Rejjorts and Proceedings — Geological Society of London. 181 



Weinschenck thinks that a reaction of this kind would explain all 

 the peculiar characters of the graphite occurrences ; the great 

 alteration of the rocks is due to the quantity of C 0^ liberated, and 

 the abundance of peroxides of heavy metals replacing silicates 

 originally poor in them is also explained. 



The common association of rutile with graphite may indicate the 

 presence of C3'anogen, which readily forms with titanium volatile 

 combinations ; the existence of nitrogen in the Ceylon graphite 

 perhaps points in the same direction. 



Passing to the Alpine localities (Styrian and Cottian Alps), we 

 find that graphite occurs in beds of Carboniferous age where it is 

 certainly of organic oi'igin. It is usual to regard any metamorphic 

 action in the Alpine regions — such as here the alteration of coal 

 to graphite — as the result of dynamo-metamorphism. But the 

 vegetable remains in the Styrian shales are not deformed, nor do 

 the quartzites in the Cottian Alps show traces of crushing or 

 brecciation. It is to a foliated gneiss (a foliated variety of the 

 Central Alpine granites) associated with the altered Carboniferous 

 beds that we must attribute the modifications met with in the 

 Carboniferous sediments, by which the shales have been changed 

 to chloritoid phyllites, the sandstones to quartzites, the coal to 

 graphite. 



So that when we review the chief localities for graphite we are 

 struck with the fact that there is never a gradual passage from 

 coal to graphite on the lines of regional metamorphism, but that 

 when graphite is formed from coal it is a contact mineral. Graphite 

 is not the final term of a series of carbonaceous rocks beginning 

 with lignite and ending with anthracite. 



Professor Weinschenck's researches show that the origin of 

 graphite is different in different cases. It is clear, however, that 

 in none of the above localities — and they are the most important 

 known — is the graphite to be regarded as the representative of an 

 ancient coal, older than any rocks containing determinable fossils. 

 On the contrary, graphite is usually an igneous emanation-product ; 

 when of organic origin it occurs as a contact mineral in rocks much 

 younger than the oldest fossiliferous strata. So that the presence 

 of graphite in ancient roclcs does not push back the origin of life 

 beyond the point at lohich loe meet with the oldest authentic fossils. 



A. K. C. 



Da:EI=OI^TS _a.3^id :F'i^ocE!DaxDii:srG-s. 



Geological Society of London. 



I.— February 21st, 1902.— J. J. H. Teall, Esq., M.A., F.K.S., 

 President, in the Chair. 



Annual Genebal Meeting. 



The reports of the Council and of the Library and Museum 

 Committee for the year 1901, proofs of which had been previously 

 distributed to the Fellows, were read. In the first place a reference 



