FAULTS PRODUCE SPRINGS. 407 



broken clay, derived from its argillaceous shale beds, at the 

 moment in which the Fracture and Dislocation took place ; 

 and hence have resulted those joints and separations, which, 

 though they occasionally interrupt at inconvenient positions, 

 and cut oft' suddenly the progress of the collier, and often 

 shatter those portions of the strata that are in immediate 

 contact with them, yet are in the main his greatest safe- 

 guard, and are indeed essential to his operations.* 



The same Faults also, while they prevent the Water from 

 flowing in excessive quantities in situations where it would 

 be detrimental, are at the same time of the greatest service, 

 in converting it to purposes of utility, by creating on the 

 surface a series of Springs along the line of Fault, which 

 often give notice of the Fracture that has taken place be- 

 neath. This important effect of Faults on the hydraulic 

 machinery of the globe extends through the stratified rocks 

 of every formation. (See PI. 69. Fig. 2.) It is also pro- 



* "If a field of coal (says Mr. Buddie) abounding in water, was not in- 

 tersected with slip Dikes, the working of it might be impracticable, as the 

 whole body of water which it might contain would flow uninterruptedly into 

 any opening which might be made into it ; these Faults operate as Coffer 

 Dams, and separate the field of coal into districts." — Letter from Mr. John 

 Buddie, an eminent Engineer and experienced Coal Viewer at Newcastle, to 

 Prof. Buckland, Nov. .30, 1831. 



In working a coal Pit, the Miner studiously avoids coming near a Fault, 

 knowing that if he should penetrate this natural barrier, the Water from 

 the other side will often burst in, and inundate the works he is conducting 

 on the dry side of it. 



A shaft was begun about the year 1825, at Gosforth, near Newcastle, 

 on the wet side of the 90 fathom Dike, and was so inundated with water 

 that it was soon found necessary to abandon it. Another shaft was then 

 begun on the dry side of the dike, only a few yards from the former, 

 and in this they descended nearly 200 fatlioms witiiout any impediment from 

 water. 



Artificial dams are sometimes made in coal mines to perform the office of 

 the natural barriers which Dikes and Faults supply. A dam of this kind 

 was lately made near Manchester, by Mr. Hulton, to cut off water that de- 

 scended from the upper region of porous strata, which dipped towards his 

 excavations in a lower region of the same strata, the continuity of which 

 was thus artificially interruptedo 



