Kleinwächter, George. "Researches into the geology of Formosa." Journal of the North-China Branch of the Royal Asiatic Society n.s. 18 (1883): 37-53.

[P. 37] On the journey from the South Cape to Takow and on different other excursions which I undertook during my stay in Taiwan, I had occasion to make some observations on the mineralogical composition and geological formation of Formosa.

I am aware that they are imperfect and only comprise some parts of that island, a fact which might deter me from giving these notes publicity, were it not, that even a few established facts may be of interest and further the object of true Geology, which is to arrive at a complete knowledge of the constitution and history of every part of our globe.

Formosa must still be considered as a "terra incognita." We know that large mountains nearly bisect the island, that the plain on the west is inhabited by the Chinese and the East by Aborigines, so called Savages. We know what her soil produces, but we know not, what her soil consists of and what treasures are hidden under it except in the northern parts, where now Coal mines and Petroleum wells are worked. Names have been given to the most prominent peaks and their heights have been ascertained or estimated; but beyond that nothing is known of the outlines of these mountain ranges or the valleys between them; and of the physical aspects of the East coast we are still less able to judge, it being closed to our view. This is however not astonishing. Those whom their vocation leads to this island, have other pursuits to attend to and those, who did spend a few days in the interior, went there out of curiosity or for Ethnological studies. The [p. 38] attraction of the Savages naturally led to a neglect of the country they live in. Hence few observations of a geographical and none whatever of a geological nature have ever been made or brought to notice, at least as far as the South and centre of Formosa are concerned.

Want of time has also prevented me from making long travels of exploration and obliged me to confine myself to South Formosa only, i.e. to that part of the Island which lies between the 22nd and 23rd degrees of latitude.

The following are the results of my investigations:

The southernmost end of Formosa on an average 5 miles broad, is protected against the waters of the ocean by two hill ranges, which run along the east and west coast; the one called Gooswa Promontory extends from the South West Cape in a straight line 7 miles northwards, its two highest points in the middle and towards the end being 538 feet and 627 feet high, respectively. The other range commences with the South Cape, runs gradually rising towards northwest, opens into a broad plateau and turning to N.E. terminates at the Savage village Shamalee. Four miles to the north west of the South Cape is a peculiarly rugged hill, 1,035 feet high, from which the land slopes gradually towards the east range forming another plateau. From Shamalee westward extends a double peaked ridge, and south of this the land is further divided by two parallel ranges, rising to more than 2,000 feet, one of which terminates in a cone shaped mountain, Remarkable Peak, 1,083 feet above the level of the sea. East of the Gooswa Promontory and Bay hill, which is a small isolated hill, south of Expedition Bay, lies a level tract of land, at its widest part 3 li broad. In the middle of this, at the foot of the Shamalee range is the District Capital Hêng-ch'un-hsien, and in its northwest corner at the mouth of a broad river lies Chê-chêng sive Langchiao. A mountain vis à vis to this walled village and bearing the same name forms the link between the hills south and north, divided from the one by a deep chasm and from the other by the Langchiao river.

Turning now to the composition of all those capes, [p. 39] mountains and hill ranges, we find in the cliffs at South Cape abundant remains of corals, which make up almost the entire mass. The crest of the east range is a series of limestone rocks with fractures and fissures, and the west range shows the same towards the seaside, but its top and inland slopes, as well as the surface of South Cape and the eastern slope of that range are covered with calcareous sand. The beach round Kualiang Bay consists of fine coral sand, and numerous recent Zoophytes red and white are found. The other mountains are thickly wooded in luxuriant tropical vegetation, the tree and shrubs which cover them up to the summits, have protected their surface from the wasting influence of atmospheric agencies, their underlying formation therefore is not so apparent to cursory observations. At one spot, however, the waters of an extensive spring have laid it open and disclosed strata of limestone. This spring, by the way, is situated in the territory of the Kualuts in a beautiful forest. Women and children of the savage tribe were sitting around it and filling their bamboo tubes with water, when I approached on the way to their village. As my escort informed me, this spring has high qualities in curing wounds and smallpox. It belongs probably to the class "Earthy waters" of which the chief contents are sulphate and carbonate of lime. The cone of Remarkable Peak is of compact limestone; limestone rocks reach out of the water at several pieces along the shore of Kualiang Bay, and within the walls of Hêng-ch'un-hsien I again found a large pile of Limestone Rocks. The soil which forms the upper layers in this district is throughout of argillocalcareous nature, varying from soft earthy shale at the foot of Remarkable Peak to fine yellow clay exposed by the rivulets of the plain.

