4 
Sandhills and ridges cover a large portion of the Cretaceous country. They extend in long ridges with 
accompanying mounds in more or less parallel lines, in patches, isolated hills and ridges, and undulating plains 
for miles across country, covering up the surface. The sand is usually brick red above, and grey and yellow 
below, and very fine grained. The fine red sand con.stit\iting the upper jiortions of the ridges is loose and 
shows no sign of stratification; the grey semi-consolidated sand and .siindy clay at the base shows a roughly 
horizontal stratification. 
Along the sandhill couutrj' between Innamincka and Iladdon station there arc isolated red and yellow 
sandhills and ridges at some distance from the main body. 'I'he same can be noticed on the Cooper and 
Diamentina at inteiwals along the courses of the river flats. The prevailing strike or bearing of these ridges 
in the northern portions of the territory which they cover is about X.X.'W. and X.W., while southward and 
to the east of tlic Flinders Range it is X.X.E. and X.E. 
In cro.ssing the country from the castcni honndarj- to the Diamentina, sandhill country is met with at 
intervals the whole distance; somelime.s the ridges are close together, at other times separated by spaces of 
stony desert or plain a mile or more in width, but always keeping a general parallel course. They 
rest indiscriminately on the clay flats .and plains or the stony downs, their elevation above these varying 
from 10 to 70 or 80 feet, and width from 100 to 200 vards at the base. There is no evidence of the sand 
having been blomi along the surface, or transported from a distance by water flowing over the surface 
of the ground, Avhich is. as a rule, quite clear of .sand between the hills. I have reason to bclier-e that in 
many cases, particularly in those of the isolate<l ridges and mounds traversing the stony desert at long dis¬ 
tances a])art, the sand has been derived from an underground source through the pressure of .subterranean 
AA-atcr. 'lliere Avas in all probability an outlet at one time connectin*' the old Cretaceous sea Avhich oceuijied the 
centre of Australia Avith the ocean. If avo suppose a sudden or 'gradual closing up of this outlet to have 
taken place through the subsidence of the lan<l, or any other cause, the Avater not having any vent to escape 
b}-, Avould accumulate in the jAorous strata until under sufficient pressure to force its Avay to the surface along 
cracks or throAigh holes caused by such pressure, and bring Avith it the .sand, in a similar m.mncr to the 
present mud and sand springs. The eruption of sand in barge ([uantities Avould cause a subsidence of the 
surroimding area, Avhereof there is BA'idence in the valleys of the Cooper .and Diamentina. and thus har-e 
created the great bakes into Avhich these riA-ers iioav Aoaa-. About thirty-five miles south-east of Clifton Hill 
station, on the Diamentina, there are tAvo ])arallel red sand ridges tr.aver.sing a stony plain in a north-north- 
AA^esterly direction ; the plain is covered Avith a pavement-like coating of flinty (piartzitc stones. On the east 
side blocks and boulders of the same rock are scattered about, amongst Avhieh arc numerous Ioav circular 
moimds of AA'hite clayey sand, the centres of Avhich are foianed of blocks of stones piled up, which are 
encircled bj- other smaller blocks, and these by scattered stones, the Avhole bearing the apjtearance of lumng 
been erupted by springs from beloAV. At numerous other places similar ajjpearances present themselves ; 
mounds of sand, gravel, and clay, ajul scattered stones occurring on the surface of many of the plains and flat 
areas, the presence of AA'hich it is difficult to accoAint for in any other Av.ay, as there are no rocks at a higher 
lev cl in the neighborhood from Avhich the sjuid or gruA'cl could liaA'c been Avashed. On the top and sides of 
several of the sandhills, also, pieces of crj-stalline limestone and blocks of (juartzite Avere seen embedded in the 
sand. Previously to the deposition of the s,and, by AA-hatever cause, the region covered bj- it Avas probably a 
plain or .shalloAv lake. At present there are many lakes connected together by natural canals or creeks Avhich 
receive the overfloAv from the riA'era, the general level of the country being so nearly alike that Avater coming 
doAvii the Cooper to Innamincka Avhen in flood may Aoav soutliAv.ard into Lakes Blanche and Frome, south- 
Avesfrrly into Lake Ej re, and iiorthAvard into Lake Goyder and the other lakes near it. The flood Avaters of 
the Cooper and Wilson flow back up the Wan-y \\'arrv and other creeks, causing the Avaterholes in them for 
long distances ^ be filled by Avater running in a contrary direction to the fall of the creeks, Avhich 
is very shght- Inese creeks are therefore supplied by Avatcr coming both from the hills aboA-e their 
sources and from their outlets Ihe creeks rising in the t.able-land range floAv through the stony doAA-ns and 
into s<andhill country, through Avliieh they pass in the form of flats with occasional Avaterholes, which are 
filled during flood time. On the deposition of the sand, some of the creek courses must have been covered 
up, in AA him case the existence of sanded up Ai-aterholes and lakes may be inferred beneath the sandhill 
country. Beds of salt and gypsum underlie the surface of some of the dry lakes, claA'pans, and .sand plains, 
and represent tlm ancient Imds of lakes Avhich have been covered up. In the neighborhood of Monti Caillinti 
station oil the Strzelecki Creek and soutlnvards the sand ridges are Ioav and of a yellowish grey color, and 
merge into undulating country of plains without sand. 
Along 
Blancheavatek to Beltana. 
1 1 X-borders of the Flinders Range, betAvecn Blancheivater and Mullig.an Siirings, the soft 
un 11 a ing, oamj c aj is spread over Avith a coating of graA’el and rock fragments, consisting of quarzitc 
sandstone, slate, quartz, &c., derived from the range, and flinty quartzite from the table liillt Inclined 
tab e hi so conglomerate, made up of similar material, Avith quartzite boulders and indurated claystone, 
resting on grej^yclloAV kaolinised and sandy slates, make their appe.Trance here. Near Freeling Water, on 
e c onne Creek, the older rocks rise aboA-e the pLains, .os kaolinised clay slates and limestone, Avith 
numerous quartz ree s and '''Cms. Near this junction are boulders and gniA-ei detritus, which point to the 
existence of a conglomerate bed between the older slaty rocks and the horizontal depo.sits of the plain. 
The clay slates and mctamorphic randstones here are highly cleaved and jointed, by Avhich means the 
beading has been obliterated in many places. Ihese continue to Piiidclpana Creek, and are overlaid by beds 
containing quartzose and calcareous bands and limestone, Avith many quarz veins. West of PindelpaAa the 
roa passes over plains and flat countrj’ of gravel and conglomerate, underlaid by flaggv limestones. Flinty 
quartzites isolated cappings and table hills are to he seen in the vicinity of Yerelina Creek; thence to 
.md m-ar Beltana. The only igneous rock observed was a greenstone dyke near Leigh Creek. 
Quartz in veins and reefs, oxide of iron, and ferruginous sandstone, quartzite and limestone outcrops, 
and Igneous and p-anitic dykes indicate the presence of mineral lodes in the localities in which they occur. 
From Freeling Water to Beltana, and thence to riiackaringa. the ranges crossed tn route show frequent 
evidences of the existence of such. i 
rnetamn^nf ■ “‘“I® of the older calcareous, slaty, and 
metamorphic rocks met Avith are of a character likely to be mineral bearing. Near Thackaringa, in meta- 
morphic 
