By THAN HTUN (GEOSCIENCE MYANMAR)
Episode:4
DR William King (1833- 1900) was a British geologist who studied civil engineering at Queen’s College, Galway, and at Queen’s University before joining the Geological Survey of India on 4 March 1857. He succeeded H.B. Medlicott in April 1887, as Director of, the Geological Survey of India. He was then already 54 years old, but the Government of India, relaxing the retiring age rule, granted him six extensions year by year and thus retained his services until 20th July 1894. At the time of his retirement, he was 60 years old and had put in a recorded service of 37 years. He was succeeded by Carl Griesbach as a Director. During his Directorship, no important change took place in the cadre of the Department, and the number of geological officers varied from 12 to 14 in the graded category. During this period the Department lost six Officers, three by retirement, one by resignation, and two by death, and their places were filled by six new appointments. The outgoing Officers included C.A. Hacket, F. R. Mallet, R. B. Foote, P. Lake, F. Fedden, and E. J. Jones.
The Officers recruited during this period included Parvati Nath Dutta, Thomas Henry Holland, William Bruce Dallas Edwards, and Frederic Herbert Smith. Besides the above Officers, Dr H. Warth, also known as Hugo Signund Freiderich, was transferred in September 1890 to the Department from the Forest School, Dehra Dun. Ten months later, in July 1891, he went to Madras as the Superintendent of the Museum, subsequently returning to the Survey in December 1893.
Regarding the Madras field, the work of C. A. Oldham King and Foote led to the mapping of the Cuddapah and Kurnool basins, and their subdivision into stages, and the discovery of the Upper Gondwanas of Guntur and Ongole. On A. C. Oldham’s death in 1868, King was appointed Deputy Superintendent for Madras and he continued with Foote the mapping of the Southern Mahratta country and adjacent districts. Foote recognized two principal elements in the gneissic rocks, viz., of granitoid and schistose nature, arranged in great bands traceable for miles with a general N. N. W. – S. S. E. strike. The schist bands he was later (1886) to separate from the gneissic complex as Dharwars. King continued his investigations on the coal measures of Chota Nagpur and Chhattisgarh until 1890. King and Foote discovered stone implements over a wide extent of the country to the west and north of Madras city. Similar finds were later made by Ball and Theobald in other parts of India and Burma. A number of economic investigations in Burma were also included in the programme of the Survey during that period. Between 1888 and 1891 Noetling investigated the oilfields of Yenangyaung and demarcated the oil-bearing zones. He also investigated the iron ores, ruby, and tourmaline occurrences in the Shan States, coal in Chindwin, and amber and jade deposits in Upper Burma. Between 1888 and 1892 Hughes examined the tin deposits in Tenasserim, which finally proved to be quite promising. Bose and Datta also worked in the Tenasserim valley in 1892 and 1893, where they found large supplies of coal.
Amber mines
Fritz Noetling, a palaeontologist, reported the amber mines and jade mines in Upper Burma, and significant points could be extracted as follows:-
The amber mines which were examined by me are situated about 5 miles to the southwest of the village of Maingkhwan on a low isolated hill, which rises abruptly from the surrounding plains. There is no doubt that this hill, which has an elongated shape, is the main axis running N. E. – S. W., formed part of a formerly wider extended river terrace, which has, however, been considerably denuded and worn away during the process of time. It is therefore a priori not improbable that amber may be found also at other localities in that part of the country near the Nangotiemaw hill. I was subsequently informed that the amber mines proper – that is to say, those which at present produce the amber – are situated west of, and are close to, a village called Lalaung.
In terms of geology, the strata in which the amber is found belong to theTertiary formation, probably to the Lower Miocene. The exact age cannot be stated yet, as no fossils have so far been discovered. The amber-bearing beds consist of soft, blue clay, which is superficially discoloured brown, the discolouring being apparently due to the disintegrating action of organic acids formed by the extremely rich vegetation; it may therefore be expected that the brown portion of clay forms only a thin covering of thickness on the exposed parts of the blue clay. It might further be anticipated that the amber found in this clay, would be of inferior quality to that which is extracted from the blue clay. The experimental shafts sunk by me have proved that both these views are correct.
It may be well to keep in mind that amber is nothing but a kind of resin that has been produced in exactly the same way as the resin is produced by trees nowadays, only that the amber-producing trees – pine trees very probably – were extremely rich in resin, and that the process of production went on during Tertiary times. The hardened resin accumulating in the amber-pine forest during the course of centuries was gradually washed away by the rains, and being of low specific gravity, easily float down in the river to the sea, which then covered the whole of Upper Burma, where it was again deposited here and there. The amber deposits were covered with clay, and the deposit of the sea, and this process may have been going on for a long period till the amber-bearing strata, as they present themselves in their present thickness of not less than 600 feet, had been formed.