On the mountains between Langchiao and the Pacific Coat "bright flames" have often been seen "jutting out of the hard-baked earth," a statement which, as I have not been there myself, must at present suffice for our researches into the composition of that region, though all details as to the height at which this phenomenon was seen and as to the nature of the ground are wanting. The hardbaked earth probably was [p. 40] thale [sic, shale] or mudstone, similar to that, which I found on Sugar loaf hill (see further on). The flame may be caused by the ignition of sulphuretted hydrogen, which would point to volcanic action, or by the ignition of the vapours of a petroleum spring, which would point to underlying strata of coal or bituminous shale and sandstone cavities. On the whole I think the latter explanation more probable. Coal indeed has been shown to me by the District Magistrate as having been found within the limits of his jurisdiction. The Langchiao river finally gives evidence of Sandstone by the reddish fragments which it contains.

Let us now follow the military road, which connects this southernmost part of Formosa with the great plain. Immediately after leaving Langchiao it passes over the east side of a low hill, apparently a sanddune, which forms Langchiao point, goes along the bay of the same name on a strand of coral sand and ascends the slopes of a sugar loaf shaped hill, 411 feet high, which fall steep to the sea and consist of mudstone containing iron. From here stretches the Liliang ridge 6 miles northward, the two southern summits of which rise to the heights of 2,263 and 2,437 feet, and the northern one, near the town of Hongkong, to 3,365 feet.(1) The gentle slopes of this range form a "raised beach," below which a second one has formed, covered with large sandstone pebbles, débris of the formerly surfworn upperterrace. Some of these are red, other variegated, showing yellow, bluish, reddish, and purple lines, some show streaks of quartz, all of them sparks of mica. Corals and coralsand do not reach beyond Langchiao Bay. At one spot, among others, where a spur reaches the sea, the road was cut through the solid rocks and disclosed dark red breccia. Horizontal lines and Tideripples were visible at different places on the sandstone cliffs at a height of about 50 feet. Further on, the strip of land, which runs between the sea and the mountain range, gradually widens into a sandy tract, on which a few acres have been cultivated with rice and sugar. The cliffs are overgrown with brushwood; but where torrents break over them, white sandstone rocks (quartzites) [p. 41] are uncovered, and a section showing huge boulders of the same material covered by a gravel and sand was also laid open to the eye.

The town of Hongkong is beautifully situated, 30 li from Langchiao, on an alluvial tract of dark sand covering strata of flagstones, which extend to the sea and form a bar around the shallow harbour. They are deposits from the two mountains, which here meet the Li-liang Sua. The coast line northwards shows shingle of a similar nature; houses and walls are built of these dark-grey sandstones; they are less micaceous than the before mentioned red ones but are mostly traversed by veins of quartz; the specimens collected one shows crystalization, the other both this and slaty texture. 5 li north of Hongkong another mountain torrent enters the sea, its banks are precipitous and at its mouth a dark cliff rises, which from its shape is called "Saitou," i.e. Lion's head.

2 miles further on, on similar ground as Hongkong, also pierced by a small river and surrounded by a stonebar, lies the village of Chetonka. The same may be said of Namchieh, the next station on the road. Except at these points the coast ion bold and steep, the hills in some places descending almost to the waters edge. On one of these projections, where a fort has been built on the rocks, I met with traces of coralline limestone; otherwise this part of the coast consists of white sandstone cliffs like those before Hongkong.

