共查询到20条相似文献，搜索用时 15 毫秒
1.
Chitoshi Mizota 《Soil Science and Plant Nutrition》2013,59(3):257-268
Relationships between the clay mineralogy and the primary mineral association were studied on seventeen Andosol samples (<3,000 years old) collected from Aomori, Hokkaido, and Iwate. Opaline silica, allophane, and imogolite were predominant in the soils derived from volcanic ashes which contained practically no quartz, while opaline silica, crystalline layer silicates, alumina-rich gel-like materials, and allophanelike constituents were abundant in the soils which contained abundant quartz. There was no positive indication of the presence of allophane in any quartz andesitic Andosols. High contents of finely comminuted amphibole and mica in the quartz andesitic volcanic ashes suggested that the crystalline layer silicates are inherited and are not formed pedochemically from amorphous materials. 相似文献
2.
Towada Ando soils consisted of five soils—Towada-a (1,000 years old), Towada-b (2,000 years old), Chuseri (4,000 years old), Nanbu (8,600 years old), and Ninokura soils (10,000 years Amorphous clay materials of these soils taken at different localities were studied by the combined use of selective dissolution and differential infrared spectroscopy, X-ray analysis, electron microscopy, etc. The main clay minerals of Towada-a soils, present-day soils, were montmorillonite-vermic-ulite chloritic intergrades and opaline silica, or these minerals and allophane in the humus horizons, and allophane in the non-humus ones. Towada-b soils overlain by the Towada-a soils showed the clay mineralogical constituents similar to those of Towada-a soils. However, allophane was one of the main clay minerals in all the humus horizons as well as non-humus ones. The main clay minerals of Chuseri soils were allophane and layer silicates consisting chiefly of chloritic intergrades and chlorite in the humus horizons, and allophane in the non-humus ones. Opaline silica was present in minor amounts in the humus horizons of Chuseri soils, but nearly absent in Nanbu and Ninokura soils. There were remarkable differences in the clay mineralogical composition of Nanbu and Ninokura soils with differences of their environmental conditions. Allophane and imogolite Were dominant in the clay fractions of both humus and non-humus horizons of very shallowly buried Nanbu soil which was subjected to the strong leaching process. Allophane was the main clay mineral of deeply buried Nanbu and Ninokura soils which showed the absence of notable accumulation of bases and silica. On the contrary, halloysite with a small amount of siliceous amorphous material appeared in very deeply buried Nanbu and Ninokura soils where bases and silica were distinctly accumulated. The amounts of halloysite in the clay fractions were larger in the humus horizons than non-humus ones, and in Ninokura soil than Nanbu soil. Soil age, soil organic matter, and depositional overburden of tephras were observed to be conspicuous among various factors relating to the weathering of amorphous clay materials in Towada Ando soils. 相似文献
3.
Chemical and mineralogical data are presented for three Spodosols (podzols) and a related Inceptisol (yellow-brown loam). Allophane with an Al/Si atomic ratio close to two is identified in the B horizons of all four soils, and minor amounts of imogolite are present in association with allophane in all but one soil where small-particle gibbsite occurs. Parent materials for these soils are essentially non-vitric. Allophane (Al/Si = 2) has been estimated quantitatively in all soils using oxalate-extractable Si (Si0) and is selected clay fractions using both Si0 and infrared spectroscopy. Maximum concentrations of allophane (Al/Si = 2) range from 5% to 18% of fine earth (< 2 mm) fractions and all occur in B horizons. Fe0 values are low relative to Al0 values except for the upper horizons of the Inceptisol. Al0 values peak in B horizons and the ratio pyrophosphate-extractable Al to Al0 decreases from about 1 in A and upper B horizons to 0.1–0.4 in lower B horizons.An interpretation of the data is consistent with recent proposals that the movement of Al in podzolisation is due primarily to the formation of inorganic complexes with Si. Chemical criteria for spodic horizons should be consistent with the total illuviation of Al and Fe (and perhaps Si), rather than just the organic-bound fraction of Al and Fe in these horizons as indicated by amounts in extractants such as pyrophosphate. 相似文献
4.
