bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clay-Mineral Environmental Relationships in Cisco (U. Penn.) Clays and Shales, North Central Texas
Authors: Shover E. F. 
Published: August 2006

AbstractThe clay-mineral composition of 142 samples of Upper Pennsylvania fluvial, deltaic, and marine clays and shales from north Texas was determined by X-ray diffraction. Deltaic lithotypes are of moderate illite, subordinate kaolinite, minor vermiculite and mixed layer composition. Nonmarine (red bed, coaly shales) lithotypes range from this composition to highly (+90 per cent) kaolinitic types, and generally lack vermiculite or chlorite. The marine shales contain a clay-mineral suite which is very similar to that of deltaic beds, but usually contain poorly- to well-crystallized chlorite. These variations are interpreted as results of two opposing mechanisms of clay-mineral genesis: degradation and desilication of detrital clay-micas, and formation of kaolinite, in nonmarine milieux; and regrading of detrital vermiculite to better-crystalline chloritic minerals by magnesium adsorption in marine waters.The study reveals three pertinent points about clay-mineral environmental relationships:1.The potential effects of nonmarine clay-mineral alteration processes are of much greater consequence than are those in marine environments. In this case, they led to the formation of beds in which the clay-mineral suite is almost all kaolinite, whereas the gross qualitative detrital clay-mineral suite was little changed in marine waters.2.The actual extent and effect of the clay-mineral formation processes is quite variable, so that there is considerable overlap in clay-mineral composition between nonmarine and deltaic deposits.(3)“Trace” clay-mineral constituents may be more sensitive environmental indicators than the gross clay-mineral composition, in this case presence or absence and crystal-Unity of the chlorite-vermiculite component was the most diagnostic parameter.
The Octahedral Layer
Authors: Gastuche M. C. 
Published: August 2006

AbstractIn the first part of this paper the formation processes of pure octahedral hydroxides are investigated. Conditions of synthesis of aluminum, magnesium, iron and mixed Al-Mg, Al-Ca, Al-Fe systems are successively reviewed. In every case crystal growth in deionized medium allows one to figure out genetic conditions.The second part deals with the conditions required for the development of the octahedral layer in the presence of silica, i.e. the clay mineral synthesis. Experimental conditions remain always as nearly as possible to those observed naturally.Trioctahedral minerals are rather easily obtained at ordinary temperature and pressure. The evolution of the magnesium-silica system is described. Synthesis of dioctahedral layer lattices, such as those of the kaolin minerals, appears more difficult to perform under the same conditions. Initial organization of the starting materials plays an important role in this case and procedures are described.Finally, interactions of octahedral and silica layers are studied. The study of infrared spectra in the 9–11μ region permits such observations. Characteristic changes in the spectral region of Si-O stretching allows one either to follow the octahedral destruction (by acid attack or dehydroxylation) or the octahedral layer formation in kaolinite synthesis.
Clay Mineralogy and Weathering of a Red-Yellow Podzolic Soil from Quartz Mica Schist in the Alabama Piedmont
Authors: Bryant J. P. , Dixon J. B. 
Published: August 2006

AbstractMineralogical and chemical properties of Madison soil derived from quartz mica schist reflected the degree of weathering. The Madison soil had sandy surface horizons and clayey B horizons. The clay in surface horizons contained more mica than clay in the subsoils; a maximum of about 40 per cent mica in the coarse clay of surface horizons. Intergradient chlorite-vermiculite was present in appreciable quantities in clays of surface horizons. The presence in the whole soil of B2 horizons of about 15 per cent gibbsite and 12 per cent free iron oxides indicated a high degree of weathering. Kaolinite and gibbsite increased with depth and were the major clay minerals in all clay fractions in the lower portion of the profiles. Kaolinite and gibbsite also were important accessory minerals of the coarse and medium silt fractions and increased in percentage with depth. The B3 horizons had much of the morphology of the schist. Results indicated a high weathering intensity in the subsoil and leaching of weathering products.
Preparation and Properties of Some Polymer-Clay Compounds
Authors: Dekking Henri G. G. 
Published: August 2006

