part 3] IXTEHGLACIAI, LCESS, ETC. OF DURHAM COAST. 1&3 



Fissure 4 is seen in the cliff, when the slipped clay has been 

 washed away, to be about 70 feet wide. Between tide-marks it 

 seems to have about the same width, and it continues out to sea, 

 where it apparently narrows considerably. It contains large masses 

 of peaty wood and tree-trunks, some of which 1 collected four years 

 ago and sent to the late Clement Keid, F.R.S., who determined 

 them as oak, alder, and pine. 



The grey and black clay in which the tree-trunks are embedded 

 is very rich in places in freshwater shells, the most conspicuous 

 forms of which are species of Anodonta, Limncea, Planorbis. 

 Vulvata, and Pisidium. 



In this fissure, in some brown clay, apparently different from 

 that containing the majority of the shells, on May 1st, 1918 (when 

 nearly all the sand had been scoured away). I found some large 

 mammalian bones which seemed to me to be elephant-remains. 

 Pieces of an atlas vertebra occurred embedded in the clay, and 

 a fragment of a rib was found, washed out among the shingle, but 

 quite close to the other bone. 



Fissure 5 is about 100 yards north of the last one, and 

 contains between tide-marks a quantity of grey and brown clay 

 with some fragments of trees not so big as those in Fissure 4, 

 and much comminuted vegetable matter. The grey clay yields 

 a large quantity of shells which do not seem to differ from 

 those in the other fissure, except that perhaps the valves of Pi si (Hum 

 are more plentiful. Some rodent-remains were washed from a 

 piece of brown clay in this fissure, and near it a mass of brownish 

 rather sandy clay (apparently distinct from the blue clay that 

 contains the majority of the shells) yielded on washing the bulk of 

 the seeds that prove to be of such great interest. 



The deposits in these two fissures are much mixed up, but traces 

 of original stratification are clearly discernible, showing that some 

 stratified deposits, together with part of the bed-rock on which they 

 rested, were torn up, canned by the ice, and thrust, under great 

 pressure, in a partly -frozen condition into the fissures and hollows. 

 The whole may be regarded as a gigantic glacial erratic, and 

 seems to have been bodily overturned, since most of the Permian 

 marls, on which the freshwater clays rested, now occupy the higher 

 part of the fissures. 



The material is very strongly slickensided in places, but tin- 

 smaller shells are generally complete, though the larger, such 

 as Anodonta and Limncea, may be crushed, indicating that the 

 material was frozen during its transport. On the surfaces of the 

 clay, when it has been washed clean by the sea, repeated faulting 

 of the bedded material on a small scale can be well seen. 



The seeds and other organisms are often pyritized, and veins of 

 pyritized material are seen in the mass, apparently having originated 

 subsequently to the thrusting of the material into the fissures. 



The whole deposit is clearly very much broken up, and a 

 separation of the different beds of clay on purely stratigraphical 

 grounds seems impossible. However, after expert examination of 



