1823.] Rothetodtliegende and Weissliegende. 339 



opinion should exist after the detailed exposition of Freiesleben, 

 which tended to reconcile all differences ; and that greater 

 weight should not have been attached to the judgment and 

 descriptions of that author, the correctness of which upon other 

 subjects has not hastily been called in question. But be this 

 as it may, I am not aware that any German writer ever included 

 any portion of the rothetodtliegende formation in the gypseous 

 and saliferous series ; while many, on the contrary, did compre- 

 hend the weissliegende in the carboniferous series. The former 

 position, therefore, assumed by my antagonist, is in opposition 

 to all German authority.* 



The propagation of error is sometimes as rapid as simple. A 



* If there be any one series in geology more distinct than another, as constituting in 

 itself a complete system, wholly independent of preceding and subsequent series, it is 

 the carboniferous. It is true that in its lower line of boundary, where imposed upon 

 transition tracts, we often hear graduations spoken of, as taking place from the one 

 series into the other. These, however, can be so considered only in a miner alogical 

 sense (particularly when the transition sandstone, one of the later members of that series, 

 and the first floetz or old red sandstone come in contact) : certainly not in a geological 

 sense ; for though, in the first place, the two series may in certain quarters be in a con- 

 formable position, yet if the line of apposition be examined throughout its extent, a 

 general unconforrnability in the arrangement of their respective strata will be found to 

 prevail, the carboniferous series being merely adapted to the form of the surface of the 

 transition (or primary, as it may happen) ; and, in the second place, the transition series 

 is commonly distinguished by a considerable variety of trilobites and other organic 

 remains, while the first floetz or old red sandstone is free from such remains ; and the 

 only trilobite that I am acquainted with (beside the Oniscites Derbiensis of Martin) as 

 occurring in the carboniferous limestone is a distinct species, and, I believe, also pecu- 

 liar to that limestone.* 



The upper confines of the carboniferous series are also equally well marked. In 

 England, the calcareous or new conglomerate (the first member of the gypseous and sali- 

 ferous series) is, I apprehend, invariably found in an unconformably overlying position ; 

 in some quarters partially overspreading the surface of the coal fields, and extending 

 thence in like manner to the carboniferous limestone, and even to the old red sandstone. 

 The weissliegende or new conglomerate in Germany also, with its companion the cupri- 

 ferous marl shale, is represented by Freiesleben as partially overspreading the carbonife- 

 rous series, conforming to the figure of its surface, following its sinuosities, and surround- 

 ing the detached portions of that series that appear in isolated hills; being also in certain 

 quarters in contact with transition tracts. Hence arises a variableness in the range and 

 dip of the weissliegende, which are sometimes conformable, sometimes unconformable 

 to the disposition of the subjacent members of the carboniferous series. That the weiss- 

 leigende or new conglomerate is wholly distinct from that series is also proved; I. By 

 its several affinities to the cupriferous marl shale ; and 2. By its being affected in com- 

 mon with that shale, and with the lower alpine limestone in general, and the zechstein 

 in particular, by various disturbances, which do not extend to the carboniferous series 

 beneath. — (See e. g. Freiesleben, vol. iii. p. 51, et seq. and p. 239, et sen. : also vol. iv. 

 p. 21— 31.) 



I may here remark, that in one respect there is a marked difference between the com- 

 position of the calcareous or new conglomerate of England, and that of the weissliegende 

 of Germany. In the former, rounded and angular fragments of limestone are very com- 

 mon, and frequently predominant ; while in the latter they are of rare occurrence. Both 

 conglomerates thus bear a close relation to the carboniferous series on which they respect- 

 ively repose, and from whose detritus they were principally derived ; the limestone 

 frequently prevailing in the British carboniferous series, and being, comparatively speak, 

 ing, only incidental in the German. 



• It is the tuberculated species depicted in pi. 4, fig. 12, of Brongniart's valuable 

 Histoire Naturelle des Trilobites, derived from the Dublin limestone. I found four 

 vpecimens of the same trilobite in the Mendip limestone. Mr. Miller has observed it 

 likewise in the limestone of Cork and Bristol. It has been met with also incidentally in 

 the carboniferous limestone of other parts of Great Britain. 



z2 