AbstractNovel polymer-clay compositions were synthesized by neutralizing hydrogen montmorillonite and hydrogen kaolinite with amine-terminated polystyrene. The latter was obtained by the amide ion-initiated polymerization of styrene in liquid ammonia at −33°C. The neutralization reactions were carried out in methyl ethyl ketone, acetone, N,N-dimethylformamide and their aqueous solutions. As a result of their chemical modifications, the clays change from hydrophilic to hydrophobic, organophilic substances. Polystyrene-montmorillonite compositions containing about 50 per cent by weight of combined polymer formed dispersions in hydrocarbon oils which were similar to high temperature lubricating greases. The basal spacings of the organo-montmorillonites indicate the deposition of a polymer layer one molecule thick.
Interstratification in Montmorillonite
Authors: Tettenhorst Rodney , Johns W. D. 
Published: August 2006

Abstract
Direct analysis by Fourier transform methods revealed
interstratification of three components for a homogeneous, potassium-treated
and organic-solvated montmorillon-ite. An initial simple interpretation
based on random mixing of two components was shown to be incorrect. Ethylene
glycol solvation showed enhanced expansion in agreement with earlier
investigations. Glycerol solvation produced a noteworthy contribution from a
14 Å component. An interpretation of the 14 Å component is suggested, based
on an asymmetric distribution of layer charge. Regular interstratification,
bending or curling of clay layers and anomalous dehydroxylation temperatures
may be a consequence of asymmetric layer charge distribution in
montmorillonites.
Authigenic Kaolinite and Mica as Evidence for Phase Equilibria at Low
Temperatures
Authors: Rex R. W. 
Published: August 2006

Abstract
Electron micrograph, X-ray diffraction, and chemical
studies of secondary clay minerals formed within sandstones provide data
supporting a portion of the phase relationships proposed by Garrels (Garrels
and Christ, 1965) for kaolinite and K-mica growing in equilibrium with
K-feldspar and quartz at about 25°C. A true phase distinction between mica
and kaolinite is found at the phase boundary and not a continuous
solid-solution series, such as proposed by Keeling (1961). Some of the
micas, however, show evidence for the presence of an interlayer impurity,
such as small amounts of hydroxymagnesium cation proxying for
K+. Electron micrographs and diffraction studies
show epitaxial growth of oriented mica crystals on kaolinite providing
evidence for the existence of these two distinct phases in mutual
equilibrium with the solution from which they crystallized.
Expansion and Electrical Conductivity of Montmorillonite in Ammonia
Atmosphere
Authors: Cloos P. , Mortland M. M. 
Published: August 2006

Abstract
The expansion of montmorillonite at various relative
pressures of ammonia up to saturation was shown to be markedly affected by
the kind of ion present on the exchange complex. A 12.3 Å spacing was
obtained with Li-, Na-, K-, Mg- and Ca-montmorillonites at low relative
pressures. This spacing was maintained up to saturation for the K and Mg
systems and apparently represents one layer of ammonia in the interlamellar
spaces. For Li-, Na- and Ca-clay, two layers of ammonia were formed at
higher relative pressures. In the cases of Cu- and Co-montmorillonite,
rational spacings at 12.8 and 15.1 Å respectively were obtained at low
relative pressures and were maintained to saturation. The results are
interpreted in terms of co-ordination complex formation.
Electrical conductance studies showed exponential increases in
conductivity as the relative pressure of ammonia increased. The apparent
activation energies showed decreases with increase in relative pressure for
all systems except Co- and Mg-clay, which remained rather constant over the
pressure range studied. The results indicated that both expansion and
electrical conductivity were influenced by the formation of the ammonium ion
and by the co-ordinating power of the exchangeable cation.
Infrared Study of Pyridine Adsorbed on Montmorillonite Surfaces
Authors: Swoboda A. R. , Kunze G. W. 
Published: August 2006

Abstract
The nature of pyridine adsorption by acid- and
base-saturated montmorillonite from Otay, California (A.P.I, no. H-24) was
studied by infrared adsorption. The spectrum for chemisorbed pyridine was
found to be distinctively different from physically adsorbed pyridine; the
latter gave a spectrum very similar to liquid pyridine. Upon exposure of the
clay films to pyridine at low vapor pressures, only the pyridinium ion
spectrum was obtained; but when the vapor pressure was increased, both
chemisorbed and physically adsorbed pyridine was detected. The intensity of
the spectrum for physically adsorbed molecules could be reduced by a vacuum,
whereas the intensities of the peaks for the chemisorbed pyridinium ions
were unaffected.
Interlayer water was replaced by adsorption of pyridine. Water, in turn,
replaced physically adsorbed pyridine from the clay surface but was unable
to replace chemisorbed pyridine.
Infrared Studies of the Hydroxyl Groups in Intercalated Kaolinite
Complexes
Authors: Ledoux Robert L. , White Joe L. 
Published: August 2006

