504 Scientific Intelligence. 
Five independent deposits of ore have been worked in this re- 
gion, These are irregular masses of ore, some five to seven me- 
ters in thickness, but with a considerable horizontal extent and 
with the greatest development in a north and south direction. 
The smallest deposit is about 140 meters long and 70 broad; and 
the dimensions of the largest are 600 and 300 meters. en ex- 
amined more closely, each of these deposits is found to consist not 
of an uninterrupted and solid body of ore, but rather of a large 
of limestone. Figure 1 gives a ground sketch. of one of the five 
ore deposits mentioned, ‘sigs cece a peculiar lenticular forms of 
“a9 ore masses (here the carbonate.) In general they extend 
a northwesterly and sicithidaatetoe direction, and are joined to- 
vethiet 4 in an irregular way, as exhibited in the plate. Figures 2 
and 3 represent two cross-sections, the first taken along the line 
ab, in figure 1, and the second alon ig ed ; these show still more 
in 8 
dene from this aed line to the lower and extend along this— — 
(figure 3). In al i 
"how separate Pagar! masses consist of the carbonate with 
more or less red Pa itermixed in some cases, , the latter being 
excess. The 
i 
ii sr seine’ with the clay. In most cases the 
is easily separated from the sides of the enclosing rock, 
pe not infrequently the javhowses is firmly bound to sine 
limestone and passes gradually into it; in such casés aa 9 
mon to find the fossil shells changed into the zinc carbon ied 
here, evidently, the mineral has arisen not by direct ress but 
by a process of alteration of the limestone. 
In regard to the origin of these deposits of zine ore the conclu- 
sion is reached that they have been made in most cases by the 
direct filling of previously made cavities and crac s in the lime- 
stone, although in some cases the deposit of the zine and the re- 
moval of the limestone must have gone on together. The form- 
