Clay mineralogy in agrochernozems of western Ukraine

The mineralogy of clay fractions separated from deep low-humus deep-gleyic loamy typical agrochernozems on loess-like loams of the Upper Bug and Dniester uplands in the Central Russian loess province of Ukraine consists of complex disordered interstratifications with the segregation of mica- and smectite-type layers (hereafter, smectite phase), tri- and dioctahedral hydromicas, kaolinite, and chlorite. The distribution of the clay fraction is uniform. The proportions of the layered silicates vary significantly within the profile: a decrease in the content of the smectite phase and a relative increase in the content of hydromicas up the soil profile are recorded. In the upper horizons, the contents of kaolinite and chlorite increase, and some amounts of fine quartz, potassium feldspars, and plagioclases are observed. This tendency is observed in agrochernozems developed on the both Upper Bug and Dniester uplands. The differences include the larger amounts of quartz, potassium feldspars, and plagioclases in the clay material of the Upper Bug Upland, while the contents of the smectite phase in the soil profiles of the areas considered are similar. An analogous mineral association is noted in podzolized agrochernozems on loess-like deposits in the Cis-Carpathian region of the Southern Russian loess province developed on the Prut–Dniester and Syan–Dniester uplands. The distribution of particle-size fractions and the mineralogy of the clay fraction indicate the lithogenic heterogeneity of the soil-forming substrate. When the drifts change, the mineral association of the soils developed within the loess-like deposits gives place to minerals dominated by individual smectite with some mica–smectite inter stratifications, hydromicas, and chlorite.     

Minerals in the three-component combination of agrochernozems in the Kamennaya Steppe

Properties and mineralogy of fine fractions separated from agrochernozems forming a three-component noncontrasting soil combination in the Kamennaya Steppe have been characterized. The soil cover consists of zooturbated (Haplic Chernozems (Clayic, Aric, Pachic, Calcaric)), migrational-mycelial (Haplic Chernozems (Clayic, Aric, Pachic)), and clay-illuvial (Luvic Chernozems (Clayic, Aric, Pachic)) agrochernozems. All the soils are deeply quasi-gleyed because of periodical groundwater rise. The mineralogy of the fraction <1μm includes irregular mica–smectite interstratifications, di- and trioctahedral hydromicas, imperfect kaolinite, and magnesium–iron chlorite. The profile distribution of these minerals slightly varies depending on the subtype of spot-forming soils. A uniform distribution of clay minerals is observed in zooturbated agrochernozem; a poorly manifested eluvial–illuvial distribution of the smectite phase is observed in the clay-illuvial agrochernozem. The fractions of fine (1–5 μm) and medium (5–10 μm) silt consist of quartz, micas, potassium feldspars, plagioclases, kaolinite, and chlorite. There is no dominant mineral, because the share of each mineral is lower than 35–45%. The silt fractions differ in the quartz-to-mica ratio. The medium silt fraction contains more quartz, and the fine silt fraction contains more micas.     

Mineralogical composition of the clay fraction and micromorphology of the Middle and Late Pleistocene loesses and paleosols in the center of the East European Plain

The mineralogical composition of the clay fraction and microfabrics of the cryogenic soil-loess sequences of the Middle and Late Pleistocene ages have been studied near the northern boundary of loess sediments on the East European Plain. Poorly ordered mixed-layered mica-smectitic minerals with different portions of smectitic layers predominate in the clay fraction; di-and trioctahedral hydromicas occupy the second place. The clay fraction also contains chlorite, clay-size quartz grains, and feldspars. Individual smectite is present in some of the samples. Interstadial chernozem-like paleosols are specified by the higher content of clay, the maximum concentration of smectitic layers in the mixed-layered minerals, and the presence of individual smectite. The clay fraction in the profiles of interglacial paleosols is sharply differentiated: in the eluvial part, it is depleted of smectite and enriched in kaolinite, hydromica, and clay-size quartz. These features allow us to suppose that interglacial paleosols were subjected to podzolization processes. According to the mineralogical indices, Middle Pleistocene paleosols can be differentiated into those subjected to lessivage (the Kamenskii interglacial paleosol) and podzolization (the Inzhavin interglacial paleosol).     