From Namchieh I made an ingress among the mountains. After crossing the alluvial plain, I arrived at a gorge through which a river flows; from its entrance a level terrace extends towards the seashore, and at the other side a narrow valley opens to the left and right, partly cultivated. I followed the river eastward and ascended one of the hills, where I had opportunity to observe the physical aspects of the neighbouring mountains: this district is made up of detached rounded hills and short anticlinal ridges, whilst parallel ranges striking from North to South are the general character of the southern system. The scenery here is also wilder and more picturesque.

[P. 42] The specimens collected near Namchieh belong to the Clayslate group, of various description and different gradation of metamorphosis.

1. Hard and compact, sub-crystalline fine grained slate, splitting into plane layers.

2. Somewhat arinace[o]us rough feeling shale, not very fissle, rather friable.

3. Shining, foliating schist.

The last named was by position the lowest having been detached from the rocky bank of the river, which washes these schistose strata.

From Namchieh the road winds around the Chao Shan, 1,340 feet high, and enters the great plain. The ground becomes darker and the beach presents a deep black sand, which continues all along the coast as far as Takow. The mountains here recede and stretch in a North-North-East direction to the foot of the Kueilei Shan (i.e. Punch and Judy Mountain) which is the backbone of the southern central range.

The hills northwest of this I have examined. They are throughout a mass of black shale of slaty, not schistose structure, much like, though inferior to the so-called roofing slates found in European primary districts. What the bamboo is to the Chinese, the slate is in many respects to the Savages, who live on the steep flanks of these rugged and barren mountains. The walls and roofs of their houses and granaries are composed of slate, slate plates are the shutters placed in front of the openings which do service as windows and doors, block of slate serve as seats, on slate again they crush the millet. This millet and a kind of potato, called "Wassa" in the Gali [sic] language, are the only produce of these regions, the one growing in the valleys, the other on thin layers of dark soil, which cover the lower hills.

About 2 miles North of Bankimsing a mountain stream has broken through the outskirts of the Kueilei Shan; a terrace of clay of about the same height as that of the Namchieh shows also here the former level of the river; the rocks at one side of the pass consist of purple coloured shale, and nearly horizontal strata dipping from West to East are visible crossing the strike of the hill. Past this gorge valleys open towards the North and South; the latter turns Eastward and reaches to [p. 43] the foot of the Kueilei mountain, which here rises abruptly to a height of 9,050 feet. The ranges flanking this valley and resting on or issuing from the main mass, at an elevation of about 4,000 feet, partly slope at an angle of about 25°, forming terraces at some places, and partly fall abruptly. The river bed, at the season I visited it, in February, contained but little water, as all the other streams of a similar nature, which in summer, however, are furious and almost impassible torrents. This river bed, when seen from the heights, looks like a white band wound through the brushwood. The stones which cover it and which extend far out into the plain, till hidden from sight by the overlying clay, are particularly interesting, because they give us a clue to the mineralogical composition of the principal mountain from which they come. Besides Black Slates, I found the following fragments :

1. Hornblende-schist, with flakes of mica, traversed by quartz veins, coated with iron and waterworn crystals of felspar;

2. Felstone-Porphyry, hard and compact veined and covered with white felspar, which shows an uneven and splintery fracture and is highly crystallized.

It remains to add, that throughout these masses of Sandstones and Slates I have found no organic remains except a stem of wood inclosed [sic] in a nodule of ironstone which I picked up somewhere near Hongkong. Although this does not prove that there are no fossils embedded, they are certainly rare, as may well be expected, considering the nature and age of these rocks.

The above notes and observations, though they may seem scanty, nevertheless enable us to draw the following deductions:

1. The highest central mass of mountains in South Formosa is of primary age, consisting of crystalline schists, broken through by igneous rocks, such as Porphyries.

2. The mountains flanking the highest central mass to the North-west, West, and South West as far as Namchieh are made up of Silurian Slates and Shales.

