Sedimentary Response of Different Fan Types to the Paleogene-Neogene Basin Transformation in the Kuqa Depression,Tarim Basin,Xinjiang Province

A group of alluvial fans formed in the early Paleogene represent marginal sedimentary facies at the foot of the South Tianshan Mountain, Kuqa Depression, Tarim Basin, Xinjiang province. Two types of fans occurred in the middle-late Paleogene Kumugeliemu and Suweiyi formations： one alluvial, and the other fan delta deposited in a lacustrine setting. Within the early Neogene Jidike Formation, coastal subaqueous fans developed, probably in a deeper water lacustrine setting. The three types of fans are stacked vertically in outcrop with the sequence in ascending order： bottom alluvial, middle fan-delta, and top suhaqueous. The subaqueous is a typical coarse-fan deposit occurring in the glutinite member of the Jidike Formation in some wells. Laterally, from the foreland to the lacustrine settings, the distribution pattern of sedimentary facies represents the same three fan types sequentially. The spatial distribution of these fans was controlled by the Paleogene-Neogene Basin transformation, and evolution with different types of fans developed in the Kuqa Depression in response. In the Paleogene, the Kuqa Depression was a rift basin where an alluvial fan was deposited in the foreland setting, which, by early Neogene, became a foreland basin when the lake level changed. With any rise in lake level, fan-deltas migrated from lacustrine to foreland settings, whereas when the lake level fell, fan migration was reversed. In the early Neogene, with increasing slope and rising lake level, fans progressed and covered the previous fan-delta and lacustrine mudstone. Eventually, subaqueous fans developed, forming the present spatial configuration of these three fan types.

Bio-geomorphologic features and growth process of Tamarix nabkhas in Hotan River Basin, Xinjiang

Tamarix nabkha is one of the most widespread nabkhas, distributing in the arid region of China. Based on the observations outdoors and the simulation experiments in laboratories, analysis in this paper refers to the biological geomorphologic features and growth process of Tamarix nabkhas in the middle and lower reaches of the Hotan River, Xinjiang. And the results indicate that the ecological type of Tamarix in the study area is a kind of Tugaic soil habitat based on the deep soil of the Populus Diversifolia forests and shrubs. This type of habitat can be divided into three kinds of sub-habitats which demonstrate the features of ecological environment of Tamarix nabkhas during the differential developed phases. Meanwhile, the Tamar, ix nabkha can exert intensified disturbance current on wind-sand flow on the ground,and its root and stems not only have strong potential of sprouting but are characteristic of wind erosion-tolerance, resistance to be buried by sand and respectively tough rigid of the lignified branches, for it has a rather longer life-time. Thus, the wind speed profile influenced by the Tamarix nabkha is different from the Phragmites nabkha and Alhagi nabkha. And the structure of the wind flow is beneficial to aeolian sand accumulating in/around Tamarix shrub, which can create unique Tamarix nabkhas with higher average gradient and longer periodicity of life. Tamarix nabkha evolution in the area experienced three stages： growth stage, mature and steady stage and withering stage. In each stage, morphological features and geomorphic process of Tamarix nabkha are different due to the discrep- ant interaction between the nabkha and aeolian sand flow.

Sequence Stratigraphy of the Desert System: A Case Study of the Lower Cretaceous in the Kuqa Basin in Xinjiang, Northwestern China

