TJic Theory of Cof'I'cr Ih-posilioii — I. (inc. 307 
clticcd tlicrchx . IIk' later alkaliiu' niiiuTals hv Ijclicvcs to have 
liciii assdciatid with thr northtrlv and ik irlhwcstcrnly tiUiiij];'. 
aiul thf I'lirmatidii aiul the liUiiiL;- of tlir lissurcs and the ini- 
prc<2^nati(in and ])artial replacnmnt (if aiiiygdaloids and con- 
glomerates with e(i])i)cr. tlu' copper not heiii«;;- derived from 
overlying- sandstones nor from trai)s, hnt prohahly hy ascending 
solntions from deep-seated sonrces. 
Returning once more to I'rof. \'an Hise's paper, we iind 
that however his theories may ap])ly to other deposits, they 
apply very largely to copper-hearing rocks. His first premise 
is that tile greater nuniher of ore deposits are the result of 
work of underground water. His second is that the material 
of ore deposits is derived from rocks within the zone of frac- 
ture. This would seem to be true, and shall give some argu- 
ments for believing that the copper is derived from the associ- 
ated igneous rocks. His third premise is that by far the major 
part of the depositing water is meteoric, liy this he means that 
it is derived from the air, rain water which w'as worked down 
into the ground. In view of the comjiosition of the water at con- 
siderable depths above given on the Kewcenawan range, it 
seems probable that this is not true, but that the largest ])art 
of the water may either have been buried originally with the 
sediments {possil)ly he would class this as meteoric), or oc- 
cluded in the original magna, as he suggests. It is a .subject 
for further investigation, just how nmch of these three classes 
o^ water we have involved. 
His fourth premise is that the flowage of the underground 
water is caused chiefly by gravitative stress. H this is true, 
and I believe, it is. then it follows, as \'an Hise himself ha? 
remarked (p. 417), that if the copper is most concentrated 
along the higher parts of the outcrop it nnust he formed by 
descending waters ; moreover, as he also calls attention ( p 
412) in case of the minor flexures and pitching folds in the 
bed, if the waters are descending the richest parts should be 
in the troughs of these folds, or possibly on lines leading from 
an anticline down to the trough of the folds. Referring once 
more to plate 10. of \'ol. \l.. Tart 11., it will be seen that in 
such a case the copper of the l^>altic and Trimountaln may be 
expected to chute to the north when followed down. So .should 
the mines around Calumet, while the Ouincv mine should 
