Use of the population potential model for predicting the growth of cities in a region (with reference to Moscow Oblast)     

Molodikova IN  Khanin SY 《Soviet geography》1986,27(2):75-83

"A modification of the population potential model is used to analyze the structure of the potential of population for cities of the Moscow region, to develop a relationship between population potential and city size, and to use this procedure to forecast future population change in Moscow Oblast cities." Cities in the region with a population of 50,000 or more at the censuses of 1959, 1970, and 1979 are included.  相似文献   

PGE Mineralization of Massive Chromitites of the Iov Dunite Body (Northern Urals)     

R. S. Palamarchuk  S. Yu. Stepanov  D. A. Khanin  A. V. Antonov 《Moscow University Geology Bulletin》2017,72(6):445-454

This work presents the results of the first comprehensive study of PGE mineralization from massive chromitites of the Iov dunite body (Northern Urals). The chromitites are composed of chromespinelides with a higher content of Cr₂O₃ with respect to those from other zonal clinopyroxenite–dunite massifs of the Urals. However, the composition of chromespinelides fits the trend that is characteristic of the dunite–clinopyroxenite–gabbro formation. PGE minerals, in particular Pt–Fe solid solutions, were identified in chromitites and in chromespinelides in the form of crystals and aggregates of a complex non-crystallographic habit and less often of an idiomorphic cubic habit. In terms of stoichiometry, Pt–Fe minerals correspond to ferroplatinum (Pt₂Fe) and isoferroplatinum (Pt₃Fe). The minerals of the isomorphic tetraferroplatinum–tulameenite–nickelferroplatinum series are widely distributed. Thus, the PGE mineralization of the Iov dunite body has features that are characteristic of clinopyroxenite–dunite massifs of the Urals.  相似文献   

The cities of the RSFSR: trends and prospects of development     

Gornostayeva GA  Khanin SY 《Soviet geography》1985,26(6):436-444

The relationship between function and city size in cities of the Russian part of the USSR with a population of over 100,000 is examined for the period 1939 to 1980. The results suggest that "the relationship between city growth and functional change is wavelike in nature. In the initial stages of development of a city, it is the construction and transport functions that predominate, and they are associated with high rates of population growth. Increasing functional complexity leads to slower rates of population growth. When the given city reaches a higher stage of development...it again begins to attract population, with relatively low rates of growth."  相似文献   

Selective blackening of bioclasts via mixing‐zone aragonite neomorphism in Late Triassic limestone,Zlatibor Mountains,Serbia     

KINGA HIPS  JÁNOS HAAS  MÁRIA VIDÓ  ZSUZSANNA BARNA  DIVNA JOVANOVIĆ  MILAN N. SUDAR  ZOLTÁN SIKLÓSY 《Sedimentology》2011,58(4):854-877

A peculiar facies of the Norian–Rhaetian Dachstein‐type platform carbonates, which contains large amounts of blackened bioclasts and dissolutional cavities filled by cements and internal sediments, occurs in the Zlatibor Mountains, Serbia. Microfacies investigations revealed that the blackened bioclasts are predominantly Solenoporaceae, with a finely crystalline, originally aragonite skeleton of fine cellular structure. Blackening of other bioclasts also occurs subordinately. Solenoporacean‐dominated reefs, developed behind the platform margin patch‐reef tract, were the main source of sand‐sized detritus. The blackened and other non‐blackened bioclasts are incorporated in automicrite cement. Radiaxial fibrous calcite cements in the dissolutional cavities are also black, dark grey or white. Reworked black pebbles were reported from many occurrences of peritidal deposits; in those cases, the blackening took place under pedogenic, meteoric diagenetic conditions. In contrast, in the inner platform deposits of the Ilid?a Limestone, the blackening of bioclasts occurred in a marine–meteoric mixing‐zone, as indicated by petrographic features and geochemical data of the skeleton‐replacing calcite crystals. Attributes of mixing‐zone pore waters were controlled by mixing corrosion, different solubility of carbonate minerals and microbial decomposition of organic matter. In the moderate‐energy inner platform environment, large amounts of microbial organic tissue were accumulated and subsequently decomposed, triggering selective blackening in the course of early, shallow burial diagenesis. The δ¹⁸O and δ¹³C values of the mixing‐zone precipitates and replacive calcite do not produce a linear mixing trend. Variation mainly resulted from microbial decomposition of organic matter that occurred under mixing‐zone conditions. The paragenetic sequence implies cyclic diagenetic conditions that were determined by marine, meteoric and mixing‐zone pore fluids. The diagenetic cycles were controlled by sea‐level fluctuations of moderate amplitude under a semi‐arid to semi‐humid climate.  相似文献   

