
SECONDARY OR MESOZOIC ROCKS. 49 
SECONDARY OR MESOZOIC PERIOD. 

All the known coal-bearing rocks of Victoria belong to this period. 
They extend over an area of about 4,000 square miles, in three 
districts, viz. :— 
Western Port to Cape Patterson, Welshpool and the Miles. 
La Trobe River near Traralgon ees soo Ial 
The Gellibrand Riyer and Cape Otway to the Barrabool 
Hills and Indented Heads ie ats .- 1,882 
The junction of the Wannon and Glenelg, and neighbor- 
hood of Casterton, Digby, Merino and Coleraine ... 349 
They are represented on the Geological Sketch Map of the Colony 
by a brown tint, and numbered 7. $ 
Plant remains of numerous genera and species have been found in 
them. A new species of Unio ( Unio Dacombii—McCoy) is the only 
fossil animal yet discovered. Coal and freestone are the only minerals 
known, as occurring in quantity-sufficient to be economically valuable. 
The coal seams are for the most part, although of good quality, too thin 
to be profitably worked. With the exception of those near Cape Patter- 
son, none have been discovered that would yield as much as 20 inches 
of good coal, and these generally occur in very inaccessible positions. 
Basalt and other forms of volcanic rock are the only igneous rocks 
associated with the Carbonaceous strata. Cale-spar frequently occurs, 
as veins, in the joints and fissures of the rock. The formation docs not 
upparently contain any metallic minerals, except iron in the form of 
carbonate (clay iron-ore) and oxide; but neither occur in sufficient 
quantity to be of economic value. i 
The coal rocks probably extend eastward, under a great part of the 
Gippsland plains, south of a line drawn from near Hayfield to Lake 
Wellington, but cannot be seen on the surface, being thickly overlaid, 
as at Bellarine and Queenscliff, by Tertiary rocks and recent alluvial 
deposits. = 
The specimens represent the general lithological character of the 
formation. 
