Variolitic Pillozv-Lava.—Daly. 73 
the Fichtelgebirge,* of Point Bonita.f of the LleynJ and of 
Mont Genevre,§ that there can be little doubt that the New- 
foundland pillow-lava is a basalt or at least that it is no more 
acid than an augite andesite. Using Rosenbusch's designation 
for these special basaltic rocks, the Newfoundland lava may be 
called a greatly altered, variolitic spilite possessing the peculiar 
ellipsoidal or pillow structure. 
The strike and other field relations, except the angles of 
dip, as well as the petrography of the thick deposits seen on 
Kirpon Island and at Fortune Ray. (dip nearly vertical) are 
essentially identical with those just detailed for the rock on 
Jacques Cartier Island. It is. in fact, believed that, notwith- 
standing the fault at the entrance to Kirpon Harbor, that the 
outcrops on Jacques Cartier Island and Kirpon Island belong 
to the same deposit. In all three localities, the pillow-lava is 
more resistant to the weather than the associated slates and 
sandstones, and forms strong ridges in the topography. 
The Origin of J'ariolitc. — Much has been written concern- 
ing the causes underlying the development of varioles in basic 
rocks. It is clear that the Newfoundland occurrence cannot. 
on account of the all but complete decomposition of the rock, 
throw much additional light on this question. From the sharp- 
ness of the boundaries between variole arid matrix and from 
the well defined difference of habit of the sets of secondary min- 
erals composing the two elements of the rock, one must con- 
clude that the varioles are, in date of formation, to be referred 
to the period of cooling of the lava from its once molten con- 
dition. The studies of the European variolites have indicated, 
too, the strong probability that in the development of the var- 
ioles, there is little, if any. chemical differentiation in the mag- 
ma. Loewinson-Lessing suggests that the causes are probably 
external, as for example, rapid cooling per se, but concludes 
that the causes are really unknown. || Cole and Gregory say : 
"The variolite of the Durance occurs in situ as a selvage on the 
surfaces of these diabases among themselves as blocks in the 
fragmental rocks, which are regarded by us as tuffs ; and 
occasionally as a selvage to the diabase dikes. This product of 
* J. W. Gregory. Quart. Jout. Geol. Soc., vol. xlvii, 1891. o. 45. 
t F. L. Ransoiie. Bull. Dept. Geol. Univ. Calif., vol. i, 1893, p. 71. 
X Miss C. A. Raisin. Quart. Jour. Geol. Soc., vol. xlix. 1893, p. 145. 
§ G. A.J. Colk and 7- W. Gregory. Ibid., vol. xlvi, 1S90, p. 29§. 
II Tscher. Min. und Petrog. Mitth. A'eue Folge, vol. vi, 1885, p. 299. 
