Geology. — ''On Tin-ore in the Island of Flores". By Prof. 



A. WiCHMANN. 



(Communicated in the meeting of June 29, 1918). 



Some j^ears ago I maintained on the ground of geological studies 

 that tin-ore does not occur in the ishind of Flores, at all events 

 not to an amount worth mentioning ^). As appeared from a memoir 

 brought forward last year by Prof. S. J. Vkrmaks, the author is 

 otherwise-minded "). I think it worth while to study the author's 

 arguments, which he pretends to be based on the doctrine of (he 

 deposition of ore, on ethnography and on metallurgy. 



Geological researches have not been made in Flores of late years, 

 so that in this i-espect there was no need for levising my j)aper. 

 Nevertheless Prof. Vf.rmaks supposes he has been fortunate enough 

 to make a discovery, which throws a new light upon the matter '). 

 This finding appeal's to be nothirjg else but a piece of tin-ore, 

 exposed in the Colonial Museum at Hailem, "weighing 131 grms 

 and composed of chlorite and tin-ore with fissures, in which occurs 

 8ome kaoline. Besides the two mentioned minerals a single grain of 

 chalcopyrite is also noticeable". 



Prof. Vermaes altogether fails to see that the finding place 

 "Gunung Rokka", indicated on the label must be fictitious, since 

 the mountain — the Inije Rije of the natives — is a volcano and 

 even now is in the condition of solfataric activity ''). Indeed, not 

 one of the researchers has ever found the least indication of the 

 occurrence of ores on that mountain and even C. J. van Schelle, 

 who never shrank from a bold hypothesis, has wisely I'efrained from 

 making inquiries after tin-ore in the volcanoes of Flores. He looked 



1) "On the tin of the Island of Klores". These Proceedings Amsterdam. Vol. 17, 

 1914, p. 474-490. 



*) Tinerts op Flores. De Ingenieur. 32. 's Gravenhage 1917, p. 5S4 — 590. 



3) 1. c. p. 584. 



■*) J. .1. Pannekoek van Rheden. Overzicht van de geographische en geologische 

 gegevens, verkregen.... van het eiland Flores in 1910 en 1911. Jaarboek van 

 het Mijnwezen in Ned.O.Ind. 40. 1911. Batavia 1913, biz. 219— i220. — Eenige 

 geologische gegevens omtrent hel eiland Flores. Jaarboek van het Mijnv^^ezen. 39. 

 1910. Batavia 1912. Verhandelingen, p. 135-136. 