Chitoshi Mizota 《Soil Science and Plant Nutrition》2013,59(3):311-318
The phosphate fixation capacity at pH 4.5 and an equilibrium concentration of 250 mM phosphate was measured. The soil samples were divided into five groups according to their clay mineralogical composition. The first group soils contain opaline silica and allophanelike constituents, and some unidentified minerals, the second opaline silica and crystalline layer .i1icates, the third opaline silica and crystalline layer silicates with additional allophanelike constituents or aluminarich gel-like materials, the fourth allophanelike constituents, allophane and imogolite and the fifth crystalline layer silicates, allophanelike constituents and alumina-rich gel-like materials, plus some halloysite-like minerals, respectively. The first group soils had phosphate fixation capacities of 3,000 to 8,000, the second group soils 1,000 to 3,000, the third group loib 2,000 to 13,000, the fourth group soils 8,000 to 15,000 and the fifth group soil. 5,000 to 12,000 mg P2O5/100 g oven-dry soil, respectively. The fourth group soils in which allophane and imogolite predominated showed the highest phosphate fixation capacity. The fractions which dissolved from almost all soil samples by treatments with 6% H2O2 Na2S2O4-NaHCO2-Na citrate and 2% Na2CO3 were estimated to have very high phosphate fixation capacities (8,000 to 19,000 mg P2O5/100 g dry-matter), and there was not much difference among the soil samples examined. Iron and aluminum combined with humus, allophanelike constituents, alumina-rich gel-like materials and halloysite-like minerals in addition to allophane and imogolite contribute to the phosphate fixation of Ando soils. 相似文献
5.
The clay mineralogical composition of soils on volcanic ashes from Mashū and Kamuinupuri-dake volcanoes, Hokkaido, which are rich in cristobalite, was determined using petrological, X-ray diffraction, differential thermal, and selective dissolution and differential infrared spectroscopic methods. The cristobalite occurred in abundance in every size of fraction from coarse sand to clay and every soli from approximately 1,700 to 8,400 years old, and was concluded to be of igneous origin. The major clay minerals were allophanelike constituents and allophane with some layer silicates as the minor clay mineral, being similar to those of andesitic ash soils and different from those of volcanic ash soils containing abundant quartz. The quartz of volcanic ashes was presumed to bederived from the groundmass-equivalent portion of the ashes which had been formed from magma at a low temperature. 相似文献
6.
The mineralogy of four Italian Andosols - derived from volcanic material either oversaturated or undersaturated with respect to silica - has been investigated by XRD, EM and IR. The crystalline clay minerals in all four profiles are essentially similar, consisting of abundant halloysite with moderate illite and 14A intergrade material, minor kaolinite and occasional gibbsite. The soils also contain large amounts of imogolite and proto-imogolite allophane. With the exception of illite all these clay minerals are believed to be of pedogenic origin. Halloysite occurs in the dehydrated form in the surface horizons but becomes progressively more hydrated with depth. At depths of > 1.4 m the clay fraction consists almost entirely of fully hydrated halloysite, supporting the suggestion that halloysite forms best in a stagnant moisture regime where there is a depositional overburden acting as a silica source. EM observations show that the halloysite may have spherical morphology and may be intimately associated with gas vesicles in pumice grains where it probably forms by the transformation of allophanic material. It seems likely that dehydrated halloysite slowly converts to poorly crystallized kaolinite in the upper horizons of these profiles. The origin of the 2/1 minerals is more problematical. Illite is probably inherited from mica in the parent material but the 14A intergrade material is so poorly ordered that a pedogenic origin seems more likely than formation by inheritance or by transformation of pre-existing 2/1 silicates. 相似文献
7.
