﻿Vol. 6r.] 



THE MARINE BEDS IN THE COAL-MEASURES. 



509 



of the sections at Norton (8 in PI. XXXIV) and Sneyd (10 in 

 PI. XXXIV), which are only 1| miles apart, illustrates the rapid 

 alteration in character of a coal-seam, which is so much relied upon 

 by practical mining-engineers for purposes of identification. 

 The following list has been obtained from this horizon : — 





H % 



p 



p 



1 



P • i 



ZOO ■ H 



i 





[a.= abundant.] 





02 j 



2 * 



13 



2 3 



9 ■— ' 

 5 d 



p 3 



2 ^ 



as O 

 oO 







i-l " 



w 



s 



EH 



W 



w. 



kn 







No. 2 



No. 3 



No. 4iNo. 5'No. 6 No. 10 



No. 8 



PI. XXXIV. 



Mycdina compressa, Hind 









* 



tt 









J Pterinopecten papy raceus (Sow.) 



# 



# 



-;f 



* 



* 



* 



# 



a. 



Posidoniella lesvis (Brown) 



* 



* 















Lingula mytiloides, Sow 





•* 







* 



* 



# 





Glyphioceras (?) paucilobum 



















(Phill) 



•X- 



7\«" 



* 





* ' * 

















* * 



*- 





Pleuronautilus sp 













•55- 





Rhizodopsis sauroides, Will. ... 



# 









# 



*- 





Beyrichia arcuata, Bean 







... 





* 



* 





Dithyrocaris testudineum (?) ... 



# 



# 







* ; 







Plant-remains (fragmentary) ... 





* 



... 





i 



* 



i 



I 



At Norton, Sneyd, and Birchenwood Collieries the uppermost layer 

 of the marine shale contains Lingula mytiloides, unmixed with any 

 other form. 



Pterinopecten and Glyphioceras occur together, both in the bullions 

 and in the shales ; Dithyrocaris has only been found in bullions. 



(8) The Weston-Sprink Bed. 



This marine horizon was discovered in 1899, by Mr. John Ward, 

 in a marl-pit at Weston Sprink, near Longton (No. 13, PI. XXXIV). 

 Its exact position is lat. 52° 59' 9" N., long. 2° 6' 15" W. Fig. 2 

 (p. 508) is a reproduction of a photograph of the measures exposed 

 at Weston Sprink, of which the following is the section, in descending 

 order : — 



Thickness in feet inches. 



1. Surface-soil. 



2. Grey marl 2 6 



3. Grit 6 



4. Unlaminated red marl 2 4 



5. Grit 2 



6. Purple marls, with large lenticular patches of grit . 9 4 



7. Thin haematite-bands 2 



8. Grey and purple marls, with haematite-nodules 6 5 



9. Dark -blue clay-shale (see fig. 2), marine band ... 2 



10. Smut-layer 0^ 



11. Dark fireclay '. 1 2" 



12. Purple marl, with large lenticular nodules of grit... 7 9 



13. Grey marl 1 11 