3. The hill ranges from Namchieh to Hêng-ch'un-hsien are [p. 44] composed of the following alterations of strata, traversed in some places by veins of quartz:

a. Arinaceous shale, which is apparently a transition from the clayslate to −−−−

b. Darkgrey micacious [sic] flagstone;

c. Grey sandstone;

d. White sandstone (quartzite);

e. Red breccia (conglomerate);

f. Red Sandstone

All of these rockmasses except the white sandstone (Silurian) which is found lowest on a level with the sea, are probably Devonian deposits, lying on Silurian strata and overspread by the Carboniferous System which contains seams of coal and ferruginous shale and ironstone.

4. The district south of Hêng-ch'un-hsien was originally a Coral Island.

So much for the mountainous part of South Formosa. The plain, however, so important and well known from an economical point of view is not less interesting geologically. It extends from Pangliao northward through the whole western part of the island; a series of hillranges, which approaches the seashore near the city of Taiwanfu, divides it into two parts, the southern of which only falls within the boundary of this paper. This, the most fertile district in the whole island, is an alluvium of posttertiary origin, a rich loam derived partly from the shales of the Central Mountains, partly from the Sandstones south and partly from the Limestone hills, which here and there reach above the level of the lowland. These are the great and small Kangshan, the Whale back, Apeshill, Saracen's head, Fêngshan, and, still surrounded by water, but belonging to the same category, Lambay Island near Tangkang.

Apeshill or Taku Shan (beat the drum-hill, so called because of the rocks dangerous to navigation, which lie at its foot and which make the junkmen appeal to the Gods by beating the gong) has been very well described by Dr. Guppy in his paper [p. 45] "Notes on the Geology of Takow"(2) and correctly characterised. It remains for me but to determine the period, in which it originated, therefore it is necessary to particularize the various kinds of Limestone and allied rocks found, and the fossils, they contain. We have:

1. Compact Limestone, a hard smooth fine grained rock, generally of bluish grey colour;

2. Saccharine or Statuary Marble, fine grained, white, resembling loafsugar in texture;

3. Oolite, composed of grains connected by a calcareous cement;

4. Marl, friable compound of lime and clay;

5. Chalk or rather indurated carbonate of lime;

6. Red clay.

To Dr. Guppy's List of Fossils only one specimen is worth adding, but an important one, namely the coinshaped, foramimiferal, shell Nummus laevigata, which however is not so much developed that I could speak here of Nummulitic Limestone. But it serves us as a guide in fixing the time of the last great upheaval of Apeshill, i.e. the beginning of the Tertiary Period. These are traces of the cretaceous system, but the main composition of Apeshill, the plateau and its fringes are decidedly Oolitic, while I am inclined to think that the summit of Apeshill and the fundamental rocks reach as far back as the Carboniferous epoch. The characteristic features of the Mountain Limestone: subcrystalline, intersected by joints and thus breaking up in large tabular masses−as well as the fragments of older corals (Lithostrotia are abundant) which are spread about below and form part of the earthy varieties, point to it. Examination of the caverns and fissures, which Dr. Guppy recommended to any resident at Takow, did not bring forward anything particular, so far as I have been in them. The fissures form a labyrinth of subterranean passages of varying width, as much as 30 feet deep, and the caves reach down to an immeasurable depth; in fact Apeshill is a vast cave, to which access would be easy enough, were not an amount of [p. 46] curiosity required that would surpass wisdom. Some of the smaller caverns, which I entered, presented stalagmites and stalactites, also columns, but none very extraordinary. The floor deposit consists of calc-tuff. Bones of goats and cattle, which fell down and died there are to be met with; of living beings large spiders, lizards and monkeys have their abode here.

Whaleback Hill is the sea bottom tilted up by subterranean force. One half of the broken crust remained standing at angles of 25-30°, while the other half tumbled together. The rocks present the petrified bottom of the ocean with its shells in situ; but it is impossible to determine by the fossils, with which of the three (not only two) traceable upheavals of Apeshill, Whaleback simultaneously arose.

