scholarly journals KARBONÁTOVÉ KONKRECE „KOBLÍŽKY“ Z LOKALITY NOVÉ DVORY U SUCHDOLA V MORAVSKÉM KRASU (ČESKÁ REPUBLIKA)

2016 ◽  
Vol 23 (1-2) ◽  
Author(s):  
David Buriánek ◽  
Jiří Otava ◽  
Vít Baldík
Keyword(s):  
Mineral Assemblage ◽  
Mineralogical Composition ◽  
Heavy Fraction ◽  
Type K ◽  
Local Material ◽  
Clastic Sediments ◽  
Local Sources ◽  
Radial Structure ◽  
Moravian Karst ◽  
Quartz Grains

Nové Dvory “donuts” are globular to elongated concretions, up to 10 cm in diameter, with remarkable radial structure. They were described from sandstone and limestone cavities in the Moravian karst. Microscopic analyses indicate that these nodules consist of about 45 mod. % of elongated calcite crystals (Ca0,999–0,998 Mg0,002–0,001 CO3). Angular to subrounded quartz grains form the dominant clast type. K-feldspar, strongly weathered plagioclase grains and muscovite are present in small amount. Mineralogical composition of the translucent heavy fraction of “donuts” and surrounding sandstones is interpreted as result of mixing of the detritus coming from the typical Cretaceous (Cenomanian) sediments and of detritus coming from local sources (such as Devonian clastic sediments). Translucent heavy mineral assemblage typical for the Cretaceous clastic sediments includes staurolite, kyanite, tourmaline, rutileand sillimanite, while the local material (Devonian) is characterized by a dominance of epidote and/or zircone. The Nové Dvory “donuts” can be interpreted as a product of precipitation of calcium carbonate in sand that filled the karst cavities (paleo-sinkholes or paleo-cave). 

scholarly journals  Sustainable forestry and iron compounds in karstic soils: qualitative and semi-quantitative results focused on the occurrence of Fe-compounds on mineral particles

2012 ◽  
Vol 58 (No. 9) ◽  
pp. 410-424
Author(s):  
K. Rejšek ◽  
M. Mišič ◽  
F. Eichler
Keyword(s):  
Mineralogical Composition ◽  
Sustainable Forestry ◽  
New Materials ◽  
Iron Compounds ◽  
Dinaric Karst ◽  
Mineral Particles ◽  
Bohemian Karst ◽  
Quantitative Results ◽  
Moravian Karst

Relic karstic soils in nine localities in the Dinaric Karst in Slovenia, five localities in the Moravian Karst and four localities in the Bohemian Karst were sampled for soil scientific, mineralogical and petrological studies focused on the presentation of descriptive aspects of particular iron compounds. The macroscopy and microscopy of Fe<sup>2+</sup> and Fe<sup>3+ </sup>compounds were determined and an interpretation of these data was performed aimed at describing sources and their palaeotransports. The presented results show that the studied karstic soils have a heterogeneous petrographical and mineralogical composition when, depending on circumstances, hematite does not dominate and goethite prevails over it or it is an opposite. Results from the chosen methods reinforce sources of the new materials as the crucial factor for the studied karstic soils. &nbsp;

scholarly journals Etude Mineralogique Des Fractions Sableuse Et Argileuse Du Remplissage Du Gisement De Montgaudier, Charente, France

2017 ◽  
Vol 13 (15) ◽  
pp. 195
Author(s):  
Boukhir Mohammed ◽  
Chaouni Abdel-Ali ◽  
Lahrach Abderrahim
Keyword(s):  
Mineralogical Composition ◽  
Surrounding Rock ◽  
The Other ◽  
Heavy Minerals ◽  
Sand Fraction ◽  
Mineralogical Study ◽  
Mineralogical Investigation ◽  
Opaque Minerals ◽  
Quartz Grains ◽  
Different Parts

