209 



Bird Rock is topped by a thin strcatuiu of hard material corres- 

 ponding with a projecting ledge on the adjoining cliff. This 

 serves to mark the dip very clearly, which was found to be 6^ to 

 the north. 



From Bird Rock, the coast curves round to the north-east, and 

 the strata become very hard and rough, in which only fragments 

 of fossils appear. The dip of this rugged limestone cannot be 

 very accurately taken, but appears horizontal when viewed from 

 the beach. At one place, however, where the cliff is cut back, 

 the true dip is seen ; it is approximately 10° to the K.N. W. 



A few yards to the east of Bird Rock, a narrow flat reef is 

 visible at low tide, commencing at the shore line and stretching 

 fully 150 yards out to sea, not however, in a straight line, but 

 with a gentle curve westward, as if forming a section of a large 

 circle. Near its shore-end the dip is to the north, but this 

 gradually changes until at the seaward extremity it is to the 

 east. The rock is very hard, but is gradually wearing away by 

 the formation of j)ot-holes on its surface. The reef is a con- 

 tinuation of the topmost stratum of Bird Rock, the intervening- 

 portions having been degraded. On the adjoining landward 

 cliff, the corresponding hard band previously mentioned stands 

 out from the inferior and superior softer strata and is continuous 

 right to the edge of the flat rock, which is in reality a seaward 

 extension of it. At very low tide, small sections of two outer 

 circles also show, representing hard bands still higher up the cliff. 



Along the coast in a south-westerly direction from Bird Rock, 

 similar extensions of the cliff-strata rise at intervals from a few 

 inches to a foot or more above low watermark, but they are 

 mainly parallel to the coast, and stretch only a short distance 

 seaward. 



' " ^' ' "" ' ' 'er. 



About half a mile to the south-west of Bird Rock, howe\ 



and close to the ledge in the cliffs which served as our retreat at 

 high tide, a spit runs out for some distance and curves in an 

 opposite direction to that on the north-east. The dip is here to 

 the south-east and the same direction is maintained on a flat 

 reef close to Rocky Point, The section is thus evidently a 

 hemi-dome, the rocks in the middle inclining seawards, i.e., to the 

 east, and those on the sides to the north and south-east respectively. 

 The strata slope more gently on the southern flank of the dome 

 than on the northern. Exact measurements of the dip in the 

 former direction are difficult to obtain, but it does not probably 

 exceed three or four degrees. In the centre of the section the 

 rocks for a short distance are apparently horizontal. The general 

 contour of the coast in the neighbourhood of Bird Rock is well- 

 illustrated in a lithograph copied from a photograph by the late 

 Mr. R. Daintree, and published in the Geological Quarter-sheet, 

 No. 28, S.E. 

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