688 



THE GEOLOGY OF MINNESOTA. 



Material resources, 318. 

 Fuel, 318. Iron, 318. 

 Lead, 319. Quicklime, 319. 

 Bricks, 321 . Gold and copper, 321 . 

 Building stone, 322. 

 Sand for mortar and concrete, 323. 

 Calcareous tufa, 324. 

 (Artificial mounds, 673.) 

 Fire-brick, 403, 451,588. 

 Fires, prairie, 345, 881, 524, 520. 

 Fish in lakes of 1'ark region, !-7, 89. 

 Flora of the state, 79, '.)5. 

 of Rainy lake, 43. 

 of the Minnesota valley, 37. 

 of the Mississippi valley, 21, 22, 28-80, 77. 

 of the Park region, 89. 

 of the Undine region, 72. 

 Flowers on prairies, 37, 520, G17. 

 Flowing wells, 389,402,453,470,486, 510, 5R5. 

 Forest bed in drift, 314, 363, 390, 5sr,. See 



Wood in drift, and Peat, interylacial. 

 Forests of the state, 136, 140, 636, 650; deso- 

 lated by fire, 136. See Timber. 

 Fort I5enton group, 308. 

 Fort Pierre group, 599. [falls, 78. 



Fossils collected by Nicollet at St. Anthony 

 Fountains. See Flouring wclh. 

 Fox Hills group, 599. 

 Freoborn county, chapter on, 376. 

 Situation and area, 376. 

 Surface features, 376. 

 Natural drainage, 376. 

 Topography, 376. 

 Elevations, 379. 

 Soil, 380. 

 Timber, 381. 



Geological structure, 382. 

 Drift, 382, 385. 

 Cretaceous rocks, 383. 

 Exploration for coal, 384. 

 G ravel and sand, 385. 

 Wells, 388. 



Vegetation in the drift, ,'ii>o. 

 Boulders, 390. 

 Material resources, 391. 

 Lime, 391. 

 Brick, 391. 

 Peat, 393. 



Fringilia vespertina, 52 f. n. 

 Frost, effect on building stones, 186. 

 in a well 70 feet deep, 671. 

 rock masses dislodged by, 540. 

 Fucoids, 79, 258, 288, 374, 500. 



Gabbro, as building stone, 147. 

 Galena, 32, 33, 259. 



Galena limestone, 84, 293, 334, 340. 362, 37 1 ,655. 

 Gary (second) moraine, 4(i, 505, 521. 52S. 605. 



621,641. 



Gas in wells, 384, 388, 4S8, 552, 62'.). 

 (ieese, 21. 



Geological survey of the state, 91, 93, 94, 106. 

 Gerolle in Winona county, 262-3. 

 ( i lacial currents, 99, 406. 408, 441 , Hill, 481 , 504, 



506, 548, 027, 62S, 041 f. n., 667- 9. See Icc- 



shcct. 

 Glacial drift. See Drift, Till. Momiws, lioiil- 



dcrK, and Modifnd drift. 



Glacial epochs, 406, 528, 580. See InlerijhirutL 

 Glacial erosion, 430, 571, 602. 

 Glacial furrows, 600, 619. 

 Glacial lakes, 408, 442, 460, 508, 509, 545, 5SO 1 , 



501, 006, 615, 622, 642, 662, 668. 



effect on deposits of till, 408, 442, 461, 544, 



581, 622, 661. 



Glacial markings, showing rock-fracture, 548. 

 Glacial rivers, 135, 388, 417, 444, 582, 622, 624, 



668. 

 Glacial striw, 99, 478, 503, 517-550, 5SO. 600. 



curved, 504; intersecting, 503. |596, 617. 

 Gneiss in the Minnesota valley, 146, 568-571, 

 Gold, 95, 321, 346. 

 Gopher knolls, 365. 

 Granites as building stones, 142-8. 

 Granites of the Minnesota valley, 36, 38, 49, 61 , 



86, 146, 568-571, 596-6, 617. 



of the Mississippi valley, 33, 142 5. 



on the northern boundary, 42, 1 45. 

 Graphite, 32. 

 Graptolithus, 297. 

 Grasses, 525-6, 595-6. 

 Grasshoppers, 498. 

 Grauwacke, 32. 

 Gravel and sand, distribution in the stale, 1 is 



soils and subsoils, 127. 



See Mmlijii d drift and Alluvium. 

 Green-sand, 224,425. 



Green shales, 218. 274, 293, 334, 342. 399, 655. 

 Gypsum (selenite) crystals, 600,619. 



Hematite, 96. 

 Hamilton formation, 360. 

 Hardpan, 512, 530, 607. See Till. 

 Hard water, 136, 512, 513, 524, 553, 51)5. 

 Hay used as fuel, 525, 537. 

 Head-lining of Hour barrels, 672. 

 Heat, effect on building stones, 186. 

 Hemlock, 139. 

 Hickories, 215, 247. 

 Hieroglyphics, 21, 33, 501, 555. 

 Ilights. See Elevations. 