Surface and buried Andosols and buried Luvisols of the Nevado de Toluca Late Quaternary tephra-paleosol sequence (Central Mexico) were studied to show whether these soils present an evolutionary sequence and to determine the pedogenic mechanisms and environmental factors involved in the evolutionary process. Micromorphological observations and mineralogical composition of fine sand and clay fractions were used to detect type and succession of soil-forming process. Some of the buried Andosols, defined as “intergrade” Andosols, have a predominantly blocky structure, humus-depleted areas, redoximorphic features and thin clay coatings in Ah horizons. Clay fractions of buried Andosols contain halloysite besides amorphous components, whereas in modern Andosols, allophane is dominant. Luvisols have micro-areas with granular structure and abundant phytoliths in the groundmass of Bt horizons assumed to be the relict Andosol features. Luvisol clay fractions are dominated by halloysite and kaolinite. Primary minerals show micromorphological weathering features in all studied soils being stronger in Luvisols; however, even in Luvisols, sand fractions consist mostly of unstable volcanic silicates. We hypothesise that the studied profiles form an evolutionary sequence: Andosols–“intergrade” Andosols–Luvisols; the soil transformation is supposed to be linked to progressive crystallisation of 1:1 clay minerals. Comparing the Nevado de Toluca paleosol properties with the existing data on volcanic soil climo- and chronesequences and assessing the regional paleopedological and lacustrine records of Quaternary paleoclimates, we concluded that wet/dry climatic oscillations took place during the formation of the studied paleosols. Rapid crystallisation of 1:1 minerals occurred during dry phases, which speeded up the Andosol to Luvisol transformation and made it independent from the primary mineral weathering status. The Andosol to Luvisol transformation accelerated by climatic fluctuations is thought to be a common soil evolutionary pathway in the subtropical and tropical regions of recent volcanism, which suffered contrasting precipitation oscillations in the Quaternary. 相似文献
8.
The clay mineralogy of 22 samples of the Ap horizons of Ando soils was determined by a combination of methods. Of these samples, 15 did and 7 did not contain allophane and imogolite. Opaline silica was found in 4 samples, whereas aluminum—humus complexes, iron oxides and layer silicates were found in all samples. The presence of allophane and imogolite and the absence of opaline silica in a few Ap horizons was related to mixing of A1 horizons and subsoils by cultivation and to lower supplies of organic matter relative to the amounts of aluminum released from volcanic ash by weathering. The contents of 2:1 and 2:1:1 layer silicates and their intergrades were larger in soils in which quartz predominated in fine fractions. It was inferred that aluminum bound with humus and in allophane-like constituents, rather than aluminum in allophane and imogolite, is important in reactions with phosphate and fluoride. 相似文献
9.
For the past ten years much work has been carried out on clay minerals of volcanic ash soils. Most investigators have reported that allophane is dominant among clay minerals of volcanic ash soils and crystallizes to halloysite or meta-halloysite with the advance of weathering (1–8). On the other hand, UCHIYAMA, MASUI and ONIKURA (1960) found that montmorillonite predominates in the clay fraction of volcanic ash soil in Kawatabi (9). Furthermore, MASUI, SHOJI and UCHIYAMA (1966) showed that the major crystalline clay minerals of volcanic ash soils in the Tohoku district are montmorillonite, vermiculite, intergradient montmorillonite-vermiculite and chlorite (10). They also showed that these minerals increase with the advance of weathering and that kaolin minerals are minor constituents. 相似文献
10.
