Geoscience Reference
In-Depth Information
Appendix 26. Texturing soils using a soil bolus
Texture
symbol
Field texture
grade
Behaviour of moist bolus
Approximate clay
content (%)
S
Sand
Coherence nil to very slight, cannot be moulded; sand
grains of medium size; single sand grains adhere to
fingers.
less than 5%
LS
Loamy
sand
Slight coherence; sand grains of medium size; can be
sheared between thumb and forefinger to give a minimal
ribbon of about 5 mm.
approx. 5%
CS
Clayey
sand
Slight coherence; sand grains of medium size; sticky
when wet; many sand grains stick to fingers; will form a
minimal ribbon of 5-15 mm; discolours fingers with clay
stain.
5-10%
SL
Sandy
loam
Bolus coherent but very sandy to touch; will form a
ribbon of 15-25 mm; dominant sand grains are of
medium size and are readily visible.
10 -20%
FSL
Fine sandy
loam
Bolus coherent; fine sand can be felt and heard when
manipulated; will form a ribbon of 13-25 mm; sand
grains clearly evident under a hand lens.
10 -20%
SCL
Ligh sandy
clay loam
Bolus strongly coherent but sandy to touch; sand grains
dominantly medium-sized and easily visible; will form a
ribbon of 20-25 mm.
15 -20%
L
Loam
Bolus coherent and rather spongy; smooth feel when
manipulated but with no obvious sandiness or 'silkiness';
may be somewhat greasy to the touch if much organic
matter present; will form a ribbon of 25 mm.
approx. 25%
Lfsy
Loam, fine
sandy
Bolus coherent and slighty spongy; fine sand can be felt
and heard when manipulated; will form a ribbon of
approx. 25 mm.
approx. 25%
ZL
Silty loam
Coherent bolus; very smooth to often silky when
manipulated; will form a ribbon of approx. 25 mm.
approx. 25% and
with silt approx.
25% or more
SCL
Sandy clay
loam
Strongly coherent bolus, sandy to the touch; medium-
sized sand grains visible in finer matrix; will form a
ribbon of 25-40 mm.
20-30%
CL
Clay loam
Coherent plastic bolus, smooth to manipulate; will form
a ribbon of 40-50 mm.
30-35%
CLS
Clay loam,
sandy
Coherent plastic bolus; medium-sized sand grains
visible in finer matrix; will form a ribbon of 40-50 mm.
30-35%
ZCL
Silty clay
loam
Coherent smooth bolus, plastic and often silky to the
touch; will form a ribbon of 40-50 mm.
30-35% and
with silt 25% or
more
Search WWH ::




Custom Search