Vol.6 9 .] 



IN THE MAGNESIAN LIMESTONE AT HAETLEPOOL. 



211 



At Gunner's Pool and Bruce's Ladder the above-described beds 

 have undergono much alteration, and calcareous segregated bands 

 are seen intercalated with yellow powdery material. The latter is 

 very apparent at the top of the section, but lower down has been 

 largely removed. The calcareous bands here coalesce, forming 

 a typical honeycomb breccia merging downwards into a hard 

 unyielding thick bed of limestone which offers an obstacle to 

 the stream. The whole mass is pierced with vertical fissures in 

 various directions, through one of which the water finds its way. 

 The fine wall of rock at the base of which the stream emerges is 

 the face of another fissure, and affords a good section of these 

 much altered rocks. The whole gorge is one of great natural 

 beauty, and in parts is thickly hung with ferns. Fossils are 

 •entirely obliterated. 



Beyond this section, towards the upper end of the dene, the beds 

 are less altered. Near an old quarry the following section is 

 exposed in the side of the stream : — 



Thickness in feet. Fauna, 



f Well-bedded, thin, yellow lime-"") 

 Middle stones. Very highly fractured I c . , , ,,. . lr . 

 Bedded <{ at right angles to the bedding. }-6- „ ,. , _ ° 



Limestones. | Collapsed in part, with powdery U S ^' 



[_ material J 



(6) Hardwick Dene. 



This is a small, post-Glacial ravine passing in a north-and- south 

 direction for slightly under a mile, and joining Castle-Eden Dene 

 about half a mile from the sea. The stream has in places cut into 

 the rock to a depth of 40 feet, exposing a good section of the Upper 

 Limestones. The ravine rises rapidly, and the dip of the strata is 

 very variable, but higher beds are encountered as one ascends 

 the stream : — ■ 



Uppermost 

 Limestones. 



Hartlepool 

 or Roker 

 Series. 



(?) 



Equivalents 



of the 



Concretionary 



Series. 



(?) 

 Shell- 

 Limestone. 



Thickness in feet. 



Fauna. 



Schizodus schlotheimi Geii 

 Mytilus septifer King. 

 Small gasteropoda. 



Soft, yellow, well-bedded, rotten^ 



limestones, which enclose large, 



i'ounded,hard masses containing I „„ 



a few fossils | 



Small-grained 'roestone,' partly | 



indurated J No fossils. 



Soft yellow limestone, more or less ") C Schizodus and Mytilus abun- 



collapsed and brecciated, es- > 20 < dant in a less altered 



pecially in the lower part j (. band. 



Hard honeycomb breccia. "^ 



'Roestone,' very porous in the 



lower beds. Large and small, J> 50 No fossils. 



flattened, irregular, lenticular j 



[_ bodies very apparent J 



f Thinly-bedded, fissile, well strati-"] 



fied, white and yellow limestones 



of marly appearance, muchbrec- 



ciated and powdery in places. 



These beds become extremely 



white, porous and friable in 



part with dusty cavities _ 



Hard, angular, limestone-breccia, 



the masses embedded in yellow 



powdery material 



^30 No fossils. 



20(?) No fossils seen. 



