Canterbury and Westhnd. 377 



impression. In several previous reports I have shown that after the 

 retreat of the great Eakaia glacier a large lake was formed behind 

 the rocks and morainic accumulations, through which in time a 

 channel was cut ; gradually this lake was filled up by glacier mud 

 (silt), and by shingle and boulders brought down by the rivers 

 emptying themselves into that lake, the latter generally covering the 

 deposits of silt. A careful examination of these shingle or boulder 

 beds — of: which some small layers are flattened by wave action of the 

 ancient lake, the greatest portion, however, having the usual sub- 

 angular form — proves beyond a doubt that all the rocks occurring at 

 the head waters of the Eakaia are represented, but no others. They 

 are, without exception, of sedimentary origin, belonging either to the 

 "Waihao or Mount Torlesse formations. Were they brought into 

 their present position by marine action, we should find an assemblage 

 of rocks, such as we meet at present on the shingle accumulations 

 between Lake Ellesmere and the sea ; in which, besides the 

 sedimentary rocks of which the Southern Alps are built up, the 

 quartziferous porphyries and melaphyres of the Eakaia, Ashburton, 

 and Hinds, the felsitic porphyries of the Eangitata, the dolerite of the 

 Timaru plateau would be represented, together with all the peculiar 

 semi-metamorphic rocks found near Mount Cook and the Waihao 

 country brought down by the "Waitaki, and taken north by the 

 currents and swell of the ocean, till they find a resting place near the 

 northern slopes of Banks' Peninsula. We also meet near the slopes 

 of Fighting Hill, and on a much larger scale on those of Mount Hutt, 

 with the remnants of ancient moraines, between which several 

 terraced river beds occur. 



In proceeding to examine the evidence offered us by the extensive 

 and remarkable morainic accumulations at the West Coast, our task 

 has been much facilitated by the destruction they have undergone 

 from marine action, so that we can study without difficulty their origin 

 and mode of formation. It is easy to trace each of these huge post- 

 pliocene glaciers, its frontal, lateral, and central moraines deposited 

 during the retreat to its present position, to examine the material of 

 which they were built up, and thus to form a clear conception of the 

 modus operandi of their deposition, and their partial destruction after- 

 wards, by rivers on the one hand, and the sea on the other. It will be 

 observed that in the map in illustration of the Great Glacier period, I 

 have drawn the principal western glaciers as having had a much greater 

 extension than the morainic accumulations that are still preserved, and 



