horizons being derived from weathered greywacke. Where
slope angles exceed about 26°, the soils are formed largely
from weathered greywacke alone.
In managed land, erosion risk may be reduced by maintaining good vegetation cover. The low bulk density, apedal
earthy, aggregates are vulnerable to erosion if exposed on
slopes following animal disturbance, vegetation clearance,
or other management activities.
2.7.3 Geotechnical Engineering
Soils containing allophane and halloysite carry a
‘user-beware’ warning for geotechnical engineers. Allophanic soil materials lose soil strength after remoulding, for
example, when loads are placed on the soil by machinery,
heavy animals, earth-moving equipment, or earthquakes.
Manipulation (such as by bulldozing) of allophanic soil
material, followed by soil saturation, may lead to catastrophic loss of bearing strength, a property described as
sensitivity. Recent studies by Max Kluger, Vicki Moon,
Jock Churchman, and others, have shown that some forms of
halloysite can also lose soil strength after remoulding. It
turns out that a newly discovered ‘mushroom-cap’ shaped
halloysite morphology, essentially spheroidal but with an
opening on one side, was responsible for the catastrophic
landslides on Omokoroa Peninsula in the Tauranga region of
the western Bay of Plenty, the most infamous being the
Bramley Drive slide dating from the very wet winter of
1979.
Lessons were learned the hard way in 1981 when a canal,
with sides formed from allophanic and halloysitic Soil
materials, built to convey water to the Ruahihi hydropower
station in the Tauranga area, collapsed the day after the
official opening of the power station. About 1.5 million
cubic metres of soil, which had formed a wall of the canal,
flowed, with the consistency of porridge, across the adjacent
farm and state highway. A 600 m stretch of the canal was
destroyed and a section of the road was washed out.
A chasm about 500 m long, 100 m wide, and 40 m deep
was gouged out in about an hour by the flowing debris.
When allophanic (or halloysitic) soil materials are saturated
with water (in this case following the filling of the canal, or
in the case of many landslides in the region, following heavy
rainfall), unsupported sensitive soils may fail suddenly, and
dramatically, with the material behaving as a liquid capable
of carrying debris over large run-out distances. It is now
suspected, following the revelation of the identical role
played by defective spheroidal halloysite in a highly sensitive layer at Omokoroa, and elsewhere, that the Ruahihi
collapse may have been caused by such halloysite as well as,
or instead of, allophane. Halloysite is the predominant clay
mineral in the pyroclastic sequences underlying much of the
Tauranga region, with allophane generally limited to the
uppermost metre or so of the modern land surface (supporting the extensive Allophanic Soils).
Further Reading
Allbrook RF (1983) Some physical properties of allophane soils from
the North Island, New Zealand. N Z J Sci 26:481–492
Alloway BV, Neall VE, Vucetich CG (1992) Particle size analyses of
late Quaternary allophane-dominated andesitic deposits from New
Zealand. Quat Int 13–14:167–174
Basher LR, Ross CW, Dando J (2004) Effects of carrot growing on
volcanic ash soils in the Ohakune area, New Zealand. Aust J Soil
Res 42(3):259–273
Bruce JG (1978) Soils of part Raglan County, South Auckland. New
Zealand Soil Bureau Bulletin 41. DSIR, Wellington, New Zealand, 102p
Childs CW (1992) Ferrihydrite: a review of structure, properties and
occurrence in relation to soils. Zeitschrift für Pflanzenernährung und
Bodenkunde 155:441–448
Childs CW, Palmer RWP, Ross CW (1990) Thick iron oxide pans in
soils of Taranaki. Aust J Soil Res 28:245–257
Churchman GJ, Pasbakhsh P, Lowe DJ, Theng BKG (2016) Unique but
diverse: some observations on the formation, structure, and
morphology of halloysite. Clay Miner 51:395–416
Degens BP, Schipper LA, Clayden JJ et al (2002) Irrigation of an
allophanic soil with dairy factory effluent for 22 years: responses of
nutrient storage and soil biota. Aust J Soil Res 38(1):25–35
Fieldes M, Perrott KW (1966) The nature of allophane in soils. Part 3—
rapid field and laboratory test for allophane. N Z J Sci 9(3):623–9
Franks AM, Neall VE, Pollok JA (1991) Soils of part Eltham County,
North Island. New Zealand, NZ DSIR Land Res Sci Rep 14, 131p
Gibbs HS (1968) Volcanic-ash soils in New Zealand. N.Z. DSIR
Information Series 65, 30p
Grange LI, Taylor NH, Sutherland CF et al (1939) Soils and agriculture
of part of Waipa County. New Zealand DSIR Research Bulletin 76
Hewitt AE (2010) New Zealand soil classification, 3rd edn. Manaaki
Whenua Press, Lincoln
Huang Y-T, Lowe DJ, Zhang H et al (2016) A new method to extract
and purify DNA from allophanic soils and paleosols, and potential
for paleoenvironmental reconstruction and other applications.
