Geology of the Harz Mountains. 219 



remains are neither very abundant nor perfect. The most 

 characteristic species are — 



Calamites transitionis. Knorria Jugleri. 



Eoemeri. ,, fusiformis. 



LepidodeTidron Veltheimianum. Bomia scroMculata. 

 „ hexagonum. 



The Upper or Grund Greywacke is a conglomeratic rock, 

 with pebbles of white quartz, quartzites, granites, and quartz 

 porphyries — all of a kind unknown either among the older 

 rocks of the Harz, or among those of the surrounding ranges. 



3. Boeder Eocks (Eandgesteine). 

 d. Coal Measures {Obere Steinkohlenformation). 



The coal measures are represented at Meisdorf on the 

 northern Harz border, near Ballenstedt (see section No. 1), 

 and at Grillenberg and Ilfeld on the southern. The series 

 at all three localities is very thin, and rests in violent un- 

 conformability on the upturned edges of the Devonian rocks. 

 At Hfeld, where it has been best explored, the series consists 

 of a basement conglomerate of grey colour, containing com- 

 pletely rounded egg- to head-sized pebbles and boulders of grey- 

 wacke, kieselschiefer, and occasionally quartzite, with inter- 

 calations of red and brown arenaceous shale and sandstone, 

 above which come the true coal-bearing strata. These are 

 principally sandstones and plant-bearing bituminous shales, 

 resting on a bed of grey conglomerate, and containing a 

 workable coal-seam in three divisions, whose thickness is 

 generally 4 to 5 feet, but sometimes amounts to 7 or 8 feet 

 (Prus.). The roof of the coal-seam consists generally of thin 

 fissile red or grey shale, or conglomerate made up of sub- 

 angular fragments of Hercynian rock. It is found at some 

 places near Hfeld to cover the coal unconformably ; and 

 for this and paleeontological reasons has been relegated to 

 the overlying New Eed or Eothliegendes formation.^ 



1 See article on the Coal formation in the neighbourhood of Ilfeld in the 

 Colliery Guardian, Nov. 12, 1875, pp. 713, 714 ; also C. F. Naumann iiber 

 die geognostisehen Verhaltnisse des Melaphyr Gebietes von Ilfeld, Leonhard 

 u. Bronn., Jahrb., 1860, pp. 1-35; also Geinitz Dyas, ii., p. 198. 



