ orientation of 396 



pressure effects in 234 



zonal structure in 193-194 



Plagioclase-basalt of Hemlock formation 108 



Poikilitic texture in amphibole-peridotite 253 



in contact of granite and sedimentary, plate of.. 300 



in granite 198 



in hornblende 235,251 



in hornblende-gabbro 241 



plate of 312 



in metadolerite 200 



in pyroxene 253 



in quartz-mica-diorite-porphyry, plate of 310 



in peridotite 250 



(See Slicropoikilitic texture.) 



Point Bonita, California 99, 108, 113 



Point Morrito, California, gabbro from 240 



Polar magnetic picrite-porpbyry 212. 219 



Porphyri tic granite 40, 45 



sketch of 45 



Porphyritic limburgite described 212-221 



Porpbyritic texture in gabbro 233,241 



plate of 312 



in gray wacke 167 



in granite 45 



in metabasalt 127, ]29 



in picrite-porphyry 217 



in quartz-mica-diorite 228 



in schistose pyroclastics 146 



(See Ebyolite-porpbyry, Granite-porphyry, 

 Aporbyolite-porphyry.) 

 Potsdam sandstone, relations to Calciferous lime- 

 stone 383 



relations to pre-Paleozoic rocks, xxiv, 26, 28, 331, 376, 473 



relations to Silurian 376 



Pressure effects in acid lavas 87, 88 



in Algonkian of Sturgeon River tongue 471 



in araygdules 120, 128 



in aporhyolite-porpbyry, plate of 276 



arkose 479 



in basic dikes 43 



biotite 43, 248 



in chert 177 



conglomerate 474 



feldspar. 42, 90. 92, 169, 234, 248, 388, 464 



plate of 276,278 



gabbro 247, 248 



granite 44,194,464 



in gray wacke X70 



Groveland formation 449 



Hemlock formation 75 



hornblende 237 



in hornblende-gabbro, plate of 316 



hornblende-gneiss 175 



mica-gneiss 171 



mica-schist ni 



in quartz 41, 51, 53, 57, 81, 82, 91 , 93, 



133, 169, 225, 388, 402, 404, 426, 464, 468, 477, 478, 484 



plate of 268, 276, 278 



in quartzite 52 



in Eandville formation 435-437 



in rhyolite -porphyry, plate of 276, 278 



in sedimentaries, caused by intrusion 195 



Pleistocene deposits, XSIV 29, 33, 75, 332, 333 



erosion of XXIV 29 



relations to Hnronian 155 



Prospecting for iron ore 185 



Platania, Gaetano, on ellipsoidal structure 121, 122 



Pseudo-conglomerate, eruptive 136 



Pseudomorpbs after olivine 213, 214,251, 253 



after pyroxene 214, 218 



of calcite, after feldspar 132 



of chlorite, after biotite 217, 228 



of pilite, serpentine, and magnetite, after i>yrox- 



ene 2I8 



of serpentine, after olivine ^51, 253 



Pumpelly, Raphirl, on amygdules 125 



on Felch Mountain series 380 



on luster mottling 200 



on Menominee iron region 377 



on Michigamme River 335 



