Glossic Horizon - Soil Geography of the USA: A Diagnostic-Horizon Approach - page 168

16.3 Classification of Soils with Glossic Horizon

There are 549 soil series in glossic categories of ST; these soils are distributed in
four orders: the Alfisols, Aridisols, Mollisols, and Ultisols (Table 16.2 ). Soils with a
glossic horizon are identified at the great-group level in the Glossaqualfs,
Glossocryalfs, Fraglossudalfs, and Glossudalfs and in Glossic, Glossaquic, and
other subgroups for the other taxa. Soils with a glossic horizon occur in other
non-glossic defined taxa such as the Argi- great groups of the Mollisols and
probably other taxa as well.
Soils with glossic horizon tend to be in silty and loamy particle-size classes (67 %),
have a mixed mineralogy (70 %), have a frigid or cryic soil-temperature regime
(60 %), and occur in active and superactive cation-exchange classes (70 %; Fig. 16.2 ).

16.4 Distribution of Soils with a Glossic Horizon

Soils with a glossic horizon are concentrated in four areas, including the Front
Range of the Rocky Mountains (Bockheim 2012 ); immediately north of the
“tension zone” in WI (Bockheim and Schliemann 2013 ), MN, and MI; on loess-
covered Pleistocene terraces in the southern Mississippi River Valley-Gulf Coast
area of LA and TX; and in northern NY (Fig. 16.3 ).

Table 16.2 Classification of soil series with a glossic horizon
Order Suborder Great group Subgroup No. of soil series

Alfisols Aqualfs Glossaqualfs [all] 68

Natraqualfs Glossic (6) 6

Cryalfs Glossocryalfs [all] 65

Udalfs Fraglossudalfs [all] 14

Glossudalfs [all] 250

Hapludalfs Glossaquic (21), Glossic (24) 45

Natrudalfs Glossaquic (2) 2

Paleudalfs Glossaquic (9), Glossic (11) 20

Ustalfs Natrustalfs Aridic Glossic (3) 3

473

Aridisols Argids Natrargids Glossic Udic (0), Glossic (0) 0

Mollisols Aquolls Natraquolls Glossic (0) 0

Cryolls Argicryolls Alfic (18)* 18

Udolls Argiudolls Alfic Veric (2)*, Alfic (5)* 7

Natrudolls Glossic Vertic (0), Glossic (4) 4

Ustolls Argiustolls Alfic (9)* 9

Natrustolls Glossic Vertic (1), Glossic (9) 10

Xerolls Argixerolls Glossic (9), Alfic (5)* 14

62

Ultisols Udults Fragiudults Glossaquic (3), Glossic (11) 14

549