scholarly journals ABOUT LITHOMINERALOGICAL COMPOSITION OF ANCIENT SEDIMENTARY DIAMONDIFEROUS ROCKS

2018 ◽  
pp. 15-23
Author(s):  
N. N. Zinchuk
Keyword(s):  
Carbonate Rocks ◽  
Material Dispersion ◽  
Crust Formation ◽  
Lower Paleozoic ◽  
Structural Formation ◽  
Stream Flows ◽  
Upper Paleozoic ◽  
Formation Conditions ◽  
The Moment ◽  
By Products

Litho-mineralogical and structural-formation generation features of Upper Devonian-Carboniferous crusts of weathering on terrigenous-carbonate rocks, kimberlites and deposits enriched by products of their redeposition, have been studied, that allowed restoring of the specific features of upper Paleozoic productive horizons generation of the main diamondiferous regions of the Siberian platform, and then, the areas, favorable for generation and preservation of kimberlite (including diamondiferous) material dispersion haloes, have been distinguished within them. Analysis of Upper Paleozoic deposits facies, as well as specific features of their location, has allowed to establish that denudation of the rocks of the region was insignificant since the moment of their crust formation and up to completion of upper Paleozoic sedimentation, and occurred only along the stream flows. The omnipresent availability of crusts of weathering on terrigenous-carbonate rocks of lower Paleozoic, preserved from washout by upper Paleozoic deposits, points on it. These formations are usually elongated in the form of narrow streams and represent fragments of most initial erosion of the crusts of weathering in post-Carboniferous time. That is why, at such minimal shear, practically all kimberlite minerals, occurring in Upper Paleozoic deposits, are redeposited from more ancient pre-Lapchanian formations. The necessity of differentiated approach to studying formation conditions of various facies of diamondiferous upper Paleozoic deposits of continental and coastal genesis has been substantiated, and firstly — studying of their specific features. The complex research is required, with application of structural-tectonic, lithological-facial and formation-cyclic analyses, which would allow allocating specific areas favorable for generation of ancient placers of diamonds or discovering kimberlite pipes.

scholarly journals Conversion of Fructose to HMF in a Continuous Fixed Bed Reactor with Outstanding Selectivity

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1802 ◽  
Author(s):  
Eric Weingart ◽  
Sarah Tschirner ◽  
Linda Teevs ◽  
Ulf Prüße
Keyword(s):  
Large Scale ◽  
Continuous Process ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Water Addition ◽  
Batch Systems ◽  
Formation Conditions ◽  
High Yields ◽  
Optimized Conditions ◽  
By Products

5-Hydroxymethylfurfural (HMF) is a very promising component for bio-based plastics. Efficient synthesis of HMF from biomass is still challenging because of fast degradation of HMF to by-products under formation conditions. Therefore, different studies, conducted mainly in monophasic and biphasic batch systems with and without water addition have been published and are still under investigation. However, to produce HMF at a large scale, a continuous process is preferable. Until now, only a few studies have been published in this context. In this work, it is shown that fluorous alcohol hexafluoroisopropanol (HFIP) can act as superior reaction solvent for HMF synthesis from fructose in a fixed bed reactor. Very high yields of 76% HMF can be achieved in this system under optimized conditions, whilst the catalyst is very stable over several days. Such high yields are only described elsewhere with high boiling reaction solvents like dimethylsulfoxide (DMSO), whereas HFIP with a boiling point of 58 °C is very easy to separate from HMF.

Intersubjectivity, Normativity, and Grammar

2019 ◽  
Vol 82 (2) ◽  
pp. 182-204 ◽  
Author(s):  
Chase Wesley Raymond
Keyword(s):  
Social Life ◽  
Background Knowledge ◽  
Shared Understanding ◽  
Normative Systems ◽  
The Moment ◽  
By Products

Interactants depend on background knowledge and commonsense inferences to establish and maintain intersubjectivity. This study investigates how the resources of language—or more specifically, of grammar—can be mobilized to address moments when such inferences might risk jeopardizing understanding in lieu of promoting it. While such moments may initially seem to undermine the normative commonsensicality of the particular inference(s) in question, the practice examined here is shown to legitimize those inferences through the very act of setting them aside. It is ultimately argued that grammar and other normative systems in social life (e.g., heteronormativity) mutually shape one another, with normative associations being routinely reconstituted as “by-products” in the pursuit of in-the-moment shared understanding.

Kinetics of Mixed Low-Level Waste Incapsulation Using Iron Phosphate Chemically Bonded Cement

2006 ◽  
Vol 932 ◽  
Author(s):  
A.S. Aloy ◽  
T.I. Koltsova ◽  
E.N. Kovarskaya ◽  
M.Yu. Silin
Keyword(s):  
Formation Process ◽  
Iron Phosphate ◽  
Structural Formation ◽  
Low Level ◽  
Second Stage ◽  
Bivalent Iron ◽  
Acid Reaction ◽  
The Moment ◽  
Two Stages ◽  
Kinetics Of

ABSTRACTThe iron phosphate cement (IPC) structure formation process has been studied by Mossbauer spectroscopy. The IPC is formed as a result of interaction of iron oxides with orthophosphoric acid and could be used as a matrix for immobilization of low-level radioactive waste.The structural formation process has been shown may be considered to consist of two stages. The first stage lasts to the moment of setting, when the diffusion process goes on in the liquid phase. At this stage the main fragments of the structural polymeric frame of the IPC are developed consisting of iron (+2) and (+3) phosphates. The rate of the oxides-with-phosphoric-acid reaction as well as the time of hardening depends on the bivalent iron content.The second stage begins from the moment of setting when the diffusion becomes slower. At this stage the process is characterized by the negligible increase in the iron phosphates (+2), (+3) content and transformation of the previously formed phosphates.The nuclear gamma-resonance (NGR) parameters have been determined of FeH3(PO4)2·2.5H2O, forming in the hematite (Fe2O3) based IPC: isomeric shift (IS) = 0.46 mm/s, quadrupole splitting (QS) = 0.197 mm/s, FWHM =0.282 mm/s.

