114 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jan, 21, 



Ridgway Range. 



\ 



Sect. 17. 



Fault. 



The annexed diagram, fig. 7, will give the general bearing of the 

 N. and S. line of sections 14, 15, 16, and 17, and also their relation to 

 sections, on the S. side of the valley, before detailed. 



In this section I have inserted the 

 Hastings sand {d) hypothetically. I 

 found on the north of the Purbeck 

 sections, and between the Purbeck 

 and the Chalk, a slight depression 

 of the surface, watered by a streamlet 

 and boggy. It seems, therefore, very 

 probable, looking at the stratigraphi- 

 cal details of the locality, that there 

 has been a severance of the Purbeck 

 and the overlying formation, giving 

 rise to this flow of water ; and the 

 3 boggy state of the ground would also 

 mark an argillaceous deposit, which 

 is the character of that portion of the 

 Hastings sand above the Purbeck, in 

 the same relative position one mile 

 further east at Ridgway. 



18. (E. of last section) Purheck: 

 dip to N. by E. at 6°, and so in the 

 next field as far as it could be made 

 out. 



19. (E. of old Ridgway road) Pur- 

 heck : dip to W.N.W. at 5°. 



20. Purbeck : dip to N.N.W. 



2 1 . Portland : dip to N. by E. at 

 15° to 20°. 



22. Purheck : dip to N. by E. at 

 30°. 



23. Purbeck : dip 55°. 



^2 



I* 





Sect. 13. 



Upway Valley. 



Upway Church. 



■^ 



sect. 3. 



* Observations on the sections of the 

 Range N. of the Valley. 



10 to 12. Show the west part of 

 i the valley to possess great regularity 



1 of dip (to the N.). 

 g 14 to 16. Lead in this case to the 



2 inference of the subsidence of the 

 e strata at Upway, resulting from a 



local fracture of the Purbeck on its 

 general upheavement. 

 19. Shows to the observer of this large quarry a dip towards the 

 old Ridgway road, — a dip which here coincides in a great degree 

 with the natural dip of the country. 



21 and 23. Show an alteration in the direction of the dip with an 

 inclination increasing to the E., and reaching its maximum at sec- 

 tion 23. 



