Sept, i, 1885.] The Australasian Scie?itific Magazine . 53 
Granite and Metamorphic Rocks . — At the old Parara mine, mica, schist, 
hornblende, and quartz-rose rocks, with quartz-veins, penetrated by dykes 
of greenstone and coarse granite, appear over a small area. Southward, 
along the coast of Muloowurtie, pink granulite with silicious limestone and 
hornblendic rocks, with ferruginous lode formations containing copper, are 
exposed. 
Copper has been mined for at several places. 
From Point Yorke round the coast to near Point Turton, granite, 
gneissic granite, gneiss, hornblende, and silicions rocks, greenstone and 
granite dykes, form the base of the chief headlands and points such as 
Cape Spencer, West Cape, Daly Head, etc. 
At Port Victoria also are crystalline beds of silicious and hornblendic 
rock with granulate, and granite dykes ; silicious, feldspathic, and gneissic 
micaceous rocks, and a massive dyke of greenstone, diorite, hornblende rock 
and syneite. 
Northward, along the coast at Wallaroo and Moonta, I have noticed 
previously out-crops of similar rocks. 
Near Maitland there are dykes of graphic and ordinary granite in meta- 
morphic grit. 
The foundation of the whole Peninsula may be, therefore, inferred to be 
granite and metamorphic rocks, with their accompanying dykes, uncom- 
fortably on which rest inclined beds of conglomerate, grit, and sandstone, 
and crystalline and silicious limestone of Palaeozoic age. The principal 
outcrops of the latter are in the neighbourhood of Ardrossan and Curra- 
mulka ; they are also visible on the coast of Muloowurtie, near Port 
Vincent, and, near Maitland and Moonta. They may, however, be 
expected to underlie the tertiary formations over a considerable area. 
At Curramulka, the crystalline limestone is extensively hollowed out 
into caves, which are caused by the action of the water acting originally on 
fissures in the strata, which caves, could they be followed down, would lead 
no doubt to the discovery of still larger caves containing large accumula- 
tions of water. 
This limestone is a continuation southwards of that forming the base of 
the South Hummocks Range, and is most probably connected with that on 
the east side of Spencer’s Gulf. 
Limestone, when in continuing masses, as it is well known, affords good 
storage space for water on account of its cavernous character, and owing 
to the fact that it dissolves in water. The extensive distribution of traver- 
tine limestone over the greater portion of the area, which I take to be 
deposited from springs, indicates that an immense quantity of carbonate of 
lime has been removed by solution from the rocks below, leaving large 
spaces to be filled with the water which is constantly passing from higher 
ranges to the sea. 
Tertiary and Recent Formations. — Horizontal beds of tertiary age con- 
sisting of limestone, loam, mottled sandy clay, sandstone, shell, nodular 
and conglomeritic limestone, and calacreous sandstone, etc., on the coast, 
and limestone, loam, clay, gravel, and sand-drift filling up the valleys of 
the higher land, form a covering of varying thickness to the rocks previously 
described. 
These beds fill up the basins on the eroded surface of the older rocks, 
whether formed by the sea or from rivers ; and it is in the porous beds of sand 
or gravel intervening between impervious beds of clay that water is likely 
to be met with, by boring, at a pressure sufficient to bring it to the surface. 
