bluuebunny/crossref_metadata_2025 huggingface dataset:
Altered Siliceous Volcanics as a Source of Refractory Clay
Authors: Sand L. B. , Ames L. L.
Published: August 2006

In the intermountain states, a region deficient in kaolinite and alumina clays, there is an increasing demand for refractory clay. In this arid region residual kaolins are not developed in quantity from feldspathic intrusives. Glassy, siliceous extrusives alter commonly to mont-morillonite of the montmorillonite-beidellite series. Zeolites, principally analcime and heu-landite, often are alteration products. Under certain conditions kaolinite, halloysite, or saponite will form; several tuffaceous deposits were investigated in an attempt to determine these environmental conditions, especially the physico-chemical environment necessary to produce kaolin clay.

Zeolites are developed where the pyroclastics are deposited in an alkaline lake; saponite is formed locally in this environment as a result of hot-spring activity. On river slopes and spurs the siliceous volcanics alter to kaolinite and montmorillonite; where associated with calcareous hot-spring activity in a fresh-water lake, halloysite results. Montmorillonite-beidellite develops where these special conditions do not obtain.

The prospects of finding a residual kaolinite deposit developed from siliceous volcanics are not good. Hydrothermal alteration appears to be the only means by which a siliceous volcanic will be converted to a sizeable refractory clay deposit in this region.
Filtration Theory for Oil-Well Drilling Fluids
Authors: Oakes D. T.
Published: August 2006

In the oil industry it has been customary to describe water loss or filtration from benton-ite drilling fluids by adaptation of Darcy’s law to the filtration process. Thus, the rate of filtration varies directly with the differential pressure and permeability and inversely with the filtrate viscosity and the thickness of the deposited filter cake. Since the thickness of the filter cake is variable, however, it is necessary that the rate of deposition of the filter cake be related to the volume of filtrate. In establishing this relation certain workers have made questionable allowance for the water adsorbed on the bentonite particles with the result that the filtration equation is not valid in certain instances (Larsen, 1938; Rogers, 1953, p. 268).

Other workers have indicated the significance of the adsorbed phase in their presentation of experimental techniques for relating the filter cake and the filtrate (Williams and Cannon, 1938; von Englehardt, 1954).

The filtration relationship may be derived analytically by the simultaneous use of Darcy’s law and mass and volumetric balances on the filtration process. Such a derivation is here presented. The validity of the filtration relationship presented is experimentally confirmed using three groups of unlike systems—Wyoming bentonite suspensions, low-yield clay suspensions, and sodium carboxymethylcellulose suspensions—as well as four sets of clay filtration data from the literature.
High Temperature Phases in Montmorillonites
Authors: Kulbicki Georges
Published: August 2006

The formation of siliceous phases in montmorillonites at temperatures up to 1500°C has been studied by high temperature continuous x-ray diffraction techniques. Oriented clay aggregates on platinum slides are heated in a small platinum-wire resistor furnace placed on an x-ray spectrometer unit. The intensity of the main diffraction lines of each phase is noted versus the temperature. The nature and the temperature of formation of the different phases are closely related to the structure and composition of the sample. The important role of some cations in exchange position is emphasized.
A Discussion on the Origin of Clay Minerals in Sedimentary Rocks
Authors: Weaver Charles E.
Published: August 2006

X-ray analyses of the clay minerals from thousands of sediments indicate that any of the major clay minerals can occur in abundance in any of the major depositional environments and there is no consistent coincidence between specific clay minerals and specific depositional environments. It is concluded that the great majority of clay minerals in sedimentary rocks are detrital in origin, strongly reflect the character of their source material, and are only slightly modified in their depositional environments.

The most common process acting on the clay minerals in marine environments is cation adsorption. The modifications produced by this process are secondary but because of the overemphasis of names rather than processes, they have been considered fundamental changes and the process has been called diagenesis. From the geologist’s viewpoint, the basic clay mineral lattice, which is inherited from the source material, is the most significant parameter of the clay minerals and modifications caused by the adsorbed cations are secondary, derived parameters reflecting the character of the depositional environment. This concept of dualism is essential to the understanding of clay genesis, and the significance of the two parameters must be understood before a genetic classification can be constructed and before clays can be used for geologic interpretation.
Statistical Relationships of Minor Constituents of Some Nontronites
Authors: Kornfeld Joseph A.
Published: August 2006

Replacement of alumina by ferric iron in the lattice structure features the nontronite member of the montmorillonite group. Chromium, in significant amounts, replaces ferric iron in the lattice structure of some nontronites.

Effect of migration of clay minerals under colloidal suspension and the transfer of true solutions complicate correlations of the chemical composition. Moreover, many nontronites are secondary and occur in fracture zones associated with kaolinitic and halloysitic clay. A tendency of certain nontronites to form lathlike crystals is well known.

Chemical composition of 15 selected nontronites from the United States of America, Germany, and Russia indicate a range of 30 to 60 percent SiO2, and a range of from 25 to 40 percent Fe2O3. Minor constituents are the oxides of magnesium, titanium, ferrous iron, and calcium, and the alkalis, potassium and sodium.

Magnesium percentages found in nontronites are proportional to the value of sigma for octahedral coordination. Ferrous iron is proportional to titanium in montmorillonite, and a similar relationship is observed in the nontronites.

