Review Article. What are the nature and formation conditions of hydroxy‐interlayered minerals (HIMs) in soil?

Abstract

Primary minerals of the parent material undergo weathering during the formation of terrestrial soils to varying extent. As a result, secondary minerals develop, which comprise, among many others, hydroxy-interlayered minerals (HIMs). These minerals have formed by interlayering of hydroxy-metal complexes (especially of Al 3+ , also Mg 2+ , Fe 2+/3+ ) into micas, expansible 2:1 phyllosilicates and forming oligomers, or by weathering of primary chlorite. The degree of interlayer filling and the stability of these fillings affect several physico-chemical soil properties, for instance the cation exchange capacity. Although many studies have been conducted on formation, occurrence, and properties of HIMs in soil during the last decades, several challenges still exist. These challenges include analytical identification and quantification of HIMs in soil, the nature of the interlayer filling and the identification of favorable conditions in soil for the formation of HIMs. In order to deepen the understanding of formation, properties, and fate of HIMs in soil, we critically reviewed the available literature. Based on the review, we recommend using a new structural model that enables quantification of hydroxy-interlayered smectite in soil by X-ray diffractometry, laboratory experiments on the formation and preservation of different types of interlayers and considering the temporal and spatial dimension of the formation of HIMs in soil in more detail.

Clay mineralogical composition and chemical properties of Haplic Luvisol developed on loess in the protected landscape area Litovelské Pomoraví

“…When taking into account the high instability of vermiculite under acidic conditions, the low pH and low amount of HIV as a weathering product of vermiculite in the studied profile, the estimated time after decarbonization in the profile based on the Finke and Hutson's (2008) simulations becomes more realistic. In agreement with the published results (reviewed by Wilson, 1999 andGeorgiadis et al, 2020), our findings (Figure 8a,b, Tables 3 and 4) pointed out the following clay mineral assemblage: illite, chloritevermiculite -HIVsmectite is on the boundaries of mineral stability. Our interpretation partly correlates with the rate of the Luvisol-forming processes, which is based on the method of chronosequences, similarly to Alexandrovskiy (2007).…”

“…A noticeable peak at about 7.5 2θ (1.18 nm) after EG solvation, however, could indicate long-range ordering R3 illite-smectite (Moore & Reynolds Jr, 1997). The HIM (hydroxy-interlayered mineral) is positioned around 7.4-7.85 2θ; 1.2-1.13 nm in magnesium and potassiumsaturated samples after heating to 300 and 550 C (Figure 8a,b; Rich, 1968;Georgiadis, Dietel, Dohrmann, & Rennert, 2020).…”

“…The hydroxy-interlayered minerals are formed by the interlayering of hydroxy-metal complexes (especially of Al 3+ , where its source could be surrounding silicates or vermiculite alone) into an expansible interlayer, forming oligomers. HIMs are represented by hydroxy-interlayered smectite (HIS) or hydroxyinterlayered vermiculite (HIV; reviewed by Georgiadis et al, 2020). The vermiculite is the most unstable phase of silicates in the investigated profile; hence, we assume that the presented hydroxyinterlayered phase is HIV.…”

Mobilisation of Al, Fe, and DOM from topsoil during simulated early Podzol development and subsequent DOM adsorption on model minerals

“…These result from weathering of primary silicates in a geochemical milieu typical of early Podzol development, i.e. pH approximately > 4.5, which prevents acidic dissolution of 2:1 layers of phyllosilicates 47 . Despite the limited duration of the experiment, mimicked weathering of the topsoil showed that masking phases were easily removed.…”

Hydrologic regulation of clay-mineral transformations in a redoximorphic soil of subtropical monsoonal China

“…Andrade et al (2019) ascribed the formation of HIMs to high rates of Al release during pedogenic weathering under acidic soil conditions, which influenced the interlayering of Al-polymers in the clay minerals. Interlayering is a common phenomenon in pedogenic 2:1 clay minerals, in which the interlayer materials include cations, hydrated cations, organic molecules, and hydroxide groups or sheets (Meunier 2007;Dietel et al 2019aDietel et al , 2019bGeorgiadis et al 2020). According to Rich (1968) and Meunier (2007), HIV is a fast-forming and unstable phase representing a moderately acidic and oxidizing condition that is often linked to frequent wet-dry cycles.…”