crops are not too small their identification does not offer any diffi- 
culties. They have a typical pattern of joints and faults; rather often it 
is also possible to observe the bedding planes and foliation, the dip and 
the strike of sedimentary and metamorphic rocks. 
Till is the most frequent of all surficial deposits, normally covering 
more than 50 % of the areas. It may be identified by help of the boul- 
ders spread on its surface which are rather easily observed on photos 
of scale 1:20 000 or larger. Observation of the boulders is made easien 
by the shadows they project. Over vast areas the till has its own mor- 
phology. Drumlins are represented by elongated ridges, oriented in the 
direction of the ice movement. They are seldom more than one km long 
and ten m high and appear in large swarms. Also in such cases when 
they are not more than one m high and then very difficult to observe 
from the ground, they are easily identified on the air photos. Especially 
in mountain valleys the Rogen moraine appears, characterized by ridges 
up to thirty — forty m in height, most of them oriented transverse to 
the valley (and also the ice movement) direction. The very high num- 
ber of big boulders is also typical. The J/eiki moraine consists, when 
well-developed, of three elements: plateaus, dead-ice hollows, and so- 
called rim ridges on the plateause and in this state offers no identifica- 
tion difficulties. 
The glacifluvial deposits include quite a few different phenomena. 
The eskers are long and sinuous ridges, very often followed on one or 
both sides by troughs with small lakes or bogs. Outwash plains usually 
have a pattern of braided channels. At the highest marine limit the esk- 
ers very often enlarge to a kind of delta. Other deltas or terraces appear 
in the mountain areas, where hanging tributary valleys connect with the 
main valleys. Very often gravel pits may be observed in the glacifluvial 
deposits. When there is forest on them it typically consists of Scotch 
pine; it is often quite sparse and gaps are familiar depending on reju- 
venation difficulties. Indications showing where glacifluvial sediments 
are to be found are given by the thousands of channels eroded by the 
meltwater streams from the inland-ice. It is of importance to map such 
drainage channels also because they may give hints about the thickness 
of the surficial deposits and about rock outcrops. As they cannot have 
been formed under a water surface they can give indirect information 
about the highest marine limit and the distribution of glacial lakes. The 
bearing of this is, that in areas with glacifluvial channels sediments of 
the type connected with such waters will not be found. 
In connection with the glacifluvial deposits wind deposits occur 
frequently. Dunes are long and winding ridges with an oblique cross 
profile; "wounds" — often made by reindeers — are common and 
expose the very bright shining quarts-sand. Outside the dune-fields 
there is often a thin cover of windblown silt not more than one meter 
thick, which, however, is very difficult to identify on the air photos. 
4