Identification Of Clay Minerals Research Articles

On the Mechanism of Squeezing-Swelling Rock Pressure of Mudstone on Tunnel Support in Relation to the Case History of Noshiro Tunnel

This paper discusses the mechanism of squeezing-swelling rock pressure of mudstone and presents the quantitative data of rock pressure measured during tunnel construction in the field together with the associated measnrements of physical and mechanical properties of the rocks.Wire-strain-gauges were used to determine the axial force N, bending moment M and the shearing force Q and the resultants of external forces P and S due to rock pressure were calculated at selected points using the method originally proposed by Prof. Murayama14), thus the pressure distribution concentric with the tunnel axis being obtained (Fig. 14).Three of the tunnels of the main irrigation water line for Noshiro Reclamation Project in Akita Prefecture provide the data for this paper. These three tunnels No.3, No.4 & No.6 were all constracted in massive, occasionally faulted tertiary mudstone named as Fujikotogawa Formation.The phenomena encountered during the construction of the tunnel No.4 were very different from those of the tunnels No.3 and No.6.In the case of the tunnel No.4, the heavy rock pressure caused an excessive deformation of the first placed light steel supports, resulting in the necessity to change to the heavier supports with invert struts.However, in the case of the tunnels No.3 and No.6, the rock pressure was considerably smaller in spite of the fact that the mudstone encountered in these tunnels was apparently similar to those of the tunnel No.4.To investigate the reason for this and to assist in the deeper understanding of the mechanism of squeezing and swelling rock pressure, tests were made to determine the unconfined compressive strength qu of the rocks, the swelling characteristics of the artificial mudstone or remoulded mudstone**, clay mineral identification and the pF water content relationships of the rock powder (Fig.10, 15, 16, 11, 19).As shown in Fig.11, expansive clay minerals (montmorillonite) were contained in the mudstone of the three tnnnels but as shown in Fig. 10 the strength qu, of the rocks sampled from the tunnel No.4 was approximately one half to one third (or even less) of those sampled from the tunnel No.3 and No.6 and nearly equal to or less than two times the initial vertical stress induced by the weight of the rock itself at the side wall, indicating that the mudstone around the tunnel No.4 was broken and plastic zone of failure was formed (Fig.4), whereas the mudstone of the tunnels No.3 and No.6 underwent little breakage by the stress of the same magnitude.On top of this, the swelling capacity of the remoulded mudstone sampled from the former tunnel was conspicuous (Fig.15) and much larger than that of the latters, indicating that the strength parameters and the unconfined compressive strength qu of the mass of broken rocks of tunnel No.4 reduced considerably in the course of time, resulting in the much increase of σi as is clear from Eq. 14 and Fig. 8.These facts not only explain the reasons of the difference of the rock pressure phenomena but also the mechanism of the squeezing-swelling rock pressure of mudstone.

A clay mineral investigation of six cores from the Gulf of Mexico

Samples were studied from each color change along six gravity cores from nearshore to deep-sea areas in the Gulf of Mexico. Analytical methods and techniques used to characterize the sediments were X-ray diffraction, differential thermal analysis, cation exchange capacity, particle size distribution and fractionation of the clay-size material with the supercentrifuge. Fractionation of clay-size material expedites clay mineral identification and semi-quantitative estimates of abundance. A 5-g, clay-size sample passed five times through a supercentrifuge should remove the < 0.2 μ fraction when the proposed sample preparation method is employed. Duplicate fractionations usually agree within 3% and fractionation efficiency is unaffected by the mineral suite. The clay minerals and semi-quantitative estimates of their abundance suggest that the sum of source conditions has remained constant during and since Pleistocene time represented by the cores in this study. Montmorillonite and kaolinite are not more abundant in warm water than in cold water sediments and illite and chlorite are not more abundant in cold water than in warm water sediments from the Gulf of Mexico. Sand-size material is usually a small weight percent of a sample. Silt and clay-size materials are approximately equal except for the cores farthest from the Mississippi Delta where clay-size material dominates. In the clay-size fraction, montmorillonite is generally more abundant than illite, while kaolinite comprises less than 20% and chlorite less than 7%. Relative contents of quartz may be obtained by using differential thermal analysis. Quartz of similar particle size as occurs in the sample is used to obtain the standard curve. Quartz and feldspar exist only in the 2–0.2 μ portion of the clay-size fraction. Possible worm fecal pellets are present in the sand-size fraction of the two cores farthest from shore. The effects of differential settling of clay minerals have not been recognized.

