INDEX

Note.—It has been deemed best to follow the example of the Admiralty surveys in the spelling of native names. In this book, therefore—

Mb = the Fijian B

Th = the Fijian C

ND = the Fijian D

NG = the Fijian G and Q

THE END

R. CLAY AND SONS, LTD., BREAD ST. HILL E.C., AND BUNGAY, SUFFOLK.

[1]. In the case of the island of Faro in the Solomon Group, I have described a similar process of island-building. (Geology of the Solomon Islands, p. 37.)

[2]. In 1897 I spent several months in travelling over this island and ascended, sometimes more than once, the three great volcanic mountains. Perhaps at some future time I may renew my examination of this interesting region.

[3]. Strictly speaking Korolevu indicated in the profile would not be visible.

[4]. Mariko is the native name of the Drayton Peak of the chart. Mbatini is the correct name for the Koro Mbasanga of the chart, the true Koro Mbasanga lying three miles to the north. Thambeyu is a native name for the Mount Thurston Range.

[5]. There has been some confusion in the native names of the peaks in this part of the island, which I have not been able to remove.

[6]. A Year in Fiji, 1881, pp. 22, 167.

[7]. Geology of the United States Exploring Expedition, 1849.

[8]. This height has been supplied from memory, as I omitted to refer to the exact level of the erosion line in my notes.

[9]. They were described to me as dry for a fortnight at a time. I was prevented from making more than an occasional visit to them.

[10]. Atlas of the United States Exploring Expedition, vol. i., Philadelphia, 1850.

[11]. This, however, is not the case with the recent changes at the mouth of the Rewa River in Viti Levu, where the bare sandy point of Lauthala has extended itself seaward between 500 and 600 yards since 1840, whilst Port Nukulau has shoaled a fathom in the same period. But I can find no evidence of any marked advance in the mangrove margins either towards Nukulau or on the Kamba side, the only change recognisable being in the bare sandy point of Lauthala, the rapid extension of which has been such as to attract the attention of residents, both whites and natives. Dana, who was in this locality in 1840, remarks in the Geology of the U.S. Exploring Expedition, that he had learned from a person who had resided there for forty years that during this period the deposits had lengthened the river half a mile. When I was on the Rewa in 1897 I heard that the natives in old time could see Suva Point from Rewa. This is probably a native legend connected with the modern extension of Lauthala Point. (The charts compared in making the above measurement of the recent advance of this point were the plan of the Rewa Roads by Wilkes, in 1840, and the Admiralty charts 1757 and 905, the former of which was based on Lieut. Dawson’s survey in 1875, the last being corrected to 1897.)

[12]. Between Mathuata Island and the coast a change is indicated from 9-10 fathoms to 8-9 fathoms, north of Motua Island 12-13 to 11-12, and between Nangano and Thakavi 16 to 14 fathoms.

[13]. By referring to the chart it will be seen that extensive mud-flats occur at the mouths of the Sarawanga and Ndreketi rivers, where the land-margin is slowly advancing.

[14]. United States Exploring Expedition, vol. x.; Geology, by J. D. Dana, p. 343.

[15]. A Year in Fiji, by John Horne, London, 1881, p. 163.

[16]. Journal, Royal Geographical Society, 1857, vol. 27.

[17]. Scottish Geographical Magazine, August, 1891.

[18]. Journal des Museum Godeffroy, heft 14, Hamburg, 1879.

[19]. Dr. Max Büchner also refers to this spring in his Reise durch den Stillen Ozean, 1878.

[20]. Bulletin Museum Comparative Zoology, Harvard, vol. 38; Geolog. Series V., No 1, Nov. 1900.

[21]. Amongst the other descriptions of these springs I may refer to that of Kleinschmidt in the work quoted on p. 22, to that of Miss Gordon Cumming in At Home in Fiji, to that of Horne in his Year in Fiji, &c. They are sketched in the descriptions of Kleinschmidt, Miss Cumming, and Commodore Wilkes. The analyses are given on a later page together with the references.

[22]. Pacific Islands, Sailing Directions, vol. ii., Central Groups, 1900, p. 185.

