10 TUTIRA 



of sandstone and limestone, the result, doubtless, 'of floodings of sand 

 over shell-strewn ocean beds. Each band is of a different thickness. 

 Each slightly differs also in material, the sandstone sometimes less and 

 sometimes more dry, the limestone bands varying in the nature of their 

 shell fragments. Where, as occasionally happens, the topmost sea-floor 

 has been stripped by gales of its earthy coverings, cleavage is revealed 

 in the form of almost exact squares, in a mosaic of grey blocks of lime- 

 stone set in packed red sand. 1 



Continuing to traverse the run, moving eastwards, we reach central 

 Tutira. Hereabouts limestone disappears, sandstone and conglomerate 

 resting on the marl, the sand of the former seemingly ground out of 

 gravel, the pebbles of the latter rolled, worn, and of a generally ovoid 

 form. In these conglomerates and sandstones, fossils are rare. In the 

 first I have found but a single specimen, a short length apparently 

 of some knotless tree stem ; in the second, one or two kinds of bivalves. 

 Usually the weathering of the alternate bands of a cliff face proceeds 

 evenly. Sometimes, however, it happens that in a loose type of sand- 

 stone erosion by frost and wind is rather more pronounced than on the 

 conglomerates above. When that occurs the cliff assumes a protuberant 

 air, a curious rotund or pot-bellied appearance. Normally the con- 

 glomerates of the central run cap the sandstones. Lacking their pro- 

 tection, the softer rock has melted into cones, domes, razorbacks, and 

 peaks. 



Proceeding once more from the west to the east we reach low lines 

 of hills, eminences hardly more than hummocks. What is visible of 

 their rock material differs but little from the earlier mentioned con- 

 glomerates ; their colour is rusty-red instead of grey, they do not appear 

 to be so thoroughly set, they can be worked with a pick, almost with 

 a shovel. There is perhaps rather less variation in the size of their 

 pebbles. 



Again advancing on our traverse of the run, crossing the lakes we 

 reach the eastern range of Tutira the eastern edge of the trough. 

 Once again the rock formations change : the typical western facing cliff 

 is built up here of limestones, sandstones, and marls, irregularly super- 

 posed one upon another in bands of different depths. Compared with 

 the sandstones and limestones of the west, the sandstones and lime- 



1 A very perfect example of such a pattern may be seen on the great wind-blow of the 

 Haungaharuru range. 



