S
saddle
The area between marine banks.
salinity
The "practical salinity unit" measures the amount of salt in marine waters. It has the same numerical value as the old measure of parts per thousand (by weight), except in very saline and very dilute waters when the difference is, at the most, 0.06 units.
salmonid
Any member of the family of fish Salmonidae, which includes salmon and trout.
salt marsh
Marshland periodically flooded by saline tidal water and characterized by organisms tolerant to saline conditions.
sand
1. A mineral soil particle between 0.05 and 2.0 mm in diameter. 2. A soil textural class containing more than 85 per cent sand and less than 10 per cent clay.
sand ridge
A long, sinuous offshore feature that stretches over wide areas of the seabed and is formed in extreme conditions, such as by subsurface tides.
sandstone
A sedimentary rock composed predominantly of sand-sized quartz grains.
sand wave
An offshore bottom feature caused by storms and tidal currents. Sand waves on the Scotian Shelf can be from 0.512 m high and from 12 m to 1 km long.
saprophyte
A plant that derives nutrients from organic material and cannot photosynthesize.
scarp
A steep slope.
schist
A medium- to coarse-grained metamorphic rock with strong foliation that results from a parallel orientation of platy minerals such as micas.
scour
Removal of material by waves and currents, especially at the base of a shore structure.
scree
See talus.
second-order stream
Tributary initiated by the confluence of two first-order streams.
sedimentary
One of the three main groups of rock; rocks formed of material derived from pre-existing rocks by processes such as weathering, erosion, and precipitation.
seepage site
A place where water oozes from the earth, often forming the source of a small trickling stream.
semi-diurnal tide
Tide in which high water occurs twice daily with intervals averaging 12.4 hours.
seral stage
A stage of development in the successional process (sere) recognized by distinct soil and water conditions and associations of plants and animals.
sessile
Attached directly to a base without a flexible joint; used when describing parts of organisms, such as leaves or flowers.
shade-intolerant
Refers to trees that require full sunlight to reproduce and thrive.
shade-tolerant
Refers to trees that can reproduce and thrive in partial sunlight or shade.
shale
A laminated sediment composed predominantly of clay-sized particles.
shell midden
See midden.
sill
A sheet-like body of igneous rock which conforms to bedrock or other structural planes.
sillimanite
An aluminum silicate mineral usually found in fine fibrous masses and associated with intensely metamorphosed mica schists and gneisses and contact-metamorphic deposits.
silt
1. A mineral soil particle between 0.002 and 0.05 mm in diameter. 2. A soil texture class containing more than 80 per cent silt and less than 12 per cent clay.
siltstone
A very fine-grained consolidated clastic rock composed predominantly of particles of silt.
Silurian
The geological period between 436 and 415 million years ago.
sinkhole
A depression occurring in karst topography, often the result of the collapse of a cavern roof.
slate
A fine-grained metamorphic rock easily split into flat, smooth plates.
slope water
A band of water consisting of Gulf Stream water diluted by approximately 20 per cent coastal water near the edge of the continental shelf and separated from the coastal water by a sharp front.
slumping
The formation of a landslide that develops where strong, resistant rocks overlie weak rocks.
smectite
A greenish variety of clay mineral.
softwood
A forestry term for coniferous, needle-leaved trees and the forests they form.
soil survey
The systematic examination, description, classification, and mapping of soils in an area.
solution lake
A lake formed in soluble material such as salt, limestone, and gypsum; water in these lakes is often alkaline.
Southern Upland
A physiographic area that comprises the southwestern half of mainland Nova Scotia.
spit
A low tongue or narrow embankment of land, usually composed of sand or gravel, formed by wave and current action, with one end attached to the shore and the other ending in open water.
spring tide
A tide that occurs at or near the time of the new or full moon and rises highest and falls lowest from the mean sea level.
staging area
An area where migrating birds congregate to rest and refuel.
staurolite
A crystallized iron-aluminum silicate mineral that occurs in regionally metamorphosed rock.
stibnite
A sulphide compound associated with arsenic and antimony minerals; the principal ore of antimony.
stones
Rock fragments greater than 25 cm in diameter.
storm surge
The rise above normal water level on the open coast that results from wind stress on the water surface.
stratification
1. Applied to rocks: the presence of layers, or strata; typical of sedimentary rock. 2. Applied to water: division of the water column into layers of different temperature or salinity.
stratigraphic
Refers to the formation, composition, sequence, and correlation of stratified rocks as part of the earth's crust.
stratum
A layer of rock (plural strata).
striae
Small grooves on the surface of a rock, formed by glacial action.
strike
The compass direction of the line of intersection created by a dipping bed or fault and a horizontal surface.
strike-slip fault
A fault along which movement is horizontal.
subaerial erosion
Erosion that occurs at or near the surface. See
eolian.
submarine valley or canyon
1. The seaward extension of a valley cut on the continental shelf during low sea level. 2. A steep, valley-like depression carved into the outer margin of the continental shelf and slope by turbidity currents.
submerged coastline
A coast which has been partially drowned as the result of a rise in sea level, a subsidence of the crust, or both.
substrate
The surface on which organisms grow; usually providing physical support and a supply of nutrients.
subtidal
Pertaining to the marine environment below the lowest level of low tide.
succession
The progressive change in the composition of a community of organisms towards a largely stable climax.
superimposed drainage
A natural drainage system established on underlying rocks independently of their structure.
surface water
All moving and standing water naturally open to the atmosphere.
surficial
Characteristic of, pertaining to, formed on, situated at, or occurring on the earth's surface; especially consisting of unconsolidated residual alluvial or glacial deposits lying on bedrock.
surf zone
The area between the outermost breakers and the limit of wave uprush on the seashore.
suspension feeder
A freshwater animal that feeds on materials suspended in water.
syenite
A wholly crystalline rock resembling granite but containing little or no quartz.
sylvite
A potassium-chloride mineral associated with sedimentary salt beds and volcanic features; the principal ore of potassium.
syncline
A fold in layers of rock caused by deformation of the earth's crust. Synclines are basin-shaped and have the younger strata towards the centre of the fold.
N through Z