Abstract
Expansion of kaolinite with potassium acetate reduces
the intensity of the 3695 cm−1 absorption band and
causes the appearance of an additional one at 3600
cm−1. Subsequent deuteration with
D2O vapor shifts the 3695 cm−1
and 3600 cm−1 absorption bands to 2725
cm−1 and 2650 cm−1
respectively. The hydroxyls absorbing at 3620 cm−1 do
not interact with the acetate anion and do not readily exchange with
D2O vapor.
Deuteration of expanded hydrazine-kaolinite complex at room temperature
shifts the infrared stretching frequencies 3695, 3670, 3650 and 3620
cm−1 to 2725, 2710, 2698 and 2675
cm−1 respectively. The OH-OD exchanges for the
hydroxyls absorbing at 3695, 3670 and 3650 cm−1 are 67,
60 and 62 per cent respectively, and for the 3620 cm−1
only 22 per cent. The 3695, 3670 and 3650 cm−1
absorption bands are correlated predominantly to inner-surface hydroxyls and
the 3620 cm−1 to inner hydroxyls located below the
holes in the silica tetrahedral layer.
The ν(OH) absorption bands at 3695, 3670 and
3650 cm−1, and the ν(OD) at
2725, 2698, and 2675 cm−1 are pleochroic, whereas the
3620 cm−1 absorption band is non-pleochroic. The
direction of the dipole moment change of OH groups absorbing at 3695
cm−1 and 3670 cm−1, and of OD
groups absorbing at 2725 cm−1 and 2698
cm−1, is nearly at right angles to the basal plane
(001); for the 3650 cm−1 and 2675
cm−1 bands, the angle is large, but less than 90°.
The inner hydroxyls absorbing at 3620 cm−1 have their
dipole moment change inclined at about 15° to the “ab” cleavage
plane.
A comparison of the ν(OH) and
ν(OD) absorption intensities for the film
rotated 45° and normal to the infrared incident radiation shows that the
pleochroism is more intense in the ν(OD) region
than in the ν(OH) region. This indicates that
partial deuteration perturbs the direction of dipole moment change of the
“hydrogen bond” with respect to the initial orientation prior to
deuteration; the net result is the formation of larger angles between the
direction of the OD dipole moment changes and the basal plane (001) than
existed for OH prior to deuteration.
Use of Negative Sorption in Studies of Ion Fixation By
Hydrobiotite
Authors: Jacobs Donald G. 
Published: August 2006

Abstract
The exclusion of anions relative to tritiated water
from the negatively charged interlamellar spacing of hydrobiotites that have
a limited degree of lattice expansion permits measurement of the
interlamellar volume. Measurement of the changes in the interlamellar volume
and in the exchange capacity, when hydrobiotite lattices are collapsed by
potassium treatment or expanded by treatment with sodium tetraphenyl boron,
provides a means for estimating the distribution of the surface charge
densities of these interstratified minerals.
In the hydrobiotite sample studied (Zonolite from Traveler’s Rest, South
Carolina), the biotite fraction was estimated to have a surface charge
density of 2.0 ± 0.14 × 10−7 meq
cm−2 and the vermiculite fraction, 1.5 ± 0.51 ×
10−7 meq cm−2. The charge
density, and its relative distribution, was reflected in the tendency of
these mineral fractions to collapse upon potassium treatment and to entrap
trace concentrations of cesium in the interlayer spacing.
Modification of Ca-Montmorillonite by Low-Temperature Heat
Treatment
Authors: Ho Clara , Handy R. L. 
Published: August 2006

