

Vol. 70.] OF DURHAM MAGNESIAS 



LIMESTONES. 





261 



At the final stage, the level of the Permian sea 



was probably 



considerably below that of the oceans. The basin 



thus 



formed, 



when the period of desiccation finally gave place to a 



different set 



of conditions, would form a convenient receptacle 



for the thick 



JBunter deposits, largely of torrential formation 



undei 



desert 



conditions. The Bunter deposits, although transgn 



jssive, 



occupy 



an area closely corresponding to that of the Permian, so 



that an 



apparent upward passage, not only of Upper Per] 



Dttian, 



but of 



Middle Permian deposits might occur. If the middle 



deposits 



of the Permian consisted of material derived from the same source 



as the overlying Bunter, the break between the two might become 



very obscure. 







The Keuper deposits are, of course, widely transgressive 



Dver all. 



VIII. Synopsis of the Main Constituents of Durham 



Magnesian Limestones. 











O tc 



11 



*8 C 



a 



.2+8 



•** « 

 S -4J 



oluble 

 esidues. 



'3 







"i 







liydrite,or 

 psum, or 

 ilphur- 

 ioxide. 



1 or 



anganese. 



Locality. 







£< 



S^ 



73 -^ 



Is 



'o 





2^ 









25 







M 



O 



Q 



1— 1 







Salt Measures. 





! 













Hard, grey, gypsiferous 



1 





rOo 0-54 97*27 



114 



0-46 



Teeside Boring. 





Hartlepool & Roker 

















Beds. 







. 











White, well-bedded, powdery . 



2 





331 2-80 



92-29 



0-15 



1-18 



Fulwell Cutting. 





White, friable, oolitic. Fossils 



3 





0'76 1 1-25 



98-62 



0-08 



045 



> Hesleden Dene. 





White, friable, massive. Fossils 



4 





0-45 1-82 



98-60 



tr. 



0-30 







5 





0-05 1-06 



98-86 





0*40 



Hartlepool. 





Thinly-bedded, small-grained 







1 















6 





O08 1-10 



98-23 





044 



Scaham Harbour. 





Upper Limestones with 



















Chondrites. 

















d 



Soft, well-bedded, fetid 



7 





2'61 1-96 



9347 



0-31 



0-93 



") South Durham 

 ) coast-section. 







8 





380 2-81 



92-61 



0-17 



0-77 



- 



Concretionary Series. 















J \ 



P 





9 

 10 

 11 



s.c. 

 s.c. 



1-23 77*80 



21 03 





0-18 

 0-60 

 0-75 



•\ 



Platy concretionary limestone . 

 Soft, fetid, well-bedded 



3-01 66-60 29-90 

 1-80 8-31 87-75 



/ South Durham 

 i coast-section. 





Spherical concretions 



12 



s.c. 



1-26 80-95: 17-30 



0-21 



0-45 



1 





Powdery matrix of the above... 



13 



S.D. 



2-65 659 



89-75 



0-23 



1-26 



^Fulwell Quarries. 





Small concretionary aggregates 



14 



S.C. 



142 7596 



22-39 



tr. 



0-47 





Powdery matrix of the above... 



15 



S.D. 



411 ' 8-23 



87-20 



tr. 



1-22 



1 





The ' great marl-bed ' 



16 





502 1 13-07 



78-42 



tr. 



241 



J 





Concretionarv ' bluestone ' 



19 



S.C. 



0-16 9634 



313 





0-19 



1 





Powdery rock associated with 

 the above 



17 



S.D. 



0'27 



579 



93-19 



;{ 



0-59 



Mn0 2 



061 



! Byer's Quarry, 

 near Marsden. 





Coarse residue in the above . . . 



18 



S.D. 



0*25 



5-54 



9305 





2-20 



J 





Flexible Limestones, etc. 





















Typicai flexible limestone 



20 





6-70 



0-71 '■ 91-37 



O'll 



1-48 



Marsden. 





, Thinly -bedded, flaggy rock 



21 





3-16 1 6-22 89-68 



017 



0-72 



Hesleden Dene. 





Hard, flaggy bedded rock 



22 





42-65 356, 5F92 





235 



West Hartlepool. 























