REPORTS OF RESEARCH COMMITTEES. 337 



The ti'end of the faults and of the strike of the folds associated 

 with them in the younger rocks is most commonly north-east, but 

 this system of dislocations occasionally bends around to a northerly 

 direction ; and in the South Island it is crossed by another system 

 with a north-westerly trend. 



Associated with the block-faulted structure are a number ol 

 characteristic features which repeat themselves in various parts of 

 the' New Zealand region. In addition to the fault-scarps (in so-me 

 cases splintered) and the fault-line scarps levealed where soft 

 Tertiary rocks have been stripped away from the fault surfaces, 

 warped surface®, or fold-scarps, in some cases from the boundaries 

 of the blocks. From these the weak cover of Tertiary, or some- 

 times Cretaceous, rocks has been removed by erosion, and the 

 floor from which these have been stripped may be completely dis- 

 sected, but in other cases it is only lightly seamed by water- 

 courses, between which inclined flat interfluves survive. 



The eroded surface of the older rocks forming the undermass of 

 the blocks, which is exposed by the removal of the weaker cover, 

 is in many places a very smooth plain of erosion. Large areas cf 

 it, which are often but slightly dissected, survive on the upper 

 surfaces of horsts and oii gently tilted blocks. 



Tilted blocks are of very common cccurrence, and many of the 

 consequent valleys of larger rivers lie in the fault-angles between 

 the inclined surfaces of tilted blocks and the fault-scarps of their 

 neighbours. 



Not only the open-water facies of the covering strata in many 

 inland localities, but also the presence of small remnants of them 

 on the higher blocks, indicate their former extension over nearly 

 the whole of the present area of New Zealand (thoaigh as terres- 

 trial deposits in the Central Otago district). The cover survives in 

 considerable areas only on low-lyine blocks, however. Most of 

 these are marginal, but some form intermont basins. 



The mature dissection of the folded Cretaceous and Tertiary 

 cover in those districts from which it has not been stripped has 

 resulted in a considerable formation of subsequent features, and 

 its softness has allowed of the development of multicycle topo- 

 graphy and abundant river terraces duimg the pauses in late 

 uplifts. 



The coasts of New Zealand were roughed out largely by fault- 

 ing, in part, probably, during the Kaikoura crogeny, but pro- 

 bably mainly by later movements. The present coasts, however, 

 are chiefly coasts of emergence and of submergence, indicating 

 recent uplift and subsidence of various parts of the New Zealand 

 region, though the moving blocks have been much larger than the 



