scholarly journals SPECIFIC FEATURES OF CLAY MINERALS IN ANCIENT CRUSTS OF WEATHERING OF VARIOUS ROCKS

2021 ◽  
Author(s):  
N.N. Zinchuk
Keyword(s):  
Clay Minerals ◽  
Carbonate Rocks ◽  
Ordered Structure ◽  
Structural Types ◽  
Layered Formation

The most important typomorphic indications of clay formations in the studied crusts of weathering are as follows: a) omnipresent dioctahedral hydromica (2М1) in the crust of weathering of terrigenous-carbonate rocks and its association in the most mature profiles with kaolinite of relatively ordered structure, than of kaolinite, having been formed at the expense of other rocks; b) constant availability of trappean formation (tuffs, tufogene rocks, dolerites) in sections of crusts of weathering together with di- and trioctahedral montmorillonite, as well as disordered vermiculite-montmorillonite mixed-layered formation, to this or that degree disordered kaolinite, associated in the crust of weathering of tufogene rocks with halloysite (at complete absence of micaceous minerals in the products of weathering); c) the content in the crust of weathering of kimberlites together with polycationic montmorillonite of a significant quantity of trioctahedral chlorite (packets δ and δ’), serpentine (structural types A and B) and altered to various degree phlogopite, including related with it hydromica 1M.

scholarly journals SPECIFIC FEATURES OF CLAY MINERALS IN ANCIENT CRUSTS OF WEATHERING OF VARIOUS ROCKS IN DIAMONDIFEROUS REGIONS

2019 ◽  
pp. 13-20
Author(s):  
N. N. Zinchuk
Keyword(s):  
Carbonate Rocks ◽  
Weathering Crust ◽  
Ordered Structure ◽  
Mixed Composition ◽  
Lower Paleozoic ◽  
Material Development ◽  
Structural Types ◽  
Bivalent Cations ◽  
Layered Formation ◽  
Weathering Crusts

Results of complex research of different age ancient weathering crusts in various rocks (terrigenous-carbonate rocks of Lower Paleozoic, dolerites, tuffs and tufogene formations, kimberlites) within the main diamondiferous regions of the Siberian platform indicated that complicated multicomponent composition of initial formations (with the exception of terrigenous-carbonate rocks), containing di- and trioctahedral minerals, the structure of which has tri- and bivalent rock-forming elements, stipulated decelerated transformation of the initial material. Development of incomplete weathering profiles is first of all caused by weak ejection of bivalent cations from primary minerals. That is why newly emerging phases will be dioctahedral and often preserve mixed composition of cations. The most important typomorphic indications of clay formations in the studied weathering crusts are as follows: a) omnipresent dioctahedral hydromica (2М1) in the weathering crust of terrigenouscarbonate rocks and its association in the most mature profiles with kaolinite of relatively ordered structure, than of kaolinite, having been formed at the expense of other rocks; b) constant availability of trappean formation (tuffs, tufogene rocks, dolerites) in sections of crusts of weathering together with di- and trioctahedral montmorillonite, as well as disordered vermiculite-montmorillonite mixed-layered formation, to this or that degree disordered kaolinite, associated in the weathering crust of tufogene rocks with halloysite (at complete absence of micaceous minerals in the products of weathering); c) the content in the crust of weathering of kimberlites together with polycationic montmorillonite of a significant quantity of trioctahedral chlorite (packets δ and δ'), serpentine (structural types A and B) and altered to various degree phlogopite, including related with it hydromica 1M.

scholarly journals Uranium Removal from Groundwater and Wastewater Using Clay-Supported Nanoscale Zero-Valent Iron

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1421
Author(s):  
Borys Kornilovych ◽  
Iryna Kovalchuk ◽  
Viktoriia Tobilko ◽  
Stefano Ubaldini
Keyword(s):  
Composite Materials ◽  
Clay Minerals ◽  
Zero Valent Iron ◽  
Uranium Compounds ◽  
Uranium Removal ◽  
Composite Sorbents ◽  
Structural Types ◽  
Nanoscale Zero Valent Iron ◽  
Natural Clays ◽  
Carbonate Complexes

The peculiarities of sorption removal of uranium (VI) compounds from the surface and mineralized groundwater using clay-supported nanoscale zero-valent iron (nZVI) composite materials are studied. Representatives of the main structural types of clay minerals are taken as clays: kaolinite (Kt), montmorillonite (MMT) and palygorskite (Pg). It was found that the obtained samples of composite sorbents have much better sorption properties for the removal of uranium from surface and mineralized waters compared to natural clays and nZVI.It is shown that in mineralized waters uranium (VI) is mainly in anionic form, namely in the form of carbonate complexes, which are practically not extracted by pure clays. According to the efficiency of removal of uranium compounds from surface and mineralized waters, composite sorbents form a sequence: montmorillonite-nZVI > palygorskite-nZVI > kaolinite-nZVI, which corresponds to a decrease in the specific surface area of the pristine clay minerals.

