VARIOLITIC DIABASE OF THE FICHTELGEBIRGE. 



55 



has been crushed and minutely faulted. This case is further of 

 interest as there is no variolite along the contact with the Devonian. 

 An equally clear section occurs in a small quarry in line with the 

 waggon-ford that crosses the stream just above the second foot- 

 bridge. The section is composed of a mass of spheroidal varioiitic 

 diabase, and across it runs a band of baked shale which thins 

 towards, and forks at, the lower and north end. Here, again, the 

 diabase is neither varioiitic nor spheroidal at the actual contact with 

 the shale, but acquires these structures at about one foot from it. 



Fig. 5. — Section of the normal compact Diabase from the Oelschnitz- 



80 

 thai, with a vacuole Jilled with chlorite. ( x -Z' See p. 50.) 



The junctions of this diabase and the neighbouring Devonians are 

 obscured, but the latter occur in mass a few yards away. 



It is unnecessary to trace the junctions of the diabase and the 

 Devonians further through the area. On the opposite side of the 

 Metziersreutherbach, in the bank of the same stream near Heiners- 

 reuth, in the wood south of Mej^erhof, and in other places, the same 

 features are repeated. The relations of the diabase to the eye-gneiss 

 S. W. of Berneck are, however, worth consideration ; the junction can 

 be seen in the road that rises steeply up the west bank of the 

 valley which leads to Micheldorf, a little south of the quarry. The 

 two rocks are certainly faulted against one another, and hence we 

 search in vain in the crushed and brecciated diabase for any trace 

 of the variolite. 



The evidence adduced is sufficient to show, at least in the case of 

 the area south of the Oelschnitz and the Metziersreutherbach, that, 

 though the variolite does occur along the line of the junction of the 

 Devonian and the diabase, when it appears as a true contact-selvage, 

 the varioles are not well developed, and usually lack the radial 

 structure. Further, that it is only in the compact, or but slightly 

 vesicular, spheroidal diabase, usually at some little distance from 

 the actual plane of contact, that the sharply-marked radial 



