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island consists of rhyolitic material described previously, but the lavas 



capping this are entirely of basalt. The lowest beds exposed on the north- 

 west corner of the island are of basalt, but at 

 the base of the cliffs facing the harbour is a bed 

 of irregular angular material, 80 ft. thick where 

 it is best developed, which may form the lowest 

 member of the series in this locality. The frag- 

 ments are of all sizes up to 1 ft. in diameter, 

 chiefly of basalt, rhyolite, and trachyte, but with 

 occasional pieces of greywacke, no doubt torn by 

 explosive action from the underlying substratum 

 in close proximity to the vent. Where exposed 

 on the shore platform at the base of the cliffs 

 the material is especially coarse, but in the cliff 

 itself appear layers of fine-grained ash with well- 

 developed stratification . Since there is an absence 

 of traces of sea action, as well as no evidence of 

 marine fossils, it is reasonable to assume that 

 the stratification is due to sorting by the wind 

 and not to water, a mode of formation of wide- 

 spread occurrence where volcanic cones have been 

 constructed on a land surface. 



At the edge of the shore platform the layer 

 of agglomerate is overlain by solid flows dipping 

 north, an arrangement suggesting that the sea 

 has cut into the heart of the cone and exposed 

 the beds in close proximity to the vent. This is 

 all the more probable since at the extreme north- 

 easterly point of the island the lava-flows dip 

 south — i.e., in the contrary direction. Another 

 fragmentary layer is exposed on the shore at the 

 base of the low cliff just north of the outer wharf, 

 the fragments in this case consisting almost 

 entirely of basalt ; and as this lies almost on 

 top of solid rhyolite in position, the junction 

 being in close proximity but obscured, this may 

 represent the oldest bed of the Quail Island series. 

 The massive layer referred to previously probably 

 outcrops on this face of the island as well, but 

 the section is difficult to make out, as would 

 be expected where the extruded material near the 

 vent consists of irregular layers of fragmentary 

 material, as well as small and irregular lava-flows. 

 Over the thick layer of fragments is a 

 horizontal sheet of rudely prismatic basalt, 50 ft. 

 thick, which is well exposed in the cliff facing 

 Lyttelton. This abuts against the underlying 

 basalt on the. east, and against the rhyolite with 

 its trachyte dykes on the west ; its continuity is 

 here broken, and it is impossible to say with 

 certainty whether the flows exposed on the cliffs 



on the north-western point of the island belong to a later flow or not. 



The upper surface was deeply eroded before the succeeding layer of frag- 



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