TRACING FAULTS 137 



not at all like that of an old ihore or unconformable 



on ; ad, there is no evidence of the granite having 



been intruded through the ruck* The latter show no 



granite veins or traces of alteration, jrd. The disturbed 



vertical and even inverted position of the strata all along 



the straight line of junction proves that line to be a fault 



upturned strata are cut across obliquely by 



the junction line, so that different horizons of them are 



successively brought against the crystalline rocks. 



fto. *.-Sciioo of (auk uh fewtad bk a. U domfeow wU. 



We cannot hesitate in such a case to treat the line as 

 a fault, which we mark on the map by a strong pencil- 

 line, at each point where there is good evidence as to its 

 approximate or actual position. We should search for 

 further traces of the line in the intermediate ground; 

 and here may be realised the use of a line of springs, 

 or of some definite bank or hollow on the surface of the 

 ground, in enabling us to carry the line of the fault with 

 confidence across a tract where no actual rock may be 

 exposed. There could be, in the present instance, little 

 hesitation in prolonging our strong pencil-line from point 