The mineralogical investigation of sand fraction of different sectors of filling of Montgaudier deposit revealed that heavy minerals are mainly composed of amphiboles and disthene in all analyzed samples. The other mineralogical species encountered appear having only a secondary role in the composition of heavy mineral processions. These minerals are: Andalusite, brookite, chlorite, epidote, garnet, pyroxene, rutile, sillimanite and sphene. The opaque minerals are relatively numerous in all the studied samples which they are in different stages of alteration, associated with other minerals presenting a fresh appearance. The light minerals consist mainly of hyaline or translucent quartz grains and milky or opalescent grains. The study of clay minerals generally showed a predominance of kaolinite in all sectors, followed by illite and chlorite. Smectite comes in only fourth place. This cortege is complemented by interstratified smectite-chlorite, which are very poorly represented. The mineralogical study of the deposits at the different parts of the layers filling of the Montgaudier deposit and the sediments in the immediate vicinity permitted to determine the origin of these deposits. Their procession is largely influenced by the geological nature of the Tardoire watershed but also of the mineralogical composition of the surrounding rock in which this cave was.

scholarly journals Brucite-Aragonite Precipitates as Weathering Products of Historic Non-MgO-Based Geomaterials

Minerals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 599
Author(s):  
Javier Martínez-Martínez ◽  
David Benavente ◽  
Nicoletta Fusi ◽  
Juan Carlos Cañaveras
Keyword(s):  
Mineral Assemblage ◽  
Chemical Weathering ◽  
Building Materials ◽  
Complex Structure ◽  
Mineralogical Composition ◽  
Pore Waters ◽  
Mineral Precipitation ◽  
City Wall ◽  
Puff Pastry ◽  
The City

This paper analyses the mineralogical composition, texture, and structure of a stalactite sampled from the city-wall storerooms of the Nueva Tabarca fortress (southeast Spain). This speleothem presents an uncommon mineral assemblage: aragonite, brucite, gypsum, silica, and halite. Internally, it shows complex structure: (1) a central soda-straw composed by aragonite; (2) an external puff-pastry cone-crust formed preferentially by aragonite and brucite; and (3) an internal branching of coralloids, showing a subtle layering between brucite and aragonite. Gypsum, halite, and silica locate in the outer coating of the cone-crust. The sequent mineral precipitation sequence has been established: aragonite > brucite > gypsum/silica > halite. Speleothem formation is directly related to the chemical weathering of the rocks and mortars used as building materials of the city-wall. Brucite precipitates has been always linked to the presence of MgO-based geomaterials. However, the lack of these compounds as building materials in Nueva Tabarca fortress makes this investigation a unique example of brucite precipitation. PHREEQC calculations showed that interaction between pore waters and the minerals of mortar aggregates (dolomite, pyroxene, and amphibole) leads to rich-magnesium solutions. Evaporation modelling of lixiviated waters describes the precipitation of the mineral assemblage of the brucite-aragonite speleothems.

The Mineral Composition of the Modern Fenland Silt, with special reference to Carbonate Minerals

1920 ◽  
Vol 57 (12) ◽  
pp. 543-551 ◽  
Author(s):  
F. Hardy
Keyword(s):  
Chemical Analysis ◽  
Mineral Composition ◽  
Mineral Assemblage ◽  
Sea Water ◽  
Mineralogical Composition ◽  
The North ◽  
The North Sea ◽  
Recent Origin ◽  
Boulder Clay ◽  
Sea Currents

SUMMARY1. A sample of modern Fenland silt containing 8·98 per cent of carbonate was found on minaralogical examination to include dolomite as well as aragonite in its mineral assemblage.2. The dolomite is present in fresh angular crystal grains which suggest a secondary and recent origin of the mineral. It has possibly been deposited from sea-water which periodically covers the foreshore of the Fenland border of the Wash.3. The general mineral composition of the silt resembles closely that of certain geologically recent deposits of Cambridgeshire, and points to the boulder-clay left by the North Sea glacier as the chief source of the material of which the silt is composed. The silt has mainly been deposited by sea-currents which carry southwards the eroded glacial deposits of the South Yorkshire and North Licoln-shire coasts.4. An attempt is made to interpret the results of a chemical analysis of the silt in the light of its mineralogical composition, chiefly with regard to carbonate, potash, and phosphate. Muscovite, is found to be the main source of potash, and apatite of phosphate in the silt.

scholarly journals Transition in chemical and mineralogical composition around unweathered relicts of granodiorite in the kaolin deposit on Bornholm, Denmark

