228 COPPER-BEARING ROCKS OF LAKE SUPERIOR. 
Thickness in feet. 
V. Diabase, including the following subdivisions: (1) amygdaloid, with 
abundant amygdules of prehnite, laumontite, calcite and chlorite, 
and with seams of laumontite and large patches of calcite, in the 
more thoroughly altered portions, having at base a heavy laumon- 
tite and calcite seam carrying copper, on which some mining has 
been done, 25 feet; (2) pseud-amygdaloid, 5 feet; (3) compact 
portion with distinct columnar structure, the rock having on fresh 
fracture a grayish color and distinctly-crystalline appearance, 
though very fine grained, 70 feet; in all .......-.........-----.. 100 
VI; Covered s2sc< i elnd ks ic Saat eee tee eee see eters 185 
VII. Diabase, with subdivisions as n V..... .------.-.-----------. ------ 92 
Vill Red sandstone andishale= ace eee oe eee ee eee eer 20 
IX. Diabase, with subdivisions as in V; compact portion dark chocolate- 
brownyes-4-. - ees a HOA Soe Jonna oon eC Oks, coer 50 
X. Reddish conglomeratic Senin REP eS ciyas DoS aoS Tato RDA eaoe 60 
XI. Diabase, including : amygdaloid, 10 feet; compact portion, 20 feet; in all 30 
XII. Diabase, including: amygdaloid, 5 feet; compact portion, 20 feet ; in all 25 
XIU. Diabase, with usual subdivisions ...-..--...---- ---..--- S6655 Gosnnae 10 
DOIG LOIN NGM nage dae Bo oSoOnbonocddckeccbeScsepoeos SancelGascnd coe} 33 
XGV, Red: sandstone amd Shaler. = ee = eta aos lal etal ee tete tate etek tote teeter 60 
XVI. Diabase, with usual subdivisions ....-..-. Lats Pp Se Rae, Ga.s BNR See 60 
KVL. Red: sandstone and! shale ~o <2 9 tee eee eee eee 20 
XVIII. Compact, dark greenish-gray diabase, with amygdaloid at top, and 
showing a tendency to a cross-columnar structure ............-.. 21 
XIX. Diabase, including: (1) amygdaloid, in many places showing a tondeney 
to cross-columnar structure, some bands almost completely made 
of amygdules, and others with but few, 15 feet; (2) compact por- 
tion; hightycolummary.s feet sy ariel eter eee elo eee 23 
XX. Diabase, including: (1) amygdaloid in distinct bands, as in-XIX, some 
of the bands showing a change to laumontite and calcite, the amyg- 
dules, in order ot abundance, being prehnite, pink orthoclase, 
orthoclase and calcite, orthoclase, prehnite and calcite, 11 feet; 
(2) compact portion, with columnar structure, 10 feet; in all .... 21 
XXI. Diabase, including: (1) amygdaloid,in many places altered into laumon- 
tite seams, 2 feet; (2) ee portion, 30 feet; in all ............ 32 
XXII. Rediciaaaee sebueed Seek Doce Pe eee emt 5 
XXIII. Diabase, without amy eanlaid « eipysibjekels wise: n Siaysle =< atee SEE eee eee 10 
XXIV. Diabase, including: amygdaloid, mostly covered, 15 feet; compact por- 
tion, 40: feet’; inlall. <\..30s6 (2 Secn sob ace ole ays ee eee 55 
XXV. Covered... scabs. amiyceioseigereecele octane sb Saree eee eee eee 185 
XK VI, (Redishate sa.25) se eee sided Weacarateld, ne Si eee eter eee eee 40 
Total... vic sas, siaisieiecethe cs eid lela iets Se Een eee 1, 212 
These layers are exposed along the stream as far as the crossing of the 
Lac Flambeau trail, near the east line of Sec. 21, T. 47, R.1 E. They 
