Palagonite Reconsidered: Paracrystalline Illite-Smectites From Regoliths on Basic Pyroclastics

Berkgaut, Vadim; Singer, Arieh; Stahr, Karl

doi:10.1346/ccmn.1994.0420511

Cited by 30 publications

(18 citation statements)

References 26 publications

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“…The range of CEC of palagonitized glass we determined by the in situ method (30 to 60 meq/100 g) is generally lower than that determined by conventional methods reported in previous studies (for example, Singer (1974) and Berkgaut et al (1994) reported 60 to 100 meq/100 g). However, the conventional measurements reported in the literature were done on bulk "palagonite," which typically contains layer silicates of a presumably higher CEC than the palagonitized glass itself.…”

Section: Cec Of Layer Silicates and Palagonitized Glasscontrasting

confidence: 79%

“…Since the bulk clay fractions of hyaloclastitic samples contain appreciable palagonitized glass, we also measured its in situ properties. Previous studies (Singer 1974;Berkgaut et al 1994) have shown that "palagonite" has a relatively high CEC (60 to 100 meq/100 g, as measured on bulk clay fractions), although the relative contribution of exchangeable cations from dominantly amorphous material versus crystalline layer silicates has not been previously explored.…”

Section: Introductionmentioning

confidence: 98%

“…Geologists traditionally characterize the in situ properties of palagonitic materials such as their textures and mineralogies with light, scanning or transmission electron microscopes (Hay and Iijima 1968;Dimroth and Lichtblau 1979;Jakobsson and Moore1986;Thorseth et al 1991;Zhou et al 1992) and their compositional variations with electron microprobes (e.g, Staudigel and Hart 1983;Fumes 1984;Zhou and Fyfe 1989;Jercinovic et al 1990; Thorseth et al 1995). Soil scientists typically measure bulk properties such as size fraction distribution, the structural response to chemical and thermal treatments as determined by X-ray diffraction (XRD) and chemical characteristics such as cation exchange capacity (CEC) and extractable cations (Singer 1974;Golden et al 1993;Berkgaut et al 1994). Collectively, these data have documented that profound compositional, mineralogical and textural heterogeneities typically accompany the palagonitization of mafic glasses.…”

Section: Introductionmentioning

confidence: 99%

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Cation Exchange Capacity of Layer Silicates and Palagonitized Glass in Mafic Volcanic Rocks: A Comparative Study of Bulk Extraction and In Situ Techniques

Schiffman

Southard

1996

Clays and clay miner.

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Abstract--The cation exchange capacities (CEC) and extractable cations in smectite, corrensite and palagonitized glass from hydrothermally-altered pillow lavas and hyaloclastite breccias were measured by both bulk wet chemical and in situ microanalytical techniques. Smectite has CEC's between 60 and 120 meq/100 g, palagonitized glass between 30 and 60 meq/100 g, and corrensite approximately 35 meq/100 g as determined by the in situ CsCl-exchange method. These experiments generally verify that Cs exchanges for those cations that are presumed (from the stoichiometry implied by microprobe analyses) to occupy interlayer sites in sheet silicates. Results of conventional CEC determinations are consistent with those determined by the in situ experiments: the individual microanalytical values for smectite and palagonitized glass bracket the bulk CEC values. The in situ experiments imply that Mg is the major extractable cation in smectite, Ca in corrensite, and both Mg and Ca in the palagonitized glass. We speculate that discrepancies between the equivalents of extractable cations predicted from elemental analysis and the equivalents of Cs sorbed may be due to the presence of charge-balancing protons that are not detected by the microprobe analyses. The sum of equivalents of cations extracted by NH~-acetate is about the same as the CEC determined by both the in situ and the bulk methods. Cation proportions indicated by NH4-acetate extractions from bulk samples are also generally consistent with the in situ results for all elements except Mg, which is a minor leachate of the NH4-acetate extractions in all the samples. To explain this discrepancy, we propose that l) Mg may occupy structural sites within palagonitized glass, which inhibit its extraction by NH 4 or Cs, and/or 2) there is a significant quantity of smectite, unsampled by the electron microprobe analyses, which contains insignificant interlayer Mg.

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Section: Cec Of Layer Silicates and Palagonitized Glasscontrasting

confidence: 79%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

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Cation Exchange Capacity of Layer Silicates and Palagonitized Glass in Mafic Volcanic Rocks: A Comparative Study of Bulk Extraction and In Situ Techniques

Schiffman

Southard

1996

Clays and clay miner.

