44 teoceedinotS of the geological society. [Dec. 20, 



rock of a diftorcnt claaractcr. It was ahvaj's accompanied by more 

 or less native gold. 



Mr. Paxtisois^ remarked that in many places where tin occurred it 

 was not present in sutKcient quantity to be remuneratively worked, 



Mr. D. EoKBES, in answer to a question from Prof. Eamsay, stated 

 that, as far as could be ascertained, the age of the stanniferous 

 granites mentioned by him must be between the end of the Silurian 

 and the early part of the Carboniferous period. 



Prof. Eamsay would carry them down to the close of the Carbo- 

 niferous period, and would be contented to term them pre-Permian.* 



2. Eejiakks 0)1 the Gkeenland Meteoeites. 

 By Professor A. E. Nordenskiold, For. Cor. G. S. 

 The meteorites which I discovered at Ofivak, in Greenland, in 1870, 

 most of which have now been brought home by the expedition of 

 this year under the command of Earon v. Otter, seem to have 

 formed the principal masses of an enormous meteoric fall, which 

 took place during the Miocene period, extending over an im- 

 mense area (some 200 English miles) ngt only pf the region 

 occupied by the Greenland basalt, but also where the country is 

 composed of granite-gneiss. 



The native iron is ver)- variable in appearace ; but as far as I yet 

 can judge, it is free from silicates, notwithstanding that pieces of 

 basalt (apparently?) are imbedded in the exterior of the blocks, 

 apparently filling cavities in the outer surface of the original me- 

 teorites. 



The basalt at a distance from this locality does not contain any 

 native iron ; it is only in the immediate vicinity of the iron masses 

 themselves that native iron along with pebbles is found in the 

 basalt, which at this place is clearly seen to be a subsequently con- 

 solidated basalt-tuff and not congealed lava. 



That this iron is of eruptive origin appears impossible to me, 

 because : — (1) the iron, upon being heated, evolves gaseous matter 

 even up to as ranch as 100 times the volume of the iron itself : (2) 

 it contains distinct isolated particles of sulphide of iron, which are 

 imbedded in the rest of the mass of iron, which in itself is free or 

 nearly free from sulpliur ; (3) the external form of the iron masses 

 themselves docs not show evidences of their having been poured out, 

 when in the molten condition, into a cavity or fissure. 



The character of the iron masses is extremely variable, as they 

 are in pai't composed of meteoric uickeliferous cast iron, or of 

 meteoric nickeUferous wrought iron, or mixtures of both ; in which 

 last case the so-called Widmannsttetten's figures are found to be 

 best developed. 



Tlie native iron found in the basalt occurs : — 



A. As enclosed and but little altered meteoric stones. 



E. Fining up cracks from one to two lines in width, and being 

 either fragments of meteorites flattened out under the influence of 

 time, or wedged into these cracks in the act of falling, or which have, 

 fallen into cracks in the subsequently consolidated tufi\ 



