528 



INDEX. 



Hornbleude, from augite. 435. 



(roin iliallasf. 115. 



froiii felcLsjiar, 118, 125, :)53. 



t'ruia pyroxene, 115, 353. 



iiichision.s, 119. 



of lUabase, 353, 359. 



of gabbro, 115. 



ofgueisa, 108. 109, 110, IKi, 118-110, 120, 121. 



ofgranite,112, 122, 123. 



of sreenstone-congloinprate. ^^77. 



of .•^.yonitp, 1)4,115,122. 



of syrnit('-sf:hi.st, 125. 



paraniorphir. 353, 412, 

 Hornhlende-biotite-ayeuite, do.soribpil, 47S, 

 Hornbli-ndp.gnoiss, 108, 109-111, llfi, 120-122,476. 



"li-iii of. 111. 

 Iloinliliiide-graiiite. di'scribod, 111-113,478. 

 IlMriibUiidf-rock, 3t>. 

 Honibli-nde-.schi.st, de.s(;ribe(l, 476. 



origin of, 111,121. 

 I lorn I ilc'nde- syenite, 114. 

 ilornstoue, character of, 200. 

 llndson river, 263. 

 Hnnt referred to. 44, 56, 79. 

 Hlironiiin, 1-2. 10, 37, 47, 48, 59, 62-65, 86-87, 468. 472, 473, 474, 



ndatious to Anitnikie. 2, 81. 



I'elatifme to basement conii>lex, 81-82, 86. 



lelations to granite, 34-36. 37-:iK. 



relations to Kewcenawan. 47. 6."i-6ll, 67, 81, 82, 86. 



relations to Laureutian, 43-44, 47, 58, 61, 82. 

 (See Pennfcrc serifn.) 

 H.ydro inica-slate, position of, 80. 

 Hyperstbene of diabase, 354. 



Iowa. 473, 474. 



Ireland, eherl of, 140, 251. 



Iron-bearin.s member, 3, 12,15,17,71-72, 146. 182-295,297,361, 



362. 363, 364, 365, 369, 429, 430, 432, 4.3,1, 436. 438, 440, 44] . 



455-456, 4.57, 458, 459, 460, 464, 465. 468, 469, 471, 472, 473, 



474, 490, 492, 494. 496, 498, 500. 502, 504. 

 content of iron in. 182-184. 

 . diabase in, 348, 350. 359. 

 dikes in, 12. 271-274, 347, 348, 355-358, 359, 465-466. 

 fle-\nres of. 437. 438. 

 .jasper fragntents from. 174. 

 magnetic attractions of, 186. 

 nonfragmental, 245, 246. 

 qiiartzile fragments in, 175. 

 relations to erniilives, 340, 361. 

 relations topgabbro, 185. 

 rr'Iations to gneiss. 185. 

 relations to granite, 71-72, 185, 187, 189. 

 relations to Kewcenawan, 187, 188,362. 

 relations to quartzito, 181, 185. 

 relations to Quartz-slate, 144. 175, 176, 181, 184-185. 188, 189, 



200. 294, 299, 363, 455, 456, 464. 

 relations to .Southern Complex, 189. 

 relations to Upper slate, 200, 294, 296, 297. 298. 299, 300, 456, 



464-465. 

 thickness of. 187, 188, 189-190, 361, .362. 

 topography of, 145, 188-189, 301. 

 Iron Helt mine, 269. 

 Iron carbonate, 280. 304, 379, 464, IW;, 4li9, 471. 



alteiation of, 199, 201, 204, 2U5, 254, 28^, 284, 286-290, 291, 202, 



294.295,393,431. 

 analysis of, 191, 



Inm carbonate, described, 190-192, 200-202, 232, 23.). 235, 236, 

 237, 238, 239, 2(i2-264, 496, 498, 506. 

 grades into actinolitic slate. 246. 257,2.58,260,262,266.267, 



294, 362. 

 grades into ferruginous chert, 199, 202, 246,2.56,259,266. 



294. 

 grades into ferruginous slate, 193, 201-202, 205, 253, 294. 

 of actinolitic slate, 258. 259. 

 of Anitnikie series. 259, 268. 

 <if concretions, 207. 208. 

 of Eastern area, 365. 

 of ferruginous I'bert. 257, 258. 

 of ferruginiHis slate, 193, 203. 204. 

 of other series, 252, 260. 

 origin of, 246-253, 263. 

 position of, 198. 

 pseudomori)hs of, 201, 

 relations to iron ore, 260, 268, 282, 283. 

 aiderite of, 256. 

 8llic-aof, 199,202,256, 

 (See Suferitt'.} 

 Iron King mine. (See Mount Hope mine.) 

 Iron mines, liirkinbinc on. 87-92. 92-96. 



Iron ore. 67. (■>9-71, 102, 198, 268, 26 ), 281, 283, 291, 471, 508, 510. 

 analyses of, 281. 

 character of. 280-283. 

 loncentration of 2.54, 283-292, 295. 

 depth of, 274-275,292-293. 

 foot wall of. 270-271, 274, 276, 277. 

 from iron carbonate, 2()0, 283, 284, 286-292, 295. 

 in Laurentian,94. 

 manganese in. 280-281. 292. 

 of actinolitic slate, 258. 

 of Eastern area, 365-360. 

 of ferrtiginons slate, 203, 204. 

 of other districts, 293. 

 origin of, 8.5-86,281-290. 

 Jiosition of. 184, 185, 198, 268-271, 294. 

 relations to clay-slate. 285. 2S6. 

 relatiims to dikes, 92, 274-275. 276, 277. 287, 289. 290.291. 292 



295. 365. 

 relatiims to felTuginous chert. 202. 203, 275, 276. 283, 287. 



295. 

 relations to graywacke. 285. 

 relations to greimsfone. 12. 

 relations to iron carbonate, 260. 268, 282, 283. 

 relations to manganese. 91-92. 282. 

 relati(raa to <|uartzite, 94, 185, 199, 274, 270, 285. 286, 287, 291, 



292, 294, .365. 

 relatiims to CJuartz-slate. 1S5, 199,269, 270, 286, 287, 294, 295. 

 relations to sandstone, 285. 

 relations to silica, 282, 284. 

 relations to soapstone, 91, 94, 294. 

 sulphnr in, 281. 

 (See Iron oxide.) 

 Iron oxide t'rom iron carbonate, 253. 268. 393. 434. 

 of actinolitic slate, 210, 212, 215, 257, 266. 

 of chert , 133. 



of concretion, 205, 206, 208. 

 of ferrngiuons Alert, 254, 257. 

 of gneiss. 119, 120. 

 of gi-ay wacke. 333. 

 of greenstone conglomerate, 375. 

 of quartzite. 153. 

 of slate, 305, 370, 376, 434. 



(.See Ferrite, Hematite, Iron ore, Magnetitg.} 

 Ironton mine, 273, 



