Observations on Mount Mary. 163 



with fine quartz pebble chnft." Note 19, "A thin layer of 

 rounded quartz pebble drift occurs here between the Miocene 

 Tertiary and Upper Volcanic. It is probably the continuation 

 southwards of the Older Pliocene auriferous drift underlying the 

 basaltic tableland about six miles north of Bacchus Marsh. . . ." 



These notes refer to deposits occurring in the cliffs along the 

 Parwan Creek, some seven miles to the north-west of Exford, 

 and they apply to a certain extent to the sections at and near 

 Exford. 



The former note quoted indicates a combined volcanic and 

 ordinary sedimentary origin for these Parwan Creek beds as may 

 be the case regarding the finer beds near Exford. In some places 

 here this bed of fine material appears to have been altered by the 

 covering basalt, being slightly hardened and of a reddish-pink 

 colour. To test the probability of this I took a piece of the 

 greenish-yellow rock and first roasted, then burnt it. The result 

 was a rock very similar in hardness, colour and general appear- 

 ance to that in question, which points towards its alteration by 

 heated contact. 



The surface pebbly drift may also be seen at the following^ 

 places :— On the top of the flat ridge between the Toolern Creek 

 and the Werribee River ; on the top of, and stretching back from, 

 the clifis on the east and west of the Werribee for some distance 

 south of the Melbourne Road ; at the junction of the Bacchus 

 Marsh and Ballan Roads in the south-west corner of Allotment 

 18b, parish of Mooradoranook. It probably extends along from 

 here to the Werribee Bridge at Exford, but this portion was not 

 examined. 



It can also be seen along the railway between Melton and 

 Bacchus Marsh, covering large areas on the north of the railway, 

 as shown in Quarter-sheet 12 N.E. This is probably the main 

 mass of which the portions hei*ein specially described are the 

 attenuated southern remnants. 



We find, therefore, that the locality near the Exford Bridge 

 shows that there are at least two flows of basalt, with an inter- 

 calated bed of pebbly drift, overlain by a thin bed of very fine 

 gritty mudstone or clay ; while overlying the upper of these two 

 flows of basalt is a bed of varying thickness of coarse to fine 

 pebbly drift. 



