474 THE GEOLOGY OF THE NEW HEBRIDES, 



at once conceded that the South Pacific Island Groups are lined 

 along great fold-chains concentric on the Australian archibole. 

 Discontinuity of the land-areas is due to a variety of local causes, 

 two of which figure most prominently; in the first place, inevit- 

 able cross-faulting of the blatter type, succeeded by its attendant 

 after-result cross trough-faulting; secondly, the fact that many of 

 the ridges would probably not be sufficiently elevated, to rise 

 above sea-level, the present isolated land-areas chained along the 

 crests, resulting from subsequent continued accumulation of 

 volcanic products, derived from eruptive centres developed along 

 the septa. 



The direction of folding has probably been defined by the 

 trend of parallel fold-ridges of Hercynian age, which can be 

 traced, one following closely the contour of the east coast of 

 Australia; another seems to pass down the Owen Stanley Ranges 

 of New Guinea,* through New Caledonia,,! to meet the great Car- 

 boniferous fold of the Southern Alps of New Zealand, which 

 latter, pointing as it does, seems to indicate a continuation to 

 the northward in the direction of Samoa, or more probably, now 

 that we know of the existence in Viti Levu| of older rocks, 

 through Fiji. It is this Hercynian folding which, by isolation^ 

 from Australia, gave birth to Mr. Hedley's Mid-Pacific Continent. 

 The similarity of the Mesozoic fossils] | in New Caledonia and 

 New Zealand, shows that the land-area in this direction must have 



• Annual Eepoit on British New Guinea. Parliamentary Papers, Bris- 

 bane, 1893. Also " The Salient Geological Features of British New Guinea." 

 By A. Gibb Maitland, Journ. West Aust. Nat. Hist. Soc. No.ii. May, 1905. 



t Piroutet, M., "Preliminary Note on the Geology of a Part of New 

 Caledonia." Bull. Soc. Geol. France, iii. 156, 1903. 



I Woolnough, W, G., "The Continental Origin of Fiji." Proc. Linn. 

 Soc. N. S. Wales, xxviii. 457, 1903. 



§ As shown by the similarity among the fossils in these two regions in 

 times preceding the later Carboniferous, and dissimilarity in succeeding 

 periods. 



II The Rev. W. B. Clarke was the first to draw attention to this, from 

 which he argued an extensive land-area connecting both these localities, 

 *' Plain Statements," 1851, p. 6. 



