10. NOTES ON A DEPOSIT OF DIATOMACEOUS EARTH AT 
DEEP CREEK, GLENGOWER. 
(By H. Herman , B.C.E., F.G.S.) 
to 
submit the following notes 
I have the honour 
diatomaceous earth at Glengower, inspected by 
instructions on 3rd March, 1900. 
on a deposit of 
me in accordance with 
The exact locality is on the east 
bank of Caralulup or Deep Creek, in 
block D 2 , parish Glengower, county 
Talbot, and is included in quarter 
sheet No. 57, N.E., upon which, how¬ 
ever, the deposit under notice, having 
been only recently discovered while 
making an excavation for a road, is 
not marked. 
The diatomaceous earth, in the 
only clear section (see accompanying 
sketch, margin) exposed at the time of 
my visit, is seen as two distinct beds, 
separated by a band of common opal, 
all of which in turn are enclosed 
between layers of basalt. The lower 
bed, which only has been worked up 
to the present, is white in colour, with 
occasional stains due to oxide of iron, 
and the upper is light-grev, while both 
are easily pulverulent. The former 
has been driven on for a distance of 
about 90' from its outcrop on the side 
of the hill, and short drives in various 
directions show the bottom to be 
rather uneven, the roof (the band of 
opal) very even, and the thickness of 
the earth to vary from 2 to 7', with 
an average of about 4b A shaft sunk 
about a chain S.E. of these workings 
passed, according to Mr. D. Irvine (the 
owner of the deposit, and the land on 
which it is situated), through 17' of 
decomposed basalt, P 6" of opal, and 
7' of pure earth, the latter resting on 
vesicular basalt. If this be correct 
the upper bed of earth must thin 
r out very quickly from its outcrop, but 
it is quite possible that, owing to 
discoloration by oxide of iron from the decomposed basalt above, it has 
been mistaken for portion of the latter, especially as the existence of an 
upper bed had not been recognised even in the principal workings prior 
to my inspection. 
