Classification of Cryosols - Cryopedology - page 70

suborder (Organic cryosols) or in mineral soils. The histic epipedon in Histels must
be more than 40 cm thick and comprise 80 % or more of the upper 50 cm of soil.
The histic epipedon is recognized at the great-group level in Turbels and Orthels and
must be at least 20 cm thick, i.e., comprise more than 40 % of the upper 50 cm. Soils
with a histic epipedon are very common in the circumarctic and occur in depres-
sions with restricted drainage in mountains throughout the world and occur to a
limited extent along the western Antarctic Peninsula and its offshore islands and
along the coast in East Antarctica.
The umbric epipedon is a thick, dark-colored mineral horizon that is enriched in
organic matter but that contains a low base saturation. Soils with an umbric epipe-
don are common in the circumarctic (Tarnocai and Bockheim 2011 ); they are par-
ticularly common in mountains containing permafrost (Bockheim and Munroe
2014 ); and they occur to a limited extent on the western Antarctic Peninsula and its
offshore islands (Michel et al. 2006 ; Simas et al. 2007 ). The mollic epipedon is a
thick, dark-colored, highly base saturated mineral horizon that is enriched in organic
matter. Soils with a mollic epipedon occur in the Kuparuk River drainage of the
North Slope of Alaska (Ping et al. 1998 ) and occur in the high mountains where the
parent materials are base-rich (Bockheim and Koerner 1997 ). The ochric epipedon
is lighter in color, lower in organic matter, or too thin to satisfy the requirements of
the mollic or umbric epipedon. The ochric epipedon is common in the High Arctic
(Tarnocai and Bockheim 2011 ), the Antarctic mountains, and in the nival zone of
high mountains (Bockheim and Munroe 2014 ).
Because of intensive cryoturbation, only 8 of the 19 diagnostic subsurface hori-
zons occur in cryosols. The albic horizon is a subsurface horizon that is 1 cm or
more in thickness, is light-colored, eluvial, and leached of clay and Fe oxides. Albic
horizons are common in Spodosols underlain by permafrost in the Russian Arctic
(Jakobsen et al. 1996 ; Alekseev et al. 2003 ), northeast Greenland (Ugolini 1966 ),
abandoned penguin rookeries in Antarctica (Bölter et al. 1997 ; Beyer and Bölter
2000 ), and in the subalpine zone in mountains underlain by permafrost (Burns
1990 ; Skiba 2007 ). The argillic horizon features an accumulation of illuvial, high-
activity silicate clays, or the presence of clay bridges or coatings. The author is
aware of only two cryosol pedons with an argillic horizons reported in the literature,
including one in Chersky, Russia (Smith et al. 1995 ) and one in the Yukon Territory
(Tarnocai et al. 1991 ). Both soils occur on nonsorted stone polygons.
Calcic horizons are moderately thick, contain abundant secondary carbonates,
and lack cementation. These occur in central Yakutia, Russia (Desyatkin et al.
2011 ), Svalbard (Kabala and Zapart 2012 ), and in alpine soils (Kann 1965 ; Nimlos
and MConnell 1965 ; Knapik et al. 1973 ; Bockheim and Koerner 1997 ). Cambic
horizons refl ect subdued pedogenesis but must have a texture of loamy fi ne sand or
fi ner. Soils with cambic horizons are common in high-mountains environments
(Bockheim and Munroe 2014 ) and are likely common in high-latitude environments
as well.
Gypsic and petrogypsic horizons occur in Antarctica (Bao et al. 2000 ). Natric
horizons feature accelerated clay illuviation, due to the dispersive properties of Na.
Soils containing these horizons are common in central Yakutia (Desyatkin et al.