183 



the horizon of the LoAver Lias.'" Another thin, but very jjersistent, 

 marine bed, occurring a little higher in the series, is the -well-kno-wn 

 Ellerbeck Bed. But, on the other hand, there are also thin coal 

 seams, such as that from whicli the Castlefcon Coal was obtained. 

 Some of these thin seams may have owed their origin tu deposition 

 along shore in sheltered shallow creeks into which much vegetable 

 matter Avas carried by wind and stream and tide. Others may 

 have been formed in marshes and lagoons. In these estuarine 

 beds it is common to find the large Horsetail, Uqidsdites 

 columnaris, in an upright position as when growing. Mr. A. C. 

 Seward says " the vertical position of such stems naturally 

 suggests their preservation in situ, but in this, as in many other 

 cases, the erect manner of occurrence is due to the settling down 

 of the drifted plants in this particular position."'-' If Mr. Seward 

 were as familiar as I am with the very constant occurrence of 

 these stems in a vertical position, and seldom in contact, in 

 Cleveland escarpments, I venture to predict that he would alter 

 his opinion. 



From the Upleatham Hill, near ]\Iar.ske-by-the-Sea, I have 

 recently obtained specimens of a thin stratum occurring in the 

 horizon ol the Lower Oolite Estuarine Beds, which is simiily a 

 tangled mass of plants such as Tcanioptens, Otozamites and 

 Williamsonia. My attention was called to this bed l\v my friend 

 Mr. J. M. Meek, who discovered it some years ago. I am 

 preparing a Paper on this Ijed, which I propose to communicate 

 to the Geological Society of London. 



The succeeding beds of Oolite Avere mostly formed in somewhat 

 deeper, though not deep, water, and the sea-bottom in the district 

 continued to sink until in all probability the sea of the Kiraeridge 

 Claj- period, and later the Chalk Sea, covered it, and some deposits 

 of clay and chalk and other rocks were spread over it. It is not 

 unlikely that the crests of the Pennines, which have indeed in all 

 probability been elevated, but which have certainly also been 

 greatly denuded since then, were submerged b}' tlie sea of the 

 U2)per Chalk Period ; and it is by no means inqirobalile that tliis 

 chalk, as we now find it in the Yorksliire "NVold district, Avas 

 formed on a sea-floor four or five hundred fathoms below the 

 surface. 



At the close of this period of great suljmergence our area 

 began to rise, the main a.^cis of uplift being in tlie line of the 

 Pennines, and since it appeared above sea-level it has, so far as we 



(1) See " Xaturalist, " July, 1902, p. 216. 

 {■I) "Fossil Plants," vol. L, p. 72. 



