ZONE OF AMALTHEUS SPLNATUS. 



105 



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



No. 



10 

 11 

 12 

 13 

 14 

 15 



16 



17 



18 

 19 



Petrology. 



Black, micaceous, marly shales, with 

 a row of limestone balls 



Laminated shales 



Friable sandy shales, with limestone 

 nodules at the bottom 



Greyish-brown marly sandstone 



Sandy marl 



Top block of main seam surface, covered 

 with small branching fucoids 



Shale 



Bottom block of main seam, surface 



covered with long tortuous fucoids... 



Shale 



Ironstone 



Shale 



Ironstone 



Shale 



Ironstone 



Shale 



Ironstone 



Shale with a ferruginous parting or 

 narrow ironstone band 



Ironstone 



Marly shale 



Total 



Thick- 

 ness. 



ft. in. 

 1 5 

 9 



3 



6 



3 







1 







2 



2 







8 







4 







6 







4 







6 







7 







10 



6 



8 



5 

 2 6 



21 8 



Organic Contents. 



Pleuromya costata, Pecten cequivalvis, Pholadomya 

 costata. Pinna spaf.hulata. 



Pleuromya costata, Rhynchonella lineata. 



Atnal. spinatus, Pleuromya costata, Pholadomya 

 costata, Pecten teqiiivalois, Unicardium sub- 

 glohosian, Modiola sculprum, Limea acuti- 

 costa, Protocardium fruncatum, Rhynchonella 

 tetraedra. 



Amal. spinatus, Pecten cequivalvis, P. lunularis, 

 P. substriatus, Unicardium janthe, Pleuromya 

 rostrata, R. lineata. 



Pholadomya amhiyua, Plicatula spinosa, Ostreu 

 siibmargaritacea, Rhynchonella lineata. 



Belemnites breviformis. 



Selem. breviformis, Pecten cequivalvis, Ifonotis 



cygnipes. 

 Mofiotis cygnipes, Arcomya arcacea, Ostrea sub- 



margaritacea, Rhynchonella tetraedra. 

 Pecten cequivalvis, P. lunularis, Monotis cygnipes, 



Plicatula spinosa, Rhynchonella calcicosta, 



TTaldheimia punctata. 

 Lima Ilermanni, Rhynchonella tetraedra. 

 Pecten cequivalvis. 



Zone of Amaltheus tnargaritatus. 



20 



Bottom seam of ironstone. 



My much esteemed friend, the late Professor John Phillips, F.R.S.,^ ^vho 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 cliffs 

 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. l.")C, 1873. 



14 



