286 Brief Notices. 



critically discussed as to whether the structure is primary or 

 secondary, due to volatile fluxes and solutions, to recrystallization 

 in the solid state or to corrosion, whether it is more recent or older 

 than the dynamo-metamorphism of the rocks in which it is displayed, 

 and finally whether it is produced during the waning phase of 

 plutonic activity, or during the beginning of a new phase which 

 brings about the metamorphisni of the rocks generated by the earlier 

 phase. The author points out that no theory is wholly satisfactory, 

 but he decides that in many gi'anitic rocks the structure is connected 

 with the consolidation of the magma of the rock in which it occurs. 

 Since, however, myrmekite has crystallized within the borders of 

 another mineral, replacing its substance, it cannot be regarded as 

 primary in the strictest sense of the word. Where it has formed 

 during the later stages of consolidation it is proposed to call the 

 change deuteric (the term paulopost already used in teaching by 

 Dr. J". W. Evans would serve equally well), as distinct from 

 a secondary formation of myrmekite due to processes accompanying 

 a later period of metamorphism. 



7. The Relation of the Titanifekous Magnetite Ores of 

 Glamorgan, Ontario, to the Associated Scapolite Gabbros. 

 By W. G. Foye. Ecou. Geol., xi, p. 662, 1916. 

 fnHE gabbro laccolith of Glamorgan was intruded into the Grenville 

 JL Series before the period of granite and nepheline-syenite 

 intrusions described by Adams and Barlow. The latter intrusions 

 gave off pneumatolytic gases which, according to the author, 

 collected beneath the gabbro and slowly penetrated it. The iron 

 and titanium carried by the gases were oxidized to titaniferous 

 magnetite which was deposited beneath the gabbro, while the 

 chlorine and other gases thus liberated passed on and scapolitized 

 the overlying gabbro. The evidence put forward seems to justify the 

 conclusion that the ores were derived from the later intrusions, and 

 not from the <rabbro itself. 



8. Are the " Batuoliths " of the Haliburton-Bancroft Area, 

 Ontario, correctly named? By W. G. Foye. Journ. of Geol., 

 xxiv, p. 783, 1916. 



riIHE following are the conclusions to which the author arrives : — 

 L 1. That the so-called " batholiths " were formed by the 



concordant injection of granite into a fissile limestone terrane. 



2. That this fissility was produced by the pressure of the overlying 

 sediments. 



3. That the layers of limestones, lying between layers of molten 

 granite, were permeated by pneumatolytic gases and fluids given off 

 by the granite, and transformed to amphibolites or grey gneisses. 



4. That the concordant injection of the granite, accompanied by 

 the upward flow of magma at centres of intrusion, produced the 

 dome-like character of the gneissic areas. 



5. That since the term " batholithic " does not describe the true 

 character of these areas, the term " stromatolithic " (ajpu^ia "a layer", 

 \i9o9 " a stone ") is suggested in its place. 