A deficiency in alkalis typifies the composition of montmorillonite and this condition is likewise true in most nontronites. Potassium is limited to a narrow statistical range of between 0.5 to 0.6 ions of Al in tetrahedral coordination against an extreme deficiency of ferric iron and magnesium (combined) of less than 0.05 ion in octahedral coordination. Thus calcium occurs as the principal large cation and is present in nearly all the nontronites studied.
Clay Mineral Distribution in the Hiawatha Sandy Soils of Northern Wisconsin
Authors: Brown B. E. , Jackson M. L.
Published: August 2006

Mineralogical analyses were made of the day, silt, and sand fractions of the Podzols Hiawatha loamy sand and Hiawatha sand. The layer silicates show chemical weathering as a function of depth in both soils. A high charge dioctahedral montmorillonite was dominant in all fractions (−5µ) of the A2 horizon and its origin was attributed to weathering of an interstratified vermiculite-chlorite similar to that in the B2 horizon. The 2 to 0.2µ fraction of the Hiawatha loamy sand B2 horizon contains 14 percent chlorite and 18 percent vermiculite with no montmorillonite, and the Hiawatha loamy sand A2 horizon contains 33 percent montmorillonite with little interstratified chlorite-vermiculite. Quartz also showed a soil depth function in the fine silt. It is higher in amount in the A2 than the B2 horizon, attributable to its relative stability in the Podzol A2. Below the B2 it drops markedly in amount, attributable to a difference in silt deposition.

The similarity of ratios of resistant heavy minerals (greater than 2.95 sp. gr.) in different horizons indicates uniform origin of the sand fractions of these soils. Light mineral contents in the sand fractions for all analyzed horizons are also similar. However, particle size data indicate silt and possible clay addition to both the A2 and B2 horizons.

Depth functions in these soils are developed to a marked extent, apparently owing to (1) low amount of fine fraction originally present for weathering, (2) greater amount of water cycled through the A2 than the B2 horizon, (3) rapid and frequent cycling of available water owing to coarse texture, and possibly (4) effects of podzolization. The Omega, Ahmeek, and Iron River soils of northern Wisconsin also showed a similar though not so marked tendency to accumulate montmorillonite in the A2 horizon.
Clay Mineralogy of Recent Sediments from the Mississippi Sound Area
Authors: Milne I. H. , Shott W. L.
Published: August 2006

Recent mud sediments of Mississippi Sound, Mobile Bay and contributory rivers contain a clay mineral assemblage composed essentially of kaolinite and montmorillonite. Illite is present as a minor component.

The montmorillonite in these sediments appears to be at least partially complexed with organic material. This association is particularly evident in river and river mouth deposits and seems to be modified or partially destroyed in sea water. Organic material has been leached from river sediments with a sodium hydroxide solution and combined as a clay-organic complex with montmorillonite from Clay Spur, Wyoming.

The clay mineralogy of sediments from Mobile Bay and areas outside of the barrier island chain is very similar to that of the river sediments. Within Mississippi Sound an apparent increase in the montmorillonite-illite content of the sediments relative to kaolinite from east to west is attributed to the invasion of mud from the Mississippi Delta into the western part of the Sound.

Chemical analyses of these sediments along a section from fresh water to Mississippi Sound localities have shown a progressive increase in magnesium, potassium, and sodium, and a decrease in calcium.
A Kinetic Study of the Dehydroxylation of Kaolinite
Authors: Brindley G. W. , Nakahira M.
Published: August 2006

When dehydroxylation of kaolinite powder is carried out in the usual way, the linear relations anticipated for first-order kinetics and for the Arrhenius plot of log k versus 1/T are satisfied only very approximately. Factors relating to the form of the specimen, (shape, size, compaction, container, etc.) are shown to be very important. A method is developed for obtaining data for a specimen in the form of an infinitely thin disc. The first-order kinetic relation and the Arrhenius relation are then linear, and the latter gives an activation energy of 65 K cal./mol. The dehydroxylation process is shown by x-ray analysis to proceed crystal by crystal and this leads to an interpretation of the first-order kinetics. The x-ray method is used to study the distribution of reacted and unreacted material throughout a disc of material. Although isothermal conditions are employed, large differences are found between the interior and exterior of a partially dehydroxylated disc. These effects are attributed to the influence of a water vapor atmosphere within the heated disc.
Experimental Structure Factor Curves of Montmorillonites
Authors: Jonas Edward C.
Published: August 2006

Diffraction from oriented flakes of four montmorillonites that had been treated with an excess of four glycols was obtained. Peak areas for the 00l diffraction from each of the treated clays were plotted against sin θ/λ.

It was assumed that the observed diffraction intensity for the complexes was equal to that of the clay plus or minus that of the organic part of the complex. By assuming also that the contribution from the organic part of the complex is the same for each clay at any one value of sin θ/λ, a systematic consideration of all the possible levels of contribution by the organic interlayer material could be made. At values of sin θ/λ where intensity data were closely spaced, it was found that only one of the possible levels of contribution by the organic interlayer material would allow a residual intensity (attributable to the clay) that fit on smooth curves.

