I Palaeozoic Geology of Victoina. 93' 



cherty slates, quartzites and quartz; stratification is visible, and- 

 the beds are here inclined at a much higher angle than usual, dip- 

 ping to the W.S.W. at about 70°. They are seen to rest against the 

 Upper Ordovician cherty slates, which are much contorted, and the- 

 junction suggests a fault line, striking north-westerly. The same 

 beds show a marked discordance in strike at another outcrop, about 

 fifteen chains to the north-west, where there appears to be a short 

 north and south fault. The strike on one side is alx)ut N.E., and 

 on the other N.W . 



The belt as a whole, however, is traceable almost continuously 

 without any noteworthy break, below the overlying rhyolite sheet, 

 and these disturbances in dip and strike, though striking, are only 

 of limited extent. 



Another deposit with some special features is exposed in the 

 bed of the Wellington River, still further to the north-west at 

 Locality H. Its exact nature and relationship is not clearly under- 

 stood, but it may be an extreme lithoiogical variation of the basal 

 beds under discussion. The extent is about 20 chains over about 

 a width of one cjiain along the bed of the river. 



Its character is that of a coarsely fragmental deposit, composed 

 very largely of fine grained diabasic rock, the interstices being- 

 filled up with granular quartz and calcite. A few angular inclusions 

 of quartz porphyry similar to that of the Wellington series were 

 noted. 



A number of thin sections from various parts of this deposit 

 were examined. 



The diabasic material is fine grained, and much altered. Fine 

 plagioclase laths and magnetite are recognisable, but there is much 

 chlorite and calcite. The interstitial material is siliceous and 

 calcareous, consisting of a coarse to fine grained mosaic of quartz 

 and calcite. 



Secondary silicification affecting both the diabase and the inter- 

 stitial material is recognisable, but an original fragmental charac- 

 ter can be recognised in some sections, showing altered fragments 

 of shale and diabase, irregular grains of quartz, showing secondary 

 growth and an occasional fragment of orthoclase. 



The porphyry inclusion shows a fine microcrystalline siliceous 

 base, with corroded and embayed orthoclase phenocrysts, showing 

 some kaolinization and secondary silicification. 



These acid igneous inclusions suggest possibly a Lower Carlwn- 

 iferous source, and though the relationship of the deposit to the- 



