( 642 ) 
a few minutes farther, west of the road, near Frosschenhäuschen 
(Vrusschehueske), where cretaceous layers cover it. 
This latter fault (IV), probably forms the west border of 
the Kohlscheid tongue. Its continuation towards the north, appears 
from the sharp, straight line, on STARING’s map separating the 
eretaceous from the tertiary formations. The northern continuation 
of this tongue, constitutes the most valuable coal-beds of Dutch Limburg; 
therefore it is advisable, not to omit trying to get from STARING as 
much information as we can, on the subject of the other tongues. 
V. More westward still, at Bochholtz, we find the coal-strata some 
hundred ells, or thereabout, higher than at Frosschenhäuschen. 
VI. Also the valley of the Zelzerbeek or the heights between Bocholtz 
and Bommerig, must hide a great alteration in the level of 
the coal-strata, the lowest layers of the coal formations lying more 
than sixty ells higher than the younger layers of the coal-formation 
at Bocholtz. 
The exact spot of this latter fault, can consequently only vaguely 
be indicated; it is even very well possible that in the stretch of 
land, between Bocholtz and Bommerig, there is more than one fault, 
I confine myself however to what STARING says, and in order not to 
make our “profile”, too complicated, I have marked only one fault. 
If we wish to limit ourselves to but one, the most probable spot 
seems to me the outrunner of the east border of the tongue of Sip- 
penaken, and for more than one reason. The line nl. runs close 
to Bommerig of which place STARING tells us the following: 
“Of importance also may become to us, the metal ore, which we 
know to occur beyond our frontiers in the coal-strata and between 
them, likewise, between those of the Devonian groups, those traces 
of ore, already having been found near Bommerig. In 1856 the Dutch 
mining-company found galena in the neighbourhood of Bommerig at 
a depth of sixty-five ells‘. 
That ore, in Belgium, principally occurring in the faults, the pre- 
sence of ore, near Bommerig, makes the existence of a fault there 
probable. When moreover, we lengthen out that line, farther north-west, 
it crosses the environs of Valkenburg of which STARING says: 
A considerable fault, presumingly of fifty to sixty ells has been 
found in the southern part of the quarries of Valkenburg. 
VII. There is every chance that also the west-border of the 
tongue, at Sippenaken, will prove to be the result of a fault. 
VIII. The east-border of the tongue of Aubel has probably also 
something to do with a fault. This opinion is at any rate supported 
by STARING, who states the following : 
