1020 



THE GEOLOGY OF MINNESOTA. 



Basalt, analysis, 141. 



Basaltic structure of the taconyto, 738, 991. 

 Bascom, F.,on apobsidian, 156. 

 on aporhyolyte, 136, 195. 

 " fielsitie slates. '.(92. 



Bashitanaqueb lake, rocks from, 699, 785, 907, 9815. 

 Bassimenan lake, granite, 321, 320, 635. 



rocks from, 320-329, 634-636, 668, 726-728, 847, 848. 

 ~cc Basawood lake. 



Bastite, as a rock forming mineral, 957. 

 Bayley, W. S., on Beaver Bay diabase, 189. 

 on muscovadytc, 697. 



" peripheral phases of gabbro, 69, 71, 697. 

 ' origin of red rock of Pigeon point, 979. 

 Bear narrows. Vermilion lake, rocks from. 604. 

 Beaver bay, apobsidian, 190, 195. 

 aporhyolyte, lit:!. 

 diabase, 59, 63, 980, 999, 1000. 

 rocks from, 185-208, 399-404, 464, 555, 557. 

 Beaver Bay diabase, 59, 63, 66, 122, 189, 1000. 

 Becker, G. P., on older rocks, 26. 

 Belle Rose island, 298. 

 Berkey, C. P., 886. 

 Bingoschick lake, rocks from, 698. 

 Big island, Vermilion lake, rocks from, 607. 

 Big Stone lake, 814. 

 Biotite, as a rock-forming mineral, 960. 

 Birch island, rocks from, 292. 

 Birch lake, Pewabic quartzyte, 68, 613, 766. 



rocks from, 611-618, 672, 673, 766, 767, 922, 924, 925. 

 Birch point, Vermilion lake, rocks from, 359, 360. 

 Biwabik, rocks from, 7.1, 929. 

 Biwabik mine, 761. 



Black Duck point, Vermilion lake, rocks from, 359, 915. 

 Black Fly bay, 996, 1006. 

 Black River Falls, rocks from, 731. 

 Black traps, 74. 

 Blake's point, rocks from, 432. 

 Bowlingite, as a rock-forming mineral, 963. 

 Breitung mine, rocks from, 589, 600, 601, 743, 744, 811. 

 Brogger, W. C., on older rocks, 26. 

 Bronzite, as a rock-forming mineral, 957. 

 Bruit? lake, rocks from, 801-805. 

 Brute mountain, rocks from, 483-485, 675. 

 Brute river, rocks from, 261-265, 410, 411, 473, 485, 675. 

 Bunsen, on older rocks, 25. 

 Burlington bay, rocks from, 175. 

 Burnt forties, near Soudan, rocks from, 883-885. 

 Burntside lake, granite, 336. 



rocks from, 333-338. 

 Burntwood lake, 546. 



Bytownite, as a rosk-forming mineral, 944. 

 Cabotian, denned, 55. 



epoch of eruption, 55, 999, 1000. 

 Calcite, as a rock-forming mineral, 947. 

 Campers' island, 523. 

 Cannon Ball bay, rocks from, 270. 

 Carbonate of iron, matrix of tuff, 995. 

 Caribou lake, rocks from, 493. 

 Caribou narrows, 514. 

 Caribou point, rocks from, 247. 

 Carlton, Animikie, 50. 



rocks from, 380, 388, 389, 748, 749. 



Carlton peak, anorthosyte, 65. 

 Carp lake, 319. 



Cascade river, rocks from, 248. 

 Castle Danger, rocks from, 181. 

 Chemical analyses, 

 andesyte, 519. 

 anorthoclase, 666, 897. 

 apobsidian, 156, 191. 

 aporhyolyte, 211, 217, 256. 

 augite, 662, 897. 

 basalt, 141. 

 chlorastrolite, 428. 

 conglomerate, 222. 

 cumberlandyte, 496. 

 diabase, 102, 149, 226. 

 dioryte, 575. 

 esterellyte, 662, 666. 

 feldspar, 83, 193, 666, 897. 

 gabbro, 85, 496, 543, 908. 

 gold ore, 842. 

 granite, 89, 161. 188, 206, 303, 315, 400. r.15. .WJ, 



553, 554, 564, 662, 666, 903. 

 heulandite, 229, 463. 

 labradorite, 83. 

 limestone, 313. 

 mesolite, 230. 

 mesotype, 465. 

 mordenite, 463. 

 nickel ore, 496. 

 porphyryte, 530. 

 quartz-keratophyre,'299. 

 quartz-porphyry, 893. 

 quartzyte, 288. 

 shale. 555. 

 silica-kaolin, 763. 

 thalite, 169. 

 thomsonite, 428. 4.33. 

 titaniferous magnetite, 496. 

 zeolite, 433. 

 zirkelyte, 121, 141. 



Chemical precipitation of silica, 40, 42. 

 Chester peak, 732. 



rocks from, 733. 

 Chicago bay, rocks from, 791. 

 Chicago mine, 762, 927. 

 Chippewa harbor, rocks from, 422-424. 

 Chlorastrolite, analysis, 428. 

 Chlorite, as a rock-forming mineral, 960. 

 Chub lake. 



see Akeley lake. 

 Cincinnati mine, 760, 761. 

 Clearwater lake, rocks from, 888. 

 Cloquet, rocks from, 648, 810. 

 Coast line of lake Superior, divisions of, 79. 



rocks from, 81-303, 390-466, 548, 549, 554-558, 571- 



573,741,788-800,813, 814. 

 see under definite localities. 

 Coleman, A. P., on Coutchiching and Keewatin, 10, 



988. 



Cone-in-cone, 797. 



Conglomerate and graywacke of Archean, 5. 

 analysis, 222. 

 Animikie, 44. 

 changing to granite, 34, 36, 648, 974. 