Curves of the diffraction intensity attributable to each of the clays resembled, in their gross features, the calculated structure factor curve of mica. Displacements of the nodes along the sin θ/λ axis and differences in loop heights are sufficient to make this experimental structure factor curve for each of the five clays quite distinctive.
Surface Areas of Clay Minerals as Derived from Measurements of Glycerol Retention
Authors: Diamond Sidney , Kinter Earl B.
Published: August 2006

The use of glycerol retention measurements to calculate surface areas of clay minerals is described. Assuming that the glycerol retained on external surfaces is monomolecular in thickness, and that both this layer and the monomolecular glycerol layers adsorbed on internal surfaces of montmorillonite, vermiculite, and halloysite are of the density of liquid glycerol, it is calculated that each percentage of glycerol retained corresponds to an area of 17.6 square meters per gram on external surfaces and 35.3 on internal surfaces. The corresponding figures for ethylene glycol retention under these conditions are 22.3 and 44.6, respectively. For nonexpanding clays, surface areas calculated from glycerol retention values agree well with published figures derived from Brunauer, Emmett, and Teller (B.E.T.) gas adsorption measurements. For montmorillonites, surface areas agree reasonably well with published determinations based on B.E.T. treatment using polar adsorbates. Values of surface area are also presented for samples of vermiculite and endellite and for the nonexpanding clay minerals—illite, kaolinite, halloysite, and allophane.

Calculations of the surface area as a function of particle size for montmorillonites of hypothetically uniform particle sizes show that montmorillonites dispersed into very thin flakes must have an appreciable external surface. The ratio of internal to total surface is shown to furnish an estimate of the thickness of the individual montmorillonite flakes. Glycerol retention data for a Wyoming bentonite saturated with a number of different cations are interpreted as indicating particle thicknesses varying from 3 unit cells (about 30A) for Na+ saturation to about 20 unit cells for saturation with a number of polyvalent cations.
Temperature Stabilities of Montmorillonite- and Vermiculite-Glycol Complexes
Authors: Bradley W. F. , Rowland R. A. , Weiss E. J. , Weaver C. E.
Published: August 2006

Stabilities of Mg-, Ca-, and Na-montmorillonite- and vermiculite-glycol complexes are compared by heating experiments with the oscillating-heating x-ray powder diffraction method. In the course of expulsion of glycol from the 17A two-layer glycol complexes of the Mg-, Ca-, and Na-montmorillonites, a 14A one-layer complex is encountered which is substantially the same as the 14A one-layer vermiculite-glycol complex. One-dimensional Fourier methods are utilized for analysis of interlayer liquid distributions.
The Surface Chemistry of Feldspars as an Influence on Their Decomposition Products
Authors: DeVore George W.
Published: August 2006

The problems of hydrous decomposition of alkali feldspars and the formation of the micaceous minerals from the decomposition products are discussed in terms of the surface chemistry and the Al-Si ordering of the feldspars, and a crystal growth model for the micas.
X-Ray Study of the Structure of Sepiolite
Authors: Preisinger Anton
Published: August 2006

Sepiolite is a valid mineral with the following chemical formula: $8MgO\, \cdot \,12Si{O_2}\, \cdot \,n{H_2}O.$$

Its unit cell characteristics are: $a\, = \,13.4{\AA};\,b\, = \,26.8{\AA};\,c\, = \,5.28{\AA};Z\, = \,2;\,D_{{2^h}}^6\, - \,P\frac{{{2_1}}}{n}\,\frac{2}{c}\,\frac{2}{n}.$

They were determined on the sepiolite from Ampandrandava (Madagascar). Its structure was determined by means of the “trial and error” method and the observed and calculated intensities rendered a good agreement.

The formula of the structure is: $\mathop 1\limits_\infty {[{H_2}O]_n} \cdot \mathop 1\limits_\infty \{ {(Mg,F{e^{3 + }},F{e^{2 + }},\,Al)_8}{({H_2}O)_4}{(O,OH)_4}[{(Si,Al)_{10}}{O_{30}}]\} \cdot n\, \leqslant \,8.$

The mineral contains zeolitic, crystal- and constitution-water. A good agreement was achieved between the chemical, thermal, and morphological qualities and the x-ray data. The mineral remains stable up to about 350°C and begins to change into an “anhydride” above this temperature.

The formula of the structure of sepiolite. “anhydride” is: $\mathop 1\limits_\infty \{ {(Mg,F{e^{3 + }},F{e^{2 + }},\,Al)_8}{(O,\,OH)_4}[{(Si,\,Al)_{10}}{O_{30}}]\}.$

Its unit coll characteristics are: $a\, = \,10.9{\AA};\,b\, = \,23.3{\AA};\,c = 5.28{\AA};\,a \approx \,{90^ \circ };\,Z = \,2;\,C_{{2^h}}^5\, - \,P_n^{{2_1}}\,11.$

The minerals xylotile, mountain wood and gunnbjarnite are isotypical with sepiolite.
Frequency Distribution of Clay Minerals in Major Great Soil Groups as Related to the Factors of Soil Formation
Authors: Jackson M. L.
Published: August 2006

The frequency distribution or relative abundance of minerals in soils varies with the five principal classes of factors that govern soil formation. The characteristics of the minerals of the parent material, the time factor, climatic factors, relief factors and biotic factors each can be shown to have important independent effects on clay mineralogy of soils under proper circumstances. The soil parent material exerts a control over the frequency distribution of minerals in soils by introduction of the clay minerals into the soil directly, by controlling the course of chemical weathering in the soil through the relative susceptibility of its minerals to weathering, by furnishing abundant divalent metallic cations, by impediment of drainage, or by acceleration of leaching when highly permeable. The time factor is conspicuous as long times give an advanced degree of weathering even in temperate climates. Climate is important, since highly weathered materials inevitably occur as a result of intense leaching in warm tropical and equatorial climates. Relief is important in concentrating leaching water and metallic cations, in affecting oxidation or reduction. The biotic factor affects minerals conspicuously where an A0 horizon develops and resulting cheluviation moves R2O3 out of the A2 horizon.