New minerals with modular structure derived from hatrurite from the pyrometamorphic rocks. Part IV: Dargaite, BaCa12(SiO4)4(SO4)2O3, from Nahal Darga, Palestinian Autonomy

2018 ◽  
Vol 83 (1) ◽  
pp. 81-88 ◽  
Author(s):  
Irina O. Galuskina ◽  
Frank Gfeller ◽  
Evgeny V. Galuskin ◽  
Thomas Armbruster ◽  
Yevgeny Vapnik ◽  
...  
Keyword(s):  
Unit Cell Parameters ◽  
Calculated Density ◽  
X Ray ◽  
Cell Parameters ◽  
Holotype Specimen ◽  
Mineral Associations ◽  
Mohs Hardness ◽  
Formation Conditions ◽  
Additional Member ◽  
By Products

AbstractDargaite, ideally BaCa12(SiO4)4(SO4)2O3, is an additional member of the arctite group belonging to minerals with a modular intercalated antiperovskite structure derived from hatrurite. The holotype specimen was found at a small outcrop of larnite pseudoconglomerates in the Judean Mts, West Bank, Palestinian Autonomy. Larnite, fluorellestadite–fluorapatite, brownmillerite, fluormayenite–fluorkyuygenite and ye'elimite are the main minerals of the holotype specimen; ternesite, shulamitite and periclase are noted rarely. Dargaite, nabimusaite and gazeevite occur in linear zones with higher porosity within larnite rocks. Pores are filled with ettringite and Ca-hydrosilicates, less commonly with gibbsite, brucite, baryte, katoite and calciolangbeinite. Dargaite is colourless, transparent with a white streak and has a vitreous lustre. It exhibits pronounced parting and imperfect cleavage along (001). Mohs’ hardness is ~4.5–5.5. The empirical formula is (Ba0.72K0.24Na0.04)Σ1(Ca11.95Mg0.04Na0.01)Σ12([SiO4]0.91 [PO4]0.05[AlO4]0.03[Ti4+O4]0.01)Σ4([SO4]0.84[PO4]0.14[CO3]0.02)Σ2(O2.54F0.46)Σ3. Dargaite is trigonal R$\overline 3 $m, the unit-cell parameters are: a = 7.1874(4) Å, c = 41.292(3) Å, V = 1847.32(19) Å3 and Z = 3. The crystal structure of dargaite was refined from X-ray single-crystal data to R1 = 3.79%. The calculated density is 3.235 g cm–3. The following main Raman bands are distinguished on the holotype dargaite (cm–1): 122, 263, 323, 464, 523, 563, 641 and 644, 829 and 869, 947, 991 and 1116. The formation conditions of dargaite are linked to the local occurrence of pyrometamorphic by-products (gases, fluids and melts) transforming earlier mineral associations at ~900°C.

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.

Formation Conditions of Ferromagnesian Metasomatic Carbonates in the Lower Riphean Terrigenous–Carbonate Rocks of the Southern Urals

2019 ◽  
Vol 54 (3) ◽  
pp. 248-261
Author(s):  
M. T. Krupenin ◽  
S. V. Michurin ◽  
A. A. Sharipova ◽  
A. A. Garaeva ◽  
D. A. Zamyatina ◽  
...  
Keyword(s):  
Carbonate Rocks ◽  
Southern Urals ◽  
The Southern Urals ◽  
Lower Riphean ◽  
Formation Conditions

SOME GEOPHYSICAL RESULTS ACROSS THE SIMPSON DESERT

1965 ◽  
Vol 5 (1) ◽  
pp. 48
Author(s):  
J. Laherrere ◽  
R. D. Drayton
Keyword(s):  
Sedimentary Basins ◽  
Seismic Section ◽  
Lower Paleozoic ◽  
Oil Companies ◽  
Subsurface Geology ◽  
Regional Features ◽  
Upper Paleozoic ◽  
Geophysical Surveys ◽  
Simpson Desert ◽  
Seismic Lines

The subsurface geology of the Simpson Desert was unknown four years ago. Since then aeromagnetic, gravity and seismic reconnaissance surveys have been carried out by several oil companies, the B.M.R., and the South Australian Department of Mines.Two different interpretations of the aeromag data show that this method, if not very accurate with regard to the depth of basement, does give very useful indications on the present basins and trends of basement.The results of the reconnaissance helicopter gravity survey outlined the main sedimentary basins and made it possible to get the best possible location for the seismic lines, and extrapolate the seismic data, saving a lot of time and money in seismic operations.The regional features of the Simpson Desert in the Mesozoic and Upper Paleozoic units are now well known; the limits of the formations can be drawn.The 400-mile-long section across the Simpson Desert through Poeppel Corner incorporates all of the known geophysical data.To overcome the main problem of defining the depth of the Pre-Devonian unconformity, the accurate and economical technique of reflection offset shooting was evolved. Below the unconformity no real continuous events can be followed, minimising the hope of defining Lower Paleozoic problems. Some examples of seismic section and offset shooting are shown.A few stratigraphic wells on the edge of the Desert have beautifully confirmed the results of the geophysical data.The estimated cost of the geophysical data in this area is very low compared with the knowledge of the regional geology obtained from these operations. Now is the time for detailed geophysical surveys to find structures and oil, but some slides show that it is not an easy-going area.

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