428 



Transactions. — Geology. 



Fig. 7 



Included block of andesite, 18 ft. 

 across, imbedded in sandstone 

 and shale at Whangaparaoa. 



But the strata round and about the block are considerably 

 weathered, one bed shading into another without any clear 



line of division, hence the 

 difficulty of explaining 

 satisfactorily what has 

 actually taken place. 



In the case of other 

 included masses the beds 

 do not seem to be in any 

 way displaced, and in no 

 case has any alteration in 

 the sedimentary strata 

 been brought about at 

 their junction with these 

 masses. This phenome- 

 non is not easily ex- 

 plained. The rocks are 

 not in the least dyke-like 

 in character. They have 

 effected no alteration in the surrounding beds. They cannot, 

 therefore, be explained as being the remains of "intrusive 

 masses. They must have reached their present position 

 when cool, and cannot have fallen with much violence on 

 the soft yielding sandstones and shales, which otherwise 

 would show more signs of being displaced. Moreover, such 

 huge masses cannot have been hurled for any great dis- 

 tance through the air, and the fact that they are not water- 

 worn forbids the assumption that they have been transported 

 far by the action of 

 water ; and yet there 

 is no indication of any 

 volcanic vent in their 

 neighbourhood further 

 than that furnished by 

 the presence of the 

 blocks themselves. It 

 may have been that 

 they were deposited 

 quietly on a relatively 

 hard firm bottom and 

 subsequently covered 

 with sediment. 



At the extreme 

 eastern point of the 

 peninsula is a series 

 of volcanic deposits 

 some 16 ft. in thick- 

 ness, with horizontal 



Fig. 



8. 



Sana's tones 

 £r shp/es 



F/negr/t 



shading into 

 coarse gr/t 

 ^M0M^t?) and coarse 

 t.^^^i^MM^ conglomerate 

 Shore //ne 



Section at end of point, Whangaparaoa. 



