Most surficial deposits in Iceland date to the end of the last Ice Age, when glaciers retreated from the landscape and processes of glacier erosion were at their most active. This is reflected in the various types of surficial deposits in Iceland and their quantity.
The most common type of surficial deposit in Iceland is glacial till, sediments eroded and entrained by glaciers during and following the last Ice Age. Other common surficial deposit types are stream terraces and ancient deltas that formed due to higher sea levels at the end of the Ice Age. Also prominent in Iceland are flood plains, sandurs created by glacier outburst floods (jökulhlaups), and sand and silt deposited by surface running waters of various types in modern times. One also finds various types of scree and talus at the foot of mountains and rock faces. These are rock fragments from cliffs and bedrock not covered by sediments that have been worn away by frost wedging in ancient and modern times.
Icelandic soils have a high concentration of volcanic ash. Soil is present in much of Iceland, particularly in lowland regions, valley heads and at the bottom of mountain slopes, where it can reach a thickness of several metres.