Ordovician Rocks at Daylesford. 177 



producing different weathering. The surfaces of the pockets 

 do not differ from the sandstone any more than is common 

 in joint surfaces and other fractures in such sandstone. At 

 Leveret's cutting in one pocket a banded arrangement of strings 

 of quartz and limonite was noticed, but here the whole rock was 

 irregularly traversed by such strings, and at the typical instance 

 at Italian Hill no concretionary action was noticed. 



The sandstone beds at many localities contain a series of more 

 or less undulating and usually discontinuous thin bands of fine 

 grained material containing mica. Sometimes these are nearly 

 parallel to the stratification, sometimes nearly parallel to the 

 cleavage or to joints. In the large railway cutting near 

 Wombat, a stepped junction with the neighbouring slate bed is 

 noticed, as if a slight slipping had taken place on these planes. 

 Near here it is possible to get clear observations of dip of sti-ata, 

 cleavage, these micaceous bands, and three sets of joints. These 

 bands here agree most nearly in direction with one set of joints. 



At Bald Hills Creek they are well developed, and form the 

 " oblique stratification " mentioned in the note to the Quarter- 

 sheet. The junction with the neighbouring argillaceous beds on 

 both sides is somewhat indefinite, and the sandstone between 

 them turns and forms lenticular patches in these beds nearly 

 parallel to their genei\al direction. They are parallel in several 

 sandstone beds, but afterwards change their direction. Mr. N. 

 Taylor's sketch shows the actual point at which the change takes 

 place, which, however, I did not see. That they are not really 

 stratification is clearly seen by their relation to the next beds, 

 and their great regularity of development would also be against 

 current bedding. 



South of Creswick in a railway cutting they are well developed,, 

 standing out somewhat in the friable sandstone (probably owing 

 to the mica flakes giving them some firmness, though soft). 

 Here they may be seen to curve considerably and become less, 

 definite on approaching the slate beds from one side, but on the 

 other side they continue unaltered to the slate. Their direction 

 is near that of the cleavage. 



Mr. E. J. Dunn notices a similar structure at Bendigo under 

 the name of " Assuring," and regards it as a coarse development 



