Micaceous Clay Research Articles

Clay Minerals in Hydrothermally Altered Rocks at Wairakei, New Zealand

AbstractGeothermal fluid discharged by steam wells, which have been core drilled to depths as much as 4500 ft at Wairakei, New Zealand, has altered Pliocene to Pleistocene, silicic, mainly glassy volcanics and related aqueous tuffs and breccias. Measured temperatures (max. 265°C) indicate epithermal to mesothermal conditions in buried fault fissures, the locus of both the hydrothermal fluid and most intense alteration.A supergene kaolinite alteration zone is distinguished from hypogene Ca-montmorillonite and combined micaceous and chloritic zones. The hypogene zones are usually wide and are temperature dependent and localized along fault fissures. Other common hypogene minerals are alkali feldspars, wairakite, epidote, quartz, calcite, laumontite, ptilolite, pyrite and pyrrhotite. Prehnite is rare.The micaceous clay minerals include illite (about 10 Å) and a series of random mixed-layer illite-montmorillonites with d(001) values ranging from 10·28 to 12·45 Å. The amount of interstratified montmorillonite is related to temperature and fault fissures. Apart from rare mixed-layer swelling chlorite, the Fe-rich chloritic clay shows little or no variation in its composition. Both the micaceous clays and the chloritic clay result from alteration of earlier formed Ca-montmorillonite.The stability of hydrothermal minerals is controlled by the temperature and chemical composition of the geothermal fluid ascending along the fault fissures. K-feldspar but not albite is deposited on fissure walls, but both alkali feldspars replace primary soda-lime plagioclase in the wall rock. The absence of albite on fissure walls is ascribed to low aqueous mNa+/mK+ ratio. Primary quartz is not affected by the altering solution but hydrothermal quartz is deposited on fissure walls and in the wall rock.

Layer Charge Relations in Clay Minerals of Micaceous Soils and Sediments

AbstractMicaceous clays (“illites”) of a number of sediments, subjected to quantitative mineralogical analysis, ranged in different samples from 58 to 65% of a dioctahedral mica of muscovite type, from 3 to 8% vermiculite, from 0 to 10% montmorillonite, from 2 to 12% quartz, from 0 to 4% feldspars, from 1 to 2% rutile and anatase, from 0.3 to 1.2% free iron oxides, and from 16 to 30% chlorite. The soil clays contained less mica (13 to 35%) but more vermiculite (13 to 16%), montmorillonite (6 to 14%) and chlorite (30 to 33%), besides kaolinite (3 to 8%) and amorphous material (6 to 15%). The presence of the various minerals was verified by X-ray diffraction. When the interlayer K of these micaceous clays was replaced by hydrated Na ions through treatment with 0.2 n sodium tetraphenylboron in 1 n NaCl, the analytically determined vermiculite and montmorillonite contents increased. The freshly produced vermiculites had an interlayer charge of 177 to 198 me/100 g. During this replacement of interlayer K in a 1 N salt solution, the pH of the equilibrium matrix solution was observed to increase instead of decreasing as would be expected if oxonium (OH3+) ions were associated with K in the interlayer space, thus precluding the possibility of interlayer ONz+. The calculated stoichiometric equivalent of the pH rise established a significant uptake of protons by the lattice as K was released.Thermal analyses of vermiculites show 0.5 to 0.7% higher OH water content than the parent micas. Oxidation of ferrous iron in the silicate structure, suggested as a possible mechanism for lowering of layer charge during weathering of mica to vermiculite, accounted for about 66% of this in samples high in iron (16.0% FeO) and only 30% of this in samples fairly low in iron. The rate of extraction of K from muscovite with no ferrous iron was found to be pH dependent, increasing at lower pH values. The data indicate proton incorporation with structural oxygens of the silicate sheet to form OH as a charge reduction mechanism in weathering of mica, independent of and additional to that involving the oxidation of ferrous iron.

