Palaeozoio Geology of Victoria. 71 



Introduction. 



The foDowing observations and conclusions are the result of field 

 work which was started in the vicinity of Mount Wellington, in 

 North Gippsland, about fifteen years ago. It was the existence of a 

 ^niall, imperfectly known mountain lake, close to Mount Welling- 

 ton, which first attracted the writer to this region. Lake Karng, 

 as it has been named, had been visited by the late Dr. Howitt about 

 fourteen years previously, but the question of its origin was not 

 ■definitely settled. Of the two views discussed by Howitt (1 and 2), 

 namely, glacial and landslip origin, the glacial was most favoured. 



No other scientific observei'" had visited the lake until the writer's 

 examination in December, 1904. A report of the excursion ap- 

 peared in the ** Victorian Naturalist," 1905 (11). Tlie landslip 

 origin of the barrier which forms the lake is there upheld, and 

 several subsequent visits by the writer have greatly strengthened 

 ■thia conviction. 



Incidentally, the first excursion showed that the whole region was 

 full of interest, both geologically and physiographically, and dur- 

 ing the years 1904 to. 1908 (11, 12, 13), four short vacation expedi- 

 tions were made into various parts of this district. The most im- 

 ■portant result of this preliminary work was to show that to the west 

 of Mount Wellington there was an extensive and complex inlier 

 of Lower Palaeozoic rocks in an area previously regarded as Upper 

 Devonian. In this region, along the Wellington and Dolodrook 

 Rivers, extensive outcrops of black cherty slates were discovered, 

 yielding abundant and beautifully preserved Tapper Ordovician 

 graptolites. Serpentine containing Corundum and Chromite was 

 also found to occur along a belt within the Ordovician area, but 

 its age and relationship to the surrounding rocks had not yet been 

 worked out. Several outcrops of grey crystalline limestone inti- 

 mately associated with the slates and serpentine were next dis- 

 covered, and these proved later to be some of the most important 

 and interesting rocks of the district. At first a small brachiopod 

 was the only fossil obtained, which Mr. Chapman regarded as a 

 "Silurian form, but later another outorop of limestone yielded 

 abundant trih)bites, whicli Mr. Chapman confidently recognised as 

 Upper Cambrian (13 and 15). Ihis came as a surprise, for tliough 

 -the field observations were limited, they had not suggested the 

 -marked stratigraphical break which the palac>ontological evidence 

 now demanded. Shortly previously to this discovery, Mr. E. J. 

 Dunn (IG), late Direit9r of the Geological Survey, in company with 