[23]. From what I remember the usual exposure at low-water in 1898 was less than a foot. I have little doubt as to the identity of the locality. This rock is one of the “sights” of the place at the present time. It would be interesting for a resident to compare carefully its present condition with that as described by Wilkes. Dana in the work quoted on p. 10, refers to this rock as a knoll of basalt; but he never visited the locality and only obtained his account from the officers of Wilkes.

[24]. Narrative of the United States Exploring Expedition, III., 199, by Commodore Wilkes. See also Dana’s Geology of the same expedition.

[25]. Journal des Museum Godeffroy, heft 14, Hamburg, 1879.

[26]. Islands of the Pacific, by H. Stonehewer Cooper, 1888 edition.

[27]. Journal Royal Society, New South Wales, 1880, vol. 14. Miss Gordon Cumming in At Home in Fiji gives the same analysis but differently stated.

[28]. To avoid error, I have given the results of each without converting them to a common standard. The numbers in brackets are taken from the form of Prof. Liversidge’s analysis given in Miss Gordon Cumming’s book.

[29]. United States Exploring Expedition, vol. 10, Geology.

[30]. Proceedings, Queensland Branch, Geographical Society, Australia, vol. 1. 1886.

[31]. I took the temperature at monthly intervals between October, 1896, and September, 1897. The mean annual temperature of the air in the shade would be about 64° at an elevation of between 3,000 and 4,000 feet.

[32]. At Ewa there are pumping plants capable of supplying 75 million gallons a day, the water being drawn entirely from artesian wells. (Report on Hawaii, by Dr. Stubbs, bulletin 95, 1901; U.S. Department of Agriculture.)

[33]. This hill is figured in Wilkes’ narrative under the name of Dillon’s Rock (vol. 3, p. 235). This, however, is not the Dillon’s Rock of his chart, where the name is given to a rock on the west side of the entrance to Wailea Bay.

[34]. See remarks on “crush-tuffs” on p. [334].

[35]. Species not identified.

[36]. In one of my traverses I crossed a level district extending a mile N.E. of Ndriti without changing my elevation.

[37]. At Delanasau, on the north or dry coast of the island, the average rainfall, according to many years’ observations by Mr. Holmes, is about 115 inches. At Wainunu, near the wet or south coast, the observations of Mr. Barratt and others extending over 16 years give an average of 160 inches. In the mountains this would be nearly doubled.

[38]. This question, which has so often been raised with respect to the propylites, will probably receive a different answer from different localities. The matter is further discussed on later pages.

[39]. The dyke-rock has a specific gravity of 2·7; but is slightly vesicular. It shows a few small plagioclase phenocrysts in a groundmass of felspar-lathes, augite grains and prisms, magnetite, and a little brown interstitial glass. The felspar-lathes average ·14 mm. in length and are for the most part not parallel. Secondary calcite occurs in the groundmass, and the powdered rock effervesces a little in an acid.

The rock forming the offshoot of the dyke differs only from the parent rock in its more vitreous character. Although the felspars and augites of the groundmass are fairly developed, the residual glass is much more copious, and in places where it has segregated, forming “lakelets,” it has been subjected to an alteration often observed in palagonite when there are concentric alternating zones of a tan-coloured fairly refractive material and calcite.

The reddish scoriaceous lava in contact with the dyke shows no phenocrysts. The groundmass displays more or less parallel felspar-lathes, ·1 mm. long, augite grains, and much magnetite. The residual glass is fair in quantity; but is mostly gathered into “lakelets” of brown altered glass with sometimes calcite in the centre.

The vitreous border of the dyke is composed of a dark glass quite opaque in the outer portion, but clearer and showing incipient crystallisation in the inner portion.

[40]. Characteristics of Volcanoes, 1890.

[41]. Referred to genus 16 of the olivine-basalts.

[42]. This subject is discussed in [Chapter XXVI.]

[43]. “Na Savu” is the Fijian for waterfall. The complete name of this fall is “Na Savu ni nuku.”

[44]. The flinty concretions are described on page [354], and the iron sand on p. [356].

[45]. Geology of the United States Exploring Expedition.

[46]. A similar arrangement was observed in the columnar basalt of Kauai in the Hawaiian Islands. It is presumed that these Hawaiian flows are sub-aërial.