Minerals of the beudantite–segnitite series from the oxidation zone of the Berezovskoe gold deposit,middle Urals: Chemical variations,behavior of admixtures,and antimonian varieties     

I. V. Pekov  D. A. Khanin  V. O. Yapaskurt  A. V. Pakunova  I. A. Ekimenkova 《Geology of Ore Deposits》2016,58(7):600-611

In the oxidation zone of the Berezovskoe gold deposit in the middle Urals, Russia, minerals of the beudantite–segnitite series (idealized formulas PbFe₃ ³⁺ AsO₄)(SO₄)(OH)₆ and PbFe₃ ³⁺ AsO₄)(AsO₃OH)(OH)₆, respectively) form a multicomponent solid solution system with wide variations in the As, S, Fe, Cu, and Sb contents and less variable P, Cr, Zn, Pb, and contents K. The found minerals of this system correspond to series from beudantite with 1.25 S apfu to S-free segnitite, with segnitite lacking between 1.57 and 1.79 As apfu. Segnitite at the Berezovskoe deposit contains presumably pentavalent Sb (up to 15.2 wt % Sb₂O₅ = 0.76 Sb apfu, the highest Sb content in the alunite supergroup minerals), which replaces Fe³⁺. The Sb content increases with increasing As/S value. On the contrary, beudantite is free of or very poor in Sb (0.00–0.03 Sb apfu). Many samples of segnitite are enriched in Cu (up to 8.2 wt% CuO = 0.83 Cu apfu, uncommonly high Cu content for this mineral) and/or in Zn (up to 2.0 wt% ZnO = 0.19 Zn apfu). Both Cu and Zn replace Fe. The generalized formula of a hypothetic end member of the segnitite series with 1 Sb apfu is Pb(Fe³⁺ M ²⁺Sb⁵⁺)(AsO₄)₂(OH)₆, where M = Cu, Zn, Fe²⁺. The chemical evolution of beudantite–segnitite series minerals at the Berezovskoe deposit is characterized by an increase in the S/As value with a decrease in the Sb content from early to late generations.  相似文献   

Thermodynamic Properties of Natural Cuspidine     

L. P. Ogorodova  M. F. Vigasina  O. V. Kononov  N. N. Koshlyakova  D. A. Ksenofontov  D. A. Khanin  V. D. Shcherbakov  L. V. Mel’chakova 《Geochemistry International》2018,56(8):865-869

The paper reports pioneering data on the calorimetrically determined enthalpy of formation from elements of cuspidine, Ca fluordiorthosilicate Ca₄Si₂O₇F₂, from the Tyrny-Auz Mo–W deposit in Kabardino- Balkaria, Russia. The data were obtained by high-temperature melt solution calorimetry. The determined value is ΔfH_el° (298.15 K) =–5190 ± 13 kJ/mol. The paper reports estimated S°(298.15 K) and Δ_fG_el° (298.15 K) of cuspidine.  相似文献   

The Cr<Superscript>6+</Superscript> impurity in supergene oxosalts in chromate mineralization occurrences of the Urals     

D. A. Khanin  I. V. Pekov  A. V. Pakunova  I. A. Ekimenkova  V. O. Yapaskurt 《Moscow University Geology Bulletin》2016,71(5):330-336

Based on the results of more than 600 electron microprobe analyses of 25 minerals the distribution pattern of the Cr⁶⁺ impurity in vanadates, phosphates, and arsenates collected in oxidation zones of six ore deposits of the Urals was studied. Among them are Pb minerals of the brackebuschite, apatite, adelite, and tsumcorite groups and alunite supergroup, as well as carminite, cornwallite, and bayidonite. Vanadates and arsenates with brackebuschite-type structures show a high affinity to Cr⁶⁺. The maximum content of the Cr⁶⁺ impurity is characteristic of minerals with specified Fe³⁺ trivalent cations (ferribushmakinite, arsenbrackebuschite, and gartrellite) or Al³⁺ (plumbogummite and bushmakinite). The prevailing scheme of isomorphous substitution, according to which chromium enters into the compositions of these minerals, is heterovalent: Cr⁶⁺ + M ²⁺ → Т ⁵⁺ + M ³⁺ (where Т = V, As, P; M ³⁺ = Fe, Al; M ²⁺ = Сu, Zn), whereas the role of isovalent substitutions Cr⁶⁺ → S⁶⁺ and Cr⁶⁺ → Mo⁶⁺ in oxosalts that formed in mineral occurrences of the Urals is insignificant.  相似文献