42 
Hex T. Prider. 
It api)ears most probable that it developed during the earth move- 
ments wliieh affected the Cardup Stndes while these rocks were- 
still at elevated temperatures following the intrusion of the green- 
stone sill. 
From 40' to 53' m—hlotite-qitartz hornfels — these rocks are hornfelsed 
argillac(‘ous sandstones. They are tine grained, dark green in 
colour and under tin* microscoi)e are seen to be made up of rounded 
quartz grains witli interstitial Oaky pale brown biotite with some 
pale green chlorite and sericite. 
From 53' to 00' in — rhlorite-albite rpirliorite sill {described in a later 
section) with a narrow intrusion of a microporphyritic epidiorite- 
between 57' and 58'. 
Fkuu f)0' to 00' Ill- contact altered sanchj slate similar to that be- 
tween 49' and 53' excejit that it is much Oner grained and 
apparently less altered, the biotite being in much smaller flakes. 
Fi’om 09' to 100' in — quart^-hiotite-aetinolite hornfels similar to the 
actinolite bearing hornfelses developed in the arenaceous sediments 
nearer the granite contact (described in the section dealing with 
the Cardup sandstones). 
From 109' to 311' in — uroHiised qaartz-dolerite. At 311' there are 
several small irregular bodies ( ? veins) of coarse grained quartz, 
(which under the microscope shows considerable cataclasis). 
From 311' to the west end — greenstone, i>robably the ehlorite-albite 
eiiidiorite but the rocks here become too weathered for exact deter- 
mination. 
■CjU'^L 
n^ure 3- 
SiatG 
Qunrrij ^ 
n weathered albitc 
epidiorire Cv)- 
Scale 
0 JO , '00 Peet. 
LEGEND AS IN 8 (beio«) 
Wesf 
riSUR£ 3 
-3 • 
' 
j 
■ P ' 
P'lh! 
r 
; 
1' ' 
'' 
' S. 1 - 
‘ \ ^ A A A, A A yyest 
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.-**.*\a A ^ A A A 
Scale 
Figure 4. 
5 0 rc£r 
A, Geological sketch plan of the tunnel leading out from the south-west corner 
of the slate quarry, Armadale. 
B. Enlargement of geological plan of east end of the tunnel from the slate 
quarry, showing the relations of the Cardup sediments, the clilorite-albite' 
epidiorite sill and the later quartz dolerite dyke (note the narrow 
intrusion of microporphvritic epidiorite into the clilorite-alVdte epidiorite- 
sill). 
