Tarim

摘要： Changes in ecological stoichiometry reflect nitrogen(N),phosphorus(P)and both N and P limitations in a plant community,which in turn affect plant diversity of the community.However,the relationship between plant community diversity and ecological stoichiometry has not yet been fully researched in arid and semi-arid regions.Ecological stoichiometry and plant community diversity indices of eighteen communities in the upper reaches of Tarim River,northwestern China,were analyzed by multivariate analysis of variance in 2016.The correlation between ecological stoichiometry and plant community diversity was assessed by redundancy analysis(RDA).Results indicated that the Margalef index was significantly correlated with carbon(C)and P concentrations,the Simpson index and Shannon-Weaner index were significantly correlated with plant C concentration,and the Pielou index was significantly correlated with plant C and N concentrations.Moreover,C:N and C:P ratios had significant impacts on plant community diversity.Our results highlight the importance of ecological stoichiometry in driving plant community diversity in the upper reaches of Tarim River,northwestern China.

摘要： Eoarchean(3.6–4.0 Ga)tonalite–trondhjemite–granodiorite(TTG)are the major component of Earth’s oldest persevered continental crust,thereby holding the key to understanding how continental crust originated and when plate tectonics started in the early Earth.TTGs are mostly generated by partial melting of hydrated mafic rocks at different depths(e.g.,Moyen and Martin,2012),but whether this requires subduction remains enigmatic(e.g.,Palin et al.,2016).Recent studies show that most early Archean TTGs formed at relatively low pressures(≤1.5 GPa)and do not require subduction(e.g.,Johnson et al.,2017).We have identified a suite of Eoarchean tonalitic gneisses dated at^3.7 Ga from the Tarim Craton,northwestern China(Ge et al.,2018).These rocks are probably the oldest high-pressure TTGs so far documented worldwide.Thermodynamic and trace element modelling demonstrates that the parent magma may have been generated by water-fluxed partial melting of moderately enriched arc-like basalts at 1.8–1.9 GPa and 800–830°C,indicating an apparent geothermal gradient(400–450°CGPa-1)typical for hot subduction zones.They also locally record geochemical evidence for magma interaction with a mantle wedge.Accordingly,we propose that these highpressure TTGs were generated by partial melting of a subducted proto-arc during arc accretion.Our model implies that modernstyle plate tectonics was operative,at least locally,at^3.7 Ga and was responsible for generating some of the oldest continental nuclei.

摘要： The Cambrian Period is the first period of the Phanerozoic Eon and witnessed the explosive appearance of the metazoans, representing the beginning of the modern earth-life system characterized by animals in contrary to the Precambrian earth-life system dominated by microbial life. However, understanding Cambrian earth-life system evolution is hampered by regional and global stratigraphic correlations due to an incomplete chronostratigraphy and consequent absence of a highresolution timescale. Here we briefly review the historical narrative of the present international chronostratigraphic framework of the Cambrian System and summarize recent advances and problems of the undefined Cambrian stage GSSPs, in particular we challenge the global correlation of the GSSP for the Cambrian base, in addition to Cambrian chemostratigraphy and geochronology. Based on the recent advances of the international Cambrian chronostratigraphy, revisions to the Cambrian chronostratigraphy of China, which are largely based on the stratigraphic record of South China, are suggested, and the Xiaotanian Stage is newly proposed for the Cambrian Stage 2 of China. We further summarize the integrative stratigraphy of South China, North China and Tarim platforms respectively with an emphasis on the facies variations of the Precambrian-Cambrian boundary successions and problems for identification of the Cambrian base in the different facies and areas of China. Moreover, we discuss stratigraphic complications that are introduced by poorly fossiliferous dolomite successions in the upper Cambrian System which are widespread in South China, North China and Tarim platforms.

摘要： Two Biradiolites species described from the Yigeziya Formation of the southwestern Tarim Basin are revised. The Maastrichtian Biradiolites boldjuanensis is small and pipe-like species that is usually preserved as clusters or bouquets. Although it was considered to be endemic to Central Asia, similar specimens are abundant in Maastrichtian of other Tethyan regions. Biradiolites minor specimens have no relationship with the genus Biradiolites because their ventral and posterior bands are protruding ridges and interband is depressed broad groove. This species is comparable with the Campanian-Maastrichtian eastern Arabian species Glabrobournonia arabica, by the character of smooth outer shell layer in right valve, and simple radial bands and ridges on margin of each shell flank, but it differs from the latter species in size and the shape of left valve. This study will be a supportive tool for the establishment and reconstruction of the palaeogeographic connection between Central Asia and other Tethyan regions.

摘要： Numeral Permian mafic-ultramafic complexes occur in the Beishan terrane atthe northeastern margin of the Tarim craton,southwestern Central Asian Orogenic Belt,including the Pobei,Cantoushan,Bijiashan,Hongshishan,Xuanwoling,Zhongposhan and Luodong etc.,intrusions(Qin et al.,2011;Zhang et al.,2017;Xue et al.,2018).These Beishan mafic-ultramafic complexes are composed of peridotite,pyroxenite.

