18 FRANK D,. ADAMS 
have developed in the limestones large amounts not only of an alumina 
garnet (grossularite), but also of an iron garnet (andradite), showing 
that the acid magma has transfused into the limestones large amounts 
of SiO,, Al,O,, and Fe,O,, which the limestones have fixed in the 
form of garnet. 
Kemp’s conclusions concerning these occurrences exactly coincide 
with those reached from a study of the occurrences in the Haliburton- 
Bancroft area, as shown by the following quotations from the paper 
referred to above: 
First of all the question may be raised as to whether the eruptive has melted 
into its substance sufficient limestone to yield the zones which have then crystal- 
lized out from fusion. This view is opposed both by the sharp contacts afforded 
by the eruptive against the garnet zones; by the variability of the zones in 
mineralogy, and by the fact that the necessary ingredient of andradite would not 
thereby be afforded. In almost all cases the eruptive is a highly acidic rock, 
a quartz-porphyry, or quartz-diorite-porphyry. ‘The percentage in iron is very 
small, far below the requirements of the iron-lime garnet, and the general com- 
position not at all adapted to yield the zones. On the contrary we are irresistibly 
led to the conclusion that from the intrusive rock has come either highly heated 
water gas or highly heated water itself in the closing stages, and that one or both 
of these have brought to the limestone the silica, iron oxide, and alumina for the 
production of the lime-silicates. After the production of the garnet and its 
associates was well under way, they brought in also the copper and iron sulphides 
which are the commonest ores. 
The silica and the other dissolved materials did not wander farther from 
the eruptive because the limestone promptly intercepted them and locked them 
up in silicates; but undoubtedly carbonated water and carbon dioxide gas were 
yielded in great quantity, an inference which falls harmoniously in line with 
what we know of volcanic emissions. 