Identification and distribution of clay minerals in some sediments of the Nile Delta, U.A.R.

Identifications of the clay minerals in some Nile Delta sediments were based upon the X-ray diffraction characteristics of the −5 μ e.s.d. fractions and their response to glycerol and heat treatments. They were also based upon the morphological features of the crystals which were detected by the electron microscope. Clay minerals identified were: montmorillonite, chlorite, mixed-layer illite-montmorillonite, illite and kaolinite. Distribution of the clay minerals in the Nile Delta sediments has been also reported. No consistent clay mineralogical variation with depth was found.

Formation and Stability of Hydroxy-Mg Interlayers in Phyllosilicates

AbstractA study was conducted to (1) determine the conditions of hydroxy-Mg interlayer formation with respect to type of clay mineral, acidity, and time; (2) evaluate the stability of this interlayer to dissolution treatments; and (3) ascertain the effects of such treatments upon the determination of clay minerals in soils and sediments. Hydroxy-Mg interlayers were formed in montmorillonite and vermiculite by adding MgCl2 and NaOH in amounts to give a wide range of pH. The resulting chloritic intergrades were examined after 10 days, 6 months, and 1 yr.Alkaline conditions favored the formation of hydroxy magnesium interlayers in phyllosilicates. Hydroxy-Mg interlayered montmorillonite which resulted from 10 days equilibration at pH 10·4 did not expand upon solvation with ethylene glycol and exhibited practically no collapse after K-saturation and heating at 550°C. A small amount of interlayer was formed between pH 6·8 and 9·8 (10 days). In contrast, vermiculite exhibited no evidence of interlayer formation at pH values up to 9·7 (10 days). Chloritic intergrades formed at pH 10·7 did not collapse after K-saturation and heating at 300°C but did so at 550°C. Hydroxy-Mg interlayers were not formed in either mineral by using a drying method. This method apparently failed to provide the required alkaline conditions for interlayer formation.The amount of magnesium interlayers present in the phyllosilicate systems decreased with time. The interlayers formed in vermiculite decreased more sharply than those in montmorillonite.Sequential dissolution treatments included boiling 2 per cent Na2CO3, buffered sodium citrate-dithionite, a second citrate-dithionite treatment, and boiling NaOH. Hydroxy-Mg interlayers in montmorillonite exhibited a higher stability to sequential treatments than the interlayers formed in vermiculite. A stable 14 Å line was observed in interlayered montmorillonite after the dithionite-citrate and NaOH treatments.The interlayers in montmorillonite showed a relatively high stability to HCl dissolution treatments. In contrast, most of the magnesium interlayer in vermiculite was removed by two HCl washings.The reagents used in this study are sometimes used to remove coatings and cementing agents from soil surfaces prior to particle size and clay analysis. The present data show that these treatments also remove some hydroxy-Mg interlayers and produce changes in properties of clays. A proper interpretation of data for clay mineral identification and characterization must recognize these changes due to treatment.

Comparison of Iron and Aluminum Hydroxy Interlayers in Montmorillonite and Vermiculite: II. Dissolution

AbstractThe stabilities of hydroxy‐Al and ‐Fe interlayers in montmorillonite and vermiculite were evaluated by subjecting the systems to HCl treatment and to sequential treatments which included boiling 2% Na2CO3, buffered sodium citrate‐dithionite, a second citrate‐dithionite treatment, and boiling NaOH.The stability of hydroxy interlayers was dependent on kind of mineral matrix, whether the interlayer was Fe or Al, and the conditions of acidity under which they were initially formed. Hydroxy‐Al interlayers formed under acid conditions were more stable than those formed under alkaline conditions in both montmorillonite and vermiculite systems. Iron interlayers formed under neutral and alkaline conditions in montmorillonite and vermiculite were more stable than those formed in acid media. The hydroxy‐Al and ‐Fe interlayers in montmorillonite exhibited a higher stability than their counterparts in vermiculite.A residual 14A line after K‐saturation and heating to 550C was observed in some samples which received the dithionitecitrate and NaOH treatments. This occurred to a greater extent in vermiculite and particularly with Fe‐hydroxy systems. The data suggested a resolution of a mixed system into collapsible and noncollapsible components.In montmorillonite, the hydroxyl‐Al interlayer, formed in alkaline conditions, showed the highest stability to the HCl treatment, whereas that formed in acid medium was the least stable. In vermiculite, the stability of hydroxy‐Al interlayer to the HCl treatment decreased from acid to alkaline media.Iron interlayers in montmorillonite formed in all media exhibited high stabilities to the HCl treatments. In vermiculite, the HCl treatments removed more interlayers from acid media than from alkaline media.Some of the dissolution treatments tested in this study are often used as pretreatments for removal of coatings and cementing agents prior to separation or analysis of clay fractions. These reagents will remove hydroxy interlayers and result in changes of properties of clays from soils and sediments. This must be recognized for proper interpretation of data for clay mineral identification and characterization.

