Geoscience Reference
In-Depth Information
24.5 Factors Influencing the Development of Lamellae
Lamellae are an example of “pedogenic equifinality,” which means that the same
form may have formed in different ways (Rawling
2000
). Parent material largely
determines the presence or absence of lamellae (Table
24.5
), since nearly
two-thirds of the soil series in lamellic subgroups in the USA have sandy or
sandy-skeletal soil textural classes. Nearly all of the 18 case studies of lamellae
in the literature included soils developed in sandy materials (Table
24.6
).
In particular, stratified sandy materials and those with textural discontinuities
contain lamellae. It should be pointed out that there are many examples of sandy
soils lacking lamellae, particularly in the Udipsamments and Haplorthods great
Table 24.5 Relation of soil-forming factors and lamellae development (Bockheim and Hartemink
2013
)
Role of soil-forming
factor
Area
Soil taxa
Citation
Organisms
New Zealand
dunes; Iowa
till
Udipsamments,
Hapludalfs
Lack of bioturbation
enables lamellae to
form
Kemp and McIntosh (
1989
)
and Johnson et al. (
2008
)
Climate
SMR: depth and
thickness of E & Bt:
udic
>
ustic, xeric
[This study]
STR: depth and thickness
of E & Bt: hyperther-
mic, thermic
>
mesic
>
cryic, frigid
[This study]
Parent material
Michigan out-
wash, Illi-
nois, Michi-
gan, and
Texas dunes
Udipsamments
Sandy materials favor
lamellae formation
Wurman et al. (
1959
),
Dijkerman et al. (
1967
),
Hannah and Zahner
(
1970
), Berg (
1984
),
Schaetzl (
1992
,
2001
), and
Holliday and Rawling
(
2006
)
Michigan
outwash
Udipsamments
Stratification of sands
may enhance
lamellae formation
Dijkerman et al. (
1967
)
New Zealand
dunes
Hapludalfs
Lamellae reflect concur-
rent sand deposition
and pedogenesis
Kemp and McIntosh (
1989
)
Michigan
outwash
Udipsamments,
Haplorthods
Pedons with more fine
sand and silt than clay
had deeper and
thicker lamellae
Schaetzl (
1992
)
Michigan
outwash
Udipsamments,
Haplorthods
Textural discontinuous
favor lamellae
formation
Schaetzl (
1992
)
(continued)
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