Abstract Properties and classification of four selected volcanic ash soils from Abashiri, Hokkaido were studied and the transition of Andisols to Mollisols was discussed. Two of the four pedons (Brown Andosol and Cumulic Andosol)1 showed morphological, clay mineralogical, physical, and chemical properties common to most Andisols in Japan. However, the properties of the other two pedons (Acid Brown Forest soil and Brown Forest soil)1 were considerably different from those of common Andisols in Japan. It was found that the changes in the andic soil properties or transition of Andisols to Mollisols was closely related to the progression of clay weathering, mainly the transformation of noncrystalline clay materials to halloysite. One of the four pedons (Brown Forest soil)1had the clay fraction dominated by halloysite from the uppermost horizon down to the bottom of the profile and satisfied both andic and mollic requirements. Thus we concluded that the pedon is a transitional soil between Andisols and Mollisols and that the transition is closely related to the duration of surface weathering under relatively weak leaching conditions. The four pedons were classified according to the Andisol Proposal (Leamy et al. 1988, New Zealand Soil Bureau) as follows: Pedon 1: Medial, amorphic (allophane/imogolite), frigid Typic Hapludand (Brown Andosol).1 Pedon 2: Medial, amorphic (allophane/imogolite), frigid Typic Melanudand (Cumulic Andosol).1 Pedon 3: Medial, amorphic (allophane/ imogolite), over kandic, frigid Typic Melanudand (Acid Brown Forest soil).1 Pedon 4: Medial, kandic, frigid Typic Hapludand (Brown Forest soil).1 相似文献
11.
Soil development processes in an Aqualf-Ochrept sequence from loess with admixtures of tephra, New Zealand 总被引：2，自引：0，他引：2
The properties of contrasting soils occurring under a 1050–1600 mm rainfall gradient are described. The soils range, with increasing rainfall, from Typic Fragiaqualfs to Andic Dystrochrepts. Sand mineralogy of these soils indicates that they have formed in essentially similar parent materials consisting largely of quartzo-feldspathic loess with admixtures of rhyolitic and andesitic tephra. The Fragiaqualfs have high bulk density, impeded drainage in winter, degraded chlorite, argillic horizons, halloysite and vermiculite. The Dystrochrepts have lower bulk density, free drainage, ferrihydrite, allophane, humus-(Al, Fe) complexes and no argillic horizons. An hypothesis to explain differences between these soil groups proposes that the dense horizons in the Fragiaqualfs arise largely from hydraulic suctions exerted by roots during periods of high summer water deficits. The consequent loss of porosity leads to impeded drainage in winter causing gleying and enhanced clay formation. In the Dystrochrepts the summer deficits are lower, consequently the soils have lower bulk densities and remain free draining. 相似文献
12.
N.R. do Nascimento G.T. Bueno E. Fritsch A.J. Herbillon Th. Allard A.J. Melfi R. Astolfo H. Boucher & Y. Li 《European Journal of Soil Science》2004,55(3):523-538
Morphological, geochemical and mineralogical studies were carried out in a representative soil catena of the low‐elevation plateaux of the upper Amazon Basin to interpret the steps and mechanisms involved in the podzolization of low‐activity clay soils. The soils are derived from Palaeozoic sandstones. They consist of Hydromorphic Podzols under tree savannah in the depressions of the plateaux and predominantly of Acrisols covered by evergreen forest elsewhere. Incipient podzolization in the uppermost Acrisols is related to the formation of organic‐rich A and Bhs horizons slightly depleted in fine‐size particles by both mechanical particle transfer and weathering. Weathering of secondary minerals by organic acids and formation of organo‐metallic complexes act simultaneously over short distances. Their vertical transfer is limited. Selective dissolution of aluminous goethite, then gibbsite and finally kaolinite favour the preferential cheluviation of first Fe and secondly Al. The relatively small amount of organo‐metallic complexes produced is related to the quartzitic parent materials, and the predominance of Al over Fe in the spodic horizons is due to the importance of gibbsite in these low‐activity clay soils. Morphologically well‐expressed podzols occur in strongly iron‐depleted topsoils of the depression. Mechanical transfer and weathering of gibbsite and kaolinite by organic acids is enhanced and leads to residual accumulation of sands. Organo‐metallic complexes are translocated in strongly permeable sandy horizons and impregnate at depth the macro‐voids of embedded soil and saprolite materials to form the spodic Bs and 2BCs horizons. Mechanical transfer of black particulate organic compounds devoid of metals has occurred later within the sandy horizons of the podzols. Their vertical transfer has formed well‐differentiated A and Bh horizons. Their lateral removal by groundwater favours the development of an albic E horizon. In an open and waterlogged environment, the general trend is therefore towards the removal of all the metals that have initially accumulated as a response to the ferralitization process and have temporarily been sequestrated in organic complexes in previous stages of soil podzolization. 相似文献
13.