Fêngshan (Phoenix-mountain, so called from its birdlike shape) is also limestone formation; it lies 6 miles South of Takow, near the Coast and its rocks reach into the sea. From Fêngshan North-east a low line of hills continues which has at one time most probably been a line of Sanddunes as the Takow spit is at the present day.

At the mouth of the Tangkang River, 9 miles S.W. from the town of the same name, lies the small island Hsiao Liu chiu (a name referring to the Chinese idea that Formosa in ancient time formed part of the kingdom of Liuchiu). Lambay Island, as foreigners name it, is of similar origin to Apeshill, but of more recent age, not older than tertiary. The fossil shells embedded in its limestone differ not at all from species at present in existence. The island is surrounded by living coral reefs, which at ebb-tide are visible above the surface and extend far into the sea, where they shimmer through the waves from a depth of 10 to 20 fathoms, so clear is the water here. The beach at the Eastside of this little isle is covered with white coralsand and the greatest variety of Cockles and shells is found, a remarkable contrast to the black shore of the opposite mainland, on which no trace of living beings is met, save crustacea burrowing in the sand. At the Southwest point of the island are some not very extensive caverns. The islanders informed me, that when they, or rather their grandfathers, [p. 47] settled there (120 years ago), they found human bones in them and a table of stone. Chinese, it appears, prefer to keep away from caverns: on Apeshill they fear the monkeys and here, the ghosts.

In crossing from Lambay Island to Tangkang, which town lies on indurated mudflats, the material of which was carried down from the Slate mountains by the same river, which they now embank, one sails over a depth of more than 300 fathoms. Such an extraordinary depression is most singular in the Formosa channel, which on an average is only about 20 fathoms deep, so much so, that the Commander of a British gunboat, who first discovered it, may be excused for taking this spot for the submerged water of a vulcano [sic]. The geological condition of the surrounding land speaks against this assumption, and we cannot, with due regard for the local circumstances explain it otherwise than as a chasm, which is gradually filling up.

From what I have said up to the present, it would almost seem as if the popular idea, "Formosa is a volcanic island," was altogether wrong. There is in truth no trace of recent volcanic eruption in the districts above described, but very close by, only 3 miles Northeast of the port of Takow is a tract of land, the peace and quiet of which has never been suspected by Takow Residents as hiding the recent seat of action of the subterranean forces, and it was not until in reading the "Taiwan fu chih," I came across a passage recording the last eruption, that I myself visited those hills. They are the "Chih Shan" known to foreigners as the Pineapple hills, where the most delicious fruit grows, that Formosa produces. The chapter of historical events says: "In the 61st year of Kang-hsi (i.e. 1722) in summer Chih Shan opened 8 chang (80 feet) long and 4 chang (40 feet) wide; black earth (mud) same out; on the 2nd day, by night, fire came out, several feet high;" and the Mountain and River chapter notes with reference to Chih Shan, the name of which is also explained as derived from the colour of the ground, that "sometimes fire is rising."

There we have an accurate description of a volcanic outburst from a Chinese record and quite in accordance with the theories [p. 48] of foreign science. The fire was, of course, only visible by night because it was not fire, but simply the glowing light of the ejected material, and this, described as black earth ('hei tu') was hot mud, which in the usual course would afterwards assume the reddish brown colour of iron dust. This was the case here; for on my exploring visit I found the hills to consist of a light and porous reddish yellow earth, very much like clay, but being in reality tufa, the chemically transformed vulcanic [sic] mud, and on the surface at some places thin layers of tuffstone, the loose tufa cemented. The district covers about three square miles and includes a small lake; it is the outcrop of not one only, but frequent small eruptions at different places. One spot, where an outburst of mud had taken place, I have traced on the extreme western hill, 3 miles East of Whaleback, and these are several points which render it probable that this is the one alluded to in the records. Where the vent was, is now a pool of water, and on the south side, where the accumulation is higher than on the northern, a thin crust of scoriae is found. Not far, S.E. from the supposed vent, I noticed a vertical cutting of a dyke, which shew [sic] the following interesting sequence of layers, form the top downwards:

Soft Ground,
Scoriae,
Yellow Tuff,
Grey Tuff,
Bluish Black Tuff,
Dark Yellow Tuff,
Light Yellow Tuff,
A Dark Yellow Line (Harder),
Whitish Tuff,
Dark Yellow Tuff,
Scoriae,
& c., &c., &c.

