160 W. H. HOBBS EEPEATING PATTERNS IN STRUCTURE OF LAND 



tresses (see plate 12, figure 2). As Beck has shown,^^ these master joints 

 are throughout the district ordered in two main perpendicular series, 

 which are directed the one north-northeast and the other west-northwest, 

 and that these have determined the directions of all the drainage lines. 

 In addition, there is a faintly indicated east-west jointing, which, how- 

 ever, is not vertical, but dips northward at angles varying from 45 to 75 

 degrees. The writer has himself confirmed the correctness of these obser- 

 vations in parts of the district in question. 



Another province of special significance in its relation to the fracture 

 map of Europe is in southwest Germany about the middle Ehine, of which 

 a fault map on large scale has recently been issued.^^ Here the faults are 

 oriented in two dominant series, which determine the major features of 



Figure 33. — View of the Pordoi-Oebirge {Sella group) in the Dolomites 



Showing on the left unfaulted dolomite blocks of large size which are separated regu- 

 larly by conspicuous joints, while in the higher block near the right of the picture 

 may be easily recognized the smaller joint blocks in the Dachsteinkalk,, which make 

 up the larger unit. (After Mojsisovics.) 



the relief, and are directed northwest-southeast and northeast-southwest, 

 with some indication of the subordinate intermediate series. 



Across the international boundary in central Bohemia the fault system 



•» R. Beck : Geologischer Wegweiser durch das Dresdner Elbthalgebiet zwlschen Meis- 

 sen und Tetschen. Berlin, 1897, pp. 09, 137-140, map. 



®i C. Regelmann : Tektonische Karte (Schollenkarte) Siiclwestdeutschlands, Heraus- 

 gegeben vom Oberrheinischen Geologischen Verein, sheets 1-4 (Strassburg, Stuttgart, 

 Metz, and Frankfurt). Justus Perthes, Gotha, 1898. 



