Bartrum. — West port-Chariest on High-level Terraces. 



257 



bable, however, that, in much the same manner as has been suggested by 

 Mr. C. A. Cotton* in explanation of similar conditions in the Tertiary- 

 beds of South Marlborough previously described as unconformity, warping 

 allowed erosion of an upraised portion of the coal-measure beds, whilst 

 deposition continued uninterruptedly in a depressed area. It is a significant 

 fact that wherever both are developed the Miocene series has been found 

 invariably to rest in perfect conformity upon the Eocene. 



Distribution of Geological Formations. 



The Westport-Charleston district is governed topographically by two 

 main earth-blocks, an upraised one forming the Paparoa Range and its 

 northern continuation, and a relatively depressed coastal block forming 

 the wide lowlands extending from the base of the upland block to the coast. 



A / v i\i\ ,i ^.i^ft^ii 



ignite measures 



Sea Level 



— SCALE.S — 



— Horizontal — 

 9040 9 



— Vertical^ — 



1000 500 



Sections along Lines AB and CD of Locality Map. 



The earth-fracture between these blocks determines the western flank of 

 the Paparoa Range and of the elevated country to the north of the Buller 

 Riyer, and has been designated by McKay f the " Lower Buller " fault. 

 East of it, south of the Buller, granitic and gneissic rocks, and to the north 

 older sedimentary rocks and various acid intrusives, capped by relatively 

 thin Eocene coal-measures, form the mass of the elevated tract. 



To the west of the great fault, which has been indicated upon the 

 locality map, soft " Blue Bottom " sandstones extend below Quaternary 

 gravels over almost the whole of the lowland block, and outcrop wherever 



* Paper read before Wellington Philosophical Society, 22nd October, 1913 (see p. 286 

 of this volume). 



t " On the Geology of Marlborough and South-east Nelson," Rep. Geol. Expl., 

 1890-91 (1892), p. 22. 



9— Trans. 



