401 
Fifteen miles from the Williams (on Fisher’s Creek waters), sandstones composed 
almost entirely of the fibrous shelly matter of Inoceramus are seen to rest on hardened 
black slates and Lydian stone. Indeed, in several places, notably near Marathon, 
I noted the presence of beds almost entirely composed of this fibrous material, sufficient 
to attest that this mollusc must have lived in almost incredible numbers. ^ 
I believe the strata above described, from AVongalee to Fisher s Creek, near 
Cloneurry, to form one continuous scries. They seem to form a large synclinal trough 
with an axis crossing the Flinders from east to west, somewhere in the neighbourhood 
of Marathon. At the heads of the Flinders the lowest beds do not mop out, as the 
tolling Downs Formation there overlaps the Palaeozoic and Metamorphic rocks of ^ e 
Dividing Kange, and arc covered by the Desert Sandstone and the basalts ot the table- 
land. To the west of Eichmond Downs, however, a gentle rise to the west brings up a 
series of strata which apparently occupy a lower horizon than those iii the centre of t e 
trou<rh. Fi-oin Hughendon to Marathon the strata consist for the most P^rt ot g ey 
shales with nodules of magnesian bmestone and grey and brown sandstones, which are 
occasionally calcareous and nodular. Hear Eichmond Downs, wlmre an easterly dip is 
for the first time, distinctly observable, the limestones assume a different character, and 
are distinguished by a prevalent cone-in-cone structure. Further west there are fewer 
shale beds and thicker and browner sandstones. The latter are extensively veined with 
gypsum, and I have been informed by squatters and others that Sc* of gypsum are 
frequently met with in sinking wells. The whole serines is fossiliferous.# 
A bed of gypsum, of workable thickness, and of great purity, occurs at Chollarton, 
near Collingwood. Specimens of this have been presented to the Geological Survey 
Collection by Mr. Julius von Berger. 
Tbe return iourney from the Transcontinental Eailway Expedition, from Clon- 
curry to Charters Towers, vid Cloneurry, Winton,and Eockwood (1881-2), afforded me 
opportunities of observing the Eolling Downs Formation on a course to the south ot 
that of the outward journey. „ , , r 
From Edington Station to the head of Eastern Creek scarcely a section of t 
strata was seen, although the shale cUhris and the markedfeaturcs of the Eolling Downs 
sufficiently attested the presence of the formation to which they give Gieir 
divide between the Gulf waters and those of the Great Australian Bight (Diamentina 
Eiver ?) was crossed imperceptibly, as it forms no “ range’’ whatever^ 
One and a-half miles down the Diamentina, from Kynoona Station, some grey 
and buff sandstones, cone-in-cone limestone, and grey shales were observed, ihe 
sandstones contained Echinus spines. if 
For the next twenty-five miles down the river, wherever the rock was visible it 
was found to be of grey or buff sandstone. Sometimes the ground was strewn with 
largo, not well-rounded pebbles of tough quartzite, occasionally incliniiig to 
and smaller and better-rounded pebbles of sandy-brown ironstone. These pebbles 
probably derived from the Desert Sandstone, cliffs of which are seen to the south 
For six miles up and five down the river, from Dagworth Old Station, sandstones 
with grey sandy shales prevail, and the sandstones get coarser in gram and greyer “ 
clouf Jtu ri,« i. follLa aown. A good doal of .iliemod wood .0 f 
lollti.doobtfol wl, other it 000,0 from the Eolling Down. Formation, or fiom the 
Desert Sandstone, which must have covered it. 
* Report by R. L. Jack on the Geological Features o part o Notes maL on'the 
posed Transcontinental Railway. Brisbane : by Authority : 1885 bupplemenrcu y 
Journey and hitherto unpublished. 
2 B 
