226 
Maitland. — Australian Geology. 
nnst ami |trescnt gi'oloo'ienl history is to 1 h' looked foi-, Aerord- 
iiyL;' to tli(‘ eoiitim-iil al disphieoment hy])othosis, tlu* Indian Ooean 
has Ikhmi formed j^railually l>y Australia hecomiiio' detaidied from 
Afiiea and wauderiiu’' slowly to tlie eastward. This iin])lies a 
horizontal inslahility of coiitimmtal laud-masses ‘whieli has an im- 
]»ortant hian'ine- on tlie (juestion of the pernianeney of oeean basins, 
about whieli much has I»een written in ro'-ent years. 
VVhab'ver may have been the eauses -whieli led up to the dls- 
inemliernient of (bindawanaland, it gave to Western Australia manv 
of its im])ortant fmitnres, and in a measure outlined the ])resent 
eonliguration of the State. An iiis[)eetion of a geological map of 
Australia shows that the continent is s]>lit right across by a 
broad lu'lt of marine strata which, sejiarates it from an eastern 
and a Avestern island. Tlu' larger of these islands ('omprises Wes- 
tern Australia, exeejit the north, and the grc'ater ]iai't of South 
Australia. Being the home of the characteristic Australian flora 
and fauna, it may be designated Australian Australia. The smaller 
is a Umg narrow island which extends from Cape York to Tas- 
mania. As this island was connected with, and received from 
A;da many plants anil animals, it might be conveniently named 
Asiatic Australia. The Cretaceous sea Avhicli separated Australian 
from .'\siatic Australia Avas shallow as is shown by the strata Avhich. 
were' deposited r.ll over its area, and in this respect resembled tin,’ 
Arafura of to-day. tlumgh tlie climatic conditions Aveve very 
diffm-ent. The climate was cmnimratively cool and reef -building 
corals could not grow. It is significant that corals are rare in 
the Aiisliallan (’Vrdaceous strata. In AVesterii Australia the gTOup 
is lapiresentml by a luwv s])ecies of Coclosiuilia, iiud with in the 
sti'ata at Cingiii, whiidi is the third representative of the coiads 
lonml anywhere in the Australian Cretaceous strata. 
Australian Australia enjoyed bountiful rains, tlius possessing 
insular as distinct from continental climates. The extent of the 
Cretaceous rocks -]Hniits to these two having been well watered, 
for it is tlie Avater-borne AA'aste of the land Avhich formed the rocks 
in the bed of the sea. This ancient Cretaceous sea extended into 
the Great Australian Bight. Tlie strata met Avith in the bore 
IHit doAvn at 337 miles 61 chains from Kalgoorlie, penetrated at 
a depth of 667 feet a series of slialey beds Avhich yielded Iavo 
fossils, the molluscs Aucrlla Jiiu/Jicndi lists and MarCoyrlla corhiensis, 
forms which are characteristic of and abundant in the Cretaceous 
n'cks of tSouth Australia and tlie I'astern portion of tin' continent. 
Uwniiaiits of tliis ancient Cretaceous sea are also to be found in 
the maritime districts of the western iiovtion of the Btate, Avliero 
tliey cover a \a'ry large surface area, and are in A’cry many places 
concealed beneath a coA-er of later deposits; Avhilst their presence 
has been ])roved liy boring operations. 