[P. 49] I am unable to explain the variation of the colours otherwise than that the different materials deposited contained different proportions of lime and silica. Among the fragments thrown up I have especially to mention a large piece of rock-crystal and one of white sandstone, which indicate the deeper strata.

Hot Springs are also said to exist in this district according to the "Taiwan fu chih;" but I have not found any. A river called Liu huang chiang (Sulphur River) rises here and runs into the Lagoon at Takow; but its name may be derived from the Sulphur springs at the foot of Apeshill.

Northeast of Chih Shan commence the outrunners of the mountains, which, as above-mentioned, bisect the Formosan plain. My stay in Takow, however, has not been long enough to allow of my exploring them and the climate of the 22nd degree of latitude is not in favour of outdoor-exercise.

From this description of the geological condition we may now deduce the following series of evolutions to have taken place, which together make up the Geological History of South Formosa and to some extent of the whole island.

1. First in order must be placed the deposition of the crystalline schists, which probably correspond with F. von Richthofen's Sinian System. By folding of these, the central mountain ranges originated.

2. A period of volcanic activity succeeded, to which the falsitic traps owe their existence.

3. Then followed abrasion of the primary mountains from which fresh clayey deposits at their base, the slates and shales of the present day were derived; sediments of a sandy nature were washed on, and while the sea was rising more and more during the Silurian and Devonian periods, all those strata were accumulated, which now form the mountainous district of South Formosa. The fissle sandstones and arinaceous shale near Namchieh show where the two substances, sand and clay, joined.

4. At the end of the Devonian Period the land appears to have risen again. The red conglomerates which occur at the [p. 50] height of about 200 feet above the present level are the remains of a then gravel or pebble beach.

5. At that time also vegetation flourished and the surface of the ground was overgrown with plants. The sandy shore was studded with that low kind of Palmtree, Cycadeae, which we now find along the sandy bank of the plain; for an ironpyrite has preserved us a piece of the trunk showing the same organic structure.

6. Periodical inundations and gradual submergence of the land followed; new sediments accumulated and covered that primary and subsequent vegetation, which compressed altered and mineralized we now find as seams of coal.

7. Earth movements or Crust motions seem to coincide with this, the Carboniferous period. Vulcanic action had long since ceased on the Formosa as it then existed, but manifested itself at the sides, giving origin to the basaltic Pescadores in the West, the Pinnacle group, Tiau-su Island in the North East, and Harp Island, which in 1853 was still in a violent state of eruption, on the East Coast. The volcanic districts near Tamsui and North-east of Taiwanfoo are also proofs of the volcanic activity, which developed at the foot of the Central Mountain ranges, at first under and afterwards above water. Under these the subterranean forces worked by upheaving the mass, too strong to be disrupted, and while the island thus more and more rose above the waves, which surrounded it at the end of the Carboniferous period, its sides gradually subsided, thus contributing to the receding of the sea and subsequent denudation.

