BY PROFESSOR STEPHENS, M:.A. GOl 



tlie glacier streams, laden from time to time ^vitli ice rafts, carried 

 it, and tlie sea at the margin, and the rivers themselves in their 

 autumn beds, separated in patches and layers, sands from pebbles j 

 and mud from sands, but left the larger blocks where they 

 happened to find them. 



AYe may I think safely assert this much ; and may regard it as 

 beyond serious question that the Marangaroo Conglomerate was 

 formed, 1. near the sea level; 2. only slightly within the 

 influence of the sea, and that principally in its older portions ; 

 3. that it was formed of mountain waste accumulated in higher 

 valleys by the action of glaciers ; and 4. that it was ultimately 

 laid down, partly in broad river valleys or straths debouching on 

 the sea, partly in straits and firths, and partly along the sea 

 margins. From the nature of the deposit, it would never extend 

 outwards more than a few furlongs. 



Similar accumulations fill the' upper valleys of the Ehone 

 and E-hine in Switzerland, and are familiar enough to the 

 geologist in Scotland, the north of England, and New Zealand. 

 Indeed they are common to all glacier districts. The surface of 

 these formations is never quite level, sloping, as a matter of course, 

 mth the rivers to which they owe their origin. And we shall 

 presently see that the N.E. dip spoken of by Mr. Wilkinson 

 indicates in all probability the direction in which the materials 

 were in this case carried. The surface moreover, is sure to be 

 subject to spring floods, bearing with them vast quantities of ice, 

 and consequently to almost annual shifting of the river currents, 

 which are perpetually at work, here to form mounds, there to 

 excavate hollows, but which nevertheless on the whole, tend to 

 sort out and arrange the materials through which they travel, 

 and reduce them by degrees to a fairly graded slope. 



Above these plains, which we must imagine as consisting in 

 great measure, of broad tracts of gravel and moraine- stuff, too 

 often shifted to be clothed with vegetation, but diversified with 



