PRE-CAMBRIAN OF SWEDEN 719 



mountains, are underlain by a thick deposit of unconsolidated deposits con- 

 taining water under novel conditions. 



PRE-CAMBRIAN OF SWEDEN, WITH COMMENTS ON AMERICAN TAXONOMIC 



PARALLELS 



BY JAMES F. KEMP 



(Abstract) 



The excursions in connection with the Eleventh International Geological 

 Congress afforded exceptional opportunities for observing the Swedish pre- 

 Cambrian, and for becoming acquainted with the local workers and their 

 results. From these three sources a sketch has been prepared, with the pur- 

 pose of describing the larger features and of running some parallels with 

 America. 



Discussion 



Dr. J. M. Clarke : What is the interpretation of the occurrence of anthra- 

 citic carbon? 



Professor Kemp replied as follows : In the papers consulted on the geology 

 of Finland in the preparation of the paper just read, only brief mention of 

 these beds was made, but they are doubtless more fully discussed in the 

 memoirs of the Finland Survey. They lay outside the excursions of the Con- 

 gress. It would seem that they must be interpreted either as old petroleum 

 asphalt deposits of inorganic origin or as accumulated carbonaceous matter 

 of organic source. The latter explanation would push life farther back on 

 the earth than has generally been thought possible. 



Prof. H. P. CusHiNG called attention to the general similarities of all dis- 

 tricts of the older rocks when studied. 



Professor Kemp spoke as follows regarding the definition and origin of 

 skarn: Associated with many bodies of magnetite in Sweden are masses of 

 dark basic minerals, hornblende, pyroxene, and biotite, which are called 

 skarn. They are believed to be basic segregations of silicates which accom- 

 panied the separation of the magnetite in the differentiation of an igneous 

 magma. They are very marked at Gellivare, and appear also in northern 

 Sweden in association with those magnetite ore bodies which are attributed 

 to differentiation. 



Prof. W. G. Miller : The geologists from America were struck by the 

 strong resemblance of the Swedish pre-Cambrian to that of the Lake Superior, 

 Huron, and other regions. The oldest series of the Kiruna district, the soda- 

 greenstone, can not be distinguished in the field from the oldest series, the 

 Keewatin, of the Lake Superior ranges. The soda-greenstone is overlain by 

 conglomerate similar to the Huronian. 



CHAZT FORMATION IN THE OTTAWA VALLEY 

 BY PERCY E. RAYMOND 



(Al)stract) 



The Chazy formation in Canada as defined in the "Geology of Canada," 

 1863, consists of two portions, each with a maximum thickness of about 150 