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“…Caballero (1985) found that hydrothermal solutions of granitic composition favored smectite formarion, and McDaniel et al (1995) reported beidellite from tephra in the presence of water with low pH and with organic metal-complexing agents. Berkgaut et al (1994) found illite-smectite (I-S) in soils developed on pyroclasrics where there was an alternation of humid and dry seasons. Halloysite and kaolinite dominate in a humid climate in soils formed form volcanic ash and pumice (Wada, 1987).…”

Section: Introductionmentioning

confidence: 99%

Electron Microscopy Study of Volcanic Tuff Alteration to Illite-Smectite Under Hydrothermal Conditions

Fuente

Cuadros

Fiore³

et al. 2000

Clays and clay miner.

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Abstract--Experimental alteration of volcanic tuff from Almeria, southeastern Spain, was performed in solutions with different Na/K ratios (0.01, 1, 10, and 100), different total salt concentrations (0.01, 0.1, 0.2, 0.33, and 1 M), and in deionized water, at 60, 80, 120, and 160~ for periods of 60, 90, 180, and 360 d. Two particle size fractions of volcanic tuff were used: 10-200 and 20-60 p,m. Alteration products were examined by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), laser-particle size analysis, scanning electron microscopy equipped with an energy dispersive X-ray spectrometer (SEM-EDS), image computer analysis, and transmission electron microscopy with microanalysis (TEM-AEM). XRD detected neoformed phases only in the products from experiments of 180-360 d at high temperatures (120-160~and with Na/K ratios above unity and in deionized water. The synthesized phase is a random mixed-layer illite-smectite (I-S) with 75% smectite. The quantity of newly formed I-S, determined by FTIR, ranged between 3-30%. There was no apparent change in grain size and shape of the grains after the experiments as compared to before.SEM-EDS and TEM-AEM revealed the following alteration sequence: 1) intense etching on glassgrain surfaces; 2) formation of hemispherical morphologies on grain surfaces; 3) precipitation of very thin, individual flakes of illite-smectite on glass-grain surfaces; 4) development of I-S at the edges of glass grains; and 5) development of I-S honeycomb structures either covering large areas of the glass grains or resulting from the complete alteration of glass grains. A direct transformation of glass to I-S seems to be the major reaction mechanism, although there also is evidence of glass dissolution and subsequent I-S precipitation.

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“…Its formation has been attributed to induce leaching by rainwater during the cyclic alternation of wet and dry seasons [4].…”

Section: Introductionmentioning

confidence: 99%

Analysis and Characterization of Paleosoil: A Preliminary Study and Possible Applications in Forensic Archaeology

Nava¹

2015

IJA

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This paper presents the results of analysis conducted on soil samples collected on the Isola delle Statue in Porto Marghera (Venice, Italy). The analyses were aimed at the mineralogical -petrographic characterization and evaluation of the possible presence of layers of a paleo soil (Neolithic age). For the characterization of the sediments have been used different techniques of microscopy, including the plating of the finer fraction of the samples with liquid paraffin and glycole on slide. This partial-destructive technique has allowed us to detect the presence of pollen and biotic remains sometimes undetected in preparations in thin section of the same. The techniques of optical microscopy has been associated with analysis by XRDMethod of powder. The combined application of these techniques and analytical methods of optical and diffractometric has a permission to obtain satisfactory results in terms of archaeological characterization. Indeed, the presence of smectite detected by XRD -Method of powder, associated with the presence of detected biotic remains pollen and plant on sample plating, has a permission to highlight the presence of a layer of paleo soil. In this preliminary study, it is seen, therefore, that the method of plating on a glass slide and the study of smectite can be of great help in forensic archaeological investigation for the verification of compatibility and discrimination of traces of soil.

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Palagonite Reconsidered: Paracrystalline Illite-Smectites From Regoliths on Basic Pyroclastics

Cited by 30 publications

References 26 publications

Cation Exchange Capacity of Layer Silicates and Palagonitized Glass in Mafic Volcanic Rocks: A Comparative Study of Bulk Extraction and In Situ Techniques

Cation Exchange Capacity of Layer Silicates and Palagonitized Glass in Mafic Volcanic Rocks: A Comparative Study of Bulk Extraction and In Situ Techniques

Electron Microscopy Study of Volcanic Tuff Alteration to Illite-Smectite Under Hydrothermal Conditions

Analysis and Characterization of Paleosoil: A Preliminary Study and Possible Applications in Forensic Archaeology

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