Separation of Clay Minerals and Soil Clays Using Isopycnic Zonal Centrifugation

AbstractThe technique of isopycnic‐zonal centrifugation in a continuous nonaqueous density gradient was used in the purification and separation of standard clay minerals and soil clays. A suspending agent (polyvinylpyrrolidone) compatible with tetrabromoethane and ethanol stabilized clay suspensions produced multiple banding of systems which otherwise flocculated into one band. Data from x‐ray diffraction analyses revealed the technique is useful in purification of clay minerals and identification of clay minerals in soil clays; however the banding obtained from the clay fraction of a Dodge silt loam did not represent discrete bands of specific clay minerals.

Clay Mineralogy of Soils Formed on Mazama Pumice

AbstractAmorphous components predominated in the clay size fraction of samples taken across a climatic transect of soils from Mazama pumice in central Oregon. The amounts were greatest in the less intensely weathered horizons, i.e., in lower horizons and at drier sites of the transect. Crystalline minerals were present in relatively small percentages and were unexpectedly complex. The phyllosilicates included beidellite, montmorillonite, vermiculite, a micaceous component, chloritic intergrades, and chlorite. Non‐phyllosilicate minerals of the suite were gibbsite, plagioclase feldspars, and quartz. The amount and distribution of the individual clay size minerals varied within and between profiles.Results of clay mineral identification were evaluated with respect to environmental data available for the transect sites. The factors primarily controlling the processes responsible for 2:1 clay mineral genesis were hypothesized to be the vesicular structure and chemical composition of the pumice material. Other factors such as climate and vegetation were believed to govern local weathering intensity.

Clay Separation and Identification by a Density Gradient Procedure

AbstractA method was developed for the separation and partial identification of clays using a heavy liquid density gradient column. The columns consisted of five different layers, theoretically permitting seven different separations in one determination. To aid in separation, the original density of the clay was altered by saturation with H, Ca, K, or Cs. The resulting densities were related to changes in the clay interlayer distance as well as to the equivalent weight of the sorbed cations.This density gradient method is simple, quick, and requires only basic laboratory equipment. The density values aid clay mineral identification and in some instances may be the only information needed.

Mineralogia da fração argila de perfis de solos da série Ibitiruna

O presente trabalho teve por finalidade o estudo minera lógico, da fração argila, da série Ibitiruna (RANZANI et al. 9), pertencente a unidade de mapeamento Podzólico Vermelho Amarelo - variação Laras (COMISSÃO DE SOLOS 1). Foram coletados três perfis de solos, pertencente a série Ibitiruna, designados por perfis P1, P2 e P3. As amostras dos horizontes foram colhidas a partir da superfície do solo até a rocha. A fração argila foi separada por sedimentação, sendo posteriormente, dividida em duas subfrações (centrifugação): 2 a 0,2 mícron e menor que 0,2 mícron, argila grossa e fina respectivamente. O material obtido nestas duas frações, sofreu determinações químicas (capacidade de troca de cátions) e determinações de raio-X (obtenção de difratogramas, com o auxílio do contador Geiger, e filmes, pelo método do pó). Através dêstes resultados, foi efetuado o reconhecimento dos minerais de argila assim como estimativa semiquantitativa. A análise mineralógica das frações argila grossa e fina, referentes à natureza e à quantidade dos minerais de argila indica o seguinte: a caolinita é o mineral dominante nas duas frações argila, com teores sempre acima de 40%; a montmorilonita e os minerais do grupo de 14 Anormalmente ocorrem com valôres inferiores a 10%.