Some chemical, physical and mineralogical properties of three soils developed in volcanic ash at altitudes of 1040 m, 1720 m, and 2350 m in Papua New Guinea's Enga Province are presented. Silt-fraction mineralogy and total chemical analyses show that fresh ash occurs in the upper approximately 30 cm of profile at each site. This fresh ash is probably only a few thousand years old and overlies an older weathered ash (Tomba Tephra;more than 50000 years old). At the lowest site the majority of the primary minerals (predominantly amphiboles, volcanic glass and felspar, and some pyroxenes) have been decomposed by weathering to produce a high clay content. With increasing altitude, greater proportions of silt-sized, unweathered and partially altered primary minerals are recognised and molar ratios of calcium, magnesium, sodium and potassium to aluminum increase accordingly. In the clay fractions, allophane with Al/Si ratios of approximately 2.0 is dominant at the highest site, whereas with decreasing altitude lower proportions of allophane occur, Al/Si ratios decline and halloysite becomes dominant. Gibbsite is found in all three profiles 相似文献
14.
The present study reports the occurrence of gibbsite and halloysite in soils derived from granitic saprolites and from glacial deposits formed from granitic saprolites of the Bayerischer Wald (Germany). Both minerals are common in soils of this area. They were formed in the initial stages of weathering, most probably before the Pleistocene and in a warmer climate. Under present conditions halloysite and gibbsite are unstable in the surface soils, as indicated by a decrease in gibbsite concentration towards the surface and by an undersaturation of the equilibrium soil solution with respect to both minerals. It is assumed that the strongly acid conditions and the high concentration of organic compounds in the surface horizons lead to dissolution of gibbsite and possibly to transformation of halloysite to kaolinite. 相似文献
15.
The clay mineralogy of the Ap horizons of Ando soils in Japanese paddies was determined by a combination of methods and compared with that of Ando soils of uplands. Six of 13 paddy soil samples contained allophane and imogolite and none contained gibbsite, whereas parallel figures were 15 and 7 for 22 upland soil samples. Substantial numbers of diatoms were found in 5 paddy and 1 paddy-converted upland soil samples. The lack of gibbsite was related to the stage of soil formation rather than the paddy condition, whereas the presence of diatoms was related to both. Regarding layer silicates, there was no particular difference between the paddy and upland soil samples but one unidentified mineral with unique morphology and infrared spectrum was found in two paddy soil samples. There was no particular difference in phosphate adsorption between the paddy and upland soil samples. 相似文献
16.
The difficulties in dispersing volcanic ash soils of Japan and New Zealand have been considered to be due to the association or aggregation of allophane (3, 5, 7–10). In particular, MIYAZAWA (9) has obtained evidence that stable microaggregates of Humic Allophane soils derived from volcanic ash have been formed by dehydration of allophane. Recently, several investigators (2, 4, 6, 8, 9, 12) have pointed out that ultrasonic vibration is effective in dispersing the fine particles of soils. With respect to the applicability of supersonic vibration to the particle-size distribution analysis of Humic Allophane soils, MIYAZAWA (9) stated that the maximum dispersion, as measured by the clay content, was obtained only with supersonic vibration using an acidic medium. KOBO and OBA (8) reported that calgon (sodium hexametaphosphate) as a dispersing agent was successfully applicable to most Humic Allophane soils, but the use of HCI was necessary for some highly allophanic subsoils, and that the effect of supersonic vibration on dispersion of the soils is attributed to the breakdown of aggregates larger than 20 microns in diameter. They also recommended a mixture of 10g of soil and 50 ml of water and 20 min. exposure for a supersonic vibrator (10 Kc, 300 W). With respect to the applicability of vibration treatment in the particle-size distribution analysis of Humic Allophane soils containing volcanic glasses in abundance, some apprehension may be entertained about the breakdown of primary minerals, especially of volcanic glasses (9, 10). 相似文献
17.