Results of Ethylene Glycol Swelling Test on Argillaceous Limestone

1974 ◽  
Vol 11 (3) ◽  
pp. 430-436
Author(s):  
Ludmila Dolar-Mantuani ◽  
Ray Laakso
Keyword(s):  
Ethylene Glycol ◽  
Construction Industry ◽  
Clay Minerals ◽  
Carbonate Rocks ◽  
Construction Materials ◽  
Immersion Test ◽  
Standard Test ◽  
Acceptance Testing ◽  
Test Results ◽  
Freezing And Thawing

Rocks which contain significant amounts of swelling-type clay minerals disintegrate when they are exposed to drying and wetting or to freezing and thawing. The ethylene glycol immersion test is used as a standard test to simulate the breakdown of rocks, containing harmful amounts of expanding clay minerals, when they are used as construction materials in wet and freezing conditions.The glycol test was assessed for petrographic evaluation of argillaceous carbonate rocks intended for use in the construction industry. This was done by conducting the test on 61 small cylinders of a Paleozoic–Verulam argillaceous limestone which contained minor amounts of an expanding clay mineral interstratified with illite and subordinate chlorite. The development and propagation of cracks located in clay concentrations, as seen under a microscope, were used as assessment criteria. Cracks developed very slowly, therefore the test is considered unsuitable for industrial acceptance testing and for petrographic assessment of argillaceous carbonate rocks when quick test results are needed.

scholarly journals Industrial uses of carbonate rocks from Thassos island (Greece)

2001 ◽  
Vol 34 (3) ◽  
pp. 1147
Author(s):  
Ν. ΚΑΝΤΗΡΑΝΗΣ ◽  
Α. ΤΣΙΡΑΜΠΙΔΗΣ ◽  
Α. ΦΙΛΙΠΠΙΔΗΣ ◽  
Α. ΚΑΣΩΛΗ-ΦΟΥΡΝΑΡΑΚΗ ◽  
Β. ΧΡΗΣΤΑΡΑΣ
Keyword(s):  
Chemical Analysis ◽  
Clay Minerals ◽  
Carbonate Rocks ◽  
Soil Conditioners

The carbonate rocks of Thassos Island are holocrystalline and present sparitic texture. The dolomites have smaller crystall size (0.7-1.6 mm) than the calcitic marbles (0.8-2.2 mm). In the dolomites except the synonymous mineral, calcite (1-10%) and traces of quartz, feldspars and micas are present. In the calcitic marbles except of the calcite, dolomite (2-28%), micas (1-6%) and occasionally feldspars, clay minerals and goethite occur. The results of chemical analysis agree with the mineralogical ones, as well as with the percentage of the isnoluble residue. The dolomites appear purer than all other marbles of the island. They most often contain Si02 (up to 0.88%). Beyond the decorative applications the calcitic marbles of Thassos are mainly suitable for the production of aggregates with any size requirement, cement and probably container glasses, for environmental uses and as soil conditioners. Respectively, the dolomitic marbles are suitable for the production of fertilizers and probably of container glasses and as fillers or whitenings in paper, paint and rubber industries.

Ba-rich micas from the Yindongzi-Daxigou Pb-Zn-Ag and Fe deposits, Qinling, northwestern China

1996 ◽  
Vol 60 (400) ◽  
pp. 433-445 ◽  
Author(s):  
Shao-Yong Jiang ◽  
M. R. Palmer ◽  
Yan-He Li ◽  
Chun-Ji Xue
Keyword(s):  
Clay Minerals ◽  
Electron Microprobe ◽  
Carbonate Rocks ◽  
Regional Metamorphism ◽  
Hydrothermal Fluids ◽  
Northwestern China ◽  
Pore Fluids ◽  
Anoxic Conditions ◽  
Sedimentary Environments ◽  
Ore Deposition

AbstractElectron-microprobe analyses of muscovite, biotite, and feldspar are reported for the stratiform Yindongzi—Daxigou Pb—Zn—Ag and Fe deposits of Qinling, northwestern China. The micas are characterized by high Ba levels in banded albite-carbonate rocks that host the deposits. The biotite is also rich in Cl, as is biotite in the nearby Tongmugou Pb-Zn deposit, although biotite and muscovite from this deposit lack Ba enrichment. It is likely that the Ba-rich micas in the Yindongzi-Daxigou deposits formed contemporaneously from the diagenesis and/or regional metamorphism of hydrothermally altered clay minerals, with the barium being derived from entrained pore fluids that may represent relict hydrothermal fluids associated with ore deposition. During the formation of coexisting muscovite and biotite, barium is preferentially partitioned into muscovite and chloride into biotite. Together with the presence of baryte rocks in the bedded ores, these data suggest that ore deposition in the Yindongzi—Daxigou deposits took place in a more oxidising environment than in the nearby Tongmugou deposit. This difference is attributed to the contrasting sedimentary environments of the two deposits, with the Yindongzi—Daxigou deposits having formed under shallow, oxic conditions and the Tongmugou deposit under deeper, anoxic conditions.

