354 Mr. Weaver on Floetz Formations. [Nov. 



by some writers quadersandstein, or freestone.* The brownish- 

 red, or reddish-brown variety is tender or friable, and liable 

 to be affected by the vicissitudes of the atmosphere ; or it is 

 firm and darker coloured, perfectly resembling some varieties of 

 the rothe todthegende. The variegated sandstone is found fine 

 grained, tender, and friable ; also porous, or reddish-brown, with 

 stripes of hair- brown, formed by grains of iron oxide, or of roe- 

 stone ; sometimes also the cement is partly calcareous, and the 

 stone full of small cavities, filled with crystals of calcareous spar. 

 This variety is connected with indurated sandy clay, containing 

 nodules of marl, the interior of which is usually occupied by 

 druses of calcareous spar. 



These varieties of argillaceous sandstone are characterized by 

 their planes of separation being coated with grey, white, and 

 black mica; and by containing clay galls; namely, round or 

 angular portions of clay, or slaty clay, mixed with mica, and of 

 a grey, red, brown, green, or yellow colour. Nodules of yellow 

 earth sometimes accompany them, and ferruginous points and 

 circular spots are frequent, beside occasional layers composed of 

 grains of ironstone, of the size of a lentil ; likewise gseodes and 

 balls of ironstone, and similar concretions of mica, indurated 

 iron ochre, and ferruginous sandstone. The thicker and firmer 

 beds of sandstone and roestone are frequently traversed by veins 

 and strings of calcareous spar, which rarely exceed one, or at 

 most a few inches in thickness. 



Organic Remains.- — M. Freiesleben notices the occurrence of 

 an orthoceratite in the variegated sandstone of Nebra ; and in 

 referring to the work of M. von Schlotheim, which appeared in 

 Leonhard's Taschenbuch, in the year 1813, he speaks of pecti- 

 nites, pinnites, pholadites, turbinites, and large ostracites, as 

 being principally characteristic of the variegated sandstone ; but. 

 M. von Schlotheim himself observed, that so great an uncer- 

 tainty has prevailed with respect to the different formations of 

 sandstone, in which organic remains have been found, that con- 

 tinued investigation alone could determine how far the lists 

 ascribed by him to the variegated sandstone, and quadersand- 

 stone, respectively, were correct. It now appears from the 

 Petrefactenkunde of that author, published in 1820, that the 

 shells noticed above occur in the quadersandstone, and not in 

 the variegated sandstone. B. von Schlotheim mentions, how- 

 ever, having observed in the latter, gryphites spiratus, palma- 

 cites annulatus, carpolithes malvaeformis, c. secalis.f 



The siliceous or quartzy sandstone, composed of fine granular 

 quartz, with a siliceous cement, occurs much less frequently in 



* The term quadersandstein is, however, now more peculiarly applied to the third 

 floetz sandstone formation. 



t The remains of organized bodies are, I apprehend, veTy rarely, if ever, rntt with 

 in the new red sandstone of England. 