Merceya ligulata in Georgia

Merceya ligulata (Spruce) Schimp. is reported for the first time from Georgia. In North America it was previously known from Arizona, Illinois, Tennessee, and Mexico. Merceya ligulata (Spruce) Schimp. is reported by Grout (1939) as rare plant in North America. In December, 1965, it was col- lected in the Providence Canyons west of Lumpkin, Stewart County, Georgia. These collections (Lampton 1865, 1889 DUKE, GA, HERB. WEST GEORGIA COLLEGE, MICH) were made near the bottom of an arm of one of the canyons, and the plants were growing on a moist substratum of fine, red, micaceous clay. All specimens were without sporophytes, but upon dissection some withered archegonia were found. Grout's (1939) description of this species ends with the statement perigonium terminal; sterile except for a few shrunken archegonia. Fruiting plants of this species have never been found in North America according to Jones (1961), which, in a dioicious species, would seem to indicate either that the antheridial plants are not present or that they are not fertile. The species has not previously been recorded from Georgia. In North America it has been reported from Arizona, Illinois, Tennessee, and Mexico (Jones 1961). Merceya ligulata is one of the so-called mosses said to grow on minerals containing copper or other heavy metals (Persson 1948). Schatz (1955) suggested that the basic requirement of the mosses is the presence of sulfur in a reduced form rather than the elemental form of copper. There is apparently no copper in quantity in Stewart County, Georgia, but the area is well known for the presence of iron ore strata rather close to the surface of the ground. These iron-ore nodules are mined by strip- mining methods. In the Providence Canyons where the presently re- ported collections of M. ligulata were made, these iron-ore strata are exposed by erosion and weathering. This might tend to substantiate Schatz's speculation that the ecological requirements for the growth of the mosses are not necessarily copper compounds.

Diagenesis in Clay Minerals—A Review

AbstractDiagenesis refers to the process, and the changes (usually excluding cation exchange) that take place in sediments after deposition, but definitions of the process vary widely over which changes, and what part (or all) of the time between the transportation of the sediment and the time that the sediment(ary rock) is studied, should be included in diagenesis. Furthermore, Weaver, Griffin, and others, have favored alternative explanations to account for many clay mineral distributions that previously have been interpreted as representing changes in clay minerals in both recent and ancient sediments, and which were referred to diagenesis.Although agreeing that such alternative explanations account best for many distributions of clay minerals, additional evidence that presumably is convincing of diagenesis is presented herein to account for the formation of certain other occurrences of glauconitic mica, glauconite, illite, corrensite, kaolinite, and vanadiferous micaceous clay. A two-stage mechanism is proposed for a possible process by which illite and probably corrensite are formed: (1) cation sorption driven by energy (activities) of the ions in solution, and binding energy of the clay minerals, and (2) subsequent rearrangement of ions in the clay mineral to produce illite. It is finally proposed that diagenesis of clay minerals is characterized by the addition to and incorporation into them of Me ions, such as Mg, K, Ca, Na, Al, Fe, V, SiO2, and others, driven mainly by chemical energy and aided by mechanical and thermal energy, but as the latter two become more effective the process is designated metamorphism (anamorphism).Long-time, diagenetic reactions after burial of sediments are probably less important, volume-wise, than provenance and terrestrial weathering in determining the mineralogy of argillaceous sedimentary rocks in the geologic column.

De miocæne Formationer i Danmark

The Miocene Formations of Denmark.The Miocene sediments of Denmark are restricted to the central and western part of the peninsula of Jutland. The Danish Miocene basin forms the northern part of the Miocene North Sea Basin which also covered parts of Northern Germany, Holland and Belgium. More than 200 metres of mainly micaceous clays and sands, often richly fossiliferous, were deposited. The distribution and thickness of the Miocene in Denmark is shown on the map, fig. 1, page 10.Since long the Danish Miocene has been subdivided time-stratigraphically in a Lower, Middle, and Upper division on the basis of paleontological studies by J.P.J. Ravn (1907) and Nørregaard (1916). Works by Sorgenfrei (1940, 1958) and Rasmussen (1956) recently increased our knowledge of the Danish Miocene molluscan faunas and formations.The following 6 formations are now recognized in the Miocene of Denmark (cf. fig. 7, page 41):6. Gram formation (marine). Rasmussen 1956, p. 16 (Age: Upper Miocene).5. Hodde formation (marine). This paper, p. 32 (Age: Middle Miocene).4. Odderup formation (limnic). This paper, p. 30 (Age: Middle Miocene).3. Arnum formation (marine). Sorgenfrei, 1958, p. 28 (Age: Middle Miocene).2. Ribe formation (limnic). Sorgenfrei, 1958, p. 28 (Age: Middle or Lower Miocene).1. Klintinghoved formation (marine). Klintinghoved clay, Sorgenfrei, 1940, p. 68 (Age: Lower Miocene).The type section of the Odderup formation is defined as the interval from 28,2 to 40,3 m below surface in DGU well file no. 103.50 (at Odderup Brickworks). The form ation consists of limnic sediments of quartz sands with lignite.The type section of the Hodde formation is from 13,8 to 23,4 m below surface in the well DGU well file no. 113.33 a, Hoddemark (NE of Varde). The formation consists of marine sediments of micaceous clays and sands with beds of quartz sand.The distribution of the Marine Middle Miocene of Denmark is shown on map, fig. 2, page 30 and the distribution of the Marine Upper Miocene is shown on map fig. 4, page 34.

