BY H. I. JENSEN. 863 



upon as a conoplain, which is composed of sedimentary strata 

 intruded by sills and capped with volcanic rocks, and has been 

 dissected by semi-arid agencies. The gorge-like valleys in the 

 mountains with vertically retreating cliff's, the steep shingle- 

 covered slopes, the want of definiteness in the watercourses when 

 they leave the mountains, and many other features are character- 

 istic of an arid cycle. This country did not have much appear- 

 ance of aridity at the time of my investigations. On the 

 contrary, it was covered with waving fields of wheat and high 

 grass, and rains occurred almost daily. However, it must be 

 borne in mind that any area in which the rain falls principally 

 at certain times in the year, the wet season, and then falls in 

 torrents, whilst other periods, the dry seasons, extend over most 

 of the year, and in which prolonged droughts occur, has the arid 

 cycle characteristics and is classed with arid regions. Round 

 the Nandewars on the west and south we have mesas of sand- 

 stone which show a N.W. dip. These are probably of Trias- 

 Jura age, but may be Upper Permo-Carboniferous. 



Mount Kaputar is the apex of the Nandewar Mountain mass. 

 The mountain group is not round but oval with the long axis 

 N.N.W.-S.S.E. It is composed of two definite masses, one north 

 and one south of Bobbiwaa Creek. The highest peaks of the 

 northern do not greatly exceed 3,000 feet in altitude. They are 

 Dripping Creek (or Castle-Top), Grattai (Couradda), Terrergee, 

 and others. The peaks of the southern mass are much higher, 

 many exceeding 4,500 feet; Kaputar, the highest, is 5,000 feet 

 high. Bullawa Creek divides the southern mass into two 

 divisions, the northern of which is very dissected, whilst the 

 southern is a compact tableland. On the large tableland are 

 the curious tower-shaped peaks of Corrunbralborawah, Ninga- 

 dhun, etc., and the long razorback dykes, like Yullundunida, 

 which indicate late intrusions of hard trachyte into softer tujBfs 

 or andesitic lavas that have more easily been denuded away. 

 Remnants of crater-rings are abundant but not very definite. 

 One fairly definite basaltic crater has been noticed south of 

 Eulah Creek. Ningadhun is probably a plug injected into the 



