416 THE GEOLOGY OF THE NEW HEBRIDES, 



usually about one mile from the mainland. These islands seldom 

 exceed 30 ft. in elevation, and are formed of decomposed basic 

 tuff covered over by a thin veneer of coral limestone. A thriving 

 fringing reef is rapidly extending the eastern shores, but does 

 not appear to the same extent on the landward side. 



Our first excursion on the mainland was to the hills above 

 Port Stanley, where recent raised coral limestone (87) was 

 •observed to give out shortly above sea-level, to be succeeded 

 above by a decidedly more ancient-looking dense, white lime- 

 stone;* this latter was traced up for a height of 500 ft., after 

 which several outcrops of decomposed tuffs were noted. 



An excursion from the island of Rano to the mainland at 

 Pinalum Point and inland about four miles was of little interest, 

 AS the track lay on fairly level ground, the only outcrop noticed, 

 besides occasional patches of hard compact yellowish fragmentary 

 limestone, was that of a basic tuff(l) underlying the limestone, 

 and though only occurring very rarely in recognisable outcrops, is 

 probably extensively developed as detected by the slipperiness of 

 the path for the whole distance. Several pebbles collected from 

 a creek-bed at the farthest point reached proved to be Miocene 

 limestones and hornblende andesites. Large slabs of Miocene 

 limestone (91) are used as seats in an amil several miles inland; 

 these had, according to the natives, been transported some 

 •distance. 



With our camp on the small island of Atchin we made two 

 ■excursions to the mainland. 



On the first of these, after landing on the shore directly 

 opposite our camp, we followed a track leading due west, and 

 Anally, after about a two miles' tramp, arrived at the upper 

 reaches of a river which enters the sea just to the north of 

 Atchin. A flat shore-belt elevated only a few feet above sea- 

 level occupied the first half mile or so, after which a gradual rise 



* According to Mr. Chapman, the absence of LepidocycUna indicates a 

 Post-Miocene age for this material, though no doubt the disparity is not great, 

 AS evidenced by the presence of abundant forms found associated in the local 

 Miocene. 