[47]. The unaltered glass, which incloses a few plagioclase phenocrysts, has a specific gravity of 2·7, and is readily fusible.

[48]. They are described on p. [322].

[49]. This absence of a healthy forest-growth, such as occurs on the level summit of the neighbouring Soloa Levu and in all like situations, has probably some geological significance.

[50]. These tuffs are probably submarine. They will be found described with tuffs of the same character on p. [333].

[51]. The track attains an elevation of about 1,300 feet, but the top of the watershed is two or three hundred feet lower.

[52]. It belongs to the 3rd order of the hornblende-hypersthene-andesites described on p. [299].

[53]. Occasional views of its summit only are obtained from the eastward, as from the Ndrandramea mountains and their vicinity.

[54]. Alluvial gold has long been known to occur in the bed of the Yanawai below Vatu Kaisia; but it has never been found in paying quantity.

[55]. Under the microscope it is shown to be granular in structure, exhibiting a mosaic of irregular quartz grains.

[56]. The blocks of the agglomerate in this last locality are from one to three feet across.

[57]. It displays in the groundmass augite prisms in flow-arrangement, and is referred to genus 20 of the augite-andesites.

[58]. Referred to genera 16 and 20 of the augite-andesites.

[59]. These foraminiferal limestones are described on p. [319].

[60]. Proceedings, Queensland Branch, Geographical Society of Australasia, Brisbane, 1886, vol. i.

[61]. Geology of the United States Exploring Expedition.

[62]. Pacific Islands, vol. ii. 1900.

[63]. It is referred to the 5th sub-order (genus 18) of the hypersthene-augite-andesites characterised by prismatic pyroxene and more or less parallel felspar lathes in the groundmass, as described on p. [289]. It displays abundant opaque porphyritic plagioclase giving extinctions of oligoclase-andesine. The pyroxene phenocrysts have dark alteration-borders. There is a little altered interstitial glass. Spec. grav. 2·55.

[64]. I did not ascend to the top of Ulu-i-mbau. It is, however, evidently composed of basic andesitic rocks, occasionally amygdaloidal. On its slopes up to at least 600 feet above the sea occur agglomerate-tuffs and finer submarine tuffs, as above described, overlying foraminiferous clays, a submergence of quite 500 feet being indicated by the investing deposits.

[65]. I did not find any foraminiferal shells or other organic remains either in this tuff or in the similar tuffs occurring on the adjacent slope of Va-lili up to 1,100 feet. My specimens, however, are very small.

[66]. It rises in the background of the view.

[67]. They are described under sample E on p. [332].

[68]. Referred to genus 37 of the olivine-basalts.

[69]. On the right side of the river close to Vatu-kawa there are some cliffs displaying a section of the mountainous spur, referred to on p. [151], that separates the valleys of the Mbale-mbale and Vatu-kawa rivers, an exposure quite apart from the rocks exhibited on the adjacent southern slopes of the main range. These cliffs are formed of bedded grey tuffs marked by single layers of blocks 6 to 8 inches across and dipping about 30° S.S.W. The tuffs in their texture are not unlike sub-aerial tuff-deposits. They contain no lime and are composed of basic materials with a little palagonite. They seem to indicate some subsidiary vent, close to the present village of Vatu-kawa, which may have been active shortly before or during the emergence of this district.

[70]. These altered tuffs on the southern slope of this range are described on p. [332].

[71]. Referred to genus 16, species A, sub-species 1, of the augite-andesites.

[72]. Referred to genus 9, sub-genus A, of the augite-andesites.

[73]. Referred to genus 9, sub-genus B, of the augite-andesites.

[74]. Both these rocks belong to the hypersthene-augite andesites, showing phenocrysts of both monoclinic and rhombic pyroxene. The first belongs to the orthophyric order described on p. [290]; whilst the second belongs to the second order (genus 13, p. [287]) where the felspars of the groundmass are lathe-like and in flow arrangement.

[75]. The highest dyke trends N. 48° E. and is inclined from the vertical about 15° N.W. The dyke, 5 or 6 yards below it, trends N. 30°E. and is vertical. The dyke, 50 yards farther down, trends N. 35° E. and is inclined from the vertical about 5° N.W. The inclination was only estimated. The bearings are true.