Inherited minerals such as illite, quartz, feldspars, ferro-magnesian minerals, carbonates and gypsum are most abundant in clays of little-weathered parent materials and soils of the zonal Desert, Brown, Chestnut and Tundra soils as well as intrazonal Mountain groups and azonal Regosols and Lithosols. Secondary layer silicate minerals such as vermiculite, secondary chlorite, montmorillonite, kaolinite and halloysite are most abundant in clays of moderately weathered parent materials and soils of the zonal Chernozem, Prairie, Gray—Brown Podzolic, Podzol, Red—Yellow Podzolic, and Low Humic Latosol groups as well as intrazonal Planosol, Rendzina, Dark Magnesium soil, and Wiesenboden groups. Secondary sesquioxide minerals such as hematite, goethite, allophane, gibbsite and anatase and residual resistant primary minerals such as ilmenite and magnetite predominate in the more highly weathered parent materials and soils of the zonal Ferruginous Humic Latosols, Hydrol Humic Latosols, Latosolic Brown, and Ando soils and Laterites, as well as the intrazonal Tropical Savannah and Ground Water Podzol ortstein soils.
The Clay Petrology of Sediments
Authors: Weaver Charles E.
Published: August 2006

Studies of the Recent indicate that, at the most, somewhat less than half the clay minerals are altered to any extent in a marine environment. Probably most of this alteration is in the form of cation adsorption or reconstitution of slightly weathered illites and chlorites to their original form. There appears to be little if any evidence that the detrital basic lattice is being altered to a measurable extent in Recent marine sediments. In the near-shore environments there is usually a coincidence of clay mineral suites and environments.

A major change in the clay mineral composition of sedimentary rock occurs within the Mississippian. Illite is the dominant clay mineral of the pre-Upper Mississippian sediments. Post-Lower Mississippian clay suites are more variable in composition; illite becomes less abundant and montmorillonite and kaolinite more abundant. This change is best related to a change in regional tectonics. The clay minerals seem to have no preferred lithologie associations, although owing to epigenetie alterations porous sandstones commonly have different clay mineral suites from those of adjacent shales and carbonate rocks.

In many instances clay mineral facies coincide with environmental facies. As the clay mineral criteria for distinguishing any given type environment are extremely variable, it is thought that segregation of clay mineral suites by sorting is usually more effective than by diagenesis.

Expanded clay minerals appear to be partially contracted by the time they have been buried to 10,000–15,000 ft. It remains to be proved whether this is caused by chemical modification of the basic lattice with burial or if the detrital clay lattice has the inherent ability to contract, without chemical rearrangement, when buried to a sufficient depth.
Flow Properties of Dilute Montmorillonite Dispersions
Authors: Granquist W. T.
Published: August 2006

A viacomotrio study of dilute montnioritlonite dispersions, using lor tho most part dilution-typo capillary viscometers supplemented by a falling-head capillary viscometer, has involved a determination of the concentration dependence of viscosity of such dispersions in both distilled and electrolyte-containing water. The resulta of the study have been interpreted in terms of a theory of incremental viscosity, and of the Solmlz—Rlaschke (1941) equation. Use of this equation yields good extrapolations to zero concentration for the determination of limiting viscosity number, and permits calculation of “interaction indices” which are considered, for reasons discussed in detail, to be a measure of paitiele-particle interaction. These indices are related to the cationie heat of hydration of the electrolyte used, and relationship is demonstrated between the yield stress of a 3 percent montmorillonite—eleetrolyte—water system and such interaction indices. The recent work of Paekter (1956, 1957) is discussed, and the relation of the results of this investigation to the data of van Olphen (1956, p. 204) is noted.
Further Observations on the Morphology of Chrysotile and Halloysite
Authors: Bates Thomas F. , Comer Joseph J.
Published: August 2006

Electron microscope studies of chrysotile show that tubes are present in bulk specimens and that these tubes commonly have fuzzy, amorphous-looking material on both the inside and outside. Similar material is associated with synthetic chrysotile and has been noted previously in halloysite specimens. The existence of such material between and within the tubes, together with apparent irregularities in size, shape and packing of tubes, explains the apparent discrepancy between the measured density of bulk samples and the calculated density of a hypothetical sample consisting of close-packed, regular, hollow capillaries.

Replicas of fractured surfaces of halloysite (2H2O) from various localities reveal that the particles occur as curved to flat laths commonly possessing “hexagonal” terminations and surface features indicative of a higher degree of crystallinity than tubes of halloysite (4H2O).

