INDEX 



1025 



Ogishke conglomerate, 5, 17. 520, 523, 650, 707. 

 Ogishke Muncie lake, conglomerate, 5, 17, 520, 52.'!. 



650, 707, 777. 

 limestone, 525. 

 marble, 16. 



rocks from, 520-526,530-535,649-656, 707-709, 711. 

 Oldest detrital rocks, 6, 987. 

 Oldest magma, 7. 



Oldest fjuartz-porphyry, 41, 976, 989. 

 Oldest rocks, 13, 27, 953, 987. 



opinions on, 22. 



Olivine, as a rock-forming mineral, 963. 

 Ontarian of Lawson, 987. 



Order of generation of new minerals, 37, 966, 969. 

 Origin of Archean granite, 27, 972. 

 Origin of fragmental rocks of Archean, 6. 

 Origin of gabbro, 70, 979. 

 Origin of quartz-porphyry, 976. 

 Origin of taconyte, 832, 845, 990, 1006. 

 "Original" hornblende, 958. 

 Original Huronian, rocks from, 673, 674. 

 Orthoclase, in Keweenawan, 29. 



as a rock-forming mineral, 940. 

 Ortonville, rocks from, 814. 

 Otter Creek, rocks from, 789. 

 Otter Tail, rocks from, G74. 

 Otter Track lake, rocks from, 318, 826. 

 Outlet bay, Vermilion lake, rocks from, 355-358, 587. 

 Owen, D. D., on thalite, 169. 

 Owl lake, rocks from, 481. 

 Palisades, Kawishiwi river, 619, 862. 



see under Great Palisades, No. 2, Eastern. 

 Palisades No. 2, rocks from, 224, 225. 

 Palms mine, rocks from, 809. 

 Paradoxides horizon, 1. 

 Pargasite as a rock-forming mineral, 960. 

 Parkerville, 296, 417, 418. 

 Partridge falls, rocks from, 304. 

 Partridge lake, rocks from, 606. 

 Partridge river, rocks from, 765, 924. 

 Paulson's camp, rocks from, 695-699, 805, 806, 908. 

 Paulson lake, rocks from, 784. 

 Pease, L. B., analysis by, 169. 

 Penokee range volcanics, 992. 

 Peripheral phases of gabbro, 69, 982. 

 Petrographic geology and descriptions, 81-936. 

 Petrographic geology of the crystalline rocks, chapter 



on, 75-936. 



Petrology of the crystalline rocks, 972, 983. 

 Pewabic quartzyte, 68, 69, 70. 



see under Pokegama quartzyte. 

 Phenocrysts in a quartz-porphyry, origin of, 884. 

 Philbrook, rocks from, 758-760. 

 Pigeon point, barite, 300, 301. 



rocks from, 292-303, 417, 418, 445-452, 795-800. 



red rock, origin, 978. 

 Pigeon river, rocks from, 296, 304, 913. 

 Pike rapids, rocks from, 568. 



staurolite schist, 16, 568, 962. 

 Pike river, rocks from, 362, 363. 

 Pine lake, 547, 



rocks from, 307, 849. 



Pine island, Vermilion lake, rocks from, 588, 601, <!02. 

 Pine mountain, rocks from, 468, 674, 675. 



Pipestone rapids, rocks from, 328, 329, 727, 728. 



Playfair, on older rocks. 22. 



Plummer, rocks from, 674. 



Pokegama falls, rocks from, 7:56. 737, 919. 



Pokegama quartzyte, 45, 737, 992. 



Poplar lake, 494. 



rocks from, 495, 509. 

 Poplar river, 454, 458, 5:55. 



rocks from. 243 245. 517 51!l. !i:(6. 

 Poplar River lake, rocks from, 547. 

 Pork bay, rocks from, 228-230. 

 Porphyrel, Kekequabic lake, 33. 



Zeta lake, 37. 



Porphyry, Kekequabic lake, .'!3, 34. 

 Porphyryte, analysis, 530. 

 Kpsilon lake, 52S. 



Mailman's peak, 527. 

 Potassium, precipitation of, 43. 



source of, 41. 

 Potsdam, confusion in use of term, 51. 



rocks from, 756. 



Prairie portage, rocks from, 861. 

 Prairie river, rocks from, 737-740, 919. 

 Prairie River falls, rocks from, 737-740. 



section at, 991. 



Primary and secondary minerals, 968. 

 Precipitation of silica, 40, 42. 

 Pre-gabbro eruptives. 55. 

 Pseudomesser lake, 319. 

 Publications relating to petrology, 7(i. 

 Puckwunge conglomerate, 50, 73, 807, 836. 



age of, 54. 



near Duluth, 47. 



at Pokegama falls, 992. 



Puckwunge river, rocks from, 807, 808, 835-837. 

 Pumpelly, R., on paragenesis of copper and associ- 

 ates, 29. 



Pyrite as a rock-forming mineral, 965. 

 Quartz, as a rock-forming mineral, 937. 

 Quartz, artificial, 939. 

 Quartz, under metamorphism, 938. 

 Quartz-keratophyre, 979. 



analysis, 299. 

 Quartz-porphyry, analysis, 893. 



chemical precipitation of, 42, 868, 976. 



oldest, 41. 



origin, 868, 976. 



Pigeon point, 979. 

 Quartzyte, Aitkin county, 58. 



analysis, 288. 



Baraboo, 54. 



Barron county, 54. 



Pokegama, 45. 



Sioux, 54. 

 Rainy lake, gold ore, 15. 



Keewatin rocks, 14, 987. 

 Randall, rocks from, 757. 

 Rccomposed granite, Sagimaga lake, 17. 

 Redrock, cutting gabbro, 51 1. 



equals Animikic. 49. 



of the Misquah hills, 979. 



origin, 978, 981, 999. 



Pigeon point. 57. H7'.. 



production of, 61, 978. 