Composition of Upper Triassic Lockatong Argillite, West-Central New Jersey

The upper Triassic Lockatong formation consists principally of hard massive gray to reddish-brown argillite and black shale and platy thin-bedded mudstone. The predominant minerals in the massive argillite which contains as much as 7 per cent soda and as little as 47 per cent silica, are analcime, dolomite, feldspar, and a 10 Å micaceous clay mineral. Quartz is very rare or absent. In the platy and shaly beds analcime is rare; dolomite, micaceous clay minerals, and feldspar are abundant; and scattered pyrite is common. Metamorphic effects of a diabase sill were restricted largely to converting poorly crystalline micaceous clay to well-crystallized biotite, analcime to albite, dolomite to calcite, and pyrite to pyrrhotite.

Nature and mode of weathering of soil‐potassium reserves

AbstractIn most partially weathered mineral soils only a small part of the total potassium is readily exchangeable to other ions; the bulk occurs in non‐exchangeable (or difficultly‐exchangeable) forms in potash feldspars, micas and micaceous clays, all of which are potential sources of potassium for plants.Some of the principles underlying the weathering processes in feldspars, trioctahedral and dioctahedral micas are discussed. The ease with which freshly cleaved potash feldspar releases potassium to water cannot be taken to indicate that the feldspar weathers easily; in soil the feldspar is protected by a surface covering of its own decomposition products. Trioctahedral micas are less stable to weathering than dioctahedral micas, particularly during the early stages of potassium depletion; the stabilities of these two main groups of micas differ more than can be accounted for in terms of ferrous iron contents. For micas and micaceous clays the relationships between parent lattices and weathering products must depend very largely on the extent to which layer‐charges have decreased on weathering. As more becomes known about the potassium‐containing minerals which occur in soils, we should be better able to understand the factors which influence the long‐term ability of soils to supply potassium to crops.

Contribution a l'etude stratigraphique et sedimentologique de l'Aalenien en Haute-Marne

Abstract The Aalenian (Jurassic) oolitic iron ore-bearing formation of Haute-Marne, France, is subdivided on the basis of a detailed paleontologic and sedimentologic study. Thirteen units are described in a section exposed at Maisoncelles. Thin sections of sediments from each horizon show that five principal microfacies can be distinguished--micaceous clay; oolitic iron ore with a calcareous marly gangue rich in shell fragments; oolitic iron ore with a more calcareous gangue and abundant quartz grains; sandy limestone, impregnated with hematite and rich in quartz; and detrital limestone rich in fossil fragments. Formation of the oolites is attributed to encrustation of the shell fragment or fragments forming the nucleus as the nucleus was rolled in the thin film of ferric gel on the bottom of the depositional basin. Associated hematite indicates an oxidizing shallow depositional environment.

Etude des roches argileuses de quelques bassins houillers de la bordure occidentale du Massif Central

Abstract Rather regular and constant argillaceous zones in Carboniferous formations of the coal basins at the western margin of the Central Massif, France, are of two principal types, those rich in micaceous clays (illite-montmorillonite) and those composed mainly of kaolinite. Both contain variable amounts of vermicular kaolinite (leverrierite) formed before consolidation by kaolinization of detrital mica particles in an acid milieu.

