OF THE OBEKMITTWEIDA CONGLOMEEA.TE. 21 



As we travelled from Annaberg south-west we crossed various types 

 of gneiss and mica-schist, and at Schlettau had an opportunity of 

 examining a continuous though shallow section in a road-cutting. 

 Different names, such as Plattgneiss, &c., are given to the massive 

 or fissile, coarse or fine varieties, names which are convenient for 

 lithological description, but did not appear to be of much classificatory 

 value. South-west of Schlettau these beds are covered by Oligocene 

 deposits capped by columnar nepheline basalt ; but the valley descends 

 into the underlying schistose series, which here contains thick beds 

 of white saccharoid crystalline limestone. This limestone is very 

 irregular, probably owing first to the plications of such hard bands 

 in the yielding schists, and, secondly, to decomposition facilitated 

 by the comminution of portions of the limestone. I had to take on 

 trust the connexion between these schists and gneisses and the beds 

 seen east of the stream at Obermittweida, but I saw no reason to 

 question the information that they belonged to the same series. 



At Obermittweida, however, the section became more complicated 

 (see fig. p. 22). Near the forge, on the east of the stream, there 

 was a coarse large-flaked Muscovite-schist associated with gneissose 

 rocks. Along the valley in which the little stream ran the sequence 

 was interrupted, and I saw no similar rocks immediately west of it. 



Ascending the hill west of the stream, we first came to a grey 

 felspathic granular rock, in which there was an apparently superin- 

 duced schistosity. In this were scattered pebbles of felsitic and 

 quartzose rock, which soon became so numerous that the rock was 

 obviously a coarse conglomerate, 



I am unable to state whether a precisely similar sequence may 

 be seen at other points along the outcrop. There was nothing in a 

 single traverse, except the character of the rocks, to suggest that 

 there was any faulting or folding of the conglomerate and associated 

 beds. I did not notice that the top of the section in the con- 

 glomerate resembled the bottom, as if it were a repetition of the 

 same set of beds. But the conglomerate was an irregular deposit, 

 and may well have varied in thickness and character within short 

 distances. Moreover, it was not clear that we saw the base of it on 

 the side next the stream. In the conglomerate were fissile sandy 

 beds which, even where crushed, were quite unlike the mica-schists 

 which cropped out above and below. 



There was plenty of room for, and strong probability of, a fault 

 along the valley below the section. 



On the whole I was inclined to believe, from an examination of 

 the rock in the field, that the conglomerate might belong to quite 

 newer beds caught in a sharp synclinal fold. 



The line of reasoning which has led me to the conclusion that 

 the conglomeratic series is folded and faulted into the gneisses is 

 briefly as follows : — 



The character of the two rocks, that is of the gneissic series and 

 of the beds associated with the conglomerate, is so different that I 

 am unwilling to admit that they can both belong to one series and 

 have been subjected to similar conditions. 



