INDEX. 



A. 



Page. 



Aa atrncture, sketch of 120, 121, 122, 123, 124 



(See Ellipsoidal structure.) 



Aci Castello, basalt from 121 



Aci Trezza, basalt from 121 



Acid intrusives, described 45-49, 190-198, 426 



age of 49 



distribution of 190 



in A rchean 45-49 



in Felcli Mountain P^ange . 426 



in Hemlock formation 77 



in TTpper Huronian 164 



Acid lavas, of Hemlock formation, described 80-94 



banding of 91,92,93,94 



micropegmatitic texture in 89 



pressure effects in 87, 88 



schiatoae, described 87-94 



Acid pyroclastics, described 94, 95 



Acid volcanica of Hemlock formation, described 80-95 



ActinoUte from liornblende 215 



of adinole 209 



of cblorite-scbist 442 



of metabaaalt 105, 133 



of picrite-porpbyry 214, 21 5 



of pyroclastics 147 



of slate 205,200 



of spiloaite 206 



orientation of 105 



(See Ampbibole.) 



Actinolite-schist from gray wacke 57 



of pyroclastics 147 



Adamello tonalite 230 



Adams, F.D., on analysis of slates and granites 58 



on pyroxene zone about olivine 256 



Adinole, analyses of 208 



compared with analyses of clay slate and spilo- 

 aite 210 



in ilansfield formation 64 



described 208-209 



Ajibik quarlzite 451 



correlation of - xxv. sxvi 



relations to Groveland formation sxi, 449, 456 



Albitefrom feldspar - 151,201 



of metabaaalt 99 



of spilosite. plate of 302 



Algonkian, contact with Archean, effect on topog- 

 raphy 386 



deposition of 456, 457 



distribution of 331, 427 



folding of 427,428 



of Felch Mountain Range, distribution of 384 



succession in 384-385 



structure of 384-385 



intrusives in, described 426 



Algonkian of Marquette district, distribution of 



of Sturgeon Kiver tongue, described 



comparison with Algonkian of Felch Moun- 

 tain tongue 



folding of 



igneous rocks of 



pressure effects in 



relations to Archean 



relations to Lower Marquette 



relations to Archean x vii, 331, 399, 



relations to drainage 



relations to Paleozoic formations 



relations to quartz porphyry 



(See Huronian, Upper Huronian, Lower Hu- 

 ronian.) 



Allanite in acid lavas 



included in epidote-zoisite 



Allen, Andrews, referred to 



Alteration of andesine 



of basic volcanics 



of biotite 



of bronzite, plate of 



of calcite 



of diabase 



of ellipsoidal basalt 



of feldspar 42, 170, 171, 192, 201. 224, 



plate of 



of glauconite 



of grit 



of hornblende 234. 



of metabasalt 



described 



of picrite-porpbyry 



of slate 



of tulfs 



Amasa ( town) 12, 



Amasa area, ore deposits of 



452-453 

 458-487 



471-472 

 482-487 



427, 458 

 334,335 

 331, 383 



168-169 

 235, 237 



(See Hemlock mine.) 



American Black Slate Co., analysis of slate from 



Amphibole of greenstone 



of metabasalt 



of mica-schist 



of picrite-porpbyry 



orientation of 127, 214, 



(See Actinolite, Hornblende, Tremolite.) 



Amphibole-peridctite, described 



crystallization of 



gradation to olivine-gabbro 



gradation to wehrlite 



Amphibole-schist of Sturgeon Kiver Archean, de- 

 scribed 



Amphibolite, analysis of 



489 



254-260 

 254-260 



