7 
the latter containing imprints of leaves, which, so far as the venation, form, margin, &c., bear a striking 
resemblance to types elsewhere referred to—the later cretaceous or early tertiary-eocene. (?) This resem¬ 
blance is not, however, a sufficient basis for establishing a definite geological horizon, as among the recent 
floras there are leaves whose form, venation, margin, &c., cannot he distinguished from such older tertiary 
types. 
Older Brown Coal. 
Although there are no outcrops of brown coal at Mirboo, yet it is improbable that such may be con¬ 
cealed beneath the wide-spread stretch of basalt in this locality. I have already drawn attention to their 
occurrence elsewhere, as at Thorpdale*, where they arc either contemporaneous or younger than the silicious 
conglomerates; also at Calignee,f Carrajung, and south of Yarragon.J 
While Pahnobotany has been considered insufficient for the determination of geological divisions 
among tertiary deposits, yet it has elsewhere proved of undoubted value as a guide. Lcsquereux has, in 
his Monograph on the Cretaceous Flora of Dakota group in the United States, offered some pregnant 
remarks on this point, as follows :—“. . . without the fossil leaves of Nebraska, the relation of the 
Dakota group, either to the Trias, the Jurassic, or the Cretaceous, would be still uncertain and subject to 
dispute, especially for the reason that the few animal remains recognised in the red sandstones of this 
group have been as yet too scant and of too little distinct characters to afford sufficient evidence on this 
point, &c. I am led to offer these remarks in consequence of recent contributions to Fakeoutology by such 
distinguished experts as Prof. Tate, F.G.S., of S.A., § Messrs. Dcnnant, Pritchard, and Hall, who have 
referred the molluscan fauna of the lower tertiary deposits which they have examined along' the Victorian 
coast and in several inland localities to the Eoeoue age, in contradistinction to the Palaeontological deter¬ 
minations of our nestor of Pakcomtologieal science, Sir F. McCoy, who recognises the deposits as Oligocene. 
And especially as a co-relation of the terrestrial tertiary deposits with the marine beds has been attempted 
by the youuger of the above observers. j| 
The quartzites and conglomerates are identical in lithological character with beds occurring along 
the northern valley of the Latrobe, as at Neerim (Frenchman’s Creek), Eaglehawk Creek, &c.,&c., covering 
large areas in the Tarwin valley, extending also from Cape Liptrap over the Silurian at Waratah to the 
Hoddlc ranges, so that they are extensively distributed. Hitherto they have been classed as Miocene. 
They appear to have undergone considerable erosion before the associated brown coals were deposited and 
the flows of basalt, known as the older volcanic, took place. 
An analysis of the carbon percentage of these coals would show them to be older than the more 
extensive beds near Morwcll, in the Latrobe valley, as follows :— 
Water. 
Yol. Hydro-carbon. 
Fixed Carbon. 
Ash. 
Thorpdale 
14-50 
31-87 
46-30 
6-36 
Calignee ... 
19-00 
28-70 
48-20 
4-10 
Carrajung 
25-09 
26-34 
45-27 
3-72 
Average ... 
19-53 
28-97 
46-59 
4-76 
The average of the Morwell Brown Coals giving (for 32 samples) 24'08, 34'66, 40T8, 2'79. 
The greatest recorded thickness of the silicious conglomerates and associated brown coal-beds does 
not exceed 200 feet. 
Older Basalt. 
The basalt classed aa older volcanic covers a considerable area. The bore at Mirboo disclosed a 
thickness of 214ft. 2in., separated by two beds of clay 12ft. lOin. thick, at a depth of 280ft. lin. from the 
surface • 
The structure varies from coarse to fine, but it is mainly that of an Olivene dolerite. It occurs at 
various elevations along the Strezlecki ranges up to 1,200 feet above sea level. At Mirboo it covers a 
flat depression in the watershed line, at an elovation of between 600 and 800 feet above sea level. 
This basalt has been hitherto classed as Miocene. 
Older Pliocene. (?) 
Overlying the basalt are ferruginous conglomerates, grits, sandy clays, clays, and lignite beds. 
Tho bore at Mirboo disclosed a thickness of such clays and drifts of 101 feet; but on the watershed line 
botween the Little Morwell River and Delburn Creek, to the west of Darlimurla, borings disclosed a depth 
of 280 feet with interbedded lignites. 
AtBoolarra, near the station, they attain a thickness of 800 feet, with 139 feet of lignite. This 
great thickness of tertiary deposits is probably due to a lowering of the area by faulting. These ferrug- 
rnous conglomerates, grits, and sandy clays are classed as older Pliocene, partly on the authority of the 
Government Botanist, who has determined some of the leaves and fruits to be similar to those of the Loddon 
valley. Yet in the absence of better material for examination than has yet been supplied, the above 
classification is merely provisional. 
The beds are distributed all round tho flanks of the Strezlecki ranges, from the Bass valley to the 
heads of the Lang Lang River, Bear Creek, Moe River, Narracan valley, Morewell and Traralgon, Flynn’s 
Creek and along the south-east flanks of the Hoddlc ranges to the Albert and Yarra River, ranging 
from 200 to 600 feet above sea level, but are also met with at still higher elevations along the watershed 
line between the Tar win and Latrobe. _ 
" Vide Specia!Eeport viotorianCoaI - flelds > p- 16 —§ r**> 
By Authority: Robt. S. Brain, Government Printer, Melbourne. 
