10 HORN EXPEDITION PHYSICAL GEOGRAPHY. 



to thtat portion of the Lake Eyre Basin, wliich is drained hy the Finke, one of the 

 most important rivers of tlie interior of Australia. 



The McDonnell Ranges and the eastern extension of the Hart Range may be 

 said to divide the drainage of the interior into two areas, of wliich the southern, 

 which forms part of tlie Lake Eyre Basin, contains the most important rivers. 

 The Finke, with its large tril)utary, the Hugh, takes its rise on the southern slope 

 of these ranges, and flows towards Lake Eyre in a general southerly to south- 

 easterly direction. The majority of the small creeks, which issue from the northern 

 slope, do not discharge their waters into any ccmimon basin, but each maintains 

 an independent course for a longer or shorter distance from the ranges, to become 

 sooner or later absorbed by the sandhills and loamy plains. These latter creeks, 

 of which the Darwent, Dash wood, Charley, Six Mile, Muller, etc., are examples, 

 leave the ranges and flow northwards over the surface of the elevated plain, which 

 is known to the north of Alice Springs as Burt Plain. 



They have dry sandy channels, the banks of which are lined with gums, 

 which are numerous and of vigorous growth near the ranges. There are a few 

 creeks of this character heading from the south-western extremity of George Gill 

 Range, e.g. King and Laurie Creeks. The former of these flows southwards in 

 the direction of Lake Amadeus, but the flow of the water at flfteen or twenty 

 miles from its source is not strong enough to form a channel, with the result that 

 the flood waters spreading out over wide " gum flats " become ab.sorbed by the 

 surrounding sandhills. 



There are, in addition to the above-mentioned small creeks, two or three larger 

 ones taking their rise on the north slope of the McDonnell and Hart Ranges near 

 their eastern extremities, which after a short northerly course sweep round to the 

 south and flow towards Lake Eyre. As an example of these may be mentioned 

 the Hale, the Sandover, and the Plenty, the two last of which ultimately unite to 

 form the Marshall or Hay River. Speaking generally, one may say that the 

 drainage from the southern slope of the McDonnell Ranges and from those ranges 

 lying immediately to the south is sooner or later collected into one main channel 

 known as the Finke, which trends in a general south-easterly direction towards 

 Lake Eyre. 



(1) Finke Basin. 



(a) Nature and Position of its Watershed. — The northern limit of the Finke 

 Basin is to a great extent formed by the McDonnell Ranges, the line of water- 