Mineralogical characterisation of some Indian Bentonites based on IL: MA ratios

The ratio of ignition loss (IL) to the moisture absorption (MA) at a particular relative humidity of a clay mineral has been used as a technique for clay mineral identification. This technique has been employed for studying the mineral components present in some Indian Bentonites. It has been found that if the three main groups of clay minerals are lined up in the order of increasing of particle fineness as kaolinite, illite and montmorillonite, the IL values increased in the reverse order MA, however, followed the same order and increased from Kaolinite to Montmorillonite. Bihar, Rajula, Akli and Hathi-ki-Dhani Bentonites were found to be typically montmorillonitic. Jaipur and Karauli were predominantly illitic.

Some Problems on Mass Movements

A hard and fast classification of mass movements can neither be given nor make sense, because its practical application to the actual or natural phenomena encounters great difficulties. For the time being a simplification is preferable to pining for a too detailed classification of mass movements. This paper is chiefly concerned with clay minerals in areas of mass movements of flowand slip-type in Canada, compared with those in Scandinavia and in Japan, and it stresses the important role of swelling clay minerals. Classification of mass movements The classification of types of mass movements proposed by Sharpe (1938, pp. 97, Fig. 14) is well-known, and it appears to be very comprehensive and nicely systematic. However, it has neither any standard measure nor scientific criterion; and thus conscientious researchers must have been sorely perplexed in its application to their own studies. In this connection, a much better classification of landslides has been recently presented by Varnes (1958, pp. 20-47). The writer (Yatsu 1966, pp. 102-103) has proposed a tentative classification of mass movements which emphasized only the mechanics of the phenomena and ignored shapes and so forth, since it is doubtful whether complicated classifications are of any practical use at all. The most important task at present is to clarify the mechanism of movement in individual cases which will then be assigned to one type or a transitional type of fall, creep, rupture, slip, flow, and others. Generally speaking, falls, creeps, and ruptures are observed everywhere under certain conditions irrespective of rock types, while slips and some of the flows seem to be conspicuously associated with materials of which the slopes are composed, especially with the type of clay minerals. Clay minerals in areas of slipand flow-types of mass movements Slips or landslips, presumably most closely corresponding to earthflows in Sharpe's classifica396 tion of types of mass movements, have a remarkable relationship to swelling clay minerals and occur on slopes more gentle than those of lope ruptures which occur withouttheexistence of clay minerals. The results of studies on this problem in Japan (Nakano, Yatsu and Teruta 1961, pp. 1-20; Yatsu 1964, pp. 7-30; Yatsu 1965, pp. 54-66) will now be compared with those in Canada and in Scandinavia. In eastern Canada, most mass movements of flow-type, called flowslide by civil engineers, have occurred in the valleys of the Ottawa and the St. Lawrence rivers where extrasensitive quick clays are observed. Also in British Columbia and in the Prairie Provinces, mass movements of slipor flow-type are frequently observed in glacial till deposits. The writer has observed mass movements of flow-type near Lakelse Lake, B.C. and near Pavilion, B.C.; and those of slip-type at Spences Bridge, B.C., and near Hixon Station B.C., (about 1.5 miles north of the station along the railway). Many slope ruptures are observed, of course, along the Fraser River which erodes the tips of the slopes and causes their occurrence. Concerning the clay mineralogy of Canadian soils, Forman and Brydon (1961, pp. 140-146) have reviewed and have mentionedthe existence of montmorillonites in prairie soils. Kodama and Brydon (1965, pp. 151-173) have reported interstratified montmorillonite-mica clays, and Maiklem and Campbell (1965, pp. 354-371) studied mixed layer clays of the Prairie Province. In Leda clay from eastern Canada, clay fractions have been examined and show a predominant composition of illite and chlorite with occasional traces of montmorillonite (Allen and Johns 1960, pp. 75-86; Brydon and Patry 1961, pp. 169-181). The X-ray identification of clay minerals was done on several samples collected from mass movement areas of flowor slip-type in British Columbia and around Ottawa, and also on Scandinavian quick clays. Some examples of This content downloaded from 157.55.39.175 on Sun, 02 Oct 2016 05:41:26 UTC All use subject to http://about.jstor.org/terms SOME PROBLEMS ON MASS MOVEMENTS

Recent Advances in Clay Mineralogy, with Special Reference to Studies on Structure and Identification of Clay Minerals

Recent Advances in Clay Mineralogy, with Special Reference to Studies on Structure and Identification of Clay Minerals

Influence of dispersion treatments on the properties of soil colloids

Abstract The identification and characterization of clay minerals in the soil have been carried out on the clay fraction separated from a dispersed soil suspension. The process of dispersion includes the replacement of exchangeable divalent cations with H-ions by the dilute acid treatment, the removal of organic matter with hydrogen peroxide, and the dissolution of free iron oxides with reducing and/or chelating agents.

