118 Post- Glacial Oeohgy of the Estuary of the Mersey. 



sand, the drifting occurring mostly between neap and spring tides, 

 ■when a large extent of the shore is hare and dry. When the sand 

 first began to blow is an interesting problem difficult to solve ; for 

 though Koman remains are found at the base of the Sandhills in 

 Cheshire, this does not settle the question, as there may have been 

 sand dunes to the northward on the new land which have since 

 encroached landvfard. In places also there are beds containing 

 fresh water or marsh shells, but I do not consider these general and 

 intercalated ; in the blown sand are traces of former cultivated soil- 

 surfaces. 



General Conclusions. — A careful consideration of the foregoing 

 facts, of which only a bare outline is given, has enabled me to come 

 to the following conclusions. 



1st. That since the laying down of the Boulder-clay, the land has 

 been elevated above its present level, and has been again depressed 

 considerably below it, the main portion of the present Lancashire 

 and Cheshire river valleys having been excavated during this period 

 and the subsequent re-emergence of the land. The waslied-drift sand 

 ■was eliminated from, sorted and re-formed out of the Boulder-drift, 

 and scattered over the country, but has been much denuded and 

 displaced since by atmospheric and aqueous influences above the 

 25-feet contour, and by sub-aerial and sub-marine denudation belo'w 

 that line. 



2nd. On re-emergence the land ■was again elevated above its 

 present level, and a pause favourable to growth occurred, during 

 which time the " inferior peat and forest beds " or subterrene land- 

 surfaces were formed. The vertical extent of this and after-move- 

 ments will be considered at a future time. 



3rd. A second period of subsidence followed, and a pause occurred 

 at or about the 25-feet contour line ; considerable denudation of the 

 inferior peat took place, and afterwards, the Formhy and Leasowe 

 marine beds were laid down. 



4th. The latest vertical upward movement succeeded the forma- 

 tion of the Formby and Leasowe marine-beds, and upon them, as a 

 land-surface, grew the forest trees, remains of which are seen at 

 the base of the superior peat-bed. They are traceable from the mouth 

 of the Douglas, by Formby and Waterloo, to a little creek at Grarston, 

 and on the opposite Cheshire shore from the Mersey to the Dee, and as far 

 up the Mersey as the Ince and Helsby marshes and the mouth of the 

 Eiver Weaver. The river-bed at Crossens was excavated during this 

 period of elevation. 



5th. The last movement of the land now took place and was down- 

 wards. The river-bed at Crossens was silted up, and the drainage of 

 Martin Mere reversed into the Douglas. The drainage generally 

 was obstructed, and here and there beds of tidal silt were inter- 

 calated in the growing peat. The tidal silt overlying the superior 

 peat-bed by the Douglas, the Alt and the Birket, the silt which over- 

 lay the peat-bed of old Wallasey Pool, and that in which the vertebra 

 of a whale, now in Brown's Museum, was discovered at the North 

 Docks, and all the deposits to which I confine the term recent, belong 



