68 COPPER-BEARING ROCKS OF LAKE SUPERIOR. 
Tabulation of observations upon jine-grained olivine-free diabases of the “ordinary type”— : 
Continued. 
Angle between 
maximum ex- 
tinctions of 
adjacent hemi- 
tropic bands of 
g ; fa Secure 
eI Place. g Ser | eanitomeareetsieeriat ave a | at eee 
A 8 P the zone O: i. 
3 & | =| Angles on| © ; 
| = = FI & opposite oe, 
3 RS 4s || el sides of| Sq 
Pay Clalal & | cross-hair.| E © 
| 
Ie ° ° ° j 
40 W-.| Montreal River, |...... 20 | 47} 1£E.) Sp.gr.,2.81.....-. Labradorite; augite largely al- 
Wisconsin. tered to green and brown sub- 
stance; chlorite pseud-amyg- 
dules. 
63 W-.| Ashland County, |...... 16/46] 2E.| Rather  fine- | Oligoclase largely altered to chlo- ’ 
Wisconsin. grained; dark- rite; magnetite in rod-like 
greenish. Sp. forms, apparently filling 
gr., 2.90. eracks; augite abundant and | 
fresh; chlorite pseud-amyg- 
dules. i 
49 W.| Ashland County, |...... 19/46) 2E.| Rather  fine- | Oligoclase, partly altered to chlo- 
Wisconsin, grained; green- rite; magnetite, as in 63 W.; i 
Flambeau trail. ish-gray to dark augite quite fresh; chlorite : 
green. pseud-amygdules. 
404S..| Moose Creek, | SE. | 2 | 44/13 W.) Medium-grained; | Oligoclase; magnetite; augite, 
Douglas County, dark greenish- largely altered to green sub- | 
Wisconsin. black. Sp. gr., stance. 
2.87. 4 
8 SW.| Copper Creek | SE. | 15 | 47 |14W.| Fine-grained; | Plagioclase in matrix and in { 
mine, Douglas | cor. dark brownish- porphyritic crystals; augite, 
County, Wis- gray. Sp. gr., | wholly altered to green sub- 
consin. 2.84. stance. 
12 SW | FondduLacmine, | NE.| 8 | 47 |14 W.| Fine-grained; | Oligoclase; magnetite very 
Douglas County, speckled brown, abundant; augite, largely | 
Wisconsin. light and dark | fresh, but partly altered to a | 
green. reddish-brown transparent } 
substance; pseud-amygdules ; 
of epidote, chlorite and calcite ; : 
metallic copper. 
: 
- 
Olivinitic fine-grained diabases, including Pumpelly’s melaphyrs.—To these 
rocks, which grade through coarser and coarser kinds directly into the 
coarse-grained olivinitic gabbros already described, Pumpelly has given the 
name of melaphyr (following the nomenclature of Rosenbusch), because 
of the presence, in those examined by him from Keweenaw Point, of a small 
amount of altered residuary magma. 
ever, found without the residuary base, which is at best but a very unim- 
portant ingredient, so that I have preferred to call them here all by the 
Precisely the same rocks are, how- 
