Search

Kalyuzhnyite-(Ce), ideally NaKCaSrCeTi(Si8O21)OF(H2O)3, is a new mineral from the Darai-Pioz alkaline massif, Tien-Shan mountains, Tajikistan. It occurs as equant grains up to 0.05 × 0.07 mm in a quartz–pectolite aggregate in a silexite-like peralkaline pegmatite. Associated minerals are quartz, fluorite, pectolite, baratovite, aegirine, leucosphenite, neptunite, reedmergnerite, orlovite, sokolovaite, mendeleevite-(Ce), odigitriaite, pekovite, zeravshanite, kirchhoffite and garmite. The mineral is colourless with a vitreous lustre and a white streak, and D calc. is 3.120 g/cm3. Kalyuzhnyite-(Ce) is monoclinic, P 2/ c , a = 18.647(4), b = 11.214(2), c = 14.642(3) Å, β = 129.55(3)° and V = 2360.9(11) Å3. The chemical composition of kalyuzhnyite-(Ce) is Nb2O5 0.53, TiO2 0.16, SiO2 43.85, Er2O3 0.13, Ho2O3 0.10, Gd2O3 0.09, Sm2O3 0.47, Nd2O3 6.22, Pr2O3 1.21, Ce2O3 6.34, La2O3 0.82, PbO 4.90, BaO 0.85, SrO 11.39, CaO 1.86, Cs2O 3.80, K2O 1.59, Na2O 2.99, H2O 5.24, F 1.55, O = F –0.65, total 100.31 wt.%. The empirical formula calculated on 26.11 (O + F) apfu is Na1.07K0.37Cs0.30Sr1.21Ca0.37Pb0.24Ba0.06(Ce0.43Nd0.41Pr0.08La0.06Sm0.03Gd0.01Er0.01Ho0.01)Σ1.04(Ti0.97Nb0.04)Σ1.01Si8.06O25.21F0.90H6.42, Z = 4. The simplified formula is (Na,□)(K,Сs)(Ca,Pb,Sr,Na)Sr Ln 3+Ti(Si8O21)OF(H2O)3, where Ce is the dominant lanthanoid. The crystal structure was solved by direct methods and refined to an R 1 index of 2.74%. In kalyuzhnyite-(Ce), the main structural units are a heteropolyhedral Na–Sr–Ce–Ti sheet, ideally [NaSrCeTiOF]7+, and a double (Si8O21)10– sheet parallel to (010). In the Si–O sheet, the Si tetrahedra form ten-membered rings. This is the first occurrence of such a double Si–O sheet in a mineral. The two sheets connect via common vertices of Na-, Sr-, Ce- and Ti-polyhedra and SiO4 tetrahedra to form a framework. The interstitial cations and H2O groups, ideally [(CaK)(H2O)3]3+, occur within the Si–O sheet. The mineral is named in honour of Vasily Avksentievich Kalyuzhny (1899–1993) in recognition of his contributions to the geology of ore deposits of Komi Republic (USSR) and the mineralogy of granitic pegmatites (Tajikistan). [ABSTRACT FROM AUTHOR]

The article gives a revision of the Semagystia monticola (Groum-Grshimaïlo, 1890) species group (Lepidoptera, Cossidae, Cossinae). The group comprises nine valid species. Detailed data on the distribution of all the species are provided. Four new species from Central Asia are described: S. churkini Yakovlev & Shapoval, sp. n. (Type locality: Kyrgyzstan, Moldo-Too Range, Kichine-Kindyk River), S. fomichevi Yakovlev & Shapoval, sp. n. (Type locality: Tajikistan, Eastern Pamir Mts., Zulumart [Palangguzar] Mt. Rg.), S. toropovi Yakovlev & Shapoval, sp. n. (Type locality: Kirgizia, Tschatkal Mt., Sary-Chelek lake), and S. uvaydo Yakovlev & Shapoval, sp. n. (Type locality: Tajikistan, Darvaz Mts., Khozratishoh Range, Khaburobot pass). The article is illustrated with imagoes of specimens from different localities and male genitalia of all new species.