Dispersion and migration of fine particles in two palygorskite‐containing soils of the Jordan Valley

Migration of different mineral particles within columns of soil‐sand mixtures containing 10 or 20 mass % of soil was investigated by establishing differences in the mineral suite between the ”︁bulk clay” and the ”︁mobile fine material” fractions. The ”︁bulk clay” fractions of all soils contained smectite, palygorskite, kaolinite, quartz, feldspar, and calcite. The soils were saturated with sodium by leaching with NaCl solution, and then leached with distilled water. Clay dispersion and particle migration occurred in the columns. Values of SAR (sodium adsorption ratio) of the effluent decreased with time due to carbonate dissolution. At a certain SAR value, the clays apparently formed aggregates, and as a consequence particle migration stopped in the column. In addition to clay‐sized particles (< 2 μm), very‐fine‐silt‐sized particles (2— 5 μm) were able to migrate in the soil‐sand mixtures, too, and to some extent fine‐silt‐sized particles (5—10 μm) as well. Average size of mobile particles decreases with increase of soil content in the soil‐sand mixtures. The mineralogical composition of the ”︁mobile fine material” changed during the experiment. At the beginning of the experiment, the ”︁mobile fine material” was enriched in the non‐phyllosilicates (especially in calcite, and in some cases in quartz, feldspar and dolomite) and contained low concentrations of phyllosilicates (smectite, palygorskite and kaolinite). At the end of the experiment, the proportion of non‐phyllosilicates decreased, and as a consequence, the proportion of phyllosilicates increased. Among the non‐phyllosilicates, calcite was the most mobile mineral. Among the phyllosilicates, palygorskite was preferentially mobilized in topsoil horizons. In subsoil horizons, on the other hand, kaolinite was preferentially mobilized. This difference was explained by the different nature of carbonates in the topsoil and subsoil horizons. Palygorskite is preferentially occluded within the soil carbonates of lacustrine origin over smectite and kaolinite. These carbonates are present mainly in the subsoil horizons. As a consequence, the presence of these carbonates in the subsoil horizons decreases the migration of mainly palygorskite.     

Mineralogy of parent rock and peaty-podzolic soil of Iremel Ridge,Southern Urals

The mineralogy of soils and parent rocks of the Iremel Ridge has been studied by the methods of micromorphology, laser diffraction, computed X-ray microtomography, and X-ray fluorescence analysis. In hard rock and soil, the major minerals have been identified: quartz, illite, and a chlorite-group mineral (Fe analogue of sudoite), as well as accessory minerals: monazite, xenotime, rutile, zircon, and florencite. It has been found that chlorite, illite, and quartz are present in all horizons of the studied peaty-podzolic soil. Insignificant amounts of mixed-layered mineral and kaolinite could be suggested in the T and EL horizons of peaty-podzolic soil. The mixed-layered mineral is most probably of soil origin, which is related to the transformation of illites inherited from the parent rock under acidic conditions.     

Mineralogy of a podzol formed in sandy materials in northern denmark

This paper deals with possible mineralogical changes from one particle size fraction to another and from one horizon to another in a Typic Haplorthod. X-ray diffraction and chemical analysis were the main methods used. The investigation indicates that a large part of the fine material in the soil is developed during weathering in situ. Less resistant minerals seem to be protected by being parts of rock fragments in coarser fractions, but once freed from that protection they quickly undergo fragmentation into finer particles. Most of the sand and silt fractions are quartz. The K-feldspar content ranges between about 10 and 20%, the Na-feldspar content from about 15 to 30% and the Ca-feldspar content is very small. The clay minerals are mostly kaolinite and mica and in the A2 horizon, expandable 2:1 minerals containing both smectite and vermiculite layers. The B horizon contains 14 A minerals that resemble interstratified vermiculite—chlorite. In the C horizon both vermiculite—chlorite and clorite occur.     

