576 MISS M. M. OGiLYIB [mRS. GORDOn] ON THE [Aug. 1 899, 



These relations at Lang Kofi are precisely analogous to the relations 

 observed in detail, as existing between the Enneberg Valley segment 

 and Sass Songe, and the analogy is presented in the case of 

 Dolomite-mountains situated at diagonally opposite 

 ends of the Groden Pass fault-system (see fig. 7, p. 578). 



Eesults. 



(A) Facts and Deductions confirmatory of the Results of 

 previous Researches. 



In summarizing the foregoing description of the geology of the 

 Groden Pass and its neighbourhood, the more general features will 

 first be noted, in which the stratigraphy of the Pass bears out the 

 result of recent researches in the Dolomites (p. 564), more widely 

 considered, in the Peri-Adriatic area of the Alps. 



(1) Combination of reversed and normal faults. — The 

 fault-system of the Groden Pass has been found to comprise faults 

 inclined at various angles to the horizon as well as vertical 

 faults. Some of the inclined fault-planes are typical planes of over- 

 thrust. The author would specially note the combination of the 

 reversed and normal faults in two oppositely-inclined fault-groups, 

 passing through the two opposite anticlinal wing-folds that have 

 been overcast southward and northward. The oppositely-inclined 

 planes of the Groden Pass faults, if continued upward, would 

 therefore meet each other as well as the vertical planes. The area 

 is comparatively small, hence very involved stratigraphical relations 

 must have ensued between the dovetailed parts of fault-blocks. 



(2) Yirgation of fault -lines. — The surface-outcrops of the 

 faults diverge from the Pass height outward on both the western 

 and eastern slopes. A divergent arrangement of fault-lines has been 

 termed a ' virgatiug system ' by American geologists, and a ^ fan- 

 shaped fault-bundle ' by Austrian geologists. It is in association 

 with the central convergence of the eastern and western fault- 

 bundles that the main faults of the Groden Pass anticline (namely, the 

 Pitzculatsch-Colfosco Pault, and the Vallbach-Corvara Eault) have 

 their throw reversed on the opposite sides of the Pass. 



The faults may be conveniently distinguished, according to their 

 geographical direction, as : — {a) Longitudinal or strike-faults, 

 directed east and west, east-north-east and west-south-west, and 

 east-south-east and west-north-west ; (6) Diagonal or oblique 

 faults, directed north-north-west and south- south-east, north- 

 north-east and south-south-west, north-west and south-east, and 

 north-east and south-west; (c) Transverse faults, directed 

 north and south, or nearly so. 



It must, however, be understood clearly that such grouping is 

 arbitrary, since longitudinal faults give off" branches in oblique or 

 transverse directions, and fault-planes may at one part of thai: 



