Page:Quarterly Journal of the Geological Society of London, vol. 35.djvu/29

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GEOLOGY OF NORTH GIPPSLAND, VICTORIA.
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If these notes are thought worthy of any consideration by geologists, I shall feel that I am amply rewarded for any labour I may have undergone, and that the many days of wanderings and solitary encampment by night among the rugged mountains and precipitous denies of the Australian Alps have not been in vain.

General Consideration of the District.

The district to be considered may be described as being all that part of North Gippsland lying eastward of the Macallister River, and also that part of the Omeo country between the Great Dividing Range and a line drawn from Mount Gibbs to Mount Hotham.

It is approximately 130 miles in length by 80 miles in width, or about 10,400 square miles in area.

It is divided into two unequal portions by the Great Dividing Range. This mountain-chain has a general trend to N. 60° E. and S. 60° W., and conforms to the outline of the coast. It is not, however, continuous in this course throughout; from Forest Hill to Mount Phipps it follows this direction, as also from Mount Hotham to Mount Howitt; but the intermediate portion lies at right angles. From Mount Phipps the general direction of the Dividing Range is continued by a line of mountains, such as Mount Birregun, Castle Hill, and Mount Wellington, through which the rivers have cut their course southward. From Mount Hotham the line of direction is similarly continued north-easterly by the Bogong Mountains and Mount Gibbs to Mount Kosciusko, which is on the Dividing Range, and the highest known mountain in Australia[1]. On this line also the Mitta Mitta and the Limestone Rivers have cut a passage through the highlands and flow to the north[2].

The Great Dividing Range, with the two extensions just noted, may be said to define the north and south limits of an extensive plateau, averaging a hundred miles in length with a width of twenty-five miles. The drainage of the north-eastern moiety falls into the river Murray, and that of the south-western moiety into the rivers flowing into the Gippsland lakes.

The transverse part of the Great Dividing Range, which thus separates the two halves of what may be called the Omeo plateau, extends from Mount Phipps to Mount Hotham. It is comparatively low in elevation; it falls suddenly into the Dargo River to the west, but has a gentle slope on the east towards Omeo.

The average elevation of the Omeo plateau is probably not less than 3000 feet above the sea-level; the highest point rises to 6508 feet in Mount Bogong; and the lowest level is found in the Omeo

  1. The heights of these mountains above the sea-level, as determined by the Geodetic Survey of Victoria, are as follows:—Mount Hotham 6100 feet, Mount Howitt 5715 feet, Castle Hill 4860 feet, Mount Wellington 5363 feet, Mount Kosciusko 7256 feet, and Mount Bogong (the highest mountain in Victoria) 6508 feet.
  2. The Limestone River, also called the Indi, is one of the sources of the river Murray.