Mica schist. Taconyte. Graywacke.] 

 Amphiboly te. 



PETROGRAPHIC GEOLOGY AND DESCRIPTIONS. 931 



No. 60S. MICA SCHIST. 



Interbanded in No. 59S. 



Ref. Annual Report, xxii, page 128. 



Meg. Micaceous. 



Mic. Quartz, muscovite, interlocked in cotemporary development, compose 



this rock. One section. 



Age. Keewatin, recrystallized. N. H. w. 



No. 61S. TACONYTE. ( Pebble from conglomerate.) 



S. E. y N. E. J sec. 6, T. 58-17, Mesabi range. 

 Ref. Annual Report, xxii, pages 122, 128. 



Meg. Green conglomerate, with rusty specks; accompanied by green shale. 



Mic. A green mass from the rock, consisting of chlorite, stained with hematite. 

 Round the green mass are taconitic pellets of the characteristic form and size, some 

 of which are replaced by siderite and siderite enters considerably, in places, into the 

 green mass. This is preferably siderite, since it is numerously and regularly cleaved 

 and is iron stained by oxidation. One section. 



Age. Cretaceous. 



Remark. Rock No. 62S is from the same conglomerate, but is wholly hematited. 



N. H. W. 



No. 77S. GRAYWACKE. (Very fine.) 



N. W. M N- E. V sec. 7, T. 58-17, Mesabi range. 

 Ref. Annual Report, xxii, page 128. 



Meg. Dark, slaty, banded with stratification. 



Mic. This rock is made up of a fine debris of quartz, feldspar, sphene, and some 

 dark mineral which is now altered to chlorite, and of muscovite. It is darkened also 

 by pyrite, hematite and apparently by a dark leucoxene, with a scant cement of calcite 

 One section. 



Age. Animikie. N. H. w. 



No. 94S. AMPHIBOLYTE. 



S. W. % N. E. % sec. 17, T. 59-17, Mesabi range. 

 Ref. Annual Report, xxii, page 129. 



Meg. Massive hornblende rock. 



Mic. Hornblende in coarse (microscopic) crystals, and a little feldspar and 

 apatite are the only minerals perceptible in this rock. One section. 



Age. Keewatin (metamorphosed). N. H. w. 



No. 125S. TACONYTE. 



N. E. ^S.'E.X sec. 17, T. 58-19, Mesabi range. 

 Ref. Annual Report, xxii, page 130. 



Meg. Glauconitic taconyte. 