8. Meanwhile corals had commenced their structures on the sedimentary bottom and built their reefs around the land. Thus in the South, for instance, Remarkable Peak originated, which now as a compact limestone cone point into the air, and a series of reefs extended around it. Simultaneously with a general rising of the island those first reefs as well as the ground, to which corals had attached themselves, rose above the surface of the ocean. The coral growth continued, not on the original rocks, but around them, forming a new series of reefs, till after again rising the whole formed a coral island [p. 51] corresponding in all its characteristics with the corralline islands existing in the Pacific Ocean, at the present day. There, a fringing reef of coral is often found immediately attached to the land, whilst in many other cases the reef surrounds a volcanic island, the intervening space of irregular, but nowhere of great width, forming a lagoon or channel of still water, protected by the reef from wind and waves. The reefs very often form an arc, the convexity of which is towards the prevailing wind, and a straight line of reef not generally rising above the reach of the tide, forms the chord of the arc. Here at the South end of Formosa we have two Mountain ranges, Coral-reefs built up by generations of zoophytes, now raised high above the sea, solidified by age and chemical agency and transformed into compact limestone. They form an arc open towards the South, whence for six months during the year the South West monsoon blows and evidently has blown for ages, and as the reef which formed the cord of this arc, we may identify the plateau between the South and South-west ranges, which, except in the middle is lower than the other hills and was at one time still below the level of the sea, whilst the higher reefs already surpassed it. The hill ranges within the circuit may be looked upon as the sedimentary bottom, raised by previous earth movements, answering to the volcanic rocks to which the corals attached themselves and around which their fringes extended. The navigable passage spoken of as leading through the reef into the inclosed [sic] lagoon is found at Langchiao, but it is by no means accidental, that this opening should be there; for as the convexity of the arc is towards the wind prevailing in summer, so this passage has been kept open by the North-east monsoon which during the winter months was driving the waters of the Formosa channel into the lagoon within the reefs. In consequence of a third upheaval, the lower reefs also rose to the surface and the channels of still water which were between the reefs and the land emptied themselves, leaving behind layers of mud, clay and sand as proof of their past existence and as a foundation for the fertile valleys that are now under cultivation.

The second great Limestone formation, Apeshill, is of a somewhat different nature. It seems to be a link in a series [p. 52] of barrier-reefs, which stretched along the whole South-west Coast of Formosa. Like the oldest rocks of the South Cape district it also was built up during the time of subsidence (Carboniferous period), hence its great height of about 1,000 feet, not reckoning the probable depth under the surface, and upheaved at three consecutive times. It stands witness to the different periods, which intervene between the Carboniferous and the Tertiary, bearing traces of the clayey and cretaceous sediments which were deposited during that time in the Formosa Channel.

9. While the denudation of the mountains went on, and afterwards by torrents of rain, which deepened the channels, widened the valleys and broke through the rocks, forming these gorges, through which now rivers rush into the sea, débris were carried down and gradually filled up the shallow sea between the land and the outlying islands; fresh sediments were washed on to these, attached themselves and gradually connecting, formed the outline of the present plain.

10. At the time of the Dutch, towards the middle of the 17th century, new Formosa was so far formed that only shoals and flat islands, Anping for instance, were still unconnected with the mainland. South of Fêngshan a large shallow Bay existed. The land generally was so marshy that the Dutch laid their roads on artificial dykes. The plain extended more and more into the sea: the city of Kushia, built on the seashore (North-east of Apeshill) 150 years ago, now lies a miles away from the tidal waves; shallow lagoons have taken the place of former expanses of water; on former islands sugar cane is now planted, and the sportsman finds almost every year more of his snipeground turned into ricefields and new marshland consoles him for his loss. The almost visible elevation of this Formosan plain is, of course, not due alone to alluvial accumulation, but the subterranean forces, which already have begun to alter the surface of the plain, by throwing up hills (mud-volcanoes) have their share in this useful work of extending the land, as the slight crust motions, which accompany the frequent earthquakes, tend to raise it. Suppose that the present conditions continue, in from 50 to 100 [p. 53] years, the inner harbour at Takow will no longer exist as such; besides having become too shallow for vessels of even the lightest draught, it may possibly be closed altogether by the masses of rock which tumble down from the sides of the narrow entrance, and although the outer harbour may replace it, it will not offer the same shelter as is found now within the precincts of Apeshill and Saracen's head. The open roadstead of Anping, already 2 miles away from the port, will be pushed out to sea more and more, and Tangkang, situated at the mouth of a powerful and for native craft navigable river, which rather deepens its bed, and already an important mart and centre of the junktrade between this part of the island and the continent of China, is likely to become the most suitable harbour and the principle seat of the Export Trade of South Formosa.

Notes [in original]:

1. These figures are taken from the "China Sea Directory."

2. Journal N.C.B. of R.A.S. vol. XVI, 1880.