AKID POBTIONS OF SOUTH AUSTKALIA. 35 



PHYSICAL ENVIRONMENT OF THE VEGETATION OF 

 SOUTH AUSTRALIA. 



PHYSICAL GEOGRAPHY. 



[j!h&-stalie-jof-South.j^ustralia cam cent of the. 



area otAugtaaJi^. JJLliesJbetsKBea-acmttLlatitude 28l.g^^ 

 and longitude 12Q^nd l^jsssLJbxwaJlrBeixmkk, 'J^hestate, there- 

 for e, is W holly JiushidedLsitMn the. temperate zone] I iiTatitude 

 South Aa sfaaljauxoughbg .corresponds with fientral. Chili, , Argentina^ 

 ^d s outhern Afr ica, and__in- the northern hemisphera with Algeria, 

 sout hern Spam .,and...scMtIieiaL-Iiial^- northern JEaaoaL Palestine,, and 

 thempst oi Asia JMmor /and.northem Ching, and Japan. So far as the 

 climate is concerned, as will be shown below, the state probably most 

 nearly resembles southern California, the Mediterranean region, and 

 southern Africa.^ 



South Australia may beiairly well divided into three ph^iographic 

 gi^CTaTregipns, as indicatjed in- figure TO,~ipage 34. These mayTTe 

 re ferred t o as _the westem..plateau,,_the (central and northwestern) 

 Highlands, and the lowlands (of theLSOuth^andAast). . 



The western plateau is an eastern, continuation of the great plateau 

 of Western' Australia, which embraces about half of the land surface 

 oi thecohtiaent. So far as concerns the portion of the plateau withiii 

 the borders of South Australia, it can be divided into three leading 

 physiographic formations, which nmy be referred to, as the Bunda., 

 plateau or Nullarbor plain s, the Lake Tokens, plateau^- and the desert 

 sandstone tableland. 



The country which lies along the Great Australian Bight, and extend- 

 ing about 150 miles inland, constitutes the region known as the Nullar- 

 bor plains, from its supposed treeless character, or Bunda plateau, 

 from thenative name for the cliffs. The plateau rises from about 250 

 feet at the sea to 800 or 1,000 feet along the northernmost portion. 

 It is a limestone plain of Miocene age and constitutes an extension of 

 the older plateau of Western Australia. 



The Lake Torrens plateau lies to the west of Lake Torrens, or, more 

 exactly, to the west of the great valley of South Australia. It is of 

 limited extent and is made up in part of flat-topped hills west of Point 

 Augusta, known as the Tent Hills. It attains its greatest width just 

 to the west of Lake Torrens (Howchin and Gregory, 1909: 93) and is 

 much older, geologically^, than the Nullarbor plains, being of the same 

 age as the FUnders Ranges (Howchin and Gregory, I. c). 



The third tableland, the Desert Sandstone, "once extended over 

 most of central and northern Australia. * * * it represents the 

 old land and fresh-water deposits which accumulated after the Cre- 

 taceous sea drained off from central Australia." The desert sand- 

 stone tableland extends from Copley north and forms the general fea- 