The nature of smectites and associated interstratified minerals in soils of the Gharb plain of Morocco

The mineralogies of ‘Tirs’ (Typic Pelloxererts), and ‘Debs’ (Typic Haploxerolls and Typic Xerochrepts) soils of the Gharb plain in north-western Morocco are investigated, with special attention given to the determination of the nature of the smectitic phase using the lithium test (Li test) and the alkylammonium method. The sand and silt mineralogy of Tirs soils is dominated by quartz with small amounts of feldspars and kaolinite. The sand and silt fractions of Dehs soils also contain significant amounts of mica, chlorite, and interstratified phyllosilicates. The clay minerals of Tirs soils are predominantly a high-charge smectite. The estimated interlayer charge for this phase is 0.61 mol(c)/O₁₀(OH)₂ and the fraction of tetrahedral charge varies from 38 to 44%. Although the percentage tetrahedral charge is less than 50%, the smectitic phase behaves as beidellite with the Li test. Dehs clays are more heterogeneous, consisting of smectite, vermiculite, illite, kaolinite, chlorite, and interstratified illite/smectite and illite/vermiculite. The Li test and the alkylammonium method demonstrate that a high-charge smectite or vermiculite is interstratified with illite. A low-charge montmorillonite is also present both in Tirs and in Dehs soils. The high-charge beidellitic phase is believed to be a transformation product of mica, whilst the low charge montmorillonite is thought to be inherited from the parent material.     

Differentiation of layered silicates and biogenic silica in meadow podbel soils of the Central Amur Lowland

Mineralogy of the fine component of meadow podbel soil in the Central Amur Lowland significantly varies depending on texture differentiation within the profile and clay categories with different binding strengths (water-peptized and aggregated clay). In the eluvial part of the profile, hydromicas are predominant, which are accompanied by kaolinite and mica-smectites with a low content of smectite layers; there are many finely dispersed quartz and feldspars; plagioclases are less abundant. The illuvial part of the profile is characterized by a high content of smectite minerals (mica-smectite and kaolinite-smectite interstratifications). Kaolinite, chlorite, and chlorite-vermiculite are also found. Fragmentary components pass into a peptized state: micas-hydromicas, kaolinite, finely dispersed quartz, feldspars, plagioclases, amphiboles, and diatom skeletons (mainly in the illuvial part of the profile). Aggregated clays are characterized by a high content of interstratifications with smectite layers. The mineral composition of two clay categories is strongly differentiated according to eluvial-illuvial type. The bulk chemical composition confirms the textural differentiation of the finely dispersed component within the profile. The chemistry of silty sand cutans on the faces of structural units in the illuvial part of the profile significantly differs from the chemistry of the enclosing horizon and is analogous to that of the eluvial part of the profile. The involvement of silica in the meadow podbel fractions with different binding strengths has been revealed.     

中国东南部某些水稻土的矿物学

Limited information is available concerning the mineralogy of paddy soils in the southeastern China. Using chemical methods in conjunction with X-ray diffractometry, we studied the mineral composition of three paddy soils: Jinghua (paddy soil on Quaternary red clay), Fuyang (Hapl-percogenic loamy paddy soil), and Shaoxing (gleyic clayey paddy soil). All the soils contained quartz, mica, vermiculite, chlorite and kaolinite, and the distribution of these minerals varied with soil particle size fractions. The clay fraction of the Fuyang and Shaoxing soils also contained smectite. Although X-ray data did not show the presence of smectite in the Jinghua soil, this mineral was identified by the chemical method, suggesting a transitional property of the mineral in the soil. Hydroxy-Al interlayered minerals were also present in the clay fraction. The amount of smectite in the soils was 31.6 (Shaoxing), 16.5 (Fuyang), and 21.4 (Jinghua) g kg^-1; for vermiculite it was 33.3 (Shaoxing), 16.5 (Fuyang), and 8.5 (Jinghua) g kg^-1. Smectite was only found in the clay fraction. In contrast, amounts of vermiculite in soil particle size fractions were 3.0~11.4 (sand), 2.1~6.0 (coarse silt), 4.6~18.9 (medium silt), 0.9~40.0 (fine silt), and 17.0~108 (clay) g kg^-1. The amount of noncrystalline aluminosilicates in the soils in g kg^-1 decreased in the order: Shaoxing (2.4) > Jinghua (1.9) > Fuyang (1.7). This study has provided useful mineralogical information that is fundamental in future development of management strategies of the soils.     

Clay minerals in the stream floodplain soils in undisturbed landscapes of the Southern Taiga (with the soil of the state central forest nature and biosphere reserve as an example)

An X-ray diffraction technique was used to study the composition of clay material from floodplain soddy- and mucky gley soils formed in the valleys of small streams in the reserve. The content of nonexpandable minerals was higher and the labile mineral content was lower in the fine fractions of the floodplain soils than in similar fractions of upland soils found in adjacent positions. Two types of disordered mixed-layered not found in upland soils-namely, illite-chlorites and chlorite-vermiculites with a variable proportion of individual layeres-were detected in the clay material. Both types of mixed-layer minerals are supposed to originate from stony fragments containing phyllosilicates of supergenic or post-magmatic origin.     

