Rice ALL COMMON. 

 By W. Deistison Roebuck. 



RiccALL Common is situated in the centre of the wide low-lying 

 plain called tlie Vale of York. TMs vale lias undoubtedly been 

 produced by natural forces acting tbrougli a long series of years, 

 wearing away the soft triassic or new red series of strata ; while the 

 harder liassic, oolitic, and cretaceous strata of the East Riding, and 

 the permian and carboniferous rocks of the West Riding, offering 

 more resistance to the disentegrating forces, marine or sub-aerial, 

 ha,ve been left standing out as hills and mountains. 



This vale may be traced from the coast of Durham through York- 

 shire and Nottinghamshire far down into the midland counties ; and 

 into it are gathered the great rivers which, by their confluence, form 

 the Humber. The Humber estuary has to escape from this vast 

 inland basin by cutting its way through the three parallel ranges of 

 hills formed by the outcrop of the lias, the oolites, and the chalk 

 which bound it on the east. It is evident that a comparatively small 

 obstruction to this outflow would convert this basin into a great inland 

 lake ; and this, indeed, appears actually to have been the case. This 

 lake, however, would in process of time become filled up by materials 

 brought down by the rivers from above, and consequently we now find 

 its site a wide alluvial plain, with a few little islets of trias rising out 

 of it. The new red sandstone is reached at Cawood at a depth of 

 about 100 feet. The lowest bed reached about Riccall is a strong 

 brown clay of unknown thickness, which is met with at Cawood and 

 Kelfield on one side, and at North Duffield on the other, and probably 

 extends beneath the whole of the common. Above the clay is a bed 

 of sand of variable thickness, which, owing to the retentive nature of 

 the clay beneath, is waterlogged in its lower part so as to become 

 a quicksand. 



In repairing the tower of Riccall church, ten years ago, it was 

 found that the Norman builders, in order to obtain a firm foundation, 

 had thrown confusedly together into the quicksand a number of trees, 

 upon which they had rested their tower. It is upon this wet sand 

 that the rich flora of Riccall Common grows. There is a great 

 similarity in the flora of Riccall Common to that of Thorne Waste, 

 but at Riccall there are many sand-loving plants, such as Plantago 

 Co7'onopus^ which do not grow at Thorne Waste. At Thorne there is 

 a thick bed of peat resting on the clay, while at Riccall the soil is 

 sandy, but full of vegetable matter in its upper part. 



