143 



impossible to say. Tlie deepest sinking bearing upon the 

 subject is at Lower Vobster, where, at a depth of 300 yards, 

 the prevailing inclination appears to be to the north at an 

 angle of 30 degrees ; but there has been so much confusion in 

 the upper part of the pit that it would be hazardous to assert 

 that the bottom of the fold has been reached and the true 

 northern dip discovered. 



When we consider the amount of disturbance to which the 

 coal measures of this part of the district must have been 

 subjected, we cannot be surprised at the amount of confusion 

 and distortion which prevails. In this respect, however, there 

 is a very striking difference in the upper and lower parts of 

 the lower division. The New Rock series, being chiefly com- 

 posed of strong sandstones, has undergone the folding over 

 without sustaining material injury. If we could penetrate 

 deep enough, we should probably find that at the axis of the 

 fold the strata have been rudely fractured ; but where we have 

 an opportunity of examining them, the veins of the series 

 maintain their continuity with great persistency, their dip 

 is tolerably regular, and altogether there is less evidence of 

 the extraordinary action to which they have been exposed 

 than might have been expected. 



The fourth or Vobster series, on the contrary, has been 

 contorted and disturbed to an indescribable extent. Being 

 composed of exceedingly tender shales, when it was rolled 

 back from the Mendips it seems to have been shattered and 

 broken up into fragments. 



Speaking generally, I would remark that the mountain 

 limestone itself, although at this point nearly vertical, has 

 not as a rule been folded back. The extreme amount of fold 

 is to be met with in the New Rock series, which has fallen 

 completely over, as already described. A much greater space 

 has consequently been thrown in between the New Rock 

 series and the limestone than is commonly taken up by the 



