SAKE, HEEM, AND JETH0T7. 



329 



dency to foliation. These structures sometimes appear vertical with 

 N.-S. strike, but at Port Goury on Little Sark there is a platy structure 

 which dips at about 30° to the south, just as bedding ought to do, 

 and at the extreme north end, close to La Grune, a similar structure 

 slopes gently to N.E., also a natural direction for bedding in that 

 place. Again, wherever lenticular nodes occur their longer axes 

 agree in direction with these structures, and though the rock is 

 usually very homogeneous, yet occasionally long stripes show, and 

 these too lie in the positions which strata might be expected to 

 occupy. Some of these streaks are well developed at the extreme 

 north end, on the slope leading down to the sea-neck. They are 

 finer-grained than the mass of the rock ; some are pink, some dark, 

 some show a banded surface. They may reach several feet in length, 

 with depth not exceeding an inch or two. I could not bring away 

 a good specimen ; but a specimen taken from near Les Boutiques 

 shows a marked streaky structure. This last is such as might 

 result from crush, but T hardly think the pink seams above described 

 could be due to that cause. They are so long and thin that one can 

 hardly believe them to be caught-up fragments *. There is a large dyke 

 near, of which some might be offshoots ; but no connexion is visible. 

 I think, however, that this is the origin of some, and it is quite 

 possible that all these suggested causes may have had shares in the 

 appearances, and have produced, some one, some another. But on 

 the hypothesis that these crystalline rocks are metamorphosed sedi- 

 ments, then these sea ms should be the last remnants of the stratified 

 structure, and they are certainly explained more easily thus than on 

 the igneous theory. 



Each hypothesis, then, presents considerable difficulties. In hope 

 of deciding the doubt, I endeavoured to examine carefully every 

 visible junction with " the underlying beds. There are six cliff- 

 sections, four in Sark, two in Brecqhou, none of them easily 

 accessible. The least difficult is that on the west side of Little 

 Sark f . Here, except at high tide, the meeting of the two rocks 

 can be well seen in the base of the cliff. The beds, highly horn- 

 blendic, dip S. at about 40° ; the upper rock has but little appear- 

 ance of structure ; between the two is a zone of intermixture about 

 10 feet wide, within which tongues and lenticular portions of 

 crystalline rock are intermingled with the schist ; but the general 

 direction of the surface of junction agrees with that of the bedding- 

 planes. A diorite-dyke close to the junction confuses some of the 

 indications. The evidence on the whole is in favour of the upper 

 rock being igneous, but I did not consider it conclusive. 



The two northern junctions appear to be faulted. That on the 

 west cliffs is beyond the north corner of the bay, near Les Autelets, 

 and appears to be in a cleft which a climber cannot reach. There are 

 some fallen blocks close to this cleft which seem certainly to contain 



* Yet at Kerscou, N. of Morlaix, I was shown in 1886 a ribbon of schist 

 30 feet long and only 1^ wide, torn off and imbedded in granite. 



t A landslip has carried away the old path to the beach at the Coupee ; a 

 descent can be effected by a grassy couloir just beyond the neck. 