1988 ◽  
Vol 37 ◽  
pp. 117-122
Author(s):  
Jan Bondam ◽  
Manfred Störr
Keyword(s):  
Transition Zone ◽  
Mineral Assemblage ◽  
Mineralogical Composition ◽  
Major Elements ◽  
Parent Rock ◽  
The Baltic Sea ◽  
Fresh Material ◽  
The Baltic ◽  
A Minor ◽  
Kaolin Deposit

In the kaolin deposit near Rønne on the island of Bornholm in the Baltic Sea a number of well-rounded, unweathered, boulder-like relicts of the granodioritic parent rock are found, embedded in kaolin. Samples have been taken of one relict at 2 cm interval from the fresh material outwards into the kaolin. The distribution pattern of the major elements in these samples has been studied in order to gain an impression of the leaching conditions at the time of formation, in the immediate vicinity of the relict. This distribution shows on a minor scale, what previously has been demonstrated in bulk for the whole deposit that leaching effects have not been uniform for the different elements, leading to a relative enrichment of calcium in the transition zone close to the unweathered parent rock. TEM and SEM observations revealed that halloysite and smectite are the dominant clay minerals of the transition zone, where kaolinite occurs only sporadically. These minerals apparently become unstable when alkalis and alkali earths are progres­sively leached, while kaolinite emerges as the pincipal clay mineral, and amphibole and plagioclase no longer remain in the residual mineral assemblage.

scholarly journals THE SILURIAN FRONTIER OF EMERSION STAGE IN THE TERRITORY OF SOUTH CIS-TIMAN (PERM REGION)

2020 ◽  
Vol 19 (3) ◽  
pp. 210-224
Author(s):  
Yu. G. Paktovskiy ◽  
Keyword(s):  
Wind Erosion ◽  
Heavy Fraction ◽  
Point Of View ◽  
East European ◽  
Mineral Associations ◽  
Mineralogical Study ◽  
Geological Section ◽  
Upper Silurian ◽  
Quartz Grains ◽  
Perm Region

At the base of the Silurian deposits in the Southern Rassolnaya Deposit, ventfacts considered as an indicator formations of deserts with a predominance of wind erosion (corrosion) processes were first discovered. In this work, the systematization of the found ventfacts was carried out, their morphology was revealed, and it is concluded that the most numerous group among the Aeolian polyhedra is the group of pyramidal ventfacts. Among the latter, the pyramidal trihedrons, otherwise known as dreikanters, are the most common. From the point of view of lithology, ventfacts are quartzite sandstones with relics of hydromicas cement, the structure of which is dominated by a cementless contact connection of quartz grains and fragments of various rocks. According to the structural position of the layers of rocks containing windmills, deposits of the Ordovician and Silurian systems are distinguished in the geological section. A mineralogical study of this section was conducted analyzing the mineral associations of the heavy fraction of lithological samples. The conclusion about possible ventfacts formation time as the border of the Ordovician and Silurian was made. To denote the time and facies boundaries of the emersive phase, the concept of the emersive frontier (or boundary) is introduced by analogy with the term mineralogical boundary. This frontier is taken by the author as the upper (Silurian) emersive boundary, after which there is a drastic change in the tectonic situation in the region. Based on the results of the study, a paleogeographic reconstruction of the Eastern margin of the East European platform on the Silurian emersive frontier is proposed, which may be associated with the Aeolian type of diamond placers of the Silurian intermediate reservoir in the Southern Cis-Timan.

TREATMENT OF SPHERICITY AND ROUNDNESS DATA OF QUARTZ GRAINS OF CLASTIC SEDIMENTS

Sedimentology ◽  
1970 ◽  
Vol 14 (1-2) ◽  
pp. 51-66 ◽  
Author(s):  
BASANTA K. SAHU ◽  
B. C. PATRO
Keyword(s):  
Clastic Sediments ◽  
Quartz Grains

scholarly journals Mineralogy of Duné s Sand of Missan Dune Fields Southeastern Iraq

2018 ◽  
Vol 26 (5) ◽  
pp. 59-73
Author(s):  
Thamer Abbas Al-Shammery ◽  
Hasan Kattoof Jasim
Keyword(s):  
Metamorphic Rock ◽  
Source Area ◽  
Mineralogical Composition ◽  
Flood Plain ◽  
Heavy Fraction ◽  
Heavy Minerals ◽  
Rock Fragments ◽  
Tigris River ◽  
Geographical Position ◽  
Heavy Liquids

