216 



ME. E. J. GAEWOOD & DE. J. W. GEEGOEY [May 1898^ 



are produced by land-ice, and we saw no means of discriminating 

 between the striae produced respectively by glaciers and floating ice, 

 "We were therefore interested to hear from Mr. Martin Ekroll that, 

 in his opinion, furrows are formed only by the latter agent. The 

 furrows he regards as always due to fragments of floes which have 

 been thrown up on their sides ; the whole weight of the slab of ice 

 then presses directly upon the surface below. The edge of the ice 

 becomes charged with rock-fragments from the beach, and as it is 

 driven forward it cuts into the rock-surfaces like the edge of a fi.le, 

 instead of polishing them like its face. 



Mr. Lamont ^ has previously described a glacial furrow on one of 

 the islands of Stor Piord, and given good reasons for thinking that 

 it was formed by floating ice ; the furrow, however, in that case 

 was not cut in solid rock. 



y. Teaces of Poemee Glaciatiox. 



The literature upon Spitsbergen abounds in references to the 

 former greater extension of some of the existing glaciers. But there 

 has been a complete agreement as to the absence of any signs of a 

 pre- Pleistocene glaciation. Sedimentary rocks belonging to the 

 pre-Devonian, Devonian, Carboniferous, Triassic, Jurassic, Cretaceous, 

 and Palgeogene systems are abundant ; but, as Baron von IS'orden- 

 skiold tells us, ' at least we in vain, in the various rocks of that 

 island, searched for stones furrowed hj the action of ice, or boulders, 

 or other beds resembling the glacial deposits of the present age.' 



We were, however, so fortunate as to discover two cases of 

 apparent glacial deposits in the Spitsbergen series. The oldest is a 

 bed of a massive conglomerate at Pox Point, which belongs to the 

 Hekla Hook series. The best section is exposed in a small headland, 

 and shows some 50 feet thickness of the series. 



The matrix is comparatively fine-grained, and has acquired by 

 pressure an imperfect ^^^_ __,,., 



foliation. (See fio* 6.) ^'^S- ^- — Diagram of the Hekla Hook glacial 



Scattered through the 

 groundmass are huge 

 boulders, of which the 

 largest was 5 feet high 

 and 7 feet long. The 

 boulders are roughly 

 rounded, and the sur- 

 faces are sometimes 

 marked by indefinite 

 groovings.but we were 

 unable to find any 

 definite striae. The 

 boulders consist of a 

 miscellaneous collec- 



heds. Bell Sound. 



a? = Boulder 5 feet high and 7 feet long. 



tion of granites and gneisses, none of which have at present any 

 outcrop near the locality where the deposit occurs. 



1 Jas. Lamont, ' Seasons with the Sea-Horses,' 1861, p. 204. 