Background Salvia korolkowii (Lamiaceae) has been considered a species of highest conservation priority due to its narrow distribution and isolated taxonomic position. The species has been known from Uzbekistan and, questionably, Kyrgyzstan and treated as endemic to the Western Tian-Shan. Its modern conservation status according to the IUCN Criteria has not been established. [ABSTRACT FROM AUTHOR]

A new species Evergestis impervialis Sinev et Korb, sp. n. is described from Central Tian-Shan, Katta-Kaindy Mountain Range (Kyrgyzstan). It differs from similar species (E. caesialis (Herrich-Schäffer, 1849), E. comealis Amsel, 1961 and E. lupalis Zerny, 1928) by the wing pattern (discal spot on the forewing absent, light middle fascia on the forewing present), by the male genitalia structure (gnathos with very tiny dents on dorsal side, ventral margin of valva distinctly S-shaped) and by the female genitalia structure (apophyses posteriores trifurcated). The new species was found on the southern exposition slopes at the elevations about 2500 m in xerophytic meadows with dominant Poaceae vegetation.

Polyphase mineral aggregates (PMAs) composed of clinozoisite + kyanite + quartz ± chlorite ± paragonite ± phengite have been found within garnet and in the matrix of talc-garnet-chloritoid schists from the Makbal ultrahigh-pressure complex in the northern Kyrgyz Tian-Shan. These mineral textures are interpreted as pseudomorphs after lawsonite, and we reconstructed the compositions of PMAs of clinozoisite + kyanite + quartz, consistent with lawsonite. Petrological study demonstrated that lawsonite was stable during the prograde to the UHP peak stage (P = 28–33 kbar and T = 530–580 °C) and decomposed to the PMAs during isothermal decompression around P = 16–20 kbar and T = 510–580 °C. Trace element characteristics of the clinozoisite grains in the PMAs (former lawsonite) show a flat rare earth element (REE) chondrite-normalized pattern, comparable with the typical reported REE pattern of lawsonite, although the abundance of REE varied from sample to sample. Thus, the REE content of clinozoisite in the PMAs included in garnet was likely inherited from the former lawsonite as the decomposition reaction took place isolated from the matrix. Discrete clinozoisite grains in the matrix have high light REE enrichment over heavy REE in the chondrite-normalized pattern, consistent with the typical epidote pattern. Our results indicate that the talc-garnet-chloritoid schists in the Makbal complex were buried to great depth (> 100 km) with a low geothermal gradient (< 6 °C/km) during the Early Paleozoic (480–509 Ma). Lawsonite decomposition and clinozoisite-forming reactions accompany fluid release during the isothermal decompression stage, implying that the fluids can be generated not only during subduction, but also during exhumation of ultrahigh-pressure rocks in cold subduction settings. [ABSTRACT FROM AUTHOR]

The study presents the results of geobotanical investigations conducted in crop fields in the western Tian Shan Mts in Kyrgyzstan (Middle Asia). The main research focused on classification of weed communities developing within this poorly investigated area, were conducted in the vicinity of Bishkek and Kara-Balta in 2010. Altogether, 299 phytosociological relevés were sampled using the Braun-Blanquet method. Based on all segetal vegetation patches, the analyses distinguished a new association: Caucalido platycarpi-Vicietum michauxii. The results of these phytosociological studies fill a gap in the knowledge about the syntaxonomical diversity of the Middle Asia region, which is one of the most crucial for segetal weed species. The study shows that anthropogenic agrocoenoses could harbour relatively rich flora. Extensively cultivated fields could especially serve as a suitable habitat for many xerothermophilous and heliophilous plants. More than 75 species in vegetation plots, mainly permament weeds, have been found. There is also a considerable share of species coming over from swards, screes and meadows. [ABSTRACT FROM AUTHOR]

