Geoscience Reference
In-Depth Information
Table 4.13 Contd...
Lithic contact
Contact with a hard material within 50 cm of
the surface
Paralithic contact
Contact with a
paralithic
material (see below)
Paralithic material
Relatively unweathered, moderately rupture-resistant
material such as sandstone or clayey schist
Permafrost
Material that stays frozen, cemented by ice or dry
Soil moisture regime
Refers to the water in the soil in normal years,
taking into account the temperatures prevailing
when the soil is saturated
(
IMPORTANT CHARACTERISTIC OFTEN
CONSIDERED
)
Aquic
Aqu
- Saturated with water and without dissolved
oxygen
Aridic or torric
- Dry during one-half of the year and moist
during the other half with temperatures staying
above 5 to 8 degrees, characterizes arid
climates
Udic
Ud
- (L.
udus =
humid) never dry for more than 90
continuous days, characterizes humid climates
Ustic
Ust
- (L
. ustus =
burnt) intermediate between the aridic
and torric regimes, characterizes monsoon climates
Xeric
Xer
- (Gr.
xeros =
dry) moist winters and dry summers,
characterizes the Mediterranean climate
Soil temperature
Refers to the soil temperature and to thermal
regime
contrast between summer and winter
(
IMPORTANT CHARACTERISTIC OFTEN
CONSIDERED
)
Cryic
Cry
- (Gr.
kryos =
cold) without permafrost but not
above 8 degrees annual mean
Frigid
- same annual mean but warmer summer
Mesic
- annual mean between 8 and 15 degrees,
difference between summer and winter temperatures
greater than 6 degrees
Thermic
Therm
- annual mean between 15 and 22 degrees,
difference between summer and winter temperatures
greater than 6 degrees
Hyperthermic
- annual mean above 22 degrees, difference
between summer and winter temperatures greater
than 6 degrees
Table 4.13 Contd...
