162 FORESTRY OF NORWAY. 
ancient marine formations terminate, and where the con- 
tinental formations begin. This point is passed ia the 
valley of the Glommen at Kongsvinger, and it is equally 
marked in numerous other localities. At a higher altitude 
in the valleys we come to a second slip, formed by the 
rocks contracting the valley, or by a moraine. Behind or 
beyond this slip there is found generally the basin of the 
valley covered with sand, or near this more rarely with 
clay; and so on, as further and further the valley is 
ascended. In proportion as the continental ice was thick, 
some valleys have remained a shorter or a longer period 
filled with ice. The lower limits of glaciers have always 
been receding to higher altitudes, and in places where 
they have remained stationary for a long time they have 
left moraines. These have there formed dykes, behind 
which was thus created a reservoir in which the clay 
carried off by the waters fell to be deposited in layers. 
Beds of clay in extensive areas above the ancient sea level 
are rarely met with; but they are met with in certain 
places behind these dykes, amongst the filling up of the 
later formed slips in the basin of the valley. 
Tn the valley of the Glommen, in the water-course of 
the Guldbrandslagen, and in the basin of the Dokka, all 
of these may be seen 
On the west coast of Norway the same succession of 
slips may be seen, but with a character somewhat different 
on account of the shortness and the depth of the valleys. 
At the extremity of the interior ramifications of the fiords 
there rises often a rampart of gravel and erratic deposits ; 
it is the moraine of the glacial period. Behind this there 
is ordinarily found a lake at a height a little above the 
level of the sea, while the depth of the lake is often con- 
siderably below the sea level. Such lakes are numerous, 
and beyond them, landwards, there are met with on many 
points a distinct slip in sandy ground, steep towards the 
sea, but flat towards the interior of the country; it marks 
the ancient level of the sea. 
In the diocese of Drontheim, where the valleys stretch 
