3 
15. Bimbowrie woolshed.—Well, in micaceous schist. 
16. Near Boolcooraatta station.—Well, in quartzose sand.stone, at a deserted mine, close to an outcrop 
of rock, stained with copper carbonates; good water. 
17. Oonatra.—Well, 18ft. to water, in granite (under .alluvium) which outcrops lower down the 
creek and forms a bar across it which probably acts as a dam. 
Tha-CKA-Rixga to Yaxda.u.v Cueek via Mooletjeooloo IIii.ls. 
From Thackaringa, close to which place the motamorphic rocks lie near the surface, and after crossing 
the border, the low undulating downs and plains of granite and metamorphic rocks dip under plains of soft 
loam with basin-shaped depressions, containing line silt pierced with cracks and holes. These plains continue 
to the Moolculooloo Hills, where the metamorphi(! clay slates and sandstones agiiin come to the surface and 
rise to an elevation of about 200ft. above the plain. These ])laius are chiefly composed of red loam and siind, 
with soft silt depressions, clay puns or hard dejjresscd floors, and dry lakes. Further north these depressions 
become deeper, and the sand ridges commence: they have a general noith-eastcrly trend, and arc very regular 
in their occurrence from here to Yandama Creek ; the}' are composed of loose red sand, and v.ary in height 
from 30ft. to 50ft., and are ])laeed in roughly parallel rows at distances of from a few chains to a quarter of 
a mile apart, being scijarated by long reaches of clay and silt Hats. Outcrojis of jointed sandstone and 
calcareous giit. apparently horizontal, were obsex'ved at one or two jilaces only. On the .surface of the hard 
claypans, as well as on the soft friable silt flats or dry lakes, there are freciucntly scattered more or less 
waterworn stones of a yellow flinty rock, ferruginous sandstone, and small pebbles of many kinds of qnurtz. 
The whole of the country from Mount .John and the, Moolculooloo Hills, and the neighboring ranges, north¬ 
ward to the (iueensland boundary, in latitude 26'^, and westward to the Diamcntina river, and probably far 
beyond it, and between the (Bicen.sland and New .South Wales boundar}' and the Flinders Ihinge, belongs to 
one vast formation, which, by the fo.ssils found in it, has been determined to belong to the Cretaceous period. 
Fossils lately brought from jiear C'ootanoorima in the neighborhood of the Peake, by Mr. Chambers, prove the 
same formation to e.Ktend wostwfird into that country. 
The Cretaceous and Tertiary Rocks .—The above-described area occupies a low-lying position, not far 
above the general level of the sea; it is therefore not often that there is an opportunity of studying the 
composition of the material, or obtaining fossils. Most of the fossils found have been obtained from wells 
in Queensland and New South Wales. The strata consists of brittle clays and calcareous shales, with bands 
of limestone and gyjisum, clay, ironstone, and ferruginous sandstone, and sandy beds ; they are, as a rule, 
irenerallv horizontal or gently undulating, and have a thickness, so far as at present known, of 300ft. to -lOOft. 
Overlvinjt this formation are beds of sandstone, argillaceous sandstone, kaolin, grit, and pebble conglomerate, 
formin'^ table-lands and hills almost invariably capped by a thin bed of yellow and red flinty quartzite or 
iasiwr rock, the total thickness varying from lOOft. to 200ft. The jjcbblcsfound in this cougiomeratc consist 
of a'mte, jaspar, calccdony, opal and colored ipiartz, flint, white and crystallized ([uartz, and fossil wood, 
shouang a' brilliant polish or gbize. The conqjosition of these supercrctaceous beds is the same over ^yide 
areas from the Wanago river in New So\ith Wales to the Diamcntina. The topmost bed of yellow flinty 
quartzite or porcclainised windstone, which forms the capping of the tjibleland formation, varies in thickness 
from 10ft. to 30ft.; it has a concoidal fracture, and .sometimes shows an amorphus stnicture, at others 
encloses grains of sand or quartz pebbles (often coated by hyalite and op.alline q\iartz), in which case it may 
be considered a conglomerate. It also occurs as rounded mas-ses and pebbles of yellow flinty rock, cemented 
too-cther into a rough conglomerate. This porcclainised rock is intensely hard, and its particles are .at a 
tension ; the most common appearance it presents Ls that of hard red or yellow bordders fitting close together, 
snlintered, cracked, and jointed into rounded and roughly prismatic shapes; it lies in ])atches on the 
ai'o'illaccous sandstones and clays, forming in some places a mere coating, in others a deposit of 30ft. or 40ft. 
tluck.' Large and small cellular boulders and slag-likc masses, with hollow stalactitic forms, are often found. 
Whether in”nasscs or pebbles the rock is invariably glazed, so as to present a shining red or yellow surf.ace. 
The most likely theory that can be advanced to account for the formation and glazed surface of this rock is 
that it has beeii formed by the infiltration of .siliceous water from hot .springs into beds of loose sand or porous 
s.andstone, the stalactite-like forms of some of the specimens from Cooper’s Creek, the occurrence of siliceous 
cores round neuclci of cemented sand in loose sand and fragments of quartzite cemented together by silica 
seem to prove this. The downs which flank the table-lands and hills are nndulating and level plains, covered 
as a rule with a pavemcnt-llko coating of blocks and pebbles, or a red and yellow glazed porcelainiscd qu.artzite 
and flinty rock resting on soft yellow and reddi.^h clayey loam ; the glazing of these stones is also probably 
due to the action of siliceous water. The table-lands and hills composed of these supercrctaceous rocks are 
elevated to a height of some 100ft. to 250ft. above the level of the surrounding plains; though generally 
horizontJil, they are sometimes inclined at a low angle. On the Nilpie Nilpic Creek, the flinty quartzite forms 
stcei) bhitfs, and also occui)ies the creek flat below, and undidatcs bencatb the soft silt flats. 
In the same neighborliood there are some jointed claystones, red sandstones, and coiiglomerate showing 
in the bed of the creek, which appear to belong to an older formation, perhaps Devonian. The greatest 
elevation of these rocks here above sea level is from 400ft. to 5()()ft. As the elevation of the Creticeous and 
•crlvin"' formation here is greater than anywhere else in the district it is to be expected that older formations 
The Grey lianges of New South Wales and 
branches off castw 
Kcrtietia Hill, being some of the chief points of elevation. 
Oucen.sl.aiid belong to the same formation. ri*i i 
^ Overlying the Cretaceous .and superincumbent hard rocks arc depo.sits of loose and consolidated clay, 
1 n silt and sand, o-ypsum, limestone, See., all of Tertiary' and recent age. 
° * What are known as claypans, arc hard areas of clayey sand, generally circular or elliptical, surrounded 
snnrl either in rid<>-es and hills or in level plains, occurring all over the Cretaceous country. Clay and silt 
Ante also hounded by sand ridges, are as well common over large areas. The clay flats arc hard, while the 
Tt iilaius and flats are of a soft friable character and traversed by fissures and holes, caused by the sinking 
of the irround through the dissolution of liniestone below. 
Strewed over the surface of many of the plains and flat areas lie fragments of gravel, ferruginous 
1 \ p and ouartzite with agates, calcedony, and other pebbles derived from the hable-hill formation, which 
san s m . * ^ these beds beneath the surface at no great depth. Limestone, in rounded and stalactitic 
lhapes, also exists under similar conditions. 
No- 146. 
