176 
AMERICAN GEOLOGY. 
middle, formed a fine and beautiful contrast with the darker and 
sharply defined wall of gneiss which inclosed it. 
The wall of rock which rises out of the low, flat and swampy 
ground, seems to terminate here, and to limit the extent of the 
vein in this direction, as no rock appears for one-fourth of a 
mile. This wide interval and absence of rock is due to dilu¬ 
vial action, at least in part, its upper part having been removed; 
but the vein and rock continues in the direction indicated by the 
strike of the vein, beneath the low grounds; and the workings 
of the vein may be carried on beneath these grounds, which are 
frequently covered with water, which sets back from Indian 
river, with which they communicate. 
I have had occasion to observe more than once, that it is a. 
rare circumstance that a vein fissure is produced without being 
accompanied with others also. This fact I propose to illus¬ 
trate again by the accompanying ground plan of veins which 
have been discovered at Rossie. 
Fig. 45. Fig- 45 exhibits four lead veins 
which constitute this mineral dis¬ 
trict. Thus, 1 shows the bear¬ 
ing of the Union vein, which is 
S. 73° E. It sends off a branch 
S. 88° E. 2, the Victoria vein, 
whose bearing is S. 84° E., with 
its diverging branch; 3, the Coal 
Hill vein, bearing S. 82° E. This 
is the vein already referred to in 
Fig. 25. 4, Indian river vein, bear¬ 
ing S. 75° 45' E. The heavy trans¬ 
verse shaded band shows the bound¬ 
ary between the high and low 
grounds already spoken of. Two of 
the veins have been extensively 
worked. The great Coal Hill vein 
was first discovered, and has been 
explored to the depth of 200 feet ? 
and has furnished f 24T000 worth 
