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Following this ridge further north, the Toora tin workings are seen. 
The visible section in the open face discloses 6 feet of red, yellow, and brown 
-clays with angular quartz gravels, under which lie 14 feet of white and 
yellowish-grey gravelly clays. The lowest portion of the workings was 
slabbed, and the deposits, 10 feet thick, therefore, not visible. 
A much more interesting section occurs in the Agnes River Tin Mine, 
on the ridge on the opposite side of the Agnes River. Here is shown a 
thickness of about 130 feet of Cainozoic deposits lying on brown felspathic 
Jurassic sandstones. 
The series, taken from top to bottom, gives approximate thicknesses of 
beds as follow :— 
Blue clays, yellow, white and grey fine and coarse quartz gravels, 50 feet; 
quartz conglomerate, ferruginous pebbly cement and yellow clay merging 
into blue in some places and sharply defined in others—very plastic in lower 
portion—3 feet; very plastic blue carbonaceous clay, 5 feet; yellowish-grey 
and fawn carbonaceous clays, some of them at the base approaching a brown 
coal, 25 feet. These clays show no stratification in section, but scale off in 
thin pieces on drying. Then come grey clays, getting micaceous and finely 
sandy, showing slight fissility, 10 feet; obscured deposits, 30 feet, lying on 
Jurassic sandstone. The sandy and gravelly beds are those principally con¬ 
taining the stream tin and other minerals. 
By going right down into the valley of Tin Greek, about 1^- miles from 
this mine, may be seen the Great Southern Tin Mine, where the following 
deposits can be traced downwards. The thickness of the*beds is approxi¬ 
mate :— 
Current-bedded yellow, white, and grey clays and gravels alternately, 
70 feet; sands and gravels, 20 feet; quartz pebbly drift, 2 feet; gravels, 
5 feet; conglomerate and ferruginous quartz drift, 1ft. Gin.; pink and white 
plastic clays, 20 feet. The lowest 30 feet of the coarser sediments are said 
to be the richest in stream tin, the overlying beds containing much less 
mineral. A bore put down by the company in these clays to a depth of 
190 feet showed—according to*Mr. Wilson—the same clays to about 70 feet ; 
it then passed into blue, yellow, and white “ pug,” 120 feet, when work was sus¬ 
pended. These clays in the bore and workings resemble those in the lowest 
portions of the Agnes River and Granite Bar Extended workings, and their 
position so much below those mentioned is an interesting feature and seems 
to lend support to the theory of a fault having taken place, with a S.W. 
bearing, approximating to the course of Tin Creek. Perhaps the boundaries 
of the Cainozoic deposits contiguous to the Jurassics,. and also the abrupt 
southern margin of the Jurassic hill country, represent lines of great faults 
during the Eocene period. 
This stanniferous series of deposits seems to have been laid down in a 
deeply eroded surface of Jurassic rocks, as pointed out* by Mr. R. A. F. 
Murray, F.G.S., andf Mr. Jas. Stirling. 
The rocks underlying these beds, both highest and lowest in altitude, are 
Jurassic sandstones. The origin, therefore, of the tourmaline and cassiterite 
is interesting, since the nearest tin-bearing plutonic rock known is that at 
Yanakie Isthmus, Wilson’s Promontory, 15 miles away in a direct line to 
the south-we r. Ail these carbonaceous deposits are probably lacustrine or 
estuarine, whde the overlying coarser ones may be of marine origin. 
:: Murray, Report on the Franklin and Agnes River Tin-field, Toora, South Gippsland. 
Quart. Kept. Dept, of Mines, Viet., Sept., 1890. 
t Stirling, Report on the Agnes River Tin-mining District. Quart. Rept. Dept, of 
Mines, Viet., Sept., 1888 ; Prog. Rept. Geol. Surv. Viet., No. VIII., 1894. 