[76]. Both the types are referred to genus 1 of the augite-andesites, the olivine, when present, being quite insufficient to give a character to the rock. They however belong to different species according to the length of the felspar-lathes, which in the doleritic rocks averages ·2 mm. and in the other type ·08 mm.

[77]. It is pointed out on p. [5] that this name is wrongly applied in the Admiralty charts to Mount Mbatini, a mountain about three miles south of it.

[78]. Referred to genus 13 of the augite-andesites.

[79]. They are blackish and somewhat compact (sp. gr. 2·67-2·71) and have very small felspar-lathes less than ·1 mm. long. They contain both rhombic and monoclinic pyroxene, and are referred to genera 1 and 13 of the hypersthene-augite-andesites.

[80]. I discovered this error in a rather practical fashion by ascending the wrong mountain. The natives were engaged to take me to Koro-mbasanga and they performed their task, my aneroid and compass soon indicating that I was not on the highest peak of the island, but on a lesser peak three miles north of it.

[81]. Vula Votu is the name of a peak lying to the east. Ngoinangai is a forked mountain still further east.

[82]. A kind of “edible” bird’s-nest is found in this cave.

[83]. This rock is described on p. [251].

[84]. It is described under Sample C on p. [325].

[85]. It is granular, but fuses in the blowpipe flame into a clear glass and gelatinises in HCl. Probably a form of natrolite.

[86]. It is described under Sample D on p. [326].

[87]. Ten Months in Fiji, London, 1864.

[88]. A Year in Fiji, pp. 154, 169; London, 1881.

[89]. It displays an abundance of small phenocrysts of plagioclase, augite, and olivine partly serpentinised, in a groundmass composed in the main of coarse augite grains (·025 mm. in size) and of felspar microliths (·07 mm. in length) in smaller proportion, with little if any residual glass. Specific gravity 2·98. It is near the Waikawa basalt, referred to on p. [202], and is placed in the same genus (13) of the olivine class.

[90]. They are described on p. [269] under the non-porphyritic sub-genus of genus 2 of the augite-andesites.

[91]. These rocks are in most cases referred to the orthophyric and felsitic orders of the hypersthene-augite andesites. The rocks of the last-named order prevail, and form the type of the group, as described on p. [291].

[92]. It belongs to genus 37 of the olivine class. The felspar-lathes average 0·2 mm. in length, and there is a little altered interstitial glass.

[93]. It is referred to genus 16, species D, of the augite-andesites. The felspar-lathes have an average length of ·3 mm.

[94]. Proceedings, Queensland Branch, Geographical Society of Australia, vol. i.; 1886.

[95]. Referred to genus 9 of the augite-andesites.

[96]. The general characters of these rocks are described on p. [308].

[97]. Geology of the United States Exploring Expedition.

[98]. A Year in Fiji, p. [22].

[99]. Described on p. [310].

[100]. These rocks are described on p. [308].

[101]. It contains small phenocrysts of plagioclase (medium andesine), and of augite and rhombic pyroxene, and is referred to genus 1 of the hypersthene-augite andesites.

[102]. See paper quoted on p. [31]. It is noteworthy that Mr. Horne refers only to a single floating island.

[103]. Journal, Royal Geographical Society, June, 1894.

[104]. Described on p. [309].

[105]. Described on p. [310].

[106]. Referred to genus 13 of the augite-andesites. The felspar-lathes average ·1 mm. in length, and there is a little interstitial glass.

[107]. Referred to genus 16 of the augite-andesites. There are two sets of felspar-lathes in the groundmass; the larger, ·23 mm. long, are more or less parallel; the smaller, ·04 mm. long, form a plexus.

[108]. Each division would theoretically also possess an orthophyric and a felsitic order; but these orders are not represented in my collection and need only be mentioned.

[109]. Not represented in the collection.

[110]. I apply the term “diorite” to granitoid rocks formed entirely of plagioclase and hornblende.

[111]. According to the size of the plagioclase phenocrysts, whether averaging less than or more than 3 mm. in size, these rocks may be divided into a non-porphyritic and a porphyritic sub-genus.