It is suggested that a complete morphological series from plates through laths to tubes exists both in platy to fibrous serpentine and in kaolinite to halloysite (4H2O). In each series a number of structural varieties are to be expected between the morphologically distinct “end members.”
Effect of Dry Grinding on Kaolin Minerals
Authors: Takahashi Hiroshi
Published: August 2006

The effect of dry grinding of kaolin minerals by a mechanical mortar was examined by x-ray, thermal, and electron microscopic methods. Base exchange capacity and apparent density were also measured. In the early stage of grinding, kaolin crystals cleave and fracture and then split into fine crystals which are considered unit crystallites. Such crystallites gradually change to a disordered kaolin and partially decompose into a noncrystalline substance as grinding progresses. The crystalline and the noncrystalline substances promptly reaggregate and these reaggregated particles have a radial shape. After further grinding, the structure of the reaggregated particle seems to be zeolitic. Finally, the kaolin mineral thoroughly changes to a completely amorphous substance similar to a silica-alumina mixed gel. Consequently, the effect of dry grinding of kaolin is related to the degree of crystallinity of the original kaolin mineral.
Postdiagenetic Clay Mineral Environmental Relationships in the Gulf Coast Eocene
Authors: Burst J. F.
Published: August 2006

An extensive survey of clay mineral relationships in the subsurface Wilcox formation (Eocene) has shown progressive diagenetic conversions with depth. Montmorillonite, a common constituent of Wilcox outcrop material, becomes loss evident below 3000 ft and is not normally found in an unmixed state below the 9000—10,000 ft overburden level. At depths between 3000 and 14,000 ft, montmorillonite lattices are commonly interpersed with illite components, the frequency of which increases with depth to a virtual elimination of montmorillonite swelling characteristics below 14,000 ft.

Chlorite is present at all stratigraphic levels including surface exposures. It appears to be a more dominant constituent at depth; however, observed increases in basal intensities in samples that had been more deeply buried may result from more perfect crystal development rather than quantitative differences.

The diagenetic conversion of montmorillonite to illite and possibly to chlorite has resulted in a distribution of the last two minerals that is related to estimated depositional environments as reconstructed from micro-paleontological criteria in at least one well in southern Louisiana. It is inferred, therefore, that different chemical characteristics in the ancient Wilcox seas are responsible for the distribution coincidence even though the mineral groups defining the distribution were not necessarily indigenous to the ancient Wilcox sea.

Correlations between clay minerals and environment are not particularly noted in the investigation of analogous environmental situations in Recent sediments, and it is thus concluded that the environment indicators which appear as minerals in lithified sediments such as the Wilcox are present in freshly deposited sediments in the form of submineralic chemical constituents such as absorbed ions, molecular groups or subcrystalline lattice configurations which are not detected by the ordinary clay mineral identification procedures. The change to mineralic form is aided by the natural “bombing” resulting from normal increases in temperature and pressure due to burial. The process is apparently a continuum through the entire subsurface residence of the sediment and the results are seemingly in accordance with phase equilibria.
Argillization in the Cochiti Mining District, New Mexico
Authors: Bundy Wayne M. , Murray Haydn H.
Published: August 2006

Volcanic and intrusive rocks (mainly andesite and monzonite) of Tertiary age are associated with gold- and silver-bearing quartz veins. Hydrothermal alteration took place in two stages. The first and less intense alteration stage is associated with economic mineralization; metallization during the second and more intense stage is limited to pyrite.

Alteration zones from the vein outward include: (1) dickite, (2) illite—kaolinite, (3) vermiculite—halloysite, and (4) chlorite—montmorillonite. Mixed-layer associations of 2:1 clay minerals are abundant and represent transitions between discrete clay minerals. Apparent occurrence of allophane in the illite-kaolinite zone indicates that amorphous aluminum silicates are intermediate phases in transitions from 2: 1 to 1: 1 clay minerals.

Alteration of ferromagnesian minerals and plagioclase resulted largely in the formation of 2: 1 clay mineral types. Orthoclase is altered chiefly to illite and kaolinite. Dickite and quartz are end products of the most intense alteration in the area.

Chemical analyses of the altered rocks in general show a decrease in basic ions toward the vein. Less significant changes are shown by acidic ions. Analyses of illites indicate that substitution of K by Na, Fe, Ca and Mg has taken place near the vein as shown by an overall decrease in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:c="http://cambridge.org/core/content" xmlns:core="http://cambridge.org/core" xmlns:m="http://cambridge.org/core/metadata" xmlns:cup="http://contentservices.cambridge.org" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:mnf="http://cambridge.org/core/manifest">KNa,KFe,KCa$\frac{K}{Na}, \frac{K}{Fe}, \frac{K}{Ca}$ and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:c="http://cambridge.org/core/content" xmlns:core="http://cambridge.org/core" xmlns:m="http://cambridge.org/core/metadata" xmlns:cup="http://contentservices.cambridge.org" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:mnf="http://cambridge.org/core/manifest">KMg$\frac{K}{Mg}$ ratios. Both sodium and potassium seem to be instrumental in the formation of well-developed illite crystals.

