20 
A. GIBB MAITLAND, F.G.S. ! 
ridge of limestone trending generally north and south, and 
dipping to the westward at alow angle. Lower down the 
south branch of the river in the vicinity of Traverse Stations 
64 and 65 the glacial conglomerate appears in very great force. 
The debris of the conglomerate which strews the surface 
consists of a heterogeneous collection of all varieties of 
crystalline rocks, some of which are markedly glaciated. 
Much further down the Minilya River, near Traverse Station 
K66, are fossiliferous limestones, which dip at low angles 
to the westward (Figs. 7 and 8, Plate VI). These limestones 
have yielded Cleiothyris Macleayana, Eth. hi. Beneath these 
limestones the glacial boulder bed may be seen in many 
localities, where its presence can be readily detected owing 
to its weathered debris (Fig. 9, Plate VII). 
The Glacial Conglomerate in the Lyndon Valley. 
While engaged on the Yanarie River in 1907, op- 
portunity was taken to visit the upper portions of the Lyndon 
River for the purpose of examining the basal beds of the 
Permo-Carboniferous Rocks, the existence of which had $ 
been reported by my colleague, Mr. H. P. Woodward, in || 
the previous year. What is believed to be the base of the ~ 
Permo-Carboniferous formation is to be seen some distance to ^ 
the southward of Tower House, on the Yanarie River, and c 
consists of a quasi-vitreous conglomerate lying practically 
horizontally upon granite. The only available water at the x 
time I visited the Lyndon River was at Windalia Pool, 
where the strata exposed consisted of horizontal beds of ^ 
fine grained clayey sandstone. * 
A horseback traverse was made to what is shown on j 
all the maps as Tchugareywurdoo Pool, in the vicinity of — 
which a boulder bed associated with limestone had previously 
been noted. This boulder bed and its debris covers a 
fairly wide expanse of country, and the boulders consist 
of a very great variety of rocks, many of them being covered 
with glacial striae. Wherever this bed was exposed it was 
found to be in every way identical with that on the Gascoyne, 
etc., and to which reference has already been made. Its 
stratigraphical position beneath the fossiliferous limestone 
shows it to be upon the same geological horizon as the 
glacial conglomerate of the Arthur and the Minilya Rivers. 
From Windalia exigencies of travel took me some miles to 
the southward as far as the dam on Kialawibri Creek, 
where it is crossed by the road from Maud’s Landing. 
Though no section showing the glacial conglomerate in situ 
was met with, nevertheless its weathered debris was fre- 
quently exposed en route. The section at Tchugareywurdoo 
Pool marks the most northerly extension of the glacial 
conglomerate yet proved in Western Australia. 
