ZONE OF AMALTHEUS SPINATUS. 



105 



Section of the Ironstone series at old Nab, near Staithes. 



No. 



Petrology. 



Thick- 

 ness. 



Organic Contents. 



1 



Black, micaceous, marly shales, with 



ft. 



in. 



Pleuromija costata, Pecte/i (Bquivalvis, Pholadomya 



2 

 3 





1 

 



5 

 9 



costata, Pinna spaf.hidata. 

 Pleuromija costata, Rhynchonella lineata. 





Friable sandy shales, with limestone 





nodules at the bottom 



1 



6 





4 



Greyish-brown marly sandstone 







() 



Amal. spinatus, Pleuromya costata, Pholadomya 

 costata, Pecten cequivalvis, Unicardium sub- 

 globosum, Modiola scalprum, Limea acuti- 

 costa, Prolocardium truncatum, Rhynchonella 

 tetraedra. 



5 



Sandy marl 



3 



6 





6 



Top block of main seam surface, covered 







Amal. spinatus, Pecten (Bquivalvis, P. lunularis, 





with small branching fucoids 



3 







P. substriatus, Unicarditim janthe, Pleuromya 

 rostrata, R. lineata. 



7 

 8 



Shale 



1 









Bottom block of main seam, surface 





covered with long tortuous fucoids... 



2 



2 





9 



Shale 







8 



Pholadomya ambigua, Plicatitla spinosa, Ostrea 

 submargaritacea, Rhynchonella lineata. 



10 



Ironstone 







4 





11 



Shale 







6 





12 



Ironstone 







4 





13 



Shale 







6 





14 



Ironstone 







7 



Belemnites breviformis. 



15 



Shale 







10 



Belem. breviformis, Pecten (Bquivalvis, Monotis 



K) 



Ironstone . 







fi 



Monotis cygnipes, Arcomya arcacea, Ostrea sub- 

 margaritacea, Rhynchonella tetraedra. 











17 



Shale with a ferruginous parting or 







Pecten (Bquivalvis, P. lunularis, Monotis cygnipes. 





narrow ironstone band 







8 



Plicatula spinosa, Rhynchonella calcicosta, 

 TValdheimia punctata. 











18 



Ironstone 







5 



Lima Hermanni, Rhynchonella tetraedra. 



19 



Marly shale 



Total 



2 



6 



Pecten cequivalvis. 



21 



8 



20 



Zone of AmaW 



eus margaritatus. 



Bottom seam of ironstone. 



My much esteemed friend, the late Professor John Phillips, F.R.S.,^ who had often 

 examined the Yorkshire Coast with great care, observed that " the Ironstone courses, which 

 have been worked to some extent, may be examined with the greatest advantage in the chffs 

 and on the shore to the eastward of Staithes, for a space of three fourths of a mile, with 

 . . . the superincumbent shales '' in natural position. " These present hard shales, with 

 septaria and petroleum, jet rock and hard shale below it, and softer shales enclosing one hard 

 bed, which elsewhere is ironstone. Then the ordinary ironstone bands appear. These, 

 ' ' Geology of Yorkshire; the Yorkshire Coast,' 3rd edition, p. 156, 18/5. 



14 