Geoderma 247:114–125
Huang Y-T, Lowe DJ, Churchman GJ et al (2016b) DNA adsorption by
nanocrystalline allophane spherules and nanoaggregates, and
implications for carbon sequestration in Andisols. Appl Clay Sci
120:40–50
Kim ND, Taylor MD, Drewry JJ (2016) Anthropogenic fluorine
accumulation in the Waikato and Bay of Plenty regions of New
Zealand: comparison of field data with projections. Environ Earth
Sci 75:147. https://doi.org/10.1007/s12665–015-4897-2
Kluger MO, Moon VG, Kreiter S et al (2017) A new
attraction-detachment model for explaining flow sliding in
clay-rich tephras. Geology 45:131–134
Lowe DJ (1986) Controls on the rates of weathering and clay mineral
genesis in airfall tephras: a review and New Zealand case study. In:
Coleman SM, Dethier DP (eds) Rates of chemical weathering of
rocks and minerals. Academic Press, Orlando, pp 265–330
Lowe DJ, Palmer DJ (2005) Andisols of New Zealand and Australia.
J Integr Field Sci 2:39–65
Lowe DJ, Tonkin PJ (2010) Unravelling upbuilding pedogenesis in
tephra and loess sequences in New Zealand using tephrochronology. In: Gilkes RJ, Prakongkep N (eds) Proceedings of the 19th
38
2 Allophanic Soils
slope angles exceed about 26°, the soils are formed largely
from weathered greywacke alone.
In managed land, erosion risk may be reduced by maintaining good vegetation cover. The low bulk density, apedal
earthy, aggregates are vulnerable to erosion if exposed on
slopes following animal disturbance, vegetation clearance,
or other management activities.
2.7.3 Geotechnical Engineering
Soils containing allophane and halloysite carry a
‘user-beware’ warning for geotechnical engineers. Allophanic soil materials lose soil strength after remoulding, for
example, when loads are placed on the soil by machinery,
heavy animals, earth-moving equipment, or earthquakes.
Manipulation (such as by bulldozing) of allophanic soil
material, followed by soil saturation, may lead to catastrophic loss of bearing strength, a property described as
sensitivity. Recent studies by Max Kluger, Vicki Moon,
Jock Churchman, and others, have shown that some forms of
halloysite can also lose soil strength after remoulding. It
turns out that a newly discovered ‘mushroom-cap’ shaped
halloysite morphology, essentially spheroidal but with an
opening on one side, was responsible for the catastrophic
landslides on Omokoroa Peninsula in the Tauranga region of
the western Bay of Plenty, the most infamous being the
Bramley Drive slide dating from the very wet winter of
1979.
Lessons were learned the hard way in 1981 when a canal,
with sides formed from allophanic and halloysitic Soil
materials, built to convey water to the Ruahihi hydropower
station in the Tauranga area, collapsed the day after the
official opening of the power station. About 1.5 million
cubic metres of soil, which had formed a wall of the canal,
flowed, with the consistency of porridge, across the adjacent
farm and state highway. A 600 m stretch of the canal was
destroyed and a section of the road was washed out.
A chasm about 500 m long, 100 m wide, and 40 m deep
was gouged out in about an hour by the flowing debris.