The Lower Cretaceous strata in the Kuqa Basin in Xinjiang are marked by a set of arid red beds. Several types of sedimentary fades can be identified in this set of arid red beds: mudstones of the plaza and intracontinental sebkha, aeolian sandstones, sandy conglomerates of the intermittent river, conglomerates of the pluvial fan, etc. These types of sedimentary facies constitute a typical desert system. Therefore, the Cretaceous strata in the Kuqa Basin provide a favorable condition for studies of sequence stratigraphic divisions of the desert system. With the rise and fall of the base level of the sedimentary basin, cyclicity is clearly revealed in stratigraphic records, which helps the identification of the third-order sequences. Based on the cyclicity in stratigraphic records, 5 third-order sequences can be found in the strata of the Early Cretaceous in the Kuqa Basin. These sequences comprise a second-order tectonic sequence. The primary feature of these third-order sequences is of an upward-fining sedimentary succession formed by a succession of 'coarse sediments of the alluvial system-fine sediments of the lake system'. The result of this study shows that aeolian sandstones are the best reservoirs of natural gas in the Cretaceous strata in the Kuqa Basin, and that the Kela-2 gas field is the first large gas field dominated by aeolian sandstone reservoirs in China.

MASTODONT REMAINS FROM THE MIOCENE OF JUNGGAR BASIN IN XINJIANG

The mastodont materials described in the present paper, associated with Amblycastor tunggurensis, Amphicyon sp., Anchitherium cf. aurelianense, Brachypotherium sp., ?Chilotherium sp., Stephanocemas thomsoni, Dicrocerus grangeri, Eotragus sp., Oioceros grangeri and O. noverca, were collected from the Haramagai formation of Junggar Basin in Xinjiang by an IVPP field team in 1982. The geology of the area has already been reported by Tong (1986, 1987). The mastodont fossils found at 5 sites on the north and west banks of the Ulungur river, Junggar Basin are abundant. They comprise 5 species, among which is one new species.The author is greatly indebted to the IVPP field team (Tong, Y., the head of the 1982 Junggar field team) allocating the mastodont materials for me to study.

Discovery of Mass Independent Oxygen Isotopic Compositions in Superscale Nitrate Mineral Deposits from Turpan-Hami Basin,Xinjiang,China and Its Significance

The Turpan-Hami Basin in eastern Xinjiang is one of the driest regions on Earth and a premier environment to form and preserve nitrate.A large nitrate ore field in this basin was found recently.It is estimated there are about 2.5 billion tons of resources of nitrate,and the amount is as much as the Atacama Desert super-scale nitrate deposit in Chile.Nitrate is one of a few minerals with mass-independent fractionation（MIF）,and the oxygen isotope MIF is an effective method to determine the source of nitrate.Theδ^（17）O,δ^（18）O of nitrate were measured by fluorination and thermal decomposition method.The date indicated that this is the first time that oxygen isotope MIF has been located in inland nitrate minerals.The results obtained by two methods are similar,⊿^（17）=δ^（17）O-0.52×δ^（18）O=12‰-17‰.The experiment and observation data proved that oxygen isotope MIF of nitrate are the result of photochemical reactions in the troposphere and stratosphere.Thus, evidence from MIF oxygen isotopic compositions indicate that long term atmospheric deposition of nitrate aerosol particles produced by photochemical reactions is the source of the deposits.

The Characteristics and Genesis of the Massive Nitrate Deposits in the Turpan-Hami Basin of Xinjiang,China

Massive nitrate deposits have been discovered in the Turpan-Hami basin in northwestern China.Previously,large ore grade nitrate minerals were thought only to exist in the Atacama Desert in northern Chile.Estimates of the

Status of Asiatic Wild Cat and its habitat in Xinjiang Tarim Basin, China

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.

Geochemical characteristics of crude oils from Well Zheng-1 in the Junggar Basin, Xinjiang,China

Well Zheng-1 is located in the combined area of the central uplift and the north Tianshan piedmont depression in the Junggar Basin. Two oil-bearing beds are recognized at 4788–4797 m of the Lower Cretaceous Tugulu Formation (K1tg) and 4808.5–4812.5 m of the Lower Jurassic Sangonghe Formation (J1s). The geochemical characteristics of family composition, carbon isotopic composition, saturated hydrocarbons, sterane and terpane biomarkers and carotane of two crude oils are described in this paper. The results show that the geochemical characteristics of the two crude oils are basically similar to each other, indicating they were all derived mainly from the high mature, brine, algae-rich lake facies sediments. Oil-source correlation revealed that crude oils of the two beds were derived mainly from the source rocks of Permian and mixed by the oil derived from the source rocks of Jurassic and Triassic. This is consistent with the geological background with several sets of source rocks in the area studied.