[112]. Petrographie des Viti Archipels; Miner. und Petrogr. Mittheil; band v, heft 1, Wien, 1882.

[113]. Physics and Chemistry, II. Report Scient. Results; H.M.S. Challenger; London, 1889.

[114]. Petrographical Notes on the Fiji Islands; Proceed. Amer. Acad. Arts and Sciences; vol. 34; no. 21; May, 1899.

[115]. Notes on the Limestones and General Geology of the Fiji Islands, Bull. Mus. Comp. Zool, vol. 5. Geolog. Ser. vol. 5, no. 1, Cambridge, Mass., U.S.A. Nov. 1900.

[116]. Wichmann describes rocks from the cliffs of the Singatoka river and from Ovalau.

[117]. Geology of the Solomon Islands, by H. B. Guppy, 1887, pp. 6, 36.

[118]. The term “felsitic andesite” is suitable for this microfelsitic type.

[119]. I have borrowed this term from Rosenbusch’s Microscopical Physiography of the Rock-making Minerals, translated by Iddings.

[120]. Challenger Reports, Physics and Chemistry II.

[121]. Neues Jahrb. fur Mineralogie, 1884.

[122]. For their mode of occurrence, see pp. [215], [220], [230-233].

[123]. Highly altered rocks of this class are exposed at the base of Mount Nailotha as described on p. [215].

[124]. See work quoted on p. 218.

[125]. See p. [230].

[126]. Quart. Journ. Geolog. Soc. xliv. 1888.

[127]. Zirkel’s Petrographie, iii., 694.

[128]. This basalt is not fusible in the ordinary blow-pipe flame.

[129]. In this connection see the description of the Soloa-levu pitchstone on p. [312].

[130]. See the note at the end of this chapter.

[131]. Quoted in Zirkel’s Petrographie, iii., 689.

[132]. I have visited this locality on several occasions with the special object of studying the relation of the basalt to the associated palagonite-tuffs and clays. A general discussion of this question would be out of place here; but I may remark that the conclusion arrived at by me is that these deposits are not sedimentary but are entirely the result of the disintegration of palagonite in situ. This is quite opposed to the view of their sedimentary origin held by Dr. Johnston-Lavis, Prof. Platania, and other Italian geologists.... The basalt is scoriaceous, semi-vitreous, and semi-ophitic, and closely approaches the type of basalt above defined.

[133]. Reisen auf den Viti-Inseln, as quoted on p. 22.

[134]. Petrographie des Viti-Archipels, quoted on p. 293.

[135]. See work quoted on p. 378.

[136]. Solomon Islands and their Natives, by H. B. Guppy, p. 78.

[137]. The region is described on pp. [224-228].

[138]. For the meaning of “talasinga” see p. [55].

[139]. The portion exhibiting the coral structure has a specific gravity of 2·54.

[140]. A good list of references to the early German authorities on the subject is given in the American Journal of Science and Arts for 1831, vol. 20.... Zirkel in his Lehrbuch der Petrographie (1893, vol. i. p. 565) gives most of these and many more recent.... Harker in his paper below named refers to a review of the earlier literature in Verh. naturh. Vereins. Bonn, 1851, vol. 8, and to a more complete bibliography by Meli in Boll. Soc. Geol. Ital. 1881, vol. 9.... British Association Report in 1889 by Professors Rücker and Thorpe on the Magnetic State of the British Isles.... Nature for August and September, 1894, &c.... Harker on magnetic disturbances in the Isle of Skye, Proc. Cambr. Philos. Soc. vol. 10, part 5.... Skinner in Proc. Cambr. Philos. Soc. May, 1894.... Clark in Journ. Roy. Instit. Cornwall, 1890-93.... Folgheraiter in Frammenti concernanti la geofisica, Rome: referred to in Nature, July 27, 1899, and Nov. 8, 1900.

[141]. Nearly all volcanic rocks at all basic are magnetic, owing to the constant presence of magnetite; but magnetic polarity, when the rock-fragment has a negative and a positive pole, is not directly concerned in volcanic rocks with the mineral composition.

[142]. Some of the earliest observations were made on granites and trachytes.