Alteration stages operative in the Cochiti district were developed by the action of solutions probably ranging in pH from 4 to 10. Alteration zones were formed penecontemporaneously with gradual outward migration of the least intense zones.
Alteration of Micaceous Minerals by Sulfide Solutions
Authors: Weintraub Judy , Sand L. B.
Published: August 2006

A mineralogical study by the Bureau of Mines and the University of Utah of the shale beds on the 1600 ft level of the Ophir Hill mine, Utah, disclosed that the micaceous minerals in the shale were altered as a function of proximity to the sulfide ore zones. The principal mineral in the shale distant from ore is 2M serieite. Within 100 ft along the bedding plane and 15 ft normal to the bedding plane, the serieite was altered successively to a modified form of serieite, two polymorphs of chlorite, and finally phlogopite.

A general sequence of the mineral changes from barren to ore-bearing ground was: (I) serieite; (2) modified serieite; (3) modified serieite and 7Å chlorite; (4) modified serieite, 14Å chlorite, and phlogopite; (5) 14Å chlorite and phlogopite; and (6) phlogopite. This sequence of alteration of serieite in the shale was not noted in the mine areas barren of ore.
Halloysite Formed in a Calcareous Hot Spring Environment
Authors: Ames L. L. , Sand L. B.
Published: August 2006

An unusual halloysite deposit occurs on the west side of the Lake Mountains in Utah County, Utah. A field and laboratory study was made of this Fox deposit to determine the paragenesis of the clay minerals, especially halloysite. Successive lenses of unaltered tuff, partially altered tuff, clay and travertine beds, indicate that the clays have resulted from alteration of siliceous volcanic tuffs in a Tertiary (?) calcareous hot spring environment. Clay minerals identified were montmorillonite, kaolinite, halloysite·4H2O (endellite) and halloysite·2H20. Montmorillonite, which developed in a zone of less intensive silica leaching farthest from the hot spring vents, is the predominant clay mineral. Irregularly distributed pockets of halloysite and kaolinite developed nearest the hot spring vents in a high-calcium environment. In the clay, or associated with it, are calcite as travertine, quartz as rounded carbonate-corroded grains, feldspar, tridy- mite, biotite and glass.

Experiments that approximate the chemical environment prevalent in the halloysite alteration zone were conducted on phase relations in part of the system lime—alumina- silica—water. Results suggest the formation of halloysite·4H2O in this kinetic system from intermediate calcium aluminate or calcium silicate hydrates with halloysite-type structures, or both.
Occurrences of Shales Partially Altered to Pyrophyllite
Authors: Ehlmann Arthur J. , Sand L. B.
Published: August 2006

Examination of samples from shale outcrops on the periphery of the Utah Valley graben has revealed an unusual association of disseminated pyrophyllite with various clay minerals. Numerous samples were obtained from exposures in brick clay pits located in the Manning Canyon formation of Mississippian-Pennsylvanian age and from the Long Trail member of the Great Blue formation of Mississippian age. Associated clay minerals in these beds include illite, illite-montmorillonite mixed-layer clays, 7 Å chlorite, 14Å chlorite, kaolinite and sericite. Associated nonclay minerals include quartz, calcite, and small amounts of dolomite. Associated secondary minerals are calcite, aragonite, jarosite, gibbsite and gypsum.

Three possible explanations of genesis have been considered in the present study: deposition of detrital pyrophyllite, surface weathering under special conditions, and hydrothermal or pneumatolytie activity. The third alternative explanation, hydrothermal or pneumatolytie activity, is believed to be the most acceptable. It is hypothesized that magnesium, iron, and interlayer cations have been removed from some of the original 2 : 1 layer clays in the shale by solutions localized along fault zones.
Effect of Sea-Water on Clay Minerals
Authors: Carroll Dorothy , Starkey Harry C.
Published: August 2006

Samples of a montmorillonite, a mixed-layer mineral (mica and montmorillonite) “illite”, kaolinite, and halloysite were immersed in 50 ml sea-water for 10 days, and additional samples of the first three were immersed for 150 days. The exchangeable cations were determined both before and after treatment. It was found that Mg2+ ions from sea-water moved into the exchange positions in the minerals in preference to Ca2+ and Na+ ions. The H-form of these minerals showed a gradual adjustment to sea-water as measured by change in pH and filling of the exchange positions with cations other than H+. Kaolinite adjusted very rapidly, but montmorillonite and the mixed-layer mineral were slow. All the minerals reacted to yield appreciable amounts of SiO2, Al2O3, and Fe2O3 to the sea-water. The quantities yielded are in the order:

montmorillonite > mixed-layer mineral > “illite” > kaolinite > halloysite The solubility is considered to be due to direct solution of SiO2 in the sea-water and to removal of Al2O3 from the octahedral layer of the minerals.

When H-clays were titrated with sea-water three distinct kinds of curves were obtained: (a) kaolinite; (b) mixed-layer mineral, “illite,” and halloysite; and (c) montmorillonite. The curves are similar to those obtained with clay minerals titrated with other alkaline solutions. Kaolinite reacts somewhat like a number of simple acids, but the curves for the other minerals are more complex and are related to the neutralization of H and its replacement in the exchange sites by metallic cations. The exchangeable cations were determined in the minerals after titration, and the results are similar to those obtained after immersing the minerals in sea-water. The volume of sea-water required to reach an end point at about pH 7.6 varies from 11 ml for kaolinite to 135 ml for montmorillonite and is related to the titratable alkalinity of the sea water and to the exchange capacity of the minerals.
Clay Mineralogy of the Bottom Sediments, Rappahannock River, Virginia
Authors: Nelson Bruce W.
Published: August 2006

