permeable layer, or where there is intermittent groundwater),
Brown (where Oxidic Soils share some properties with
Brown Soils), and Typic as the central concept of the Orthic
Oxidic Soils group.
9.1.4 Origin of the Soil Order Name
‘Oxidic’ is derived from the Soil Taxonomy name Oxisols
(originally Greek ‘oxus’ and French ‘oxide’), and reflects the
high proportion of iron and aluminium oxides present.
9.2 Soil Profile Genesis
In the relatively geologically stable Northland region the
mafic lavas and associated deposits have been exposed to
weathering for long periods (often millions of years) in
landscapes that have remained stable under conditions of
strong weathering and leaching, and potentially with marked
movements in water table in lower landscape positions. Thus
Fig. 9.2 Distribution of Oxidic Soils Photo: Allan Hewitt
Fig. 9.3 Groups within the Oxidic Soil order. Vertical axis is depth
(cm) Photo: Allan Hewitt
9.1 Important Features of Oxidic Soils
135
Brown (where Oxidic Soils share some properties with
Brown Soils), and Typic as the central concept of the Orthic
Oxidic Soils group.
9.1.4 Origin of the Soil Order Name
‘Oxidic’ is derived from the Soil Taxonomy name Oxisols
(originally Greek ‘oxus’ and French ‘oxide’), and reflects the
high proportion of iron and aluminium oxides present.
9.2 Soil Profile Genesis
In the relatively geologically stable Northland region the
mafic lavas and associated deposits have been exposed to
weathering for long periods (often millions of years) in
landscapes that have remained stable under conditions of
strong weathering and leaching, and potentially with marked
movements in water table in lower landscape positions. Thus
Fig. 9.2 Distribution of Oxidic Soils Photo: Allan Hewitt
Fig. 9.3 Groups within the Oxidic Soil order. Vertical axis is depth
(cm) Photo: Allan Hewitt
9.1 Important Features of Oxidic Soils
135