Upper Palaeozoic Pocks. 
51 
Creek, the eastern branch of the Freestone, winding thence round 
the south of Yellowman's Nob, on the Crooked River road, and 
thence northward to Tabberabbera at the junction of the Mitchell 
and Wentworth Rivers. 
The southern boundary is, as before stated, formed by the 
flanking Tertiary deposits as far as Iguana Creek. The Mitchell 
River itself flows approximately along the line of junction of the 
Tertiariesand the Upper Palaeozoic rocks, forming the south-western 
boundary of the latter from Iguana Creek to near Bairnsdale, 
whence their north-eastern margin or line of contact with the 
Silurian rocks runs north-westerly to Tabberabbera. From near 
Tabberabbera to Iguana Creek, the Mitchell runs between cliffs 
of the rocks of the Iguana Creeks groups. 
Outside the eastern margin of the main mass, Mount Taylor, 
whose base consists of porphyritic granites, and several other hills, 
are capped with outliers of these Upper Devonian rocks. The 
term “ Iguana Creek beds ” was adopted, and the reference of the 
rocks to the Upper Devonian period determined, because charac- 
teristic fossil plant-impressions were found in the shales interca- 
lated with the sandstones and conglomerates, which form lofty 
cliffs on either side of Iguana Creek, above its junction with the 
Mitchell. The fossil plant-impressions from here which have been 
determined, figured, and described by Professor McCoy, are as 
follows : — Cord (rites Australis (McCoy), Archccopteris Howitti 
(McCoy) — allied to the Canadian Upper Devonian, A. Jackso?ii , 
and to the A . Hibernica of the Upper Devonian of Kilkenny 
and Berwickshire, and Sphenopteris ( Eremopteris ) Iyuaiiciisis 
(McCoy), somewhat differing from, but apparently most nearly 
allied to, the Sphejiopteris Artemesifolia of the Lower Carboni- 
ferous rocks of Northumberland. 
In an interesting account of a canoe voyage down the Mitchell 
from Tabberabbera (Geological Progress Report, No. III., page 
214 and following), Mr. A. W. Howitt describes the nearly vertical 
Middle Devonian rocks, exposed in the river gorge, as being over- 
laid by very slightly dipping Upper Devonian beds of the Iguana 
Creek group, which, as the river is followed down, gradually slope 
down to its bed, the older rocks passing out of sight beneath. The 
lowest beds of the Upper Devonian group, observed here, appear 
to be bedded felstones, over which lie conglomerates and sand- 
stones, fine and coarse siliceous conglomerates, quart zose sand- 
stones, with pebble bands, gritty flags, and reddish sandstones. 
(Fig. 13.) 