Abstract: The Upper Paleozoic orogenic belt of South Tian-Shan (STS) in Kyrgyzstan, Uzbekistan and Tajikistan consists of two structural domains: the south-vergent Bukantau–Kokshaal (BK) in the north and continuing into Xinjiang (China), and the north-vergent Zeravshan–Hissar (ZH) in the south, in Tajikistan. The Bukantau–Kokshaal fold belt was thrust south onto the Kyzylkum–Alai and Tarim continents in the Late Carboniferous. The BK belt is the most prominent collision-related, alpine-type part of the Paleozoic Tian-Shan and, as a prolongation of the Tian-Shan structure, shows close resemblance to the western (outer, west-vergent) part of the Urals. The Kazakhstan continent acts as a hinterland to the BK collision belt. Kazakhstan was constructed by accretion processes in which ancient (presumably Gondwanan) continental terranes and ocean-derived crustal elements of the Early Paleozoic to Early Carboniferous age played a role. The main episode of terrane amalgamation took place during the Middle and Late Ordovician. This appears to reflect active margin development in the Paleoasiatic Ocean, and resembles processes occurring in the recent Western Pacific. Geological differences in construction and protolith age of continental crust in the region are in general agreement with Pb– and Sm–Nd isotopic data. Relatively early (Visean) north-vergent thrust structures in Zeravshan–Hissar and eastern Alai (southwestern STS) bear some resemblance to the Central European Hercynides of Rheic origin, although this region became the location of active margin tectonic processes associated with the closure of the Paleotethys Ocean during the Carboniferous. Post-collisional magmatism occurred from ca. 300 to 270Ma and is represented by a variety of magma types from A-type granites to nepheline syenites. The spatial distribution of plutons appears to be controlled by transtensional structures associated with east–west, left-lateral wrench faulting. The presence of coeval alkali intrusions and plateau basalts in adjacent areas suggests that this magmatism may have been associated with a mantle plume. [Copyright &y& Elsevier]

Abstract: We crossdated spruce (Picea schrenkiana) tree rings of archaeological timbers from the Asi-2 settlement and Turgen-1 barrow associated with the Andronovo in the Tian-Shan Mountains, an archaeological culture known for the development of pastoral transhumance in this particular area of the Eurasian steppe, in order to establish a chronological framework for the Bronze Age period of southeastern Kazakhstan. Age of the Asi-2 semi-subterranean house was determined by radiocarbon dating between ca. 1610 and 1490cal. BC, which places the settlement in the transition between the Middle Bronze Age and Late Bronze Age. Sixty-two percent of tree-ring specimens (20 wood samples) collected from construction timbers of a collapsed roof, entryway and an interior wall of the house were suitable for crossdating. The crossdating success resulted in developing a 121-year tree-ring width chronology of the Asi-2 house and a 101-year tree-ring width chronology of the Turgen-1 barrow. The archaeological tree-ring width series have high mean sensitivity (0.2–0.4) and significant values of interserial correlation that indicate strong common signal in variance of the tree-ring indices. The archaeological timbers from the house and burial mound construction appear to have been cut in a closed-canopy stand of young spruce trees (40, 80 and 100-years old) at this high-elevation locality (2400m asl). The Ulken tree-ring width record developed from modern spruce subalpine forest growing on a steep slope just 300m above the archaeological site (2610–2760m asl) showed a strong negative relationship with April temperature, mainly (R=−0.61, R2 adj.=0.37, F (1,59)=35.03 at p<0.000). This is contrary to positive relationship between tree-ring widths and summer temperature that have been previously reported for the Tian-Shan upper tree-lines in the region. This negative relationship could be related to spring moisture stress when the growing season starts in April with mean daily temperature range from 4.4 to 9.9°C and merely 50mm of monthly precipitation. Likewise, tree-ring width variability in the archaeological records could be dominated by moisture availability in the area. This provides a framework of archaeological tree rings for modeling migration patterns of ancient cultures in search of pastures and water. The study suggests good dendrochronological potential of archaeological timbers from Andronovo archaeological sites of this region. We discuss peculiarities in application of climatically sensitive spruce tree rings to developing an Andronovo absolute chronology and reconstructing environmental changes for the 2nd millennium BC in Central Asia. [Copyright &y& Elsevier]