Crktackuus iSTiiAXiCiRAPiiY OF LowFil ^luiiCHiaojs UiVFR Aufa, 
W'estehn Austraeia. 
21 
ill aub.sequeiil years the junior author frequently crosi^ed this same aixa 
by aeroiilane; the senior auiiiur liiul already seen it frtiin the air in 1927. 
i’rom these observations it was clear tliat the h)wer sandstones which could 
be seen outcroiiiiing all along the boltoni and the sides of the Aliu’chison 
Ki^er \‘alley were overhiiu by a series of whitish rocks which formed an 
escarj.ment a few miles noiih of the river and more or less |>aralled to it. 
These white dill's extended inland at least as far as the l(*leg‘raph linCj more 
than 10 mih's iqir^tream from the coast, and since Sinqjson's discovery of 
dialk in th(‘ vicinity ol' Alurdiison llous(‘ I!oine?^tead the conviction grew 
that llu'se dill's in their entirety were nioie tir less composed ttf the same 
kind of rock. 
In ^lardi lil-ld the IJriti.'h ITiosj.hate Commissioners de<*idcd to in\'esli- 
gate in somewhat greatcu’ detail the phosphate occiii-rences described by 
Siinjison and the junior author was fortunate enougli to be invited to ac- 
company the dovernment (Jeologi>t td' Westein Australia, Mr. F. (I. Forman, 
and th(‘ repi'esentati ve of tin* Hiltish ITiosphate Commissioners, Mi’. J. C. 
Dulfer, on an exiiloi'atory trip which took jdace in March of that year. The 
approach to the sedimentary area was made iVom the east, entering the 
<'Ountry from the Xorthamplon-Caiuarvon road, but very bad conditions 
were encountered and it was only with dil'Iicidty that tin* party readied the 
telegraph line at a small, now abandoned, (‘mergtuiey aerodronu', four miles 
north of Bettie, where* the lelegratih line crosses the river. It was soon found 
that the country was virtually impas>ahle I'or nuflor cars and since the (larty 
Avas not e(|uipiK‘d for any other form of transport its radius of acti\'ity 
Avas small and tin* results ol' tlie triji limited. However, the country along 
the telegraph liiu* AA'as (examined in some detail from the river Innl as far 
as the Avliite clilTs in lln* vicinity of the aerodrome, more than four miles 
from the river. Tin* lower samlstoncs wen* found to be strongly evoss- 
beddt'd and the cliff s(*clion was found to consist of glauconitic sands, glau- 
conitic shales and siliceous shales, ovei'lain liy chalk which contained a 
typical Tapper (h-etaceous (Siuionian) fauna, including Vintavrivnfi and 
Marsnpifesi. identical Avilh the AA*ell-knoAvn chalk fauna of Cingin, 280 miles 
to the south. Tn addition, several localities up to a distance of about 20 
miles east of the telograpli line were examined, especially the vicinity of 
Weerinoogudda Dam, the upper ])art of Bungnbandy Ch-eek, and the country 
as far as Warranjabahlja Spring. 
2. lOn-'.SKNT I XVFSTICATIONS. 
Tn August, 1944, Ave Avere enabled to visit the T.oAver ]^rurchison River 
.\rea and, hi tlu* sixteen days at our disposal, Ave tried to obtain a general 
jiiotiire of the geology of the main valley and its tributaries from the 
coast to a little Imyond tlie (leraldton-Farnarvon telegraph line. AVe 
also suw' sonudliing ol the coastliiu* irom the mouth of the ii\er to a 
lioint about ten miles farther north. 
This Avork was made possible by an invitation from Messrs, lluliert 
Evans and A. J. Sims of Evans. MaAvley and Sims Avho provided motor 
transport from Northampton to Murchison House homestead, a distance 
of seventy-two miles and, 'on the I’cinrn journey, from the Inmiestead to 
(Jeraldton, a distance of more than one hundred miles. Hu amval at 
the honn'-^tead a native jniide, ami riding ami ])ack liorses Averc placed 
at onr disposal I’m* tlie entln* dural ion of our stay. The first week Avas 
spent in camp at Buhu Avimlinill Avith Mr. Tom Pepper and his family 
