270 
HRr:NJ)AN P. Tetomson. 
In ilio adit of Iho barite working’s near the eontaet the same suceession 
of beds as oeeurs at the Hriekworks (L>narry is found diitpitig w(*st at ()5°. 
In the Cardti]) (Quarry at least three epidioi’ite dykes intrude tlie slat(*K, which 
a])i)ear to dip almost vertically. The bedding of the slates is obscnnal hy 
dosely s])ac(‘d fracture ]>la.nes, cans<‘(] probably by the intrusion of the 
epidiorite dyk('s, because 5 chains west of the large dyke on the west side 
of the dardnp Quarry the dip of tin' slat(' rcdurns to tlie normal 60° west. 
I he wider ('xposnres of slate in the south<‘rn i)arts of the area may 
best be exi)lained as a more complete scHimmce of tin* Cardtip Series whicii 
has Ix'en protected from erosion by (piarl;; blows and basic <lykes. Isoclinal 
folding may I)e advanced as an alternative ('xplanation but no evidence of 
rej)etition of the black slates or tlie basal sandy beds has been obtained and 
di agd oliliiig, whicli may have yi(*lded some iiiformation in this connection, 
has bemi obscured by weatliering. 
The (jiiart?: Idows interleave the slates and outcrop “en echeloid’ as 
north-south ridges. Tn the section (‘xposod in tlie Cardiip Quarry the blow 
quaitz forms lenses up to (i f(x*t wide. Other f|uartz veins oc'cur in the 
seri(‘s; these will be d('scribed later in the petrograjihy section. 
C. Basie Intrusives. 
These aia* epidiorites, the main types an*: — 
1. llralitisial (juartz dolerites. 
2. Porphyritic chlorite-albite ejiidiorite. 
All the <lykes in tin* granite grn'iss are of uralitised (piartz dolerite. In 
the north of tin* area tlie large dykes have a dominant east-west trend, 
narrower dykes strike north to Tiorth-north-w(‘st. IP'iice the dyke jiattern in 
the north corresponds to that of Armadale (Prider, 1!)41). In the central 
part of tlu* area the dykes strike mainly nortli-wesl. In tlie south there 
are very t(‘w dykes — the trend of these bc'ing noiih-easl. 
Dykes intrude the Cardu]) series at sint^ral places at the contact of the 
series with the granite gneiss. At C'a.rdup several dykes occur completely 
in the slate's and being roughly parallel to 1h(*ir strike, may be sill-like bodies. 
Tin* porphyrite chhu'ite-albite epidioilte (the albite porphyrite of Esson, 
is tound only as scattei'cd boulders on the north baid\ of AVoiigong 
Brook and to the south of Cardup P>rook. This epidiorite outcrops south 
of the area, at Whitby Fails and Mundijong (Esson, 1920). 
Xo reliable' field evidence can be obtained in the Wongong-Cardup area 
concerning tin* relationship between this porphyritic epidiorite and the 
uralitised (juartz dolerite. 
I). Later Bocl's. 
The later rocks are : — 
(1) Ijaterite.~Vh\s~ forms a ca])])ing over most of the area above 
BOO teet elevation. Baterite boulders and ])ebbles occur on the lower levels 
;at the foot of flu* scarp. 
(2) Allwmal deposits . — These occur along the courses of Wongotig and 
Cardup Brooks. Silt and sand (-over much of the plain (sege pae 266) Iving 
west of the scar|>. 
(d) Talus slopes . — ’These are formed on the steeper sides of the valleys, 
and are composed of aplogranite, gneiss and dokwite. 
