The marine Carboniferous of Nortli east Greenl. and its Brachiopod Fauna. 549 



On the whole, the Carboniferous measures of north-east Green- 

 land can be divided into three groups, a Lower, terrestrial, and two 

 Upper, marine, in the following series: 



С Upper Marine Group: . Limestones without intermediate 



marl-shale strata; light in colour; 

 partly silicified or altered into 

 dolomite. 



B. Lower Marine Group: Limestones with marl-shale inter- 

 mediate strata ; partly light, fine- 

 grained or almost dense ; partly 

 dark and bituminous and then, 

 as a rule, coarser; sometimes 

 alternating with sandstones. 



A. Terrestrial Group: Sandstones and sandy shales with 



plant-fossils. 



A. The Terrestrial Group consists of a continuous series of 

 sandstones and sandy shales, containing a flora (poor, it is true) of 

 Lower Carboniferous age w^hich, as stated before, has been described 

 by Nathorst. These deposits have evidently been formed on a 

 continent consisting of greatly weathered Archæan , or of some 

 similar crystalline rocks, in small fresh water basins which, after 

 the transgression of the Carboniferous sea, have become portions of 

 the latter. 



Formations belonging to this group have been met with, with 

 certainty, only at localities in Holm's Land ; in Amdrup's Land they 

 have probably been covered by detritus and were, therefore, not 

 accessible. 



Some of the places where these beds were observed lie pretty 

 far to the west on the shore, where only free-lying boulders were 

 found, while others were rather near to the profiles made here: 

 Koch's section and the Conglomerate section. 



West of Koch's section we have absolute certainty that the plant- 

 bearing shales occupy a position between 85 and 155 metres above 

 sea-level, but, on the other hand, we do not know what lies above 

 them. On the shore, it is true, there have been discovered free- 

 lying boulders of light-red limestones, derived from some unknown 

 higher level. 



In Koch's section there have been obtained plant-fossils at dif- 

 ferent levels which we cannot more definitely determine, but of 

 the localities which Nathorst (1911, pp. 344—345) gives for his 

 plant-fossils, 1 and 3 are levels in Koch's section, while 4 — 6 refer 