Oil is Found in Yanqi Basin in Xinjiang

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Analysis on Hydrological Regimes of the Medium and Small Rivers in Hami of Xinjiang——Take Toudaogou Basin as an Example

[ Objective] The research aimed to analyze hydrological regimes of the medium and small rivers in Hami of Xinjiang. [ Method] According to actual observation data at Toudaogou hydrological station during 1956 -2010, climate, runoff, flood, sediment and water quality in the basin were analyzed. [ Result] Runoff in Toudaogou River was mainly from bedrock fissure water and rainfall, and depended on temperature and precipi- tation in the catchment zone. Runoff in Toudaogou River had very big change during the year. Runoff in whole year mainly concentrated during April -June, which occupied 57.9% of annual runoff. Flood in Toudaogou basin was divided into spring and summer flood from time, and snowmelt and rainstorm flood from type. Sediment load was related to terrain, gradient, runoff, precipitation, flood and process. Suspended sediment load at Toudaogou hydrological station had close relationship with the annual maximum flow capacity of flood peak, and related coefficient was 0.917. [ Conclusion] Hydrological regime in Toudaogou basin basically represented corresponding hydrological information of rivers without glacier water supply in Hami even whole western arid zone of China. The research could provide theoretical basis for scientifically using water resources of the medium and small rivers in the zone.

Cretaceous-Paleocene Foraminiferal Communities from the Western Tarim Basin and Their Environmental Significance

Foraminifera is one of the most important fossil faunas of the marine Cretaceous and Paleocene in the Western Tarim Basin, which can be divided into 9 communities. This paper deals mainly with the changes of environments in which the foraminiferal communities existed,especially with the changes of temperature and salinity revealed by analyses of test composition and trace elements in the tests , and by statistic studies of species density, richness , diversity ,equitability and dominance .

Reservoir geochemistry of the Tazhong Oilfield in the Tarim Basin, China, Part II. Migration, accumulation and mixing of crude oils

Measurements of the absolute and relative concentrations of nitrogen-containing compounds in crude oils from different reservoir strata (Ordovician, Silurian and Carboniferous) in the Tazhong region of the Tarim Basin, Xinjiang, China, showed that even though there are quite a number of factors affecting the distributional and compositional characteristics of neutral nitrogen-containing compounds in crude oils, the distributional and compositional characteristics of crude oils whose source conditions are approximate to one another are influenced mainly by the migration and fractionation effects in the process of formation of oil reservoirs. In addition, crude oils in the Tazhong region show obvious migration-fractionation effects in the vertical direction. Carboniferous crude oils are characterized by high migration parameters and low compound concentrations, just in contrast to Ordovician crude oils. This indicates that crude oils from shallow-level oil reservoirs were derived from those of deep-level oil reservoirs via faults, unconformable contact or carrier beds. Crude oils from the Tazhong region show some migration-fractionation effects in the lateral direction, but mixing of crude oils derived from different hydrocarbon source rocks in the process of formation of oil reservoirs made it more complicated the migration and accumulation of crude oils, as well as the formation of oil reservoirs.

Structural characteristics of the basement and the prospective of favorable oil and gas blocks in the Tacheng basin

The Tacheng basin has been identified as a Carboniferous basement with a central uplift, sur- rounded by orogenic belts. This identification was based on the comprehensive analysis of field outcrops, regional magnetic and gravimetric data, skeleton seismic profiles, magnetotelluric profiles and drilling data. Here, we present gravimetric and magnetic data analyses of the basement structures of the Tacheng basin and its base formation. We also provide a magnetotelluric profile analysis of the structural features and tectonic framework of basin-mountain patterns. We use local geology, drilling data, and other comprehensive information to document the tectonic framework of the basement of the basin. Small-scale nappe structures are found in the northern basin, whereas stronger and more pronounced thrusting structures are found to the south and east of the basin. The basin is divided into four first-order tectonic units： a central uplift, a northern depression, a southeastern depression and a western depression. In addition, the Emin sag is suggested as a possible reservoir for oil and gas.

