THE VICTORIAN NATURALIST, 163 



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Lobelias should lead to more attention being paid to the fungus- 

 parasites which affect our native vegetation, then I will feel amply 

 rewarded for the time bestowed upon their examination. 



NOTES ON THE GEOLOGY OF KING ISLAND. 



By a. G. Campbell. 



{Read before the Field Naturalists^ Cluh of Victoria, 9tli Feh., 1903.) 



In November, 1887, an expedition consisting of some twenty-six 

 members of this Club visited King Island, in Bass Strait, about 

 50 miles to the south of Cape Otway. The reports published in 

 the Victorian Naturalist of January, 1888, show that the only 

 regret was that more time could not be given to the geology of 

 the island. 



A few observations which I was able to make during a recent 

 visit, I trust will be of some service, not only from an economical 

 point of view, but also in making more complete the said reports 

 of the fifteen-year-ago expedition. 



Between then and now King Island has established itself in the 

 industries of cattle-rearing and dairy farming, and has become a 

 very valuable asset to Tasmania. The natural herbage and scrub 

 gave little promise of the soil's capacity to bear such magnificent 

 pasture as is now found throughout the length and breadih of the 

 island. It should, of course, be recognized that the governing 

 influence in the productiveness of any tract of country is just its 

 geological formation, plus the amount of that most essential thing, 

 rain or drainage water, with which it is blessed. Some 

 formations deliberately waste this magic substance, and no amount 

 of man's ingenuity can save sufficient to keep the surface soil 

 productive ; but, on the other hand, of all the areas where Nature 

 assists man by conserving the waters for him, it is doubtful if any 

 are so favoured as King Island. Here geology shows as plainly 

 as anywhere in the southern part of this continent its beneficent 

 connection with agriculture. 



Looking at a map of Bass Strait, it is seen that on the eastern 

 side a continuous chain of islets runs from Wilson Promontory 

 to the north-east point of Tasmania, and we believe that this is 

 all that now remains of a once existing land bridge between the 

 two. On the west islets again lead out from Tasmania as far as 

 King Island, but between there and the mainland at Cape Otway 

 is a deep strait, doubtless marking the place where the first 

 disruption in earlier geological times took place. 



All the islands, both 00 the east and on the west, are built of 

 the one class of material — igneous granitoid rock — (this fact is 

 strong evidence of their connection once upon a time). 



The base rock of King Island is no exception — it is granitoid, 



