36S 
THE GEOLOGIST. 
them are loaded yvit\i fossil debris, particularly tlie stems of cncri- 
nites. It may be argued that as the contorted beds occur at intervals 
among the other beds, they must have possessed some peculiarities 
that caused them to undergo such great mechanical changes, while 
the otlier beds are comparatively unaffected. It may be answered 
that this was probably the case, and that these beds, moreover, are 
exposed by circumstances to a greater amount of compressing force ; 
for it must be borne in mind that all the sti'ata show more or less of 
contortion, and that it is only in limited areas that the bearing beds 
themselves exhibit the phenomenon in the utmost degree, inasmuch 
as there is an almost undistinguishable difference in this respect 
between these strata and the others at their crop*, as before observed. 
The mentioning of these facts is necessary, lest it may be 
thought that these contorted strata were formed and transformed 
previously to the deposit of the overlying beds, against which sup- 
position there is every evidence. 
But to return. During the re-emergence of the mass of the 
strata, for which we have been supposing the changes above 
imagined, we may conceive the dislocations and separations of the 
beds, whether separately between themselves, as in the saddles, or in 
whole masses, more or less vertically, as in the veins, to have 
occurred. The complicated fissures forming the pipe-veins, with 
their associated rake-veins, w^ere in all probability formed simnl- 
tancously with the fissures in the bearing beds. It the same time, it 
is likely that the great east and west faults called the " lums," were 
of more recent origin, and formed by a wholly separate system of 
dislocations ; and it may be taken that the saddle-beds arc the lines 
of least resistance, along which these last manifestations of the dis- 
ruptive force displayed themselves. Moreover, there is great reason 
for supposing that the infilling of the fissures and joints in the bear- 
ing beds, with their cupreous contents, were efiected through the 
media of the lums which were thus formed. The lead, on the other 
hand, was probably supplied to the pipe-veins through the agency of 
their intersecting rake-veins, which continue to descend indepen- 
dently of tliem to unknown depths, and are probably the channels 
through which the plombiferous menstrua originally ascended. 
The parts stated at the conclusion of the last paragraph point to a 
remarkable natural distinction between the saddles and the pipes in 
* The outcoming of the bearing-beds is recognized, among other appearances, 
by the more crystalUne character of the hinestono, but with the exception of the 
occasional presence of the peroxide of iron, there is nothing to indicate the 
metalliferous condition which obtains in them elsewhere ; and, it may be, though 
I have no positive knowledge of the fict, that their unfossilifcrous state, as re- 
marked in the text, is also only partitive. It is not difficult to imagine that the 
intense squeezing, necessary to produce the often fantastic contortions of the ore- 
bearing parts of these beds, would be sufficient to crush and obliterate any re- 
mains of organisms previously preserved, particularly if aided by any subsequent 
aiTangement in the molecular agglomeration of the rock, of which there is 
abundant evidence in, at least, the productive portions of these strata. 
