1G0 Mi?i era logical Description of the Island of Banka. 



The succession of strata was very distinctly exhibited in this 

 mine ; the lowest was peculiarly characteristic ; and afforded me 

 an opportunity of observing a vertical section of the stratum con- 

 taining the ore in its natural situation ; the fragments which com- 

 posed it could be separately removed ; they were of different 

 sizes, from less than an inch to several inehes in diameter. 



Although it was evident that they consisted of portions of the 

 -decomposed or disseminated primitive rocks of the surrounding 

 districts, their present arrangement shewed that they had under- 

 gone a revolution, and had been removed out of their natural situ- 

 ation. A considerable proportion of the feldspar was in a state of 

 decomposition, and appeared as a clayey substance ; to these the 

 particles of tin ore often adhered. Grains of sand were mixed, 

 but in comparatively small quantity, with the coarse fragments 

 which formed the stratum. 



The surface which had been exposed by the successive works 

 of this mine was very extensive : they had been commenced in 

 a low situation, and the productiveness of the stratum had grad- 

 ually diminished as the acclivity of the hill increased ; the min- 

 ers, supposing it to be near its termination, had given up the 

 work. The stones which remained here resembled those usually 

 found at the aqueducts. The abundance and size of the frag- 

 ments of red ironstone and pudding-stones shewed here, as at 

 Towallam, that the miners had met with extensive veins of this 

 stone. 



The next mine is situated two miles further north ; from the 

 chief miner who administers the work, it is called Hopsun. On 

 the road to it, I passed extensive districts which had formerly 

 been worked. Large fragments of ironstone and pudding-stones 

 were abundantly dispersed over this tract ; they were mostly de- 

 tached and had been removed from their natural situation by the 

 process of mining, and by the formation of canals. The veins 

 from which they were taken, had in many instances run near the 

 surface. In this mine 1 noticed the following strata : 



1. Soil. — 2. Sand imbedded in clay of a gray color. — 3. Black 

 clay.— 4. Coarse white sand. 



The stones ajt the aqueducts were fragments of the common 

 siliceous kind, large and mostly of a white color ; very iew brec- 

 cias were mixed with them. 



in the next mine called Lakuntouw, situated about half a mile 

 east northeast of the last mentioned, 1 found the strata — 



1. Soil. — 2. Sand imbedded in whitish clay. — 3. Sand in dark 

 colored clay. — 4. Sand in beds of variegated colors. — 5. Black 

 clay. — 6. White sand. 



The stones at the aqueducts resembled those found at the last 



mine ; they contained comparatively few conglomerates or breccias ; 

 those which occurred resembled those of the mine of Belinya 



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