80 



ihillet, but not the least indication of a terre.strial wave was 

 experienced. 



Between the Cavenagh and Barrow Ranges, 

 miles, the surface features are low sand-ridges, 

 travertine deposits. The Barrow Range is 

 parallel series of g)-anite hills, having' a north 



a distance of 25 



alternating with 



constituted of a 



and south trend, 



at least in its southern section, which alone was visited by us. 

 At its southern end the range attains its highest elevation in 

 Mount Squires, of 2,270 feet above sea-level. It consists chiefly 

 of semiporhyritic rocks, and the much-broken country gives rise 

 to several creeks, which water alluvial flats carrying a rich growth 

 of herbage and other vegetation. South from Mount Squires are 

 low ridges of sandstone, which are connected towards the west 

 with Townsend Ridge. 



The principal axes of elevation in Central Australia are the 

 Macdonnell, Musgrave, and Everard Ranges, which represent a 

 series of almost parallel waves or undulations of contemporaneous 

 origin. The most southerly is the Everard Range, which con- 

 tinued through Mount Agnes and Blyth Hill, is obliquely con- 

 nected with the Tomkinson Range ; the westerly extension of 

 the Musgrave Range. This gigantic upheaval, viewed as one, is 

 bounded on the south by a belt of sedimentary rocks, probably 

 of Devonian age, which commences with the ranges about Mount 

 Chandler and Chambers Bluff' on the east, and ends in Townsend 

 Ridge on the west. The country examined by me, which lies be- 

 tween these two boundaries, viz., to the north the Archijeans of the 

 Central Australian elevation, and to the south the less prominent 

 upheavals of a more recent date, is occupied })y the debris of the 

 " formerly overlying sedimentary formations. Thus the general 

 geology of this section of the journey is of a simple kind ; but 

 the stratigraphical phemonena in detail are not without interest, 

 as may be gathered from the following description. 



II.— DKSCRIPTIVK GEOLOGY. 



A. Sedimentaky Rocks. 



1. Recent Suepace Deposits and Tektiary Rocks. 



From the Everard Range the country slopes gradually to the 



west as far as Ferdinand River, on either side of which, but at 



some distance ofl^, outcrops of travertine, with alternating ridges 



of chalcedony appear (see fig. 4, pi. 3). These strata as superficial 



deposits are next in importance to the loams and sands, which 



occupy a very large area of country between Everard and Barrow 



Ranges. In some localities the limestone is interstratified with 



layers of chalcedony and lenticular masses of a travertine 



blackened by carbonaceous matter ; both T regard as a secondary 



