Introduction - Geotechnics of Organic Soils and Peat - page 5

Figure 1.6 Lacustrine soil deposit ( Source : http://soilweb.landfood.ubc.ca/landscape/parent-material/
water-environment/lacustrine-environment).
be deposited. However, when the water flows more slowly, more of the finer soils
(silt and clay) are also deposited. Rivers flow rapidly after a period of heavy rain-
fall or snowmelt, and slowly during drought. Alluvial soils often contain alternating
horizontal layers of different soil types.
Rivers in relatively flat terrain move much more slowly and often change course,
thus creating complex alluvial deposits, such as meander belt deposits.
1.2.4 Lacustrine soils
Lacustrine soils are soils deposited beneath lakes. These deposits may be still under
water, or may now be exposed due to lowering of the lake water level (Figure 1.6).
Most lacustrine soils are primarily silt and clay. Their suitability for foundation ranges
from poor to average.
1.2.5 Marine soils
Marine soils are also deposited under water, except that they are formed in the ocean.
Deltas result in a special type of marine soil deposit formed when rivers meet large
bodies of water, gradually building up to the surface. This mode of deposition creates
a very flat terrain, so water flows very slowly. The resulting soils are primarily silt and