CHAPTER XXVII

SOME CONCLUSIONS AND THEIR BEARINGS

Vanua Levu, a composite island formed during a long period of emergence, 372.—The submarine plateau probably produced by basaltic flows, 373.—The distribution of the volcanic rocks, 374.—Comparison with Iceland, 374.—The mountain-ridges, 375.—The emergence of the Fiji Islands, 376.—Wichmann’s view of the early continental condition not supported, 376.—Age and character of the emergence, 377.—The evidence of the Lau Group and of the Tongan Islands, 378.—Two principal stages of the emergence, 379.—Relative antiquity of the Hawaiian, Fijian, and Tongan Islands as indicated by their floras, 379.—Islands have always been islands, 380.—The hypothesis of a Pacific continent not yet needed, 381.—The great dilemma, 381.—Much remains to be learned of the possibilities of means of dispersal in the past and in the present, 382

_Pages_ 372-382

APPENDIX.

(1) Note on microscopical examination of stone-axes.

(2) Note on the ascent of the tide in the Ndreketi River.

(3) Note on the “talasinga” districts.

INDEX 385

LIST OF ILLUSTRATIONS

PLATES

TO FACE PAGE

Na Raro (2,420 feet) from the south-west, a peak of acid } andesite } } _Frontis- Ndrandramea (1,800 feet) from the south-east, a peak of } piece_ acid andesite rising about a thousand feet from its base }

The Ndrandramea District from the westward 98

Mount Tavia (2,210 feet) from Vatu Kaisia } } 108 The magnetic peak of Navuningumu (1,931 feet) from the south }

Mbenutha Cliffs, showing volcanic agglomerates overlying tuffs and clays, containing shells of pteropods and foraminifera, which are raised 1,100 feet above the sea 111

Duniua Lagoon, representing an old mouth of the Ndreke-ni-wai 153

LITHOGRAPHS

Vanua Levu, Fiji Islands 1

Fiji Islands 373

FIGURES

PAGE

Profiles of Vanua Levu as Viewed from the South. Graphically Represented on a Horizontal Scale of about 16 miles to the inch 4

Korolevu Hill (800 feet) from Wailea Bay 46

Profile and Geological Section of the western end of Vanua Levu from the Wainunu estuary across the summit of the basaltic mountain of Seatura to the edge of the submarine platform off the Ndama coast as limited by the 100-fathom line 62

Profile, looking north from off the mouth of the Wainunu River 83

Rough plan of the Ndrandramea district in Vanua Levu; made with prismatic compass and aneroid by H. B. Guppy 99

Profiles of Ngaingai and Wawa Levu from Nambuna to the south-west. Both are dacitic mountains 101

Profile and Geological Section of Vanua Levu, across the island from the Sarawanga (north) coast to the Yanawai (south) coast 107

Profile-sketch of the Vatu Kaisia district from S.S.E. 113

Section of the Vatu Kaisia district 115

Profiles of Na Raro 124

Profile-sketches of the Va-Lili Range 141

Profile-sketch of the mountainous axis of Vanua Levu 167

Koro-mbasanga from the north-north-east 167

Mount Mbatini from the top of Koro-mbasanga 173

View from Muanaira on the south coast of Natewa Bay 173

Ideal Section of Thambeyu 177

Diagram illustrating the two sets of felspar-lathes in a dyke 238

Magma-lakelet, ·25 mm. in size, magnified 290 diameters, from a basalt at Navingiri 339

Showing fragments of glass with eroded borders and of plagioclase with more even edges in a matrix of palagonite traversed by cracks 342

Diagram showing the succession of deposits below the Nandua tea-estate 345

OBSERVATIONS OF A NATURALIST IN THE PACIFIC