1821.] Mr. Weaver on Floetz Formations. 249 



upon the primary tract of the Riesengebirge, appears to be free 

 from coal. In the carboniferous portion, the red sandstone con- 

 glomerate and sandstone alternate with slate clay, coal, por- 

 phyry, basaltic trap, amygdaloid, and limestone.* Of these, the 

 sandstone conglomerate, sandstone, slate clay, coal, and lime- 

 stone are, in general, very distinctly stratified; the porphyry 

 very seldom ; and the basaltic trap and amygdaloid apparently 

 never. The sandstone, particularly the conglomerated, passes, 

 not unfrequently, through a hybrid compound of sandstone and 

 jorphyry into porphyry containing pebbles, and thence into true 

 jorphyry. The porphyry and trap are found in distinct beds, 

 jut they constitute also high, extensive, mountain masses, of a 

 nearly round, or of an elongated form, which have a sensible 

 influence on the stratification of the adjacent country. Thus 

 we find that around the great porphyritic masses of the Hochwald 

 and Hochberg, situate between Waldenburg and Gablau, the 

 coal seams and concomitant strata, the lower portion of which 

 underlie, and the upper repose on the porphyry, undergo great 

 inflections, conforming in a great measure to the outline of the 

 masses, which they thus enclose.^ 



In the carboniferous portion of the tract, there appears to be 

 an uninterrupted connexion and interstratification of the whole 

 series. But M. von Raumer, in considering the formation in a 

 general manner, has distributed it into three principal masses. 



1 . The lorvest, composed of red conglomerate, alternating with 

 red sandstone, slate clay, coal, and porphyry. 



2. The intermediate, red sandstone alternating with claystone, 

 porphyry, basaltic trap, and amygdaloid. 



3. The upper, red sandstone with subordinate beds of lime- 

 stone. 



It is to be observed, however, that the limestone is found also 

 in five places within the division No. 1, and in several places 

 within the division No. 2; so that, in fact, it is more or less dis- 

 tributed through the whole formation, having been observed 

 altogether in 22 different places,;}: and forming beds which seldom 

 exceed 10 to 14 feet in thickness.^ On the other hand, beds 

 and masses of porphyry, basaltic trap, and amygdaloid, are 

 found also within the division No. 3. 



In the slate clay, which accompanies the coal, the usualimpres- 

 sions resembling ferns, reeds, Sec. are met with; and similar impres- 

 sions occur in the slate clay which accompanies the black lime- 



* The porphyry of this tract was formerly considered as more ancient than the old red 

 sandstone formation ; but the researches of M. von Raumer, combined with the actual 

 experience of the mining officers of Waldenburg, have proved that the porphyry in 

 question in of contemporaneous origin. 



+ See the map of the <oal fields near Waldenburg, in M. von Raumer's work, 

 reduced from that constructed by the mining officers. 



t See p. 106. 



1 Von Buch, Oeog. Beob. vol. i. p. 105. 



I 