Bottom sediment clay mineral assemblages from the Rappahannock River and estuary contain kaolinite, illite, unorganized illite, dioctahedral vermiculite, 12.4Å montmorillonite, 14.2 Å montmorillonite, chlorite, feldspar and quartz. The x-ray diffraction characteristics of these species and their thermal modifications at 25–500°C are described and illustrated. Progressive changes in the mineralogical composition of bottom sediments occur between the fresh-water and saline-water portions of the Rappahannock system. Chlorite and feldspar occur exclusively in the saline portions of the estuary. Illite shows progressive increase in crystallization quality. There appears to be less kaolinite, proportionately, in the estuarine sediments of the most saline zone. x-Ray diffraction diagrams showing these progressive changes are illustrated.
Regional clay Mineral Patterns in the Gulf of Mexico
Authors: Pinsak Arthur P. , Murray Haydn H.
Published: August 2006

A semiquantitative study of the surficial clay mineral distribution from 79 cores in the Recent sediments in the Gulf of Mexico shows a regional pattern which can be related to source and environment. The dominant factor controlling distribution of these surflcial sediments appears to be source. Montmorillonite is the most abundant clay mineral, and illite, chlorite, kaolinite and mixed-layer minerals are present in almost every sample.

Alteration of the clay minerals is influenced by (a) change of environment, and (b) length of exposure. Initial ion exchange, which is caused by a tendency to reach equilibrium with a new environment, occurs so rapidly in the clay minerals after they enter the marine environment that rate of sedimentation is a minor factor in comparison to environmental change. Slow alteration and adjustment toward a stable end state are most complete in areas of slow deposition and extended exposure of the clay minerals to the environment.
Geology of the Clay Deposits in the Olive Hill District, Kentucky
Authors: Patterson Sam H. , Hosterman John W.
Published: August 2006

THE Olive Hill fire clay bed of Crider (1913) is the principal source of the raw material used in the refractory industry of eastern Kentucky. The bed is a discontinuous underclay from 1 to 20 ft above a prominent unconformity which separates Mississippian and Pennsylvanian rocks. Upper Mississippian rocks consist of ten marine limestone and shale units all truncated by the unconformity. Pennsylvanian rocks are chiefly: (a) massive deltaic sandstone; (b) cut-and-fill deposits of shale, siltstone and sandstone which contain several beds of coal and underclay including the Olive Hill fire clay of Crider (1913); and (c) dark-gray shale beds.

The Olive Hill fire clay of Crider consists of approximately one-third flint clay, two-thirds semiflint clay, and minor amounts of plastic clay. The clay mineral content ranges from nearly pure kaolinite to kaolinitic clay containing about 40 percent illite and mixed-layer clay. The kaolinite ranges from highly crystalline to very poorly crystalline “fireclay” kaolinite. The degree of crystallinity of the kaolinite and hardness of the clay vary inversely with the amount of illite and mixed-layer clay present. The nearly pure kaolinite is believed to have formed by removal of silica and alkalies from mixtures of kaolinite, illite and mixed-layer clay by leaching shortly after deposition.

An isopach map shows that Crider’s Olive Hill fire clay occurs in irregular, lens-shaped deposits. Fossil plant rootstocks with rootlets attached in the clay clearly indicate it supported plant growth. The overlying coal and presence of some organic material in the clay suggest that the Olive Hill fire clay was deposited under a reducing environment in swamps.
Clay Partings in Gypsum Deposits in Southwestern Indiana
Authors: Harrison Jack L. , Droste John B.
Published: August 2006

Gypsum deposits of Mississippian age in southwestern Indiana contain several argillaceous partings. A study of these partings was made to find out what clay minerals are present in such an evaporite association.

The most abundant minerals in the clay partings are dolomite, gypsum, quartz, illite, chlorite and mixed-layer illite-montmorillonite. No kaolinite was found in any of the samples.
Time Factor and the Genesis of Soils on Early Wisconsin Till
Authors: Hensel D. R. , White Joe L.
Published: August 2006

Radiocarbon dates indicate that the maximum time of weathering for soils of the Tazewell substage may be about 6400 years longer than that available for weathering of soils of the Cary substage.

Detailed mineralogical and chemical studies were made of the 2–0.2 μ fractions of 0–6 in. and 30–36 in. samples from 24 sites along a traverse extending from the Cary substage across the Tazewell substage in east-central Indiana. The major clay mineral constituents of the 0–6 in. samples were illite and 14 Å material; illite and montmoril-lonite were the main components in the 30–36 in. samples. The correlation coefficients between illite content and percentage K2O for the 0–6 in. and 30–36 in. samples were 0.85 and 0.92, respectively.

The end and terminal moraines of the Tazewell substage were found to have a higher illite content than the ground moraines. This was attributed to superglacial movement and enrichment of foreign materials, i.e. mica schists from the Canadian shield, on end and terminal moraines.

The results of saturation of the clay fraction with potassium and magnesium on the proportion of 10Å, 12.7Å and 14Å spacings indicated that weathering had lowered the surface charge density of the micaceous minerals in the 0–6 in. samples to a greater extent than in the 30–36 in. samples. This effect, in addition to other weathering reactions, resulted in partially expanded micaceous minerals in the 0–6 in. samples which were much more resistant to collapse than were the minerals in the 30–36 in. samples.