摘要： The early Cambrian carbonaceous shale and laminated chert-phosphorite assemble (the black rock series) are widespread at the northwest margin of the Tarim Basin, Northwest China. In combination with previously reported data, we present stable molybdenum isotope (δ98/95Mo), TOC, and redox-sensitive trace elements to evaluate the sedimentary conditions in early Cambrian water column during the deposition of the black rock series in the Tarim Basin. Redox variation was documented based on enrichment factors (MoEF, VEF, and UEF) and redox-sensitiv elements ratios (Ni/Co, V/Cr, δU), etc. During the early Cambrian, there was transgressive event, and the sea level continues to rise. In the basal Cambrian, laminated chert-phosphorite assemble with low TOC concentrations suggest the oxic sedimentary condition in a restricted basin. Light Mo isotope values and redox sensitive elements enrichment in the carbonaceous shale layer indicate lack oxygenic sedimentary condition, and was suboxic/anoxic conditions during the transgressive phase. The hydrothermal fluids from the open ocean affected the whole deposition process of the black rock series.

摘要： Evaporite series is both an important target area looking for high-quality large potash deposits,but also one of the main types of hydrocarbon cap.Outcrops and drilling results indicate that five sets of evaporites were

摘要： The Asiatic Wild CatFelis silvestris ornataisregarded as “Least concerned” (LC) first, as “Vulnerable” (VU) and following “Endangered” (EN) and then “Critically endangered” (CR) species as finally and originally concentrative distribute in Xinjiang Tarim Basin region in northwest China. This paper provides comprehensive information on bio-morphology, habitat selectivity, environmental condition, habit, preyfeed source and every item of composition, and relationship among Wild Cat and domestic cat at presence investigated in 2004-2006 and 2011- 2013 as especial study. The paper also illustrated some dynamical statistics of wild cat’ pelt collection by national trade from three prefectures in the last 40 years. Briefing the results of indication that large scale and continuous openup land for cotton in unplanned, exploit petroleum and natural gas, misapply water and destroy desert vegetation, poaching and killing prey objectives, etc., of them long-term effects on plants functional density and qualities of the cat surviving habitat and productivity, whereas pressures of increasing human population to fragile desert ecosystem showed efficiency and desirable effects of the cat surviving.

摘要： In order to get the correct isotopic age, SHRIMP U-Pb zircon date of Precambrian hornblende granite in Well TD2, located in the central aeromagnetic belt in the eastern of the Tarim basin, was carried out. The result showed a dependable age of 1908.2 ± 8.6 Ma, which demonstrated that the granite pluton is the result of the magmatic activity in early Palaeoproterozoic. It is indicated that the central aeromagnetic belt across Tarim basin, divided it into north and south block, is formed before Neoproterozoic by a large scale tectonothermal events based on the seismic and drilling date. The Tarim continent may have different age and type basements formed the united crystalline basement in Precambrian. This result has yielded new intraplate evidence to constrain the relation between the Tarim plate and the Colombia supercontinent.

摘要： Discovered in S15 and some other wells, the Lower Ordovician in the northern Tarim Basin consists mainly of brown gray-dark gray very fine-fine crystalline dolomite, with a minor portion of locally light gray-white medium-coarse crystalline dolomite. Silicification can be observed in the medium-coarse dolomite, and some euhedral drusy quartz can also be found in pores and fractures of the dolomite. The homogenization temperature of the fluid inclusions in the medium-coarse dolomite is between 110 and 200°C with maximum between 140 and 190°C, and the salinity is between 10.7 and 18.5 wt.% NaCl Eq. The homogenization temperature and salinity of the fluid inclusions in the medium-coarse dolomite are similar to those in the drusy quartz. Compared with the very fine-fine dolomite, the medium-coarse phase contains relatively high Fe and Mn. The average concentration of FeO and MnO in the medium-coarse dolomite is 1.917% and 0.323%, respectively. The medium-coarse dolomite has a remarkable negative Eu anomaly, consistent with the REE pattern of the intermediate-felsic igneous rocks in the Tarim Basin. The oxygen isotopic composition of the medium-coarse dolomite is relatively lighter than that of the very fine-fine dolomite. The δ18OPDB values of the medium-coarse dolomite are between -10.35‰ and -7.31‰. The δ18OSMOW values of the fluid associated with the medium-coarse dolomite can be calculated according to homogenization temperature and oxygen isotope fractionation factor between dolomite and fluid, and the calculated values are between +4‰ and +10‰, consistent with those of the hydrothermal fluid. The medium-coarse dolomite has relatively high 87Sr/86Sr ratios as well, indi- cating an origin associated with intermediate-felsic igneous rock. The homogenization temperature, element composition, REE pattern, oxygen and strontium isotopes demonstrate that the medium-coarse dolomite is the result of recrystallization of very fine-fine dolomite under hydrothermal environment. The hydrothermal dolomite recrystallization is a special event but exists extensively in the Tarim Basin. The recrystallized dolomite becomes well reservoir bed for many intercrystalline pores and dissolution pores are produced in this event, so that more attention should be paid to the altered dolomite during the petroleum exploration in the lower Paleozoic in the Tarim Basin.