(’l.AUKE AXl) Wll. LIAMS. — Croloiiii of })(irlin(/ Haiif/r. 
Aira. wliicli orctijiif.s aluiUl () s(|iiai'i’ luilcs in a !ir(*a<l luirtioii 
of tiic IleliMta \’aik'v 10 tnih-s cast of Poilli and iiudiidns, or 
near, tlie most iiiii)oi'taiit (juan-ies, is the oiivious place in whieii 
to he^'in any examination of l);ii'!inj^' Ranj^'e j^'eolo^y. Next to 
the Helena, tin' ('annini*' and Swan \’alleys si-em likely to offii’ 
most infonnation of the kind laMjuired. One and a halt* s<jiiaie 
miles of the (’anniiiii' \'alh\v, the Roleystone Art'a, 18 miles B.E. 
ot I'ertli, have theiH'fore been examine<l, and a iK'g'inning' ha^ 
been ma<le on an area in the Swan \'alh'y. 
Both tlu' Roleystone and l)ai-liii,iiton Areas rc'ceive on the 
aveva^'e- about ■>(> inches of rain per annum, and in their natural 
state were coverml with forest consistino- mainly of Jarrah {Kuca- 
hijitu.‘< uttfi'f/iiKila) and Marri (/A cdlojih i/IUi ) . IMncli of the Roley- 
sUme area has been (dt'ai't'd and cultivat-nl (lii>'. 1), The narlinj>'to i 
Area (Platt* XXI) has lost most of its lai\ii’e trees l)v (ire ami 
felling', but only a small portion is cultivated. 
1— The valley of Slal) Gully (Teek, a typical view in 
the Koleystoiie Area. 
Both areas have been subdivided by accurate surveys made 
for the j)ur[)ose of sale, etc., into Itlocks of a tew acres. Iht'se 
l)!ocks Avere ]i!otted on our working' i)laiis and were used as a 
basis for geological and topograiuiical mapping which was dtme 
either by paeiiig, by chaining, or ity tacheonietry. The form-lines 
were determined mainly by aneroid, corrected either by com- 