Some Hydrous Micas in South African Clays and Shales

At the 4th International Soil Science Congress held in Amsterdam (1950) a special meeting discussed the nomenclature of clay minerals and suggested “hydrous mica” as a general term for those clay minerals that are neither well crystallised micas nor pure expanding minerals.In the past various names have been used for the hydrous micas. As early as 1912, Galpin, and later, in 1920, Bayley, introduced the terms “hydro-mica” and “hydrous mica” respectively, to designate a micaceous clay mineral. Since then, reports have been made of the presence in soils of a potash-bearing clay mineral (Wherry et al., 1929), and in clays of a mica-like clay mineral (glimmerartige Tonmineralien) (Endell et al., 1935), and a sericite-like mineral (Grim, 1935). In 1937 Grim et al., for the first time proposed the term “illite” as a “general term for the clay mineral constitutents of argillaceous sediments belonging to the mica group.” Other names include bravaisite (Ross and Hendricks) and sarospatite (Maegdefrau and Hofmann, 1937), but the validity of these as specific minerals is questionable since they have been found to exist as mixtures of hydrous micas and montmorillonoids (Bradley, 1945; Brindley, 1951).

FISSILITY OF MUDROCKS

Research Article| August 01, 1953 FISSILITY OF MUDROCKS ROY L INGRAM ROY L INGRAM DEPARTMENT OF GEOLOGY AND GEOGRAPHY, UNIVERSITY OF NORTH CAROLINA, CHAPEL HILL, NORTH CAROLINA Search for other works by this author on: GSW Google Scholar GSA Bulletin (1953) 64 (8): 869–878. https://doi.org/10.1130/0016-7606(1953)64[869:FOM]2.0.CO;2 Article history received: 22 Nov 1948 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation ROY L INGRAM; FISSILITY OF MUDROCKS. GSA Bulletin 1953;; 64 (8): 869–878. doi: https://doi.org/10.1130/0016-7606(1953)64[869:FOM]2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The breaking characteristics of a mudrock can be represented on a triangular diagram with massive, flaky-fissile, and flaggy-fissile as end members. Fissility in shales is usually associated with a parallel arrangement of the micaceous clay particles and nonfissility with a random arrangement. Experiments and observations indicate that the clay minerals attain a parallel arrangement by gravity settling or by flocculation and compaction, unless the particles are adsorbed on irregularly shaped sesquioxide or silica particles or grow randomly in a gel. The nature of the cementing agent determines whether a shale will be flaky or flaggy. If the cementing agent can hold the material in a large slab, the shale will be flaggy. If the amount or the tenacity of the cementing agent is small, the shale will be flaky. Cementing agents other than organic matter tend to hinder cleavage parallel to the clay particles causing a decrease in fissility and an increase in massiveness. Moderate weathering increases the fissility of a shale. In general the type of fissility does not correlate with the type of clay minerals present in a random collection of mudrocks. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

THE MINERALS OF BENTONITE AND RELATED CLAYS AND THEIR PHYSICAL PROPERTIES1

AbstractBentonite is a very widely distributed clay material that is the result of the devitrification and chemical alteration of glassy volcanic ash or tuff. Bentonite should be used as the name of a rock derived from volcanic glass and it is commonly composed of the mineral montmorillonite but less often of beidellite. Its characteristic minerals are completely crystalline and have a micaceous habit, high birefringence and facile cleavage. It contains no gel colloids, and few of its crystal particles are so small as to reach “colloidal size.” It shows high adsorptive powers and this property is more dependent upon physical form than upon chemical composition. That is upon the micaceous structure and easy cleavage which give very great surface area and the‘felt‐like texture which facilitates permeability.The clay minerals of the type here described resemble the micas in many ways, but do not seem to possess the marked chemical variability of that group. A large number of analyses of the clay minerals from bentonite indicates that the most widespread of these is montmorillonite with the formula (Mg, Ca)O A1203 5SiO2, nH20.A reanalysis of the type montmorillonite from Montmorillon, France, gives the same formula, and the mineral has also been recognized in lithium‐bearing pegmatites and in fullers' earth.A few bentonites are composed of beidellite, a mineral first identified from the gouge clay of ore veins. It has the formula A12O3·3SiO2·nH2O where n= about 4, and A1203 may be partly replaced by Fe203.A third micaceous clay mineral has the composition of halloysite Al2O3· 2SiO2· nH2O, but it is completely and visibly crystalline and has a high birefringence.