Mci^iiimi Scries of Noz'a Scotia. — Wood man. \n 
(latum ])lain.s which can Ije used as a basis for the larger struc- 
tural problems, it may be that, on the whole, the whin is 
more abundant and somewhat coarser near the base of the 
formation, becoming finer above ; but the differences are neith- 
er strong nor persistent. At certain horizons, in restricted 
districts, the whin forms a noticeably small proportion. 
Characteristics of sediments: slates. — The slates vary less 
than the whin. Their color is usually a bluish or greenish 
black, often altered by chlorite to a somewhat lighter green, 
or by the rusting of sulphides to a brown. Their commonest 
surface color when well weathered is gray. Color changes are 
by no means so frequent or so violent as in the green slate 
section at the base of the Halifax formation. In thickness 
the slate is often a mere parting in the quartzyte, and seldom 
attains a greater amount than a few feet in a single stratum. 
Usually it is a few inches or less . The rock is in places graph- 
itic, but not commonly or so noticeably as in the overlying 
formation. Near the base of the series slate is said to be less 
abundant, and the belts thinner on the average; yet at Moose 
River, whose rocks lie almost at the lowest known level in the 
formation, there is a belt of slate of considerable thickness, with 
a very small amount of whin within it. The highest propor- 
tion of slate to whin is stated to be found near the center of the 
Goldenville, but of this we have as yet no proof. In most of 
the gold districts this rock is distributed in thin belts between 
well-defined quartzyte walls ; and this has determined in large 
part the position and character of the mining districts. Old- 
ham, Goldenville, and Montague are good examples. 
Proportion of slate to quart::ytc. — By far the larger part 
of the Goldenville formation is composed of sandstones, 
quartzytes, and their more metamorphosed schistose equiv- 
alents. At what may conveniently be called the "horizons of 
most abundant slate,'' exposed on the domes now worked for 
gold, it yet, by measurements in a number of districts, averages 
less than 20% of the whole. In parts of Moose River it 
amounts to much more, but the district is exceptional. In 
the westernmost quarry, areas 70 and 71 block 1, the rock is 
33% slate ; in one of the cross-cut trenches 60%^ and in several 
other parts of the district nearly 50%. Estimates based upon 
the thickness of these slate horizons on the different anticlines, 