The Use of Piperidine as an Aid to Clay-Mineral Identification

It is suggested that piperidine may be useful in the identification of clay minerals during differential thermal analysis, particularly in the differenti- ation of expanding and non-expanding lattice minerals. Differential thermal analysis of two montmorillonites showing similar X-ray powder photographs indicated large differences in the distribution of cation- exchange sites. Allaway (1949) introduced the use of piperidine as an aid to clay- mineral identifcation, making use of its function as a strong base which will fill the interlattice cation-exchange positions of smectite minerals. Differential thermal analysis in an oxidizing atmosphere of acid clays which had been titrated to pH 7-5 with a 0.1N aqueous solution of piperidine gave traces which show large exothermic reactions at 300-350~ and subsequent exothermic reactions which depend on the nature of the mineral under investigation. Thus magnesium-rich montmorillonites gave exothermic peaks at around 700~ while clays typical of the nontronite group gave peaks in the 450-500~ range, The presence of aluminium in tetrahedral co- ordination was considered to be associated with exothermic peaks at 600~ Kandites sorbed insignificant amounts of piperidine and illites yielded reactions on a much smaller scale than smectites. Amines other than piperidine also produced similar effects. By comparing the rates of carbon dioxide and water production during the differential thermal examination of a piperidine-saturated clay Allaway concluded that the 300-350~ exothermic peaks were due to the oxidation of hydrogen produced by thermal decomposition of the piperidine, as more than 90 per cent. of the total carbon was unoxidized at temperatures below 430~ remaining as a black deposit of elemental carbon which was only oxidized when the clay lattice was disrupted. Carthew (1955) has confirmed some of these findings, and con- eluded that, on differential thermal curves for piperidine-saturated clay minerals, (a) nontronite and montrnorillonite give large exo- thermic peaks at 500~ and 700~ respectively; and (b) illite can be identified in mixtures with kaolinite or with montmorillonite using

Effect of Iron Removal and Dispersion Methods on Clay Mineral Identification by X‐Ray Diffraction

AbstractThe clay minerals identified in soil samples were found to be dependent on the pretreatment of samples for iron removal and dispersion. Treatments affected the characterization for chlorite, montmorillonite‐type minerals, vermiculite, and intergrade components. Increases in the degree of expansion upon solvation and in degree of collapse upon K‐saturation and heating were related to the severity of treatments used for dispersion. Iron removal treatments also increased the ease of expansion and collapse to 2:1 lattice clays. It was concluded that certain pretreatments tended to remove interlayered materials which were present in these samples.The degree to which clay mineral interpretation was affected by methods of pretreatment was not the same for all soils. Samples of the Astoria soil exhibited the greatest differences in diffraction patterns as a result of dispersion and Fe removal treatments while the Aiken was the least affected. The Willamette was found to be intermediate. The evidence suggested that the Astoria samples contained interlayer materials (intergrade components) which were poorly crystallized and thus more labile and subject to removal. On the other hand, the interlayer material in the Aiken seemed to be better crystallized and more toward the chlorite end of the spectrum.It has sometimes been assumed that the methods which permit the identification of the largest number of components with “clean‐sharp” peaks are the ones which should be used in sample preparation. It is suggested that the objective should be to obtain methods which permit the identification and reflect the properties of clay minerals as they existed in situ.

Problems in Clay Mineral Identification by X‐Ray Diffraction

AbstractX‐ray diffraction studies of Oregon soil clays during the past few years have resulted in the observance of a number of phenomena that were somewhat disconcerting. Results of a number of different studies have indicated that the clay minerals identified in a given sample are dependent upon specimen carriers, method of Fe removal, dispersion reagents, cation saturation of clay, and in some cases, peeling of specimens. Further, the situation is complicated by the fact that the effects vary not only with different soils, but also to some extent with different size fractions of the same soil.Data obtained lead to consideration of the possible extent that clay mineral identification by X‐ray diffraction may be arbitrary and empirical. A question is raised as to differentiation of clay minerals which may occur naturally in a given soil from those which may appear as a result of sample preparation. Certainly, the results reported here strongly suggest the need of a combined and intensive effort to establish clay mineral identification on a better and more universal foundation than appears to be the case at the present time.