When allophanic (or halloysitic) soil materials are saturated
with water (in this case following the filling of the canal, or
in the case of many landslides in the region, following heavy
rainfall), unsupported sensitive soils may fail suddenly, and
dramatically, with the material behaving as a liquid capable
of carrying debris over large run-out distances. It is now
suspected, following the revelation of the identical role
played by defective spheroidal halloysite in a highly sensitive layer at Omokoroa, and elsewhere, that the Ruahihi
collapse may have been caused by such halloysite as well as,
or instead of, allophane. Halloysite is the predominant clay
mineral in the pyroclastic sequences underlying much of the
Tauranga region, with allophane generally limited to the
uppermost metre or so of the modern land surface (supporting the extensive Allophanic Soils).
Further Reading
Allbrook RF (1983) Some physical properties of allophane soils from
the North Island, New Zealand. N Z J Sci 26:481–492
Alloway BV, Neall VE, Vucetich CG (1992) Particle size analyses of
late Quaternary allophane-dominated andesitic deposits from New
Zealand. Quat Int 13–14:167–174
Basher LR, Ross CW, Dando J (2004) Effects of carrot growing on
volcanic ash soils in the Ohakune area, New Zealand. Aust J Soil
Res 42(3):259–273
Bruce JG (1978) Soils of part Raglan County, South Auckland. New
Zealand Soil Bureau Bulletin 41. DSIR, Wellington, New Zealand, 102p
Childs CW (1992) Ferrihydrite: a review of structure, properties and
occurrence in relation to soils. Zeitschrift für Pflanzenernährung und
Bodenkunde 155:441–448
Childs CW, Palmer RWP, Ross CW (1990) Thick iron oxide pans in
soils of Taranaki. Aust J Soil Res 28:245–257
Churchman GJ, Pasbakhsh P, Lowe DJ, Theng BKG (2016) Unique but
diverse: some observations on the formation, structure, and
morphology of halloysite. Clay Miner 51:395–416
Degens BP, Schipper LA, Clayden JJ et al (2002) Irrigation of an
allophanic soil with dairy factory effluent for 22 years: responses of
nutrient storage and soil biota. Aust J Soil Res 38(1):25–35
Fieldes M, Perrott KW (1966) The nature of allophane in soils. Part 3—
rapid field and laboratory test for allophane. N Z J Sci 9(3):623–9
Franks AM, Neall VE, Pollok JA (1991) Soils of part Eltham County,
North Island. New Zealand, NZ DSIR Land Res Sci Rep 14, 131p
Gibbs HS (1968) Volcanic-ash soils in New Zealand. N.Z. DSIR
Information Series 65, 30p
Grange LI, Taylor NH, Sutherland CF et al (1939) Soils and agriculture
of part of Waipa County. New Zealand DSIR Research Bulletin 76
Hewitt AE (2010) New Zealand soil classification, 3rd edn. Manaaki
Whenua Press, Lincoln
Huang Y-T, Lowe DJ, Zhang H et al (2016) A new method to extract
and purify DNA from allophanic soils and paleosols, and potential
for paleoenvironmental reconstruction and other applications.
Geoderma 247:114–125
Huang Y-T, Lowe DJ, Churchman GJ et al (2016b) DNA adsorption by
nanocrystalline allophane spherules and nanoaggregates, and
implications for carbon sequestration in Andisols. Appl Clay Sci
120:40–50
Kim ND, Taylor MD, Drewry JJ (2016) Anthropogenic fluorine
accumulation in the Waikato and Bay of Plenty regions of New
Zealand: comparison of field data with projections. Environ Earth
Sci 75:147. https://doi.org/10.1007/s12665–015-4897-2
Kluger MO, Moon VG, Kreiter S et al (2017) A new
attraction-detachment model for explaining flow sliding in
clay-rich tephras. Geology 45:131–134
Lowe DJ (1986) Controls on the rates of weathering and clay mineral
genesis in airfall tephras: a review and New Zealand case study. In:
Coleman SM, Dethier DP (eds) Rates of chemical weathering of
rocks and minerals. Academic Press, Orlando, pp 265–330
Lowe DJ, Palmer DJ (2005) Andisols of New Zealand and Australia.
J Integr Field Sci 2:39–65
Lowe DJ, Tonkin PJ (2010) Unravelling upbuilding pedogenesis in
tephra and loess sequences in New Zealand using tephrochronology. In: Gilkes RJ, Prakongkep N (eds) Proceedings of the 19th
38
2 Allophanic Soils