scholarly journals PETROLOGICAL INVESTIGATION OF CARBONATE ROCKS FROM THE IONIAN ZONE (ETOLOAKARNANIA, WESTERN GREECE)

2017 ◽  
Vol 43 (5) ◽  
pp. 2540
Author(s):  
P. Bourouni ◽  
B. Tsikouras ◽  
K. Hatzipanagiotou
Keyword(s):  
Clay Minerals ◽  
Deep Water ◽  
Carbonate Rocks ◽  
Shallow Marine ◽  
Water Basin ◽  
Marine Platform ◽  
Western Greece ◽  
Deep Water Basin

The petrographic features of the carbonate rocks from the Ionian Zone in the Etoloakarnania Prefecture are presented. They are represented by limestones with minor dolomite. The limestones include: (i) wackestones (or sparse micrites), with poor presence of allochems within a mud matrix; (ii) packstones (or packed micrites) with increasing levels of carbonate grains that are still surrounded by micrite matrix, and (iii) grainstones (or sparites) containing allochems that are cemented with sparry calcite crystals, while the mud matrix is absent. Bioclasts are the dominant carbonate components in most of the samples accompanied by infrequent pelloids, intraclasts, lithoclasts and ooids. Crystalline limestones were not identified. Quartz, apatite, barite, anhydrite, halite, clay minerals, magnetite and ilmenite have been determined as accessory phases. The results show that mineralogical and petrographic features of the analyzed carbonate rocks are related to their evolution during the development of the Ionian Zone from a shallow-marine platform to a deep water basin.

Hydrated form of some clay minerals observed using a film sealed environmental cell

1978 ◽  
Vol 36 (1) ◽  
pp. 72-73
Author(s):  
N. Kohyama ◽  
K. Fukushima ◽  
A. Fukami
Keyword(s):  
Clay Minerals ◽  
Morphological Changes ◽  
Carbon Film ◽  
Electron Microscopic Observation ◽  
Adsorbed Water ◽  
Electron Microscopic ◽  
Hydrated Form ◽  
Thin Carbon ◽  
Environmental Cell ◽  
Thin Carbon Film

Since the interlayer or adsorbed water of some clay minerals are quite easily dehydrated in dried air, in vacuum, or at moderate temperatures even in the atmosphere, the hydrated forms have not been observed by a conventional electron microscope(TEM). Recently, specific specimen chambers, “environmental cells(E.C.),” have been developed and confirmed to be effective for electron microscopic observation of wet specimen without dehydration. we observed hydrated forms of some clay minerals and their morphological changes by dehydration using a TEM equipped with an E.C..The E.C., equipped with a single hole copper-microgrid sealed by thin carbon-film, attaches to a TEM(JEM 7A) with an accelerating voltage 100KV and both gas pressure (from 760 Torr to vacuum) and relative humidity can be controlled. The samples collected from various localities in Japan were; tubular halloysite (l0Å) from Gumma Prefecture, sperical halloysite (l0Å) from Tochigi Pref., and intermediate halloysite containing both tubular and spherical types from Fukushima Pref..

Planar defects in ordered (Ga,In)P

1988 ◽  
Vol 46 ◽  
pp. 902-903
Author(s):  
S. McKernan ◽  
C. B. Carter ◽  
D. Bour ◽  
J. R. Shealy
Keyword(s):  
Electron Diffraction ◽  
Vapor Phase ◽  
Growth Direction ◽  
High Density ◽  
Ordered Structure ◽  
Planar Defects ◽  
Diffraction Patterns ◽  
Ternary Semiconductors ◽  
Anion Species ◽  
Metallic Vapor

The growth of ternary III-V semiconductors by organo-metallic vapor phase epitaxy (OMVPE) is widely practiced. It has been generally assumed that the resulting structure is the same as that of the corresponding binary semiconductors, but with the two different cation or anion species randomly distributed on their appropriate sublattice sites. Recently several different ternary semiconductors including AlxGa1-xAs, Gaxln-1-xAs and Gaxln1-xP1-6 have been observed in ordered states. A common feature of these ordered compounds is that they contain a relatively high density of defects. This is evident in electron diffraction patterns from these materials where streaks, which are typically parallel to the growth direction, are associated with the extra reflections arising from the ordering. However, where the (Ga,ln)P epilayer is reasonably well ordered the streaking is extremely faint, and the intensity of the ordered spot at 1/2(111) is much greater than that at 1/2(111). In these cases it is possible to image relatively clearly many of the defects found in the ordered structure.

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