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The physiography of the meadows Valley, 

 MOUNT Lofty Ranges. 



By E. O. Teale, D.Sc. 



(Commuriicated by Professor W. Howchin.) 



» 



[Read July 13, 1922.] } 



The broad outlines of the development of the phyeio- 

 graphical features of South Australia have been admirably 

 traced out by Prof. Walter Kowcliin.(2) Relics of ancient 

 topography, and the deposits of "dead rivers" have been 

 widely recognized, and in piecing this evidei.ce together, the 

 great importance of tectonic movement in the form of warping 

 and faulting has been rightly emphasized, for it has certainly 

 had an important influence in the development of the existing 

 conditions of climate and topography. The highlands of the 

 Mount Lofty Ranges provide a noteworthy example in this 

 direction. They were recognized by Howchin as owing their 

 origin to block faulting, whereby several segments moved 

 differentially with regard to each other. 



Remnants of very ancient and mature topography are 

 still to be found alongside of fresh and youthful features, 

 where erosional activities, revived by differential earth move- 

 ments, are energetically working towards the destruction of 

 those relics which throw so much light on the past geographical 

 history of the region. j 



The observations of this paper centre around the Meadows 

 Valley, in the southern portion of the highlands, and were 

 gathered by the writer (3) during his geological and soil survey 

 of the Kuitpo Forest Reserves and their vicinity. j 



The nearest part of this region to Adelaide lies about 1 

 20 miles in a straight line to the S.S.E., and the valley trends 

 in a S.S.W. direction for 10 or 12 miles, eventually joining 

 the Finniss River through a narrower and more steeply graded 

 course. It is a broad, flat-bottomed, mature, high-level valley, 

 with its floor at nearly 1,000 ft. above sea level, and covered 

 with a thick deposit of clay resting on grit and waterworn 

 gravel. Remnants of drift material consisting of sand and 

 waterworn gravel with occasional large boulders are also found 

 at varying heights above the bottom of the valley, and clearly 

 do not belong to the present stream conditions. The bound- | 



aries of the valley to the east and west are sharply defined by 

 two parallel ridges, remarkably straight and of even height — 

 the Bull Creek Range, on the east, and the Wickham Hill 



