The River Port Hutton to Smithford 



type of stratification is called current-bedding, and the 

 confusion of the layers is due to the ever-changing 

 direction of the currents of the river, in which the 

 alluvium was deposited. 



v Close to the surface of the ground the deposit 

 became much more regular and, except where the bed- 

 ding had been obliterated by the action of roots and 

 surface weathering, the layers were horizontal. The 

 material in this upper part of the section was very fine- 

 grained and appeared to be the mud deposited by the 





FIG. 12. Section in Alluvium showing current-bedding. 



waters of successive floods, as they spread out over the 

 alluvial flats. 



The pebbles in the gravels were of several different 

 kinds of material. The greatest proportion was of 

 white or pale-yellow quartz, but hard bluish grits, gray 

 and cream-coloured limestones, brown ironstone and some 

 fragments of granite and other igneous rocks were also 

 present. As in all probability the whole of the material 

 had been brought down the valley by the river, we 

 thought it probable that we should find all these rocks 

 in situ in some part of the river bed or in those of its 

 tributaries. 



101 