[143]. Geology of the United States Exploring Expedition, 1849, p. 294.

[144]. Quarterly journal Geological Society, vol. li., p. 469.

[145]. Wilkes’ Narrative of the U.S. Exploring Expedition, iii., 185.

[146]. Of the tuffs and clays, almost all submarine and often containing tests of foraminifera and sometimes molluscan shells, about 90 per cent. exhibit simple magnetism in a slight degree, but out of nearly 100 specimens tested none show polarity.

[147]. On p. [357] will be found some notes on the magnetic iron sand that occurs in great abundance in river and stream beds.

[148]. These values represent the number of degrees that the magnetic needle is repelled. The method is described above. A note on the average amount of polarity found in all my polaric rocks is given at the end of the chapter. The term “dacite” is here an equivalent of “felsitic andesite.”

[149]. This name has been wrongly applied in the Admiralty chart to the mountain of Mbatini. Koro-mbasanga, 2,500 feet, lies three miles to the north.

[150]. This rock is described on p. [109]. There is no exceptional development of magnetite for a basic rock in the groundmass.

[151]. Unfortunately, I have no data for the peaks of Na Raro and Vatu Kaisia, except that specimens obtained below the summits are non-polaric. In the case of Na Raro I did not retain the specimen obtained at the top; whilst in my ascent of Vatu Kaisia I did not quite reach the summit.

[152]. The mode of measurement is described on p. [366].

[153]. See pp. [2], [15], [18], [56], [62], [72], &c.

[154]. The Islands and Coral Reefs of Fiji, Bull. Mus. Comp. Zool. Harv. Coll. vol. 33, 1899.

[155]. Scott. Geogr. Mag. 1895.

[156]. Ancient Volcanoes of Great Britain, by Sir A. Geikie, 1897, ii. 260.

[157]. See Wichmann in Min. und Petrog. Mitth. band v. heft 1.

[158]. Amer. Journ. Sci. VI. 165, 1898. See also Agassiz on the Islands and Coral Reefs of Fiji, before quoted.

[159]. Proc. Linn. Soc. N.S.W. 1879-80, p. 358.

[160]. Quart. Journ. Geolog. Soc. vol. 44, 1888.

[161]. See Preface to the report of Mr. Andrews quoted on a later page.

[162]. Das Antlitz der Erde, French edition by E. de Margerie, ii. 534.

[163]. See the paper before quoted on the coral reefs of Fiji.

[164]. Bull. Mus. Comp. Zool. Harv. Coll. vol. 38. Geolog. Ser. vol. 5, no. 1, 1900. On the Limestones and General Geology of the Fiji Islands, by E. C. Andrews.

[165]. Quart. Journ. Geolog. Soc. vol. 47, p. 590, 1891. See also Mr. Harker’s paper below quoted.

[166]. Geolog. Mag. June, 1891.

[167]. Seemann’s Flora Vitiensis, Horne’s Year in Fiji, Hillebrand’s Flora of the Hawaiian Islands, Hemsley’s “Flora of the Tonga Islands” in Journal Linnean Society, Botany, vol. 30.

[168]. See Hutton Proc. Linn. Soc. N.S.W. 1896, Baur, Amer. Nat. 1897, Pilsbry, Proc. Nat. Sci. Philad. 1900, Hedley, Proc. Linn. Soc. N.S.W. 1892, 1899, &c.

[169]. The term “basalt” is here used in a general sense to include olivine-basalts, basaltic andesites, and other basic types of the augite-andesites and hypersthene-augite andesites.

[170]. The usual signification of “koro” as a prefix or part of names of hills and mountains is a “prominence” or “projection.” It is a mistake on my part to assume that in such cases it is as a rule equivalent to a town or village.

Transcriber's Note

There is some inconsistent spelling and hyphenation in this book which has not been normalized.

Some corrections have been made to the text. In particular, punctuation was corrected. Additionally, the following changes have been made:

p. [10] beween -> between

p. [75] ·15 m. long -> ·15 mm. long

p. [114] ts -> its

p. [208] aud -> and

p. [244] Pyroxyene -> Pyroxene

p. [270] adoped -> adopted

p. [345] tea-estat -> tea-estate