142 The American Geologist. March, i890 
tained a considerable thickness, the lower part would necessar- 
ily become more compact and firm. Such conditions sug- 
gesting an ''overflow" are reversed at cape Blomidon. The 
scoriaceous vesicular material forms the lower stratum while 
the more dense variety is superimposed. On the other hand 
if the ridge was a tjqDical "intrusive" its metamorphosing ef- 
fect along the line of contact with the underlying sandstones 
would be more marked than was observed by the writer. 
These apparently reversed features, however, may prove on 
further examination to be only a local variation. 
Little substantial evidence can at present be found of a vol- 
canic vent, which, if it ever did exist, was subsequently worn 
away by the denuding forces of the Drift period. Yet the 
physical features of the deposit suggest that such may have 
existed contemporaneously with its formation. There is also 
at cape Blomidon some local evidence of the formation of its 
northern extremity by a limited overflow of an immense dyke 
extending from the vicinity of Amethyst beach, towards 
cape Split. 
This trappean mountain received the attention of geolo- 
gists as early as 1836 when we find it quite accurately de- 
scribed by Dr. Gesner in his "Geology and Mineralogy of 
Nova Scotia," and later (1868) much more fully treated by 
Sir William Dawson in his Acadian Geology.^ 
The more compact columnar trap is light grey in color, of a 
somewhat gritty texture, and having a specific gravity of 2.93. 
The lower stratum consisting of volcanic ashes and scoriae is 
bronzy reddish-brown in color and full of small cavities in 
which are found minerals belonging mainly to the Zeolite 
group. Some of the most common ones occuring in this re- 
gion are, analcite^ chabazite., acadialite, natrolite^ stilhite^ 
heulandite, apopliyllite, prehnitey agate and amethyst. In fact 
cape Blomidon and its ou.tliers have long been noted for the 
great variety and beauty of their mineral productions, as well 
as for the unique character of their scenery. The bold prom- 
ontory of "Blomidon" as seen from the classic "Hill of Aca- 
dia," is a scene not to be easily forgotten even by the most 
casual observer. 
^ For a minute and full description of the extent and geological fea- 
tures of this obscure formation the reader is referred to the above 
works. 
