366 The American Geologist. J"ne, i904. 
siliferous part of his lowest series Cambrian (p. 187). This is 
the gold-bearing series. The chief work in separating it from 
the various later ages, especially Silurian and Devonian, was 
accomplished by Sir Williani Dawson ('55, '68), in the first 
two editions of "Acadian Geology.'' Yet even he did not recog- 
nize the complete unity of the series ; and. indeed, this has never 
been sufficiently emphasized. 
Chief strnetural features. — The most pronounced structural 
characteristic of these thoroughly altered rocks is the presence 
throughout their extent and thickness of parallel anticlines and 
synclines, striking northeast or east. They were noted by Ges- 
ner in '43. But the feature which has made economic exploita- 
tion possible is the. location on the anticlines of many small 
structural domes of various degrees of development, giving 
under denudation a curved and often elliptical strike to the 
strata. They seem not to have been noticed until after the 
discovery of gold in i860 had excited observation on the struc-' 
ture of the economic areas. The first detailed work to bring 
out the presence of such domes as a type structure was done 
at Waverley by H. Y. Hind, and published in '69. The only 
survey embracing a wide area in sufficient detail to print on sheet 
maps has been that of Mr. E. R. Faribault, of the Geological 
Survey of Canada. These excellent studies, covering all of the 
series from the eastern end at least as far west as the Xova 
Scotia Central railway, and published as far west as the longi- 
tude of Halifax, deserve to be much more widely known; foi 
their structural accuracy is considerable, and has been achieved 
in the face of difficulties of no small importance. In many 
cases, domes opened by mining operatiojis have been especially 
mapped by him, on a very large scale. Tl^e work of professor 
L. W. Bailey, summarized in his report of '98. gives the only 
account of the geology of the western quarter of the province, 
but does not confine itself to the gold-bearing series. 
In '63 Campbell recognized the two-fold' nature of these 
rocks, chiefly arenaceous in a low^cf division and argillaceous in 
an upper one. This discrimination was based upon study in 
the eastern part of the province, and is still valid for that sec- 
tion. In the west, however. Bailey has added a division be- 
tween these two ('98). 