The amber is found in lumps of various sizes up to the size of a man’s head; these are either rounded or more frequently flattened, having exactly the same shape as the pebbles on a beach, thus proving that they have undergone a considerable amount of wear and tear before they were deposited.
The colour of the amber varies from light yellow to dark brown, in all shades and various degrees of transparency, the most common colour is a dark reddish-brown, which may very well be compared with the colour of dark Madeira wine. Specimens of this kind are nearly always flawed and contain streaks of minute fragments of wood. Transparent pieces are of a reddish colour. The colour most valued by the natives is honey-yellow; larger pieces of this kind are rare. The milky-white, cloudy-coloured variety, such as is at present particularly appreciated in Europe, does not occur in the Burma amber.
The amber is extracted in the most primitive fashion. No surface indications reveal the presence of a pocket of amber; the selection of a spot where mining operations are going to be started is perfectly accidental. Having selected a spot, a man digs a square hole of about 1.5 feet by two feet by means of a rude tool, which resembles the Burmese taywin, that is to say, a short chisel-shaped iron affixed to a heavy wooden club-shaped handle. It is perfectly clear that under this system of extraction, the output solely depends on luck; one man may find a large quantity, while another works for weeks without getting more than a few pieces.
Although I have no doubt that amber is found in large quantities either at Lalaung or elsewhere, it may safely be said that it will never form an article of export to Europe unless the fashion changes. The two qualities which are against it finding a market at home are, its colour; second, is fluorescence. There is, however, no doubt that the very moment the Burmese amber, which in its physical qualities is similar to the amber produced by smelting the refuse of European amber, would appear on the market as a serious competitor to Europe amber, the firm would at once take up the manufacture of artificial amber. In conclusion, I would recommend that experiments on a large scale should be carried out either at Lalaung or elsewhere with a view to ascertain whether there exists a sufficient quantity of amber to pay a more systematic mode of working.
Jade mines
Two different groups of mines may be distinguished, which we may call the pit and quarry mines, respectively. The pit mines are situated along the bank of the Uru river, beginning at about Sankha village and extending for a distance of about 40 miles further down. The quarry mines near Tawmaw village are situated about eight miles to the west of Sankha village on the top of a plateau rising to about 1,600 feet above the level of the Uru River.
Although it is quite probable the mineral which is commonly called jade and which forms the object of an extensive industry in the Mogaung sub-division is different from the jade proper, I may be allowed to use the old name till chemical and microscopical analysis will have revealed the true nature of this mineral. The Tawmaw mines afford the best opportunity for the study of the geological condition under which the jade is found. It here forms a vein of considerable thickness in an igneous rock of blackish-green colour. The jade is purely white crypto-crystalline mineral much resembling the finest marble, containing here and there green specks of various sizes, which form the jade proper. The jade vein is separated from the black rock by a band of a soft and highly decomposed argillaceous mineral. The strike of the vein is approximately north to south, and the dip at about an angle of 20°, varying considerably towards the east.
It is difficult to determine the age of these igneous rocks. Before Sankha is reached a similar rock may be seen breaking through Tertiary sandstones, but unfortunately, the relationship of the Tawmaw trap to the surrounding strata cannot be observed owing to the denseness of the jungle.
The jade extracted from the pit mines is found in the shape of boulders, which are undoubtedly derived from localities hitherto unknown, in the neighbourhood of the Uru river. It is probable that this kind of jade, which has undergone a considerable amount of wearing much harder and therefore of better quality, than the jade extracted from the quarry mines, which has hitherto only laid open the outcrop of the vein; but there is no doubt that once the mining operations have reached a greater depth, where the jade has no longer been subjected to the superficial disintegration, a material will be found which, if not better, will at least be equal to the jade extracted from the pit-mine.
There are at least 500 men engaged every season in working the quarry mines at Tawmaw. The mining operations are carried on in the rudest fashion. No blasting powder being available, the rock is heated by large fires and having again cooled down, is broken into pieces by means of enormous iron hammers. The operation in the pit mines is less difficult as the alluvial gravel in which the jade boulders are found does not require the tedious process of heating the rock. The miner simply digs a pit and selects the boulders from the stuff dug out of the pit; good pieces of jade are sometimes found in the laterite, which forms beds of varying thickness along the Uru. These pieces have superficially undergone a certain discolouring in such a way that the original green or white is changed under the influence of the hydrated oxide of iron into a dark red colour. Specimens of this kind are generally known as “red jade”.
There is no doubt that the jade mines, especially the jade vein of Tawmaw, form a most valuable property; and there is further no doubt that, besides the Tawmaw jade vein, others will be discovered sooner or later, as we know now that jade is intimately associated with a dark igneous rock (trap). As the country abounds in rocks of this kind, it may fairly be expected that a closer examination of these rocks, perhaps some extensive prospecting operation, will result in the discovery of other jade mines.
References: Record of the Geological Survey of India, 1892. Volume XXV.
