\ULTS-STRIKE-rAUI ui 



To judge of the character and cffccu of faults upon 

 the geological structure of a country, the rodent should 

 consult tome good detailed inapt, such as the large coal- 

 ;lans of the Geological Surrey of Great Britain. 

 It is good exercise, too, in the practical treatnu 

 faults in field-geology, to study some coast-section where 

 the strata are considerably faulted, and where they are 

 exposed in plan upon the beach as well as in section 

 upon the cliff. A rivi-r r.ivinr in summer weather, 

 when the water is low, sometimes furnishes admirable 

 lessons in this as well as in other branches of the 

 subject 



frud Fault*. These are chiefly found among 

 disturbed and plicated rocks, where one side of 

 a dislocation has been pushed over another. Lower 

 strata are thus found overlying higher, and the hade, 

 instead of pointing in the direction of down-throw, indi- 

 cates that of up-throw. Examples of this kind of fault 

 may be observed even in regions where the stratified 

 formations remain over wide spaces undisturbed, but 

 where they have locally been so much affected as to 

 show that they have undergone a good deal of lateral 

 pressure. Thus the Cretaceous and Tertiary groups of 

 the south-east of England may be said to have suffered, 

 on the whole, hardly any disturbance. Vet along 

 some belts of ground they have been subjected to 

 such terrestrial stresses as have caused them to be 

 ridged up into sharp folds and to stand on end 

 In these tracts reversed faults may be observed among 

 them. 



Thrust -plants. In districts where the rocks have 