The impact of long-term irrigation on the degree of aggregation and the mineralogical composition of the clay fraction in dark chestnut soils of the Transvolga region

Dark chestnut soils of the Ershov Experimental Station in the Transvolga region are characterized by the even distribution and aggregation of clay minerals in the profile. Hydromica, chlorite, kaolinite, and smectitic minerals predominate in the clay (<1 μm) fraction. The smectitic phase consists of randomly ordered mixed-layered minerals of the following types: mica-smectite with a low (<50%) content of smectite layers, mica-smectite with a high (>50%) content of smectite layers, and chlorite-smectite. In some horizons, the smectitic phase occurs in the superdispersed state. The long-term irrigation of these soils with fresh water of the Volga River has led to certain changes in the composition and properties of the clay particles. The weakening of bonds between them has taken place. As a result, the content of water-peptizable clay has increased by two times, and the content of aggregated clay of the first category (AC1) has increased by 1.5 times at the expense of a decrease in the contents of tightly bound clay (TBC) and aggregated clay of the second category (AC2). Also, the redistribution of organic matter bound with clay particles has taken place: its content in the AC1 fraction has decreased, whereas its content in the AC2 and TBC fractions has increased. In the topsoil horizon, the amount of the smectitic phase has lowered, whereas the contents of hydromica, kaolinite, and fine-dispersed quartz in the clay fraction have increased. In general, some amorphization of the clay material has occurred. The periodic alkalization of the soil solutions upon irrigation has led to the conversion of the smectitic phase into the superdispersed state in the entire soil profile.     

Specific Features of Profile Distribution and Crystallochemistry of Phyllosilicates in Soils of the Cisbaikal Forest-Steppe

The mineralogical composition of agrogray, dark gray, and agro-dark gray soils (Luvic Greyzemic Retic Phaeozems); agro-dark gray residual-calcareous soils (Calcaric Cambic Phaeozems); clay-illuvial agrochernozems (Luvic Chernic Phaeozems); and agrochernozems with migrational–mycelial carbonates (Haplic Chernozems) developed in the forest-steppe of Central Siberia within the Irkutsk Depression has been studied. The clay (<1 μm) fraction separated from these soils consists of mixed-layer minerals with alternating layers of hydromica, smectite, vermiculite, and chlorite; the proportions between them change within the soil profiles. The clay fraction also contains hydromicas, kaolinite, chlorite, and some admixture of the fine-dispersed quartz. Each type of the soils is characterized by its own distribution pattern of clay material with specific alternation of layers in the mixed-layer formations. Mixed-layer minerals of the chlorite–vermiculite type predominate in the upper horizons of texture-differentiated soils. Down the soil profile, the content of mixed-layer mica–smectitic minerals increases. In the clay fraction of arable dark gray-humus soils with residual carbonates, the distribution of the clay fraction and major mineral phases in the soil profile is relatively even. An increased content of well-crystallized kaolinite is typical of these soils. The parent material of agrochernozems has a layered character: the upper horizons are generally depleted of clay, and the middle-profile and lower horizons are characterized by the considerable kaolinite content. In general, the clay material of soils of the Tulun–Irkutsk forest-steppe differs considerably from the clay material of foreststeppe soils developed from loesslike and mantle loams in the European part of Russia. In particular, this difference is seen in the proportions between major mineral phases and between biotitic and muscovitic components, as well as in the degree of crystallinity and behavior of kaolinite and chlorite.     

