40 
Geology and Physical Geography: 
CHAPTER Y. 
Middle and Upper Palaeozoic Rocks. Snowy River Por- 
phyries — character and origin; scenery. Middle Devonian 
Rocks — limestones, fossils; Bind! and Buchan limestones; 
igneous beds of the Buchan group; Mr. A. W. Howitt's 
remarks ; character of Devonian limestone country. The 
Tabberabbera Middle Devonian Rocks. Upper Palceozoic 
Rocks. The Grampian Sandstones. The Avon and 
Macalister Rocks ; the Mansfield beds ; the Mount Tarnbo 
beds. Conglomerate of Wild-duck Creek. 
Middle and Upper Palaeozoic Rocks. 
In this group are included — (1) Certain igneous rocks occur- 
ring in Gippsland, and known as the Snowy River porphyries ; 
(2) Limestone and other rocks occurring in various localities, and 
shown on palamutological evidence to be of Middle Devonian age ; 
(3) A series of conglomerates, sandstones, shales, and contem- 
poraneous trappenn rocks, some of which can be referred to the 
Upper Devonian period, and others, though also provisionally 
classed as such, may bo of later date. 
In describing these three groups of rock, I avail myself largely 
of the information given by Mr. A. W. Howitt, in his contributions 
to the Geological Progress Reports (No. III., pages 189 to 249, 
and No. V., pages 117 to 129), and simply give a general synopsis 
of that gentleman’s observations and conclusions, though 1 have 
had the pleasure of personally examining, in his company, much 
of the country described. 
The Snowy River porphyries constitute a belt which passes into 
Victoria from Now South Wales, and occupies at the boundary 
line a breadth of nearly 20 miles, extending between the head 
of the Murray, near Forest Hill, and a little to the east of the 
Snowy River. The western boundary of the belt includes the 
Cobberas, and runs south to near the head of Lake Tyers. The 
eastern boundary runs southward, keeping parallel with, and 
slightly eastward of, the Snowy River ; and the porphyries con- 
stituting the belt extend down to and disappear under tlio Ter- 
tiary deposits which border the coast on either side of the Snowy 
River mouth. 
The rocks to the east and west of the belt consist of granite, 
“ regional,” metamorphic schists, and Silurian rocks. The 
main portion of the belt forms a mountainous plateau, lying 
between the Snowy River and its western tributary, the Buchan ; 
and this plateau has a general slope, from an elevation of from 
4,000 to 6,000 feet, near the Cobberas, to a level of about 1,000 
feet above the sea, near the margin of the marine Tertiaries under 
which the porphyries disappear near the coast line. 
