Mcgiima Scries of Xova Scotia.- — Ji'oodinait. 15 
of the GoldenviUe formation. The usual syncHiie of the Halifax 
has been puckered into two, with an anticline between ; and 
this has been domed up at Caribou, and eroded far enough to 
show the summit of the GoldenviUe strata beneath. In the 
west, elliptical areas of this group, on the "banded argillyte" 
as a background, arc mapped as occurring in several instances, 
up to a score and more miles in length (Bailey, '98, map) . 
Contact icith the Halifax formation. — The contact between 
the two divisions of the series is always sharp where actually 
observable. It is usually marked by a striking change in 
color of the strata, from the greenish and grayish of the lower 
rocks to the black, or less often light green, of the upper. 
Faribault ('87, pp. 146-147) speaks of the contact as charac- 
terized by "a few layers of greenish, soft, smooth slate :"• but 
these are absent in many regions. They are the eastern equiv- 
alents of the "banded argillyte" of Bailey. Nowhere has the 
slightest unconformity been seen between the two; one being 
a continuation of the other as regards process of sedimenta- 
tion, and differing from it only in color, texture, and kind of 
material . 
Base unknoien. — The problem of the base of the series is 
insoluble at present. It is easy to find the lowest rocks, funda- 
mental to our observation ; but there is no information which 
gives any clue as to the depth of unknown ]\Ieguma below the 
surface of the earth, in the center of the Moose River — Fifteei 
Mile Stream anticline, which holds the lowest known strata 
in eastern X^ova Scotia. 
Thickness . — This makes impossible of answer the ques- 
tion as to the real thickness of the formation. The exposed 
thickness of the series and its subdivisions has been computed 
by several students of the field. Hind ('70, '70% '70**) first 
estimated the thickness of the whole series, calling it 12.000 
feet. The opposite extreme is Prest's estimate of 28.000 feet 
(Bailey. '98. p. 83).. Hind (loc. cit.) gave 9,000 feet as the 
thickness of the lower formation. Faribault ('87) gave 15,- 
000 feet at first, and later (99, p. 2) regarded three miles 
as the depth to which erosion had exposed these beds. Bailey 
('98, p. 31) gives 5,000 feet as a minimum, indicating thus 
the greater difiicultv of exact structural work in the west. 
