112 Von Richthofen on the Nummulitic formation in China. \ 



and rest on ancient sandstones, the strata of which are inclined 

 at an angle of about twenty degrees. These sandstones are 

 supposed by Mr, Kingsmill to have a thickness of about ten 

 thousand feet 



Before visiting Si-Tung-ting, I had observ^ed the occurrence of 

 limestone in the neighborhood of the sea coast, near Hang-cku 

 in the province of Che-Kiang, a place mentioned in Mr. Pum- 

 pelly's list of localities distinguished by the occurrence of use- 

 ful minerals. As it rests there quite unconformably on sand- 

 stone similar to that which underlies it at Tung-ting, and hi 

 a similar hthological character, I believe that I may safely refer 

 it to the same formation with that of Tung-ting. I shall hence 

 look out for its further distribution in China. The subject is 

 not without some practical interest, in a country where all lime- 

 stone was assumed to underlie the coal and iron-bearing forma- 



In 1861, the easternmost place where the Nummulitic forma- 

 tion was known to occur was northern India. I succeeded in 

 that year in proving its existence so far east as Japan and tte 

 Philippines, a notice of which you may find in a paper pub- 

 lished in the Jahrbuch der deutschen geologischen Gresellschafl 

 of 1861 or 1862. I do not know whether the same formation 

 has since then been found in the regions intermediate between 

 those two countries and India. The occurrence in lake Tai-liQ . 

 is one of the connecting links, and it is now quite likely that 

 this interesting formation, occurring in places so far apart, is 

 among the most widely distributed in Eastern Asia ; and it i^ 

 quite possible that one unbroken area of submergence may be 

 proved to have extended during the short existence of t!ie 

 genus Nummulina, from Spain to the Philippines and Japan. 



I may add, as a sort of voucher for the correctness of mj 

 observation, that its communication places me into the dis- 



agreeable position of taking opposite views from those of Hr. 

 KmgsmiU, a gentleman who has, besides his professional ac- 

 tivity as architect in Shanghai, worked of late years with ad- ^ 

 mirable success in the geology of some parts of China, lie 

 informed me, some time before I visited Tuner-ting, that he W 

 sent a paper on the geology of that locality to the London 

 Geological Society, in the Journal of which it mav be pncted 

 by this tima The views which he informed me he had taken 

 therein are, that the limestone of Tung-ting is Devonian ^J 

 Subcarboniferous, and that the great sandstone formation, whict> 

 plays a very important part in the geology of Eastern CbiD| 

 preceded it in age. The relations observed at Si-Tung-ting JJ 

 no longer justify this conclusion, after the discovery of tti« 

 nummuhtes, and the age of the sandstone (Tung-ting-gntJ J' 

 Mr. Kmgsmill) must therefore be considered as not yet sateJ) 



