T. B. Brooks— Rocks observed in the Huronian Series. 199 
(9.) Pyroxenyte (augite rock). (10.) Lherzolyte. (11.) Ossipyte. 
(12.) Unakyte. 
3. Helsitic, Epidotic, and Garnet Rocks (L. ?), 
Having the mass, or base, compact (crypto-crystalline). 
No typical rocks of this family have been observed. The 
nearest kind is a gray, magnetic, amphibolic schist, containing 
garnets, and closely related to the anthophyllite schists, but 
which Dr. Wichmarin designates eklogyte—2z. 
4, Chrysolite (or Olivine) Rocks. Not observed. 
5. Hydrous Magnesian Series. 
_ (1) Protogine (L.)\—8. Not abundant. Quartzyte graduates 
into this rock in the Marquette Region. In the owas Huro- 
nian of the Menominee Region, holding pebbles of granite, 
gneiss and quartz—65. 
(2.) Feldspathie Protogine Gneiss?—147. Has been called 
graywacke. Occurs only in the Menominee Region in one bed. 
(8.) Talcose Slate—74, A typical kind has been observed only 
at Marquette. Unctuous-feeling micaceous and chloritic rocks, 
often called talcose, are more abundant. 
(4.) Steatyte or Soapstone.—Said to exist. 
(5.) Chloritic Slate (schist). (L.?) Abundant. A hard, very 
unevenly schistose, gray-green variety, associated with green- 
stones and hornblendie schists, of bok it appears to an 
altered or chloritic form, (has received different names)—138, 
0? Gray-green, splitting into somewhat uneven thick slates, 
and related to micaceous and argillaceous rocks—182, 134. 
A fissile variety, graduating into clay slate, under which it 
should perhaps be classed—s5, 114? Dark-green, pure, massive, 
rontaining pseudomorphs after magnetite, garnet, and amphi- 
le, oceurs in iron-ore—&p. Ferruginous. Micaceous, in green- 
stone. Compact, magnetic, conchoidal fracture—28 
. (6) Chioritic Argillyte. A slate termed chloro-argillaceous, 
; very abundant in the Menominee Region-—114. Often car- 
“a ) Ser ed 
. ‘pentine—78§, Very rare. Apparently altered green- 
stone, and having Rae rt 4 of an cunts character. 
(8) Ophiolyte. (9.) Schilleryte. 
6. Hydrous Aluminous Rocks. Not observed. 
7. Quartzose Rocks. 
1.) Quartzyte, Very abundan duating into marble on 
— hand, ns ge orenals on The othet containing beds of 
clay slate with oblique cleavage. White to light-gray, massive, 
aceous, often with lassy grains, occasionally with ripple- 
marks, and on Black River showing the false stratification 