Mineral Composition and Weathering of Soils Derived from Xiashu Loess

Mineralogical, physical and chemical analyses of the soils derived from Xiashu loess were carried out. The primary minerals of these soils were found to be mainly composed of light minerals, such as quartz, feldspar and mica, with traces of heavy minerals. Clay minerals, more complicate in composition, were dominated by hydromica, accompanied by smectite, vermiculite, chlorite, kaolinite, 2:1/1:1 randomly interstratified minerals and small amounts of quartz, goethite, lepidocrocite and hematite, Clay minerals were characterized by low crystallinity and fine particle size. In light of the quartz/feldspars ratio of the 0.01-0.05mm silt fraction, and the clay mineral composition, the freeness of iron oxide, and the silica/sesquioxide and silica/alumina ratios in < 0.002mm clay fraction, it is concluded that the weathering intensity of these soils was lower than those of red soil and yellow earth, but higher than that of brown earth, and that the soil allitization, depotassication and hydroxylation of cl     

Mineralogical composition of silt fractions and its transformation under the impact of different cenoses in model lysimeters

A lysimetric experiment has made it possible to trace changes in the fine and medium silt fractions of soils developing from the noncalcareous mantle loam under typical phytocenoses of the southern taiga zone during a 33-year-long period. The silt fractions were separated by the Gorbunov method, and their mineralogical composition was analyzed by X-ray diffractometry. The fine silt fraction consists of quartz, kaolinite, chlorite, hydromica, smectite, and feldspars. The medium silt fraction consists of quartz, kaolinite, mica, and feldspars. In both fractions, the content of feldspars in the upper horizons has increased in comparison with the initial parent material due to the physical disintegration of coarser fractions. The chemical decomposition of mica has been registered in the layer of 10–30 cm. In lysimeters under artificially planted mixed forest cenoses, acidic hydrolysis may take place at this depth. Cryogenic processes play an important role in the soil formation at the early stages.     

Diversity of clay minerals in soils of solonetzic complexes in the southeast of Western Siberia

Data on the mineralogical composition of clay in soils of solonetzic complexes of the Priobskoe Plateau and the Kulunda and Baraba lowlands have been generalized. The parent materials predominating in these regions have loamy and clayey textures and are characterized by the association of clay minerals represented by dioctahedral and trioctahedral mica–hydromica, chlorite, kaolinite, and a number of irregular interstratifications. They differ in the proportions between the major mineral phases and in the qualitative composition of the minerals. Mica–hydromica and chlorites with a small amount of smectitic phase predominate on the Priobskoe Plateau and in the Kulunda Lowland; in the Baraba Lowland, the portion of mica–smectite interstratifications is higher. An eluvial–illuvial distribution of clay fraction in solonetzes is accompanied by the acid–alkaline destruction and lessivage of clay minerals, including the smectitic phase in the superdispersed state. This results in the strong transformation of the mineralogical composition of the upper (suprasolonetzic) horizons and in the enrichment of the solonetzic horizons with the products of mineral destruction; superdispersed smectite; and undestroyed particles of hydromica, kaolinite, and chlorite from the suprasolonetzic horizons. A significant decrease in the content of smectitic phase in the surface solodic horizons of solonetzic complexes has different consequences in the studied regions. In the soils of the Priobskoe Plateau and Kulunda Lowland with a relatively low content (10–30%) of smectitic phase represented by chlorite–smectite interstratifications, this phase virtually disappears from the soils (there are only rare cases of its preservation). In the soils of the Baraba Lowland developed from the parent materials with the high content (30–50%) of smectitic phase represented by mica–smectite interstratifications, the similar decrease (by 10–20%) in the content of smectitic phase does not result in its complete disappearance. However, the smectitic phase acquires the superdispersed state and the capacity for migration.     

Short‐time clay‐mineral evolution in a soil chronosequence in Oléron Island (France)

Major weathering sequences in soils are well established; however, knowledge on rates of mineral transformations remains unknown, because it is often difficult to date precisely soil processes. This work was carried out on soils developed on recent (< 188 y) sand dunes on the W coast of Oléron Island (France). The coast has been protected against marine and wind erosion by constructing five consecutives barriers close to the coastline since 1820 (1820, 1864, 1876, 1889, 1948) defining the maximum age of the soil parent material, as before the areas between the barriers were under water. Soils on the older dunes have low clay content (> 94% of sand) and exhibit a bleached E horizon that overlies a yellowish brown B horizon. The process responsible for their formation is podzolization promoted by the high permeability of the material and complexing organic matter produced by coniferous vegetation. Initial mineralogy of C horizons is homogenous and constituted of chlorite, illite, illite/smectite mixed‐layer minerals, and kaolinite, quartz, calcite (≈ 8% related to shell fragments), and feldspars. The initial clay‐mineral assemblage of the E horizons is dominated by illite (well‐crystallized WCI and poorly crystallized PCI) and chlorite. With progressive podzolization, poorly crystallized illite is first transformed to illite/smectite mixed‐layer minerals and in a further step into smectite. In addition, transformation of well‐crystallized illite leads to formation of ordered illite/smectite mixed‐layer minerals in the E horizons, which is not commonly described in soils. In the B horizons, illite/smectite mixed‐layer minerals are present with traces of smectite, as well as Al and Fe oxi‐hydroxides as revealed by DCB and oxalate chemical extractions. This chronosequence illustrates that over short distances and short time (< 188 y) intense mineral weathering and soil development occur. Major clay‐mineral changes occur between 132 and 188 y in agreement with development of the pine forest producing acidic litter.     

