PUKPLE SANDSTONE. 8& 



fifty to one hundred feet immediately succeeding the red salt marl 

 are very earthy, but of the usual purple colour, and appear like a transi- 

 tion from the marl up Into the sandstone ; the latter is generally soft 

 and splintery below, where the lines of bedding are not very clearly 

 marked. Above the earthy portion argillaceous inter-stratifications are 

 rare or absent, and the beds are all of a nearly equal hardness, 

 considerably less than that which is usual in palaeozoic rocks. The 

 sandstone is absorbent or hygrometric, frequently covered with a white 



saline efflorescence, and contains both carbonates of 

 Composition. ' ^ ... • • jt t i 



lime and magnesia in its composition.* Its colour 



near the top of the group changes from the prevailing dull purple to 



much paler shades, in places banded with warm yellowish streaks. 



Dr. Fleming's and Mr. Theobald's descriptions of this sandstone 

 group vary somewhat. The former describes it as containing congljo- 

 merate and ripple marks, the latter as never containing a pebble and 

 having none of these markings. As a rule, no doubt, Mr. Theobald is 

 correct in these particulars, some earthy conglomerate bands in the 

 western part of the district being only doubtfully referable to the forma- 

 tion; but it would scarcely be safe to assert that ripple marks never 

 occur in these sandstones, though they are certainly not characteristic 

 of the group. 



In one exceptional instance only, in the eastern part of the range, a 

 Exceptional appearance "^^^^ed diflPerence in the arrangenient of these 

 of a dark shale band, ijg^jg ^^s met with, a strong band of greenish-gray 



flags and shales appearing to intervene between the red marl and purple 

 sandstones at the base of Dandot cliffs. The occurrence being quite 

 unusual, it is very probable that a concealed fault or other dislocation has 

 placed the next overlying group in an apparently inverted position, and 

 even though traces of the break have not been found, its presence may be 

 almost presumed from the many dislocations of the rocks of the vicinity. 



* Dr. Fleming's 2nd Report, p. 253. 



( 85 ) 



