MAPPING OF THE CRYSTALLINE SCHISTS 865 



lines of faults, and, following the theory of the time, supposed 

 the mountain masses upon either side of the Rhine valley to 

 have been forced up above their former level so as to produce a 

 deep channel. That there are many parallel faults which follow 

 the direction of the valley walls of the Rhine has been 

 abundantly proven by later investigations. 1 Today the presence 

 of numerous dislocations in parallel and often intersecting series 2 

 has been recognized in many European areas extending from 

 the steppes of southern Russia upon the east, to the Pyr- 

 enees upon the west, to describe which there have been 

 brought into use a considerable number of special terms. Some 

 of these terms have no equivalent English expresssion, and such 

 as have are, in some cases, unnecessarily long. Among the 

 foreign terms are : Ger. Bruchfeld, Fr. champs des fractures 

 (area of dislocations); Ger. Bruchnetz, Fr. reseaux regulier des 

 failles (fault net-work); Ger. Senkungsfeld (sunken area) ; Ger. 

 Horst, Fr. horst or mole (elevated area left between two or more 

 sunken areas); Ger. Scholle (orographic block); Ger. Grabe?i 

 (long and narrow sunken block); Ger. Briicke (long and 

 narrow elevated block) ; Ger. Thurm (relatively high block of 

 nearly equal basal dimensions) ; Ger. Kessel (relatively low block 

 of nearly equal basal dimensions) ; etc. 



It has been especially the work of Suess to correlate the 

 many scattered observations and in the first volume of his 

 monumental work upon Face of the Earths to show how the 

 lineaments of the continent are lines of normal faulting, between 

 which great crustal blocks have been depressed by different 

 amounts. In America the description of what I have called the 



x Daubree, Description geologique et mineralogique du departement du bas-rhin 

 (Strasbourg, 1852), pp. 384-406; Benecke and Cohen, Geognostische Beschreibung 

 der Umgegend von Heidelberg (Strasbourg, 1881), pp. 595 ff.; AuSFELD Geologische 

 Skizze der Gegend von Rheinfelden, Mitth. d. Aarg. naturf. Gesell., Vol. Ill (1882), 

 pp. 83-102 ; etc. 



2 In German usage the term System is generally employed to cover any grouping 

 whether of parallel or of intersecting faults. The author has described under the 

 term " series of faults " a group of parallel faults, restricting the use of the larger 

 term" system of faults " to the network composed of parallel series. Twenty-first Ann. 

 Report U. S. Geol. Survey, Part III, pp.98 ff. 



3 Antlitz der Erde, Prag and Leipzig, 1885. 