The behavior of the clay fraction in model ecosystems of soil lysimeters

Changes in the mineralogical composition of the clay fraction (<0.001 mm) sampled from soils of the model lysimetric experiment of Moscow State University have been studied. The mineralogical composition of clay is represented by the paragenetic association of minerals typical of noncalcareous mantle loams in the center of the Russian Plain. The predominant smectitic phase consists of complex mixed-layered minerals (mica-smectite with high and low contents of the smectitic layers, chlorite-smectite with different ratios between the chloritic and smectitic layers) and individual smectites. Tri-and dioctahedral hydromica, kaolinite, chlorite, and clay-sized quartz are present in lower amounts. At the early stages of the experiment, the distribution of the smectitic phase in the soil profile is more contrasting than the distribution of the clay fraction. Under the impact of artificially planted meadows, forests, and agrocenoses, soil profiles with different distribution patterns of the clay fraction are formed. The weakly pronounced eluvial distribution pattern of the clay fraction has been registered. Under spruce and mixed stands, the loss of the clay fraction from the upper horizons is due to the hydrolysis of smectitic minerals in the acidified medium. Under broad-leaved stands, perennial herbs, agroecenoses, and fallow, the depletion of smectites from the upper horizons is due to lessivage. The relative accumulation of hydromica and kaolinite is observed in the uppermost soil layer.     

ALPINE PODZOL SOILS ON THE BEN LAWERS MASSIF PERTHSHIRE

Characteristics of the soils include well-defined horizons, very low pH values and base saturation percentages, and a slight but general increase in the silt-plusclay content down the profile. X-ray diffraction shows that the soil clays are rich in mica and chlorite with subsidiary amounts of kaolinite, goethite, and lepidocrocite. The general distribution of the clay minerals in the profiles studied suggests that the weathering of chlorite leads to the formation of kaolinite in the A horizons and to the accumulation of crystalline iron-oxide minerals in the B horizons. The presence of kaolinite, taken in conjunction with recent clay mineral studies of Scandinavian and Canadian podzols, indicates that the Ben Lawers soils may pre-date the last glacial period.     

Mineralogies of silt and clay fractions of twelve soil profiles in the Bolivian Andes (Callavaya Region)

Mineralogies of a soil catena in the Pampa of Ulla Ulla (4,300–4,600 m) and the soils of the steep slopes of the Cordillera de las Muñecas (“steep area”) were investigated. The latter area includes three altitudinal zones: herbaceous zone (3,900–4,800 m), shrub zone (2,700–3,900 m), and mountain forest zone (up to 2,700/2,800 m). The soils were classified according to Soil Taxonomy as Entisols, Mollisols, and Inceptisols. They were mainly derived from quartzitic schists and slope debris. Each horizon of each profile was representatively sampled for analyses.Muscovites and illites were the dominant minerals in the fine silt and clay fraction, respectively. Besides kaolinite, pyrophyllite and vermiculite, regular illite/vermiculite mixed layers, chlorite, feldspar and quartz were detected in both fractions. In a Typic Cryaquent from the Pampa of Ulla Ulla, smectites had been formed. Pyrophyllite, illite/vermiculite mixed layers and chlorite seemed to be unstable under acid conditions in most of these soils.     

中国土壤胶体研究 Ⅵ.西藏高原几种主要土壤的粘土矿物组成和演变

西藏高原突起于我国西南,绝大部分地面的海拔高度在4000米以上,为世界上最高的大高原。它大致在第三纪开始形成,后来曾受第四纪冰川的深刻作用,高山顶部至今仍是冰川的活动场所^[1,2]。高原为昆仑山、唐古拉山、喜马拉雅山和横断山等大山脉所盘踞。