8 Mr Theodore Kjerulf on the Phenomena 
ing the valleys as great heaps of debris, sometimes stretch- 
ing right across, directly transverse to the course of the 
stream. 
All these masses were originally true moraines. 
It seldom happens that a good section of these banks can 
be seen; but as a rule they consist of debris (aur), with 
sand, clay, small and large stones, all irregularly heaped 
together without any trace of stratification. They rest 
directly on the surface of the rock, and are obviously the 
oldest of all the superficial deposits. 
Besides such masses as have been now described, and 
which really deserve the name of banks, smaller heaps of 
debris and blocks exist, generally lying covered up and 
hidden, or protected by some projection of the rocks. Their 
origin and composition is exactly the same as those of the 
banks, from which they differ only in being less likely to 
attract notice. These are the glacial debris heaps. 
(2.) There are also found in some places, resting imme- 
diately on the scratched surface of the rock, thin alternating 
layers of sand and clay. The sand is chiefly reddish and 
brown in colour, and sometimes preponderates decidedly over 
the clay. The sand and clay are occasionally twenty-five feet 
thick. Accumulations of big stones are at times found at 
the bottom of this deposit, in places where the form of the 
ground had afforded them shelter. Such stones are also 
scattered irregularly through the bed. This marly clay was 
formed from the destruction of Silurian limestones and 
schists. It was in all probability carried down by muddy 
rivers from the inland ice, and deposited as mud wherever 
the sea presented the necessary conditions of stillness. 
Freshly dug, this clay is always damp, often dripping with 
water. Its colour is bluish, seldom brown. ‘Traces of a 
thin leafy or stratified structure may often be seen. Lime — 
is pretty uniformly present to the extent of about two per 
cent. Exposed to the air this marly clay disintegrates more 
or less, but gets baked together again by rain. Its presence 
may generally be recognised by the thick clumps of the 
tussilago which it bears. 
Balls or knots so round as almost to seem artificial are 
found in this marl, and have been considered as concretions 
