Kodama and Ross (1991) showed that the amounts of allophane
, imogolite and weakly crystalline Fe oxides extracted by Tiron arc similar to those extracted by ammonium oxalate solution (Tamm 1932; modified by Schwertmann 1964).
2003), whereas allophane
soil derived from volcanic ash is dispersed under high pH conditions (Wada 1985; Horikawa et al.
However, orthopyroxene, olivine and mangnetite were also detected in contaminated soils including allophane
and quartz (Table 2).
The fact that the soil samples consists mostly of poorly crystalline allophane
and /or halloysite clays plus beta quartz with no ma.
Fieldes M, Perrott K (1966) The nature of allophane
in soils Part 3.
In these soils, the short-range-order mineral allophane
can also be found (Wada 1989).
3]-N, Br and Cl can also be adsorbed in volcanic materials containing allophane
present in soils was determined according to the method of Parfitt and Wilson (1985) and Parfitt (1986).
Several of the soils in this study are derived from volcanic ash and do not have significant amounts of crystalline aluminosilicates, but instead consist of allophane
, which are clay-sized, short-range ordered aluminosilicates associated with the weathering of volcanic ashes and glasses.
Parfitt RL (1990) Allophane
in New Zealand--a review.
content was estimated from the values of oxalate-extractable Al and Fe, as described in Saggar et al.
This was to avoid using oven-dried material from the core, because allophane
clay changes density slightly on drying.