1873.] WARD — LAKE -DISTRICT GLACIATION. 437 



So that the facts iu this district point to : — 1st, the gradual ap- 

 pearance, the continuance, and the disappearance of a great ice-sheet 

 more or less enveloping the district ; 2nd, a mild period and gradual 

 subsidence to at least 800 feet ; 3rd, a cold period with a continued 

 subsidence and subsequent re-elevation. 



b. Amount of Submergence. — Finally, the question arises, to what 

 extent Avas this submergence ? 



There are some facts which have been brought forward under the 

 head of boulders and their positions, that are more easily explained 

 by the action of floating ice than of land-ice. If we grant that the 

 stratified sand and gravel up to 1000 feet is sufficient evidence of 

 submergence to that point (though at present no marine shells have 

 been detected in these deposits), we may perhaps also conclude that 

 the occurrence of the subangular drift-gravel up to 1500 feet also 

 points to a submergence to that depth. Boulder-evidence strengthens 

 this conviction ; thus the boulders borne on to Broom Fell from a 

 couple of miles to the north, at a height of 1200 feet, point clearly 

 to floating ice, as" the direction is not that of any possible land-ice 

 stream. On the southern side of Kirk Fell (adjoining Broom Fell), 

 a boulder of the Buttermere syenite rests at nearly 1200 feet ; its 

 presence there is most readily explained by floating ice ; for it could 

 not have been left by the Buttermere- and-Lorton -Valley glacier 

 when at its largest, because other great sheets of ice, shed from the 

 Grisedale Pike and Whiteside mountains, would have staved off the 

 Buttermere ice more to the west, and prevented its running up 

 among the mountains on the east side of the valley. 



The syenite boulders upon the top of Starling Dodd, at a height 

 of 2084 feet, are suggestive of submergence even to that amount ; 

 for it is difficult to see how they could have got there by the action 

 of land-ice, since the only syenite at an equal height is near the 

 summit of Red Pike (19), one mile due east, upon the same water- 

 shedding line passing over Starling Dodd, which line is depressed be- 

 tween the two summits to 1880 feet. I am therefore inclined to 

 think that these boulders must have been floated either from Bed 

 Pike westwards, or northwards from the high syenite mountains 

 upon the south side of Ennerdale and west of Haycock (25). The 

 position of ash and trap boulders on syenite, along Lingcomb Edge 

 (the western boundary of the combe below Red Pike), up to a height 

 of 1750 feet, is also more readily explained by flotation from east 

 to west than by land-ice, when the relative lie of the various rocks 

 is taken into consideration. Many other instances might be given 

 which seem to support the idea of submergence to over 1500 feet ; 

 and although future evidence may modify opinion upon the subject, 

 I cannot but think it highly probable that the submergence even 

 reached to the height of 2000 feet or rather more. 



During this submergence the vast quantity of moraine matter left 

 in all the low grounds by the preexisting ice-sheet, was much re- 

 modelled and converted in great part into the subangular drift-gravel 

 already described. 



c. Direction of Marine Currents, — It becomes an interesting ques- 



