410 Canadian Record of Science. 
mining engine rs in the west, after a very thorough 
study of Aspen Mt. made while preparing for these 
apex-side-line law suits, published (loc cit.) a resumé of 
his views as to the location of the ore and the character 
of these deposits, in which paper he claimed that the 
bedding contact between the “ brown” and “blue” 
limestones had not been the channel for mineral-bearing 
solutions, nor the place of deposition of these ores, but 
that with astrike nearly coincident with that of the strata 
and a dip of 45° to nearly verticality, was a series of faults, 
some causing a displacement of a few feet, others of much 
more, that thus allowed the ‘‘ brown” and ‘‘blue” lime- 
stones to be adjacent to each other for hundreds of feet on 
the dip, but the contact at such places would be along a 
“fault contact” or place of faulting. That, also, ore-bear 
ing solutions passing along these fault-planes, did not de- 
posit the minerals from solution in these fault planes, but 
that finding in places conditions physically and chemically 
favorable, these solutions impregnated toa greater or less 
distance the rock on one side or the other, or even both, of 
the fault plane, and some of the mineral contents being 
precipitated as sulphides, part or all of the rock was 
locally replaced by ore, by metasomatic or chemical re- 
placement, and that ore might be found along a “bedding 
contact” but only a limited distance from the faults. 
These views, at first, were derided by all but a few of the 
mining men, but within two years a mining location was 
hardly thought valuable unless a fault was known to 
traverse it, and faults were diligently being sought out and 
prospected everywhere, as it became evident, beyond doubt, 
that the “contact” between the two limestones near which 
such wonderful ore bodies were being found, was a “fault 
contact.” Some of the faults, probably of later fracture have 
been barren, also faults running obliquely to the first series, 
although some of these cross faults have had a very im- 
portant influence upon its ore-bodies. 
In the famous “ Aspen” mine at Aspen, from whose 
small area of seven acres, millions of dollars have been 
