241 



and carried glacial striae (plate xl.). Some of the granites 

 and a piece of gneiss also showed glacial abrasions. 



The surrounding country is covered with a light, white- 

 coloured, sandy soil, underlain by a whitish stiff clay of glacial 

 origin. Sections of these beds can be seen in most of the 

 creeks of the neighbourhood. At Giles Flat, about a mile 

 west of the road-cutting just described, Giles Creek 

 crosses the main road, and was followed for some 

 distance on the south side of the road, where the exposures 

 of the glacial beds showed at the water-level a very tenacious 

 white, blue, and pinkish clay, which, when dry, has a char- 

 acteristic concave fracture. Resting on this clay are soft, 

 gritty sandstones, covered with recent stream-wash. The beds 

 in the creek, so far as they came under my observation, con- 

 tain but few boulders. 



Going further west, on the same road, small erratics (up 

 to 1 ft. in length) occur by the roadside. Just before reach- 

 ing the Bull's Creek Ranges the main road descends to the 

 level of Bull's Creek at the point where it emerges from the 

 ranges and receives the waters of Baulderstone Creek. A dis- 

 trict road branches off from the main road on the north side 

 and goes up the Baulderstone Creek Valley. At the junction 

 of the two roads a small washout in glacial clay with erratics 

 occurs. Following the district road for about three-quarters 

 of a mile, a number of small erratics were found on Mr. Jas. 

 Stone's ground (Sections 1837 and 1839), consisting of gran- 

 ites, porphyry, and quartzite, the greater number occurring 

 on a low sandy ridge in Section 1837 ; one erratic showing 

 a highly-polished facet. The range of hills through which 

 Bull's Creek has cut its gorge appears to be the limits of the 

 glacial deposits on the north-western side of the basin. 



South of the junction of Baulderstone Creek with Bull's 

 Creek the latter flows outside of the range, on its eastern 

 side, until it unites with the River Finniss, about a mile 

 south of Ashbourne. The country on the eastern side of the 

 range is comparatively low, and is characteristically glacial- 

 sand country. The Ashbourne flats are included in the same 

 class of country with the line of division (separating the 

 glacial beds from the Cambrian) running along the base of 

 the hills on the western side of the Victor Harbour main road. 

 At the Finniss Bridge near Ashbourne, and in the river-bed 

 to the south, the stream has cut down into the glacial sand- 

 stones and clays, making deep ruts, potholes, and fantastic 

 carvings at various places. 



The physiographical features of Mount Observation 

 (forming a great inlier of old rocks in the glacial beds) have 