Weathering of Montmorillonite in Soils

Abstract In the last decade much effort has been exerted by a number of Japanese soil workers to identify the clay minerals of their soils. Generally speaking, results of this work indicate Japanese soils should be said to be halloysitic, but some soils are montmorillonitic, and some others are allophanic. Montmorillonites were identified in marine alluvial soils1)2), paddy soils3)4)5)6), extremely strong acid soils1, and others7)8)9)10)11)12)13). Soil montmorillonites have arrested attention in regard to the characteristic behavior of high cation adsorption and expansion in water from the point of view of soil productivity. Routine works for identification of clay minerals have disclosed soil montmorillonites different in degrees from a typical montmorillonite as that in Wyoming bentonite. X-ray diffraction patterns have revealed low intensity of (001) reflections ; differential thermograms have represented development of an endothermic peak at about 550°C accompanying ecay of the peak at 700°C, and chem...

A Paste Method for Preparation of Slides for Clay Mineral Identification by X‐ray Diffraction

Soil Science Society of America JournalVolume 26, Issue 1 p. 90-91 Note A Paste Method for Preparation of Slides for Clay Mineral Identification by X-ray Diffraction† A. A. Theisen, A. A. Theisen Instructor Department of Soils, Oregon State University, CorvallisSearch for more papers by this authorM. E. Harward, M. E. Harward Associate Professor of Soils Department of Soils, Oregon State University, CorvallisSearch for more papers by this author A. A. Theisen, A. A. Theisen Instructor Department of Soils, Oregon State University, CorvallisSearch for more papers by this authorM. E. Harward, M. E. Harward Associate Professor of Soils Department of Soils, Oregon State University, CorvallisSearch for more papers by this author First published: 01 January 1962 https://doi.org/10.2136/sssaj1962.03615995002600010034xcCitations: 10 † Technical Paper No. 1398, Oregon Agr. Exp. Sta., Corvallis. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume26, Issue1January-February 1962Pages 90-91 RelatedInformation

Identification of Clay Minerals and the Study of Argillaceous Rocks By the Imbibo-Metric Method

AbstractThe imbibition of liquid by argillaceous rocks containing predominating kaolinite, illite, “open” illite, and montmorillonite with the use of absorption apparatus is described. Results of the following studies are given: (1) imbibition by pulverized and freely poured samples; (2) imbibition by specimens pressed (30 atm) into the form of small cylinders having a base of 100 mm2; (3) the course of imbibition by artificial aggregates of kaolin from Sedlec, Bohemia, pressed under different pressures (20, 30, 40 atm); and (4) imbibition by natural, oriented, ground, flat sections of the same samples which were prepared in the form of rectangular prisms, with a base of 100 mm2.The constant k in the sorption equation, which is dependent on the form of clay particles and the tortuosity of pores in argillaceous aggregates under particular working conditions, has been computed. This constant has been calculated for water (polar liquid) and tetraline (nonpolar liquid).A new quantitative diagram for identification of clay minerals by the imbibometric method has been constructed. In it, not only the time of imbibition and the qualitative features expressing themselves on the ground, flat section—such as swelling and nature of contours (Konta, 1961)—are taken into consideration, but also the area occupied by a drop of water and a drop of ethylene glycol and the wettability ratio Pegl/aq.

Some Problems in the Identification of Clay Minerals in Mixtures by X-Ray Diffraction II. Chlorite, Swelling Chlorite and Montmorillonite

The possibility of the identification by X-ray diffraction of montmorillonite and swelling chlorite, in the presence or absence of each other, is discussed. Swelling chlorite or montmorillonte, even in mixture with normal chlorite, but in the absence of mica, can be identified by heating to 500~ with immediate sealing of the tube, or by acid treatmen~ followed by solvation with ethylene glycol. If mica is present, however, only the latter procedure will usually ensure positive identification. The same procedures will differentiate montmorillonite and swelling chlorite in mixture only when normal chlorite is absent.