《Soil Science and Plant Nutrition》2013,59(3):362-368
Abstract The aluminum solubility of acidified soils both from furrows and under tree canopies of a tea garden was studied using equilibrium experiments in 0.01 mol L?1 CaCl2 solution systems. The soils were originally classified as allophanic Andosols. The furrow soils were more severely acidified because of the heavy application of nitrogen fertilizer, especially in the upper soil horizons (pH[H2O] of 3.6–3.8 in the A1 and 2A2 horizons). These acidified soils were characterized by the dissolution of allophanic materials (allophane, imogolite and allophane-like materials) and by an increase in Al–humus complexes. Ion activity product (IAP) values of the strongly acidified soil horizons were largely undersaturated with respect to imogolite (allophanic clay) or gibbsite. Plots of p(Al3+) as a function of pH strongly indicated that Al solubility of the soils was largely controlled by Al–humus complexes, especially in the A1 horizon. In the canopy soils, which were more weakly acidified (pH[H2O] 4.9–5.0), Al solubility was close to that of gibbsite and allophanic materials, indicating that the solubility is partly controlled by these minerals. 相似文献
18.
The various morphological, physico-chemical and mineralogical properties of soils derived from tephra and pyroclastic flow deposits of the Taal volcano were characterized and evaluated. 1. As compared with the pumiceous sandy soils of Mt. Pinatubo, soils of the Taal volcano showed generally a finer texture (silty clay to clay) with the exception of the base surge materials consisting of loam. 2. Parent ashes ranged from basaltic-andesite to basalt, as compared with andesitic to dacite for Mt. Pinatubo. Lithologic nature as well as the age of the tephra seemed to account for the advanced degree of weathering and resultant high clay content in the Taal soil. 3. Clay consisted predominantly of crystalline silicate mineral dominated by halloysite. Dominance of crystalline clay could be due to the ustic moisture conditions with a long dry period. In common with Mt. Pinatubo soils, soils of the flood plains were dominated by 2 : 1 clay minerals. 4. Based on the data on andic soil properties the soils studied could not be classified as Andisols. Basically, the typical andic soil properties did not develop under a ustic soil moisture regime which contributed to the clay mineral composition. Two of the pedons examined in this study were classified as Andic Eutropepts while on the pedons studied had been classified as Ustarent. 相似文献
19.
20.
The mineralogy of the clay fractions separated from the B horizons of two Hydrandepts (Hilo and Akaka soils), a Torrox (Molokai soil) and a Humitropept (Kolekole soil) was determined by a combination of methods.The Hydrandept B horizons were characterized by predominance of hydrous non-crystalline alumina and iron oxides associated with considerable amounts of humus and with very small amounts of silica. Allophane, allophane-like constituents and imogolite were present but in minor amounts. Gibbsite, goethite, chlorite and illite were also present as accessory minerals.The Torrox and Humitropept B horizons were characterized by predominance of kaolinite, hematite and goethite. The iron oxide minerals were present as fine particles (40–80 A diameter) often clustered to form larger aggregates. Neither imogolite nor allophane and allophane-like constituents were detected. Considerable amounts of dithionite-citrate soluble Al and humus were, however, present in the Humitropept B horizon, which may reflect the effect of an admixture of volcanic ash to the parent material. 相似文献