236 LAW AND SIMPSON : DRIFT DEPOSITS AT MYTHOLMROYD. 
were laid and separated by the gravelly matrix, preclude the 
possibility of the deposit being that of running water ; whilst 
the presence of the erratics throughout the mass, without a 
lower layer of more local stones, does not lend support to any 
theory of local ice being over-ridden by spurs of ice thrust 
down the valley from over the Pennine watershed. 
There are superficial indications further down the valley on 
the southern side between Mytholmroyd and Luddenden Foot 
of hummocky drift patches, which offer scope for and should 
repay further investigation. 
