84 
tation on the plains usually shows no sign of any appreciable wear- 
ing down of the surface soil by wind erosion. 
TKATEKTIXn DEPOSITS. 
Turning to another feature of many of the lake plains, it does 
not appear to have attracted much notice hitherto that deposits of 
im])ure limestone are not uncommon in many of them. Usually it 
has the appearance of travertine, and where it has been described 
it seems often to have been somewhat hastily assumed to he formed 
by emanations of lime-bearing solutions from weathering of under- 
lying basic rocks. This may quite well be true in some cases, and 
the association of the closely allied magnesite dejiosits with basic 
rocks seems fairly well established in some of the occurrences of 
this mineral in this State, though there seem to be others in which 
no such association has yet been made out. Some of the largest 
travertine deposits seen by the writer, however, do not appear to 
be on basic rocks at all. so far as can be seen. On the south side 
of Lake Annean on the road to Cue, there is a large amount of 
this travertine, apparently on granite bedrock, and another exten- 
gi\'e occurrence is seen near Nallan, at a favourite picnic ground to 
the north of Cue, where the railway authorities have established a 
ballast ])it from which the travertine is extracted for ballasting the 
railway. Another large patch of similar limestone is passed over 
to the south-east of Quinn's, on the road to Erroll’s, in an area 
where the visible bedrock is mostly granite. Other occurrences 
are near Lake Aliranda and Lake Way. a short distance out from 
the margin of the iwesent salt-jians. Several other little patches of 
similar limestone have been found useful on the goldfields for 
burning for lime for cyaniding and building oj^erations. although 
the mineral is usually too impure to give good ([uicklimc. short 
distance out from Southern Cross on tlie road to Marvel Loch, 
there is a large amount of concretionary limestone, in sjdierical 
nodules from the size of i^eas up to that of cricket-balls, which 
was burned for lime in the earlier days of the Southern Cross Gold- 
field. These are on a (li{)ritic bedrock, but where the deposit 
occurs this rock croi)s out at surface in what appears to the eye to 
be a remarkably unweathered condition giving little support to the 
explanation that the carbonate of litne is derived from it. The 
position of the lime dei)osit is only a few feet above the plain of 
Lake lk)laris. and on the margin of it. 1’hc travertine deposits at 
the south end of the Causeway at Norseman are quite similar to 
most of those just mentioned — except for the spheroidal concre- 
tionary one at Southern Cross, which ap])cars to l)e dii'fcrcnt from 
the rest — and are found in patches for some distance up on the 
Norseman hill, and at first there was no reason to think that they 
were anything else then superficial travertines derived from the 
greenstone bedrock. l>ut the discovery l)y Mr. W. D. Campbell, 
of several species of marine fossils in these limestones, here much 
opalised. has thrown quite a new light u])on them. In this case 
