380 Transactions. — Geology. 



In the clay stones forming the first hne of low reefs on 

 the beach south of Campbell's Creek I identified Halobia 

 and Sjnriferina, which would indicate a repetition of the Wilt- 

 shire beds in that direction. 



Hay's Gap to Nugget Point. 



The distance between these points is about two miles, the 

 direction from Hay's Gap for the first mile being almost due 

 south (true meridian), and thence, for the second mile, south- 

 east. 



At Hay's Gap the Trias rocks consist of sandstones and 

 claystones, in places alternating in thin laminae, often highly 

 indurated, jointed and seamed with veins of iron-peroxide. 

 Their strike is E.-W., and the dip south at an angle of 58°. 

 Some 5 chains south of the Gap the strike changes to a 

 direction between E. and E.N.E., with a nearly S.S.E. dip at 

 an angle of 49° ; at 6 chains south the strike is about 

 E.S.E.-W.N.W., and the dip nearly S.S.W. at an angle of 

 78°; while at a distance of 7| chains the strike is exactly 

 between E. and E.S.E., with the dip still southerly at an 

 angle of 57°. 



Thus in a distance of less than 170 yards the strike has 

 changed through an arc of about 30°. The nipping of the 

 beds caused by this sudden change of strike has resulted in a 

 steepening of the dip towards the centre of the nip. Pro- 

 ceeding southward, the strike bends still more to the south- 

 ward, and at a distance of half a mile from the Gap is 

 N.W.-S.E., and the dip S.W. at an angle of 42°. 



Towards the Nuggets the sandstones become coarse in 

 texture, and in places assume the character of greywacke. 

 They form high rocky points and numerous isolated flat reefs 

 on the beach below high-water mark, separated by stretches 

 of sand. 



Immediately north of "Boat-landing" the strike varies 

 between N.W." and W.N.W., while the dip is still southerly 

 at angles generally about 65°. 



At the point where the road leading to the lighthouse 

 leaves the beach— that is, about 300 yards south-east of Boat- 

 landing — the strata are intruded by a dyke of augite porphy- 

 rite which is well exposed in the south side of the road- 

 cutting. 



This dyke is of especial interest, as it is the only igneous 

 rock found associated with the Trias formation in this 

 district. It runs almost parallel with the bedding-planes of 

 the enclosing rocks, and can be traced across the saddle into 

 Shaw Bay, a distance of 50 chains. Near Boat-landing it is 

 about 9 ft. thick, but in two places on the ridge dividing Boat- 