The rate of weathering of K2O from the 2–0.2μ fraction of the 0–6 in. samples located on ground moraines was estimated to be about 0.1 percent per 1000 years. This value was used in estimating the ages of the morainie systems of the Tazewell in Indiana. The estimated ages were as follows: Mississinewa, (radiocarbon date) 13,140 years; Union City, 14,500 years; Bloomington, 15,500 years; Champaign, 18,700 years; Shelbyville, (radiocarbon date) 19,500 years.

The fertility status of the soils on the Tazewell has been influenced appreciably by the length of the weathering period, the potassium-supplying power of the soils decreasing with increasing age.
Review of the Relationships in the Montmorillonite Group of Clay Minerals
Authors: Ross Clarence S.
Published: August 2006

Since the publication of the paper on the minerals of the montmorillonite group by Ross and Hendricks (1945) some species have been added to the group, and minor changes in the acceptable species have become advisable. No radical changes are proposed, but a review of the members and their grouping will be presented. The acceptable dioctahedral members of the group appear to be montmorillonite, nontronite and volchonskoite. Beidellite should be discontinued. The acceptable trioetahedral members of the group appear to include saponite, hectorite, sauconite, stevensite and medmontite. Griffithite is probably a useful term for an iron-rich saponite. Representative chemical analyses and formulas have been assembled to illustrate relationships.
A Discussion of the Water Content of Vermiculite
Authors: Bradley W. F. , Serratosa J. M.
Published: August 2006

Selected chemical and diffraction analyses from the literature, supplemented by thermal and thermogravimetric analyses and infrared absorption observations, are utilized to construct a rational model of the water arrangement in natural vermiculites.

A super cell is arranged by simple modification of the Hendricks water nets to accommodate the somewhat higher water contents, indicated by weight loss analyses, and the exchangeable cations.

A three-cell unit (15.6 × 9 Å) contains two Mg2+·6H2O octahedra centered at the corners and face centers and four 4H2O squares centered about ±5.2 Å along a between the octahedra. The arrangement affords twenty hydrogen bonds near 2.75 Å, twelve between silicate and water layers and eight between water layers, and thirty-two hydrogen bonds near 3.0 Å within water layers. The remaining four hydrogens are not active in the bonding system. The environment of each water molecule is a distorted tetrahedron.

A broad infrared absorption band shows maxima at about 3600, 3450 and 3350 cm−1 at normal incidence, with increased activity in the highest and lowest energies when a flake is tilted. It is concluded that OH axes in the shortest bonds are more inclined to the cleavage planes than are the intermediate length axes.
Some Aspects of the Mineralogy of the Northern Atlantic Coastal Plain
Authors: Groot Johan J. , Glass Herbert D.
Published: August 2006

Studies of the mineralogy of the northern part of the Atlantic Coastal Plain indicate that the heavy mineral content of the Cretaceous and Cenozoic sediments consists basically of two suites, a restricted mineral suite characterized by very stable minerals, and a full suite consisting of a great variety of igneous and metamorphic minerals. The restricted suite occurs in the nonmarine sediments and the full suite in the marine deposits.

The nonmarine Cretaceous deposits consist of kaolinite, with variable amounts of illite and its alteration products. Transition sediments like those of the Magothy formation contain kaolinite, illite, chloritic material and, occasionally, some montmorillonite. The marine sediments are characterized primarily by illite and montmorillonite. Thus, a limited heavy mineral suite and kaolinite are associated in nonmarine deposits, and a full suite and montmorillonite are found in marine sediments.

On the basis of available data the conclusion is reached that the different heavy mineral and clay mineral suites are a result of different source areas for the marine and non-marine sediments.

The suggestion is made that the formational concept cannot be employed with regard to the nonmarine sediments of the northern Coastal Plain but that, instead, a new concept be adopted based on depositional conditions within the framework of the control of the heavy and clay mineral assemblages.
Geology of the Clay Deposits in Parts of Washington and Idaho
Authors: Hosterman John W.
Published: August 2006

The clay deposits of eastern Washington and northern Idaho are along the eastern edge of the Columbia River Plateau physiographic province. Three types of clay occur in the area: (a) residual clay derived from the Columbia River basalt of Tertiary age; (b) residual clay derived from the Cretaceous granodiorite and related intrusive rocks of the Idaho batholith; and (c) transported clay. The two types of residual clay were formed during a protracted lull in the outpouring of the Columbia River basalt, when the relief of land surface was low to moderate and the climate was warm and humid. The topography and climate during this interval were probably ideal for leaching and oxidation. The transported clay is chiefly a product of the weathered granodiorite and related intrusive rocks. Most of it accumulated in basins formed by damming of streams by basalt flows.

Kaolinite and halloysite are the principal clay minerals found in the area. The residual clay derived from basalt is chiefly composed of halloysite. Most of this clay is colored blue, gray or grayish black by finely disseminated ilmenite and locally it is stained blown by limonite; most of it has a relict basaltic texture.

The residual clay derived from granodiorite and related intrusive rocks contains both kaolinite and halloysite, and the transported clay is predominantly kaolinite. Both of these clays are white and contain abundant quartz grains and mica flakes. The residual clay has a relict granitic texture, and the transported clay has a well-developed bedding and is interbedded with elastic material.