GEOLOGY OF THE COUMA DISTRICT, N.S.W. 211 
reversals are found. High dip-angles are the rule, and the 
cleavage planes are often vertical. Possibly the present 
state of affairs results from the erosion of a series of 
isoclinal folds. On the slopes of ridges one occasionally 
found discordances of dip—beds on one side dipping towards 
those on the other side, apparently indicating a fold-trough, 
but in some instances this was clearly seen to be merely a 
surface phenomenon, the beds, originally vertical or nearly 
so, inclining over towards the downhill side of the ridge 
under the influence of gravity." Nothing but extremely 
detailed mapping of individual horizons could determine 
the nature of the folding. 
With regard to the metamorphic series, the gneisses are 
quite definitely intrusive into the schists, and the question of 
age therefore centres round these schists and the phyllites. 
A number of traverses were made across the strike, both 
to the east and west of the axis of the complex, and in no 
case could an abrupt transition in the rock-type be found. 
Starting from Kiaora homestead, on crystalline schists, as 
-one goes west the rocks become more micaceous and phyl- 
litic in appearance: there is a considerable belt of these 
rocks, about 14 miles wide, which I have named the Slack’s 
Oreek phyllites from their typical development and the 
good sections shewn there. Near the Dry Plain road and 
beyond it to the west, the phyllites have graded into micace- 
ous slates which are in the same line of strike with the 
‘slates in which graptolites occur at McCarty’s Crossing, 
about a mile to the north. 
On the eastern side there is the same gradual passage 
from schist through phyllite into micaceous slate, but here 
the transition belt is not so broad, practically no knotted 
phyllite is developed, and there is the intrusion of white 
gneiss which interrupts the succession of the beds. 
+ Mr. E. C. Andrews informs me that he too has found this ‘false dip,’ 
as it may be called, troublesome in the field. 
