O Hoizon

> 25% OM

litterlayer

A Hoizon

< 25% OM

mostly mineral

darkend by OM

C Hoizon

relitivly little soil formation

rocklike, but not solid

R Hoizon

Bed rock

may or may not be

the parent material

subdivision

All master horizons can be subdevided

ex. A₁, A₂, A₃

No Hoizon should be deeper then 40 cm

Transition Hoizons

A transition betwen 2 master Hoizons

ex, A, AB, B; A, CA, C

Order of letters is based on dominance

Lithologic discontinuity

significant change in texture and/or mineralogy

Subordinate distinctions

t

ex, Bt

t = clay has accumulated

Subordinate distinctions

k

ex, Bk

k = CaCo₃(Calcium carbonate) has accumulated

Subordinate distinctions

s

ex, Bs

s = Fe and/or Al has accumulated

(illuviation = water)

Subordinate distinctions

o

ex, Bo

o = Fe and/or Al has accumulated

(in place, heavy weathering - tropical)

Subordinate distinctions

w

ex, Bw

w = distict color or structure

alltered from parent material

Subordinate distinctions

h

Bh

h = accumulation of OM

illuvial (water) deposits

Subordinate distinctions

g

ex, Bg

g = grey color from high water table

Subordinate distinctions

x

ex, Bx

x = fragipan (dense, brittle)

Subordinate distinctions

km

ex, Bkm

km = cemented by CaCO₃

Subordinate distinctions

i

ex, Oi

Oi = slighty decomposed OM

Subordinate distinctions

e

ex, Oe

Oe = moderatly decomposed OM

Subordinate distinctions

a

ex, Oa

Oa = highly decomposed OM

Subordinate distinctions

b

ex, Ab

b = buried

ex, Ab = buried A by another deposit

Subordinate distinctions

p

ex, Ap

p = plowed (tilled for agriculture)

Subordinate distinctions

Cr

Cr = soft/weatherd bed rock

B Horizon

has a defined steructure

subsurface accumulation

E horizon

Leach = light in color/white

lighter then above

often found with water perching