Abstract
The objectives of this investigation were to measure
the effects of moderate heat treatments, below the dehydroxylation
temperature, on physical and chemical properties of a
calcium-montmorillonite clay. Previous workers have noted the reductions in
cation exchange capacity and swelling property after heating in the range
200°–400°C, and have suggested several possible explanations, such as
hysteresis effect, increased interlayer attractions owing to removal of
interlayer water, or changes in the disposition of interlayer or
layer-surface ions.
The liquid limits of Ca-montmorillonite steadily decreased with
increased treatment temperature, until they reached a constant level at 450°
to 500°C. The plastic limit decreased slightly up to 350°C. Above this
temperature samples could no longer be rolled into threads. The gradual
change is in contrast with sudden major changes noted for weight loss
(maximum rates of change at 100°C and 500°C), glycol retention surface area
(maximum change at 520°C), and changes of peak intensity and breadth
character after glycolation of the first diffraction maximum (530°C). Other
properties showing more gradual reductions with heat treatment were: cation
exchange capacity by NH4Ac method,
d001 intensity (21 Å
spacing) after storing at 100 per cent r.h. one month and re-wetting with
water, and amount of calcium exchangeable without water soaking. Previous
water soaking allowed much greater release of fixed
Ca++ up to 450°C. Similar results were obtained
with cation exchange capacities when samples were treated with In
CaCl2 solution.
The 21.0 Å peak intensity curve showed close similarity to the liquid
limit and plastic index curves in the low temperature range, and an
explanation is suggested.
Effect of Impurities on the Rheology of Two Kaolins
Authors: Langston R. B. , Jenne E. A. , Pask J. A. 
Published: August 2006

Abstract
Two kaolins were given five successive processing
steps designed to remove a number of impurities: (1) removal of nonclay and
soluble fractions; (2) removal of organic material; (3) removal of iron
oxides; (4) removal of allophane; and (5) removal of three- layer lattice
minerals. After each of these steps, consistency curves were obtained for
each of the clays at both 6.5 and 9.0 pH on slurries containing up to 50
weight % solids.
Photomicrographs and electron micrographs showed that Ka-7 from Bath,
South Carolina, contained generally smaller particles than Ka-2 from Macon,
Georgia. Lowering the pH from 9.0 to 6.5 in Ka-2 produced no change in
plastic viscosity at the lower concentrations and a decrease of about 30 per
cent at higher concentrations after processing step 1. A comparison of the
same evaluations of step-1-treated Ka-7 showed that the decrease in pH
reduced the plastic viscosity by 50 per cent at 5 per cent clay
concentration and increased the plastic viscosity by 100 per cent at 35 per
cent clay concentration. After complete processing, lowering the pH from 9.0
to 6.5 increased the plastic viscosity at all concentrations for both
kaolins by 5–20 per cent. At a clay concentration of 30 per cent, complete
processing decreased the plastic viscosity of Ka-2 from 0.4 to 0.02 poise
and of Ka-7 from 0.4 to 0.06 poise. Ka-7 showed progressive viscosity
changes due to the processing, while Ka-2 showed only a marked change in
viscosity for processing step 5. The rheological changes of Ka-2 and Ka-7
with processing are supported by the X-ray diffraction data at the various
processing stages. X-ray diffraction data confirm that processing step 5
effectively removed a three-layer lattice expandable mineral from Ka-2,
while processing step 3 effectively removed a different three-layer
expandable mineral from Ka-7.
Quantitative Analysis of Kaolinite and Gibbsite in Soils by Differential Thermal and Selective Dissolution Methods
Authors: Dixon J. B. 
Published: August 2006

AbstractClay fractions from four soils were analyzed for kaolinite and gibbsite by differential thermal analysis (DTA) and selective dissolution analysis (SDA). The kaolinite values by the two methods had a standard deviation of ±0.95 for the 2–0.2 μ clay of the three most highly weathered soils. Apparently some kaolinite was dissolved with amorphous material in the 0.2–0.08 μ kaolinite standard and probably in 0.2-0.08 μ soil clays. Accuracy of kaolinite determination for the 0.2–0.08 μ soil clays by DTA was reduced because of uncertainty of exact composition of the standard. Presence of montmorillonite in Sango soil clays, particularly the 0.2-0.08 μ fraction, apparently contributed to the error in kaolinite determination by SDA. More precise values for gibbsite were obtained by DTA than by SDA because of the dissolution of alumina from sources other than gibbsite.
Concentration of Dioctahedral Mica and Vermiculite using a Fluoride Solution
Authors: Rich C. I. 
Published: August 2006