The aim of this study is to define the mineralogical composition of Missan dune fields South Eastern of Iraq, and try to determine the origin or the source of these dunes . Three main types of dunes were recognized in the studied area, these are: barchanoid ridge, barchans and nabkha dunes. The direction of these dunes is northwest to southeast. The dunes in Missan dune fields were divided into three fields according to the vari- eties in the composition and geographical position in the studied area, these three fields are: Al-Manziliyah, Middle Chailat, and Said Subair dune fields. 9 samples were collected from these fields, the samples were separated into light and heavy fraction by heavy liquids. The light fraction composed from quartz, feldspar, and rock fragments, the rock fragments composed mainly of carbonate, chert, igneous, and metamorphic rock fragments . The heavy minerals are mostly opaques, chlorite, pyroxenes, amphiboles, epidotes, zircon, garnet, muscovite, biotite, kyanite, staurolite, and rutile . The percentages of heavy minerals fraction to light minerals fraction was very vari- able in which the percentage of heavy minerals in Sayid Subair field are higher than the percentage in Al-Manziliyah field.The source area of these sediments is the recent sed- iment that deposited in the flood plain and traces of the Tigris river and the outcrops    of upper Miocene-Pliocene rocks in the eastern of studied area (Himreen Anticline and Zagros Mountain).

The Effects of Drying Techniques on Clay-Rich Soil Texture

1974 ◽  
Vol 32 ◽  
pp. 466-467
Author(s):  
T. G. Naymik
Keyword(s):  
Critical Point ◽  
Liquid Nitrogen ◽  
Liquid Nitrogen Temperature ◽  
Drying Methods ◽  
Air Drying ◽  
Freeze Dried ◽  
Critical Point Drying ◽  
Set Up ◽  
The Relationship ◽  
Quartz Grains

Three techniques were incorporated for drying clay-rich specimens: air-drying, freeze-drying and critical point drying. In air-drying, the specimens were set out for several days to dry or were placed in an oven (80°F) for several hours. The freeze-dried specimens were frozen by immersion in liquid nitrogen or in isopentane at near liquid nitrogen temperature and then were immediately placed in the freeze-dry vacuum chamber. The critical point specimens were molded in agar immediately after sampling. When the agar had set up the dehydration series, water-alcohol-amyl acetate-CO2 was carried out. The objectives were to compare the fabric plasmas (clays and precipitates), fabricskeletons (quartz grains) and the relationship between them for each drying technique. The three drying methods are not only applicable to the study of treated soils, but can be incorporated into all SEM clay soil studies.

Applications of SEM/EDXA in cement clinker investigation

1990 ◽  
Vol 48 (4) ◽  
pp. 870-871
Author(s):  
Arezki Tagnit-Hamou ◽  
Shondeep L. Sarkar
Keyword(s):  
Mineralogical Composition ◽  
Physicochemical Characteristics ◽  
Cement Clinker ◽  
Accurate Information ◽  
Phase Identification ◽  
History Of ◽  
Bulk Chemical ◽  
Resolution Imaging ◽  
Proven Method ◽  
Instantaneous Chemical

All the desired properties of cement primarily depend on the physicochemical characteristics of clinker from which the cement is produced. The mineralogical composition of the clinker forms the most important parameter influencing these properties.Optical microscopy provides reasonably accurate information pertaining to the thermal history of the clinker, while XRDA still remains the proven method of phase identification, and bulk chemical composition of the clinker can be readily obtained from XRFA. Nevertheless, all these microanalytical techniques are somewhat limited in their applications, and SEM/EDXA combination fills this gap uniquely by virtue of its high resolution imaging capability and possibility of instantaneous chemical analysis of individual phases.Inhomogeneities and impurities in the raw meal, influence of kiln conditions such as sintering and cooling rate being directly related to the microstructure can be effectively determined by SEM/EDXA. In addition, several physical characteristics of cement, such as rhcology, grindability and hydraulicity also depend on the clinker microstructure.

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