308 



200 feet (pi. xxiv., figs. 1 and 2). The Sellick's Hill Creek, which takes its rise 

 to the eastward of the township, does not reach the sea, but becomes absorbed 

 in the gravel beds while on its way. The best section of the beds can be obtained 

 from a deep and long washout, which has almost reached the dimensions of a 

 creek, that opens to the beach near the end of the first exposure of the Miocene 

 beds in the clififs (Sec. 277, Hundred of Myponga). This small creek has cut 

 a steep and deep valley in these beds, almost down to sea level, and goes back 

 for about half a mile in the same alluvial deposits. 



On going up this creek the bed is burdened with large blocks of stone 

 which are 2, 3, or 4 feet in length, mostly of a buff colour, but sometimes pink, 

 and sometimes almost black (carbonaceous). These stones of Cambrian age 

 have been derived from the indurated shales (or slates with imperfect cleavage) 

 which underlie the Cambrian limestones and are seen in outcrop at the lower part 

 of the Sellick's Hill road, near the Sellick's Hill Creek. At the distance of 

 about one-eighth of a mile up the creek a bar of weathered buff-coloured shale 

 crosses the stream and forms a waterfall about 50 feet high, capped by gravels. 

 It is at this waterfall that the large blocks in the bed of the stream, just referred 

 to, are quarried. These buff-coloured shales were probably, originally, dark 

 coloured (as occur elsewhere in the neighbourhood), but have been bleached 

 by weathering. 



So far as observed, these very thick gravel beds show little variation as to 

 the kinds of stone they contain. The beds are horizontal and consist of clay, 

 sandy clay, and stones. The majority of the latter are light coloured, siliceous, 

 and saccharoidal quartzites, which are a common feature as bedding in the 

 Cambrian Series. There are also a considerable number of the greyish-coloured 

 shales, and a few bluish, very siliceous, and rather coarse-grained quartzites, but 

 limestones are very rare. At the outlet, where the creek debouches on the 

 beach, a few rather large limestone boulders occur, but these are not always to 

 be seen, as they are sometimes covered either by sediment brought down by the 

 creek or by sand washed up by the tide. At one place in the creek a block of 

 the bluish, coarse-grained quartzite occurred, in situ, 2 feet in length. At a few 

 horizons there are layers of larger stones that measure from 1 foot to 18 inches in 

 length, but the majority of the stones composing the gravel beds do not exceed 

 6 or 9 inches, and by far the greater number are less than 6 inches in diameter. 

 Clay is often mixed with the gravel. The pebbles usually show some wear, but not 

 generally excessive, being mostly of subangular outline. At one place, along the 

 cliffs, near the high-pitched Tertiary beds, there is a section showing large rounded 

 stones. 



On the southern side of the creek there are several small outlets to the 

 drainage, but all of these are confined to the face of the gravel cliffs and are 

 the effects of rain wash on the cliffs. In these small gutters the stones are 

 similar to those in the main creek, mentioned above ; that is, mainly, fine-grained, 

 light-coloured quartzites and some bluish quartzites and buff-coloured shales, but 

 no limestones. 



The high gravel cliffs, facing the sea, extend for about a mile in length. 

 The material is banked against the Cambrian outcrops, on the southern side, at 

 a high cliff face, but the exact junction is obscured on account of a talus. The 

 alluvial beds are undergoing rapid waste, occasioned by rain wash, soakages 

 from behind, and numerous landslips, showing many remarkable features of 

 earth sculpture as peaks, recesses, and slopes of various angles in a most pic- 

 turesque manner. The waste from these alluvial cliffs has given rise to extensive 

 shingle-banks on their northern side and to beach-travelled stones that are in 

 evidence far up the Gulf. 



The Sellick's Hill Creek (that crosses the main road a little south of the 

 hotel) has cut its bed in the Cambrian shales, and, for some distance, the latter 