AbstractA Solution containing fluoride (0.4 n NH4F, 0.1 n HCl, n NH4Cl), permits the concentration of dioctahedral mica and dioctahedral vermiculite in mixed clay systems. Allophane, halloysite, kaolinite, and in particular, Mg-rich montmorillonite, biotite, and vermiculite of clay size, are destroyed in 24–48 hr at room temperature. A salt-free, NH4-saturated sample, weighing 80 mg, is shaken in 80 ml of the fluoride solution. The residue is washed with water and X-ray diffraction patterns made.The method has use in characterizing some of the 2:1 layer silicates in clays. Anatase, if present, is also concentrated and is more positively identified by X-ray diffraction.
Electrostatic forces Between Clay and Cations as Calculated and Inferred from Electrical Conductivity
Authors: Shainberg I. , Kemper W. D. 
Published: August 2006

AbstractEquivalent conductivities of adsorbed cations were determined in clays saturated with Na+, Cs+, Ca++ and with mixtures of these cations. Measurements were also made on Ca++ clays which had been forced by previous drying into bundles of platelets or tac-toids. The average mobility of adsorbed Ca++ and Cs+ is much lower than that of adsorbed Na+.It was concluded that the average mobility of adsorbed Ca++ is low because most of this Ca++ is on the internal surfaces of tactoids. Ca++ adsorbed between these internal surfaces appears to have a mobility much lower than Ca++ on the external surfaces which has a mobility of the same order of magnitude as Na+. Polarization of adsorbed Cs+ accounts at least partially for its low mobility in these clays.Demixing of adsorbed cations (segregation with Na+ dominant between some platelets and Ca++ between others) is suggested as an initial step leading to breakup of a Na+-Ca++ clay mass into tactoids. The tactoid model, with Ca++ and Na+ preferentially on the internal and external surfaces respectively, furnishes an explanation of the instability of clay and soil aggregates with 15% exchangeable sodium.
Quantitative Study of Clay Minerals in Some Recent Marine Sediments and Sedimentary Rocks from Japan
Authors: Oinuma Kaoru , Kobayashi Kazuo 
Published: August 2006

AbstractClay mineral compositions in specimens of Recent marine sediments in the neighbourhood of Japan and sedimentary rocks from Japan were studied. Identification of the clay minerals was made chiefly by X-ray, differential thermal and infrared analyses. Their relative amounts were determined by comparing the intensities of their basal X-ray reflections.Recent marine sediments: Specimens from the bottom of the Northwestern Pacific Ocean contain montmorillonite, illite, chlorite and kaolinite. The amount of mont-morillonite varies locally, but that of kaolinite is generally small. Clay mineral compositions of the Eastern Sea specimens are different from those of the Northwestern Pacific Ocean and the crystallinity of clay minerals seems to be better in the Kastern Sea. It is most likely that the clay minerals in the Eastern Sea sediments were supplied from the continent. Specimens of the bottom sediments at the entrance of Tokyo Bay contain montmorillonite, illite, chlorite and a lesser amount of kaolinite. The amount of montmorillonite varies markedly with locality and tends to be low where the movement of sea water is relatively intense. This may be due to a finer particle size of montmorillonite in comparison with the other clay minerals.Sedimentary rocks: The relationship between sedimentary formations and clay mineral compositions shows that the compositions are characteristic of the depositional environments. For example, kaolinite is abundant in the formations deposited in fresh water but its content is low in the formations deposited under marine environment. The Paleozoic formations from the Tohoku region contain chlorite and illite without exception; however, the Mesozoic formations contain them in various proportions according to localities.
Clay Minerals in Recent Sediments of the Niger Delta
Authors: Porrenga D. H. 
Published: August 2006

AbstractRecent sediments of the Niger delta contain the detrital clay minerals kaolinite, mont-morillonite and a small amount of illite. The montmorillonite content increases with water depth and distance from the shore, and the results of laboratory experiments on natural Niger delta clay support the assumption that this is due to differential floc-culation and sedimentation.The easterly Guinea Current, transporting montmorillonite-rich floccules in suspension, may cause an increase in the montmorillonite content of the clays in the ©cistern part of the delta.Mineralized faecal pellets are present in most marine sediment samples. Chamosite occurs authigenically in coastal water shallower than 35 fathoms, as brown and dark-green pellets. Green pellets, composed of highly expandable, montmorillonite-type glauconite, are particularly common around the 100 fathom isobath. Both chamosite and glauconite have a high magnesium content, which seems to be usual during their early stages of formation.The formation of chamosite and glauconite is governed by redox potential and the availability of iron. If no reduction takes place, the pellets remain grey and their composition is similar to that of the clay matrix. Grey pellets are less restricted to a particular depth than are the chamosite and glauconite pellets, but distinct maxima occur around the 250 fathom isobath.