1821.] Mr,, Weaver on Floetz Formations. 339 



Article III. 



On Floetz Formations, By Thomas Weaver, Esq. MRIA. 

 MRDS. MWS. MGS. 



(Continued from p. 254.) 



Floetz. — Series II. 

 1. The Weissliegende of M. Freiesleben. 



Calcareous Conglomerate and marly Sandstone.* 



M. Freiesleben has the merit of being the first who distin- 

 guished this formation in Germany, most preceding writers 

 having either entirely overlooked, or given an imperfect account 

 of it, among the latter of whom may be reckoned Lehman, Ger- 

 hard, Heim, &c. ; while others have confounded it with the old 

 red sandstone (rothe todtliegende), considering it as the upper- 

 most bed of that formation, e. g. M. Voigt, and indeed almost 

 all later geologists. 



The weissliegende, as the first member of a new series, like 

 the rothe todtliegende, the first member of an older series, varies 

 also in its composition and structure, accordingly as, in the course 

 of its extent, it comes in contact with, and reposes upon forma- 

 tions of an earlier era 5 upon the first floetz group, upon transi- 

 tion, or upon primary tracts. 



In MansJ'eld and Sanger hausen, its general character is that of 

 a calcareous conglomerate, marly sandstone, indurated sandy 

 marl, indurated slaty clay marl, or a fine grained, partly siliceous, 

 sandstone. The calcareous base is usually of a yellowish or 

 greyish cast, with iron-shot spots and streaks, and occasional 

 brownish-red layers. Numerous scales of white mica, and single 

 grains of white or dark coloured quartz and flinty slate, appear 

 incidentally in the finer-grained varieties. The conglomerate 

 itself consists of grains of quartz, hornstone, and flinty slate, of 

 greyish and blackish colours, compacted by a slight marly 

 cement, usually of a whitish cast, in which are lodged rounded 

 and angular fragments of compact and sandy marl. The marly 

 sandstone contains sometimes spheroidal and ovoidal pieces of 

 compact limestone, and sometimes thin layers of bituminous 

 marl shale. 



Nearer toward the Hartz, in Stollberg, and the adjacent dis- 

 tricts, the more common appearance of the weissliegende is that 

 of a siliceous conglomerate of larger or smaller grain : the ingre- 

 dients consisting of rounded and angular pieces of hornstone, 



• It may not be useless to notice in this place an error of the engraver in the tabular 

 arrangement of M. Greenough's Geological Map. The " various sandstones, rarely 

 calcareous ; post, crowstone, ganister, pennant," which there occupy the lowest line of 

 Group No. 17, ought to have been included in the circumflex of Group No. 18, namely, 

 in the coal formation. 



7. 2 