塔里木河流域土地利用及人类活动强度的时空演化特征研究

[研究目的]人类活动引起的土地利用/覆被变化是全球环境变化的重要组成部分,旱区土地利用对区域水文和生态的影响尤为显著,探究土地利用变化及其对人类活动的响应对西北干旱内陆生态与资源环境可持续发展具有重要意义。[研究方法]基于1980-2018年间共5期遥感影像,结合土地利用动态度、土地利用转移矩阵和人类活动强度指数分析塔里木河流域各水资源分区土地利用变化特征。[研究结果]近40年中,塔里木河流域耕地、建设用地和林地面积分别增加1.58×10^(4)km^(2)、1.2×10^(3) km^(2)和347 km^(2),而草地、未利用地和水域面积分别减少1.33×10^(4)km^(2)、0.32×10^(4)km^(2)和815 km^(2)。各水资源分区中塔里木河干流土地利用类型变化最大,其次为渭干河、阿克苏河和喀什噶尔河流域。自2000年以来,塔里木河流域建设用地当量面积和人类活动强度增加相对较快,特别是2000-2010年间呈显著增长趋势。[结论]塔里木河流域各水资源分区的人类活动强度呈显著的空间差异性。社会经济发展和政策的导向性作用是塔里木河流域土地利用变化和人类活动强度的主要影响因素。

新疆东准噶尔红山铜矿床地质特征及成矿规律研究

红山铜矿是在新疆东准噶尔老爷庙一带新发现的铜矿床,红山铜矿铜矿体均赋存于红山铜矿化蚀变带内,并严格受黑园山深大断裂控制。红山铜矿的赋矿围岩为下石炭统黑山头组蚀变火山碎屑岩,铜金矿化与中酸性浅成斑岩体具有成因联系,围岩蚀变中的黄铁绢英岩化、硅化、黄铁矿化与铜金成矿关系密切,铜矿体规模大、数量多,2号和8号矿体为主矿体,钻孔中见到厚大富铜矿体,矿床深部具有较大的找矿潜力。研究表明,中酸性浅成斑岩体控制着铜矿体的规模和质量,且对金属矿物分带也产生影响,成矿时代晚于斑岩体的侵位时间,大致为石炭纪末—二叠纪初。红山铜矿的矿床类型为与中酸性浅成斑岩有关的岩浆热液型(斑岩型)铜金矿床。

新疆叶尔羌河流域景观生态风险评价及预测

景观生态风险评价是衡量一定范围内生态系统安全的重要手段。以叶尔羌河流域为研究区,综合Markov-PLUS模型与景观生态风险评价指数,分析并预测土地利用与景观生态风险的演变特征及未来多情景下的变化趋势,划分风险重点管理区域。结果表明:(1)2005—2020年叶尔羌河流域耕地、水体与建设用地增加,林地、草地与未利用地减少。2035年Ⅰ情景下土地利用遵循历史发展模式变化。相较于Ⅰ情景,Ⅱ情景下耕地增加,其他地类减少;Ⅲ情景下林地、草地与水体增加,耕地、建设用地与未利用地减少。(2)2005—2035年叶尔羌河流域景观生态风险整体呈上升趋势,空间分布呈“西南部低、东北部高”的特征。风险恶化区主要聚集在海拔较低的冲积平原,风险保持区主要分布在海拔较高的山地与冰川。(3)较Ⅰ情景与Ⅱ情景而言,Ⅲ情景景观生态风险指数均值较小,是未来流域实现生态保护和经济发展双赢的最优情景。(4)叶尔羌河流域东北部冲积平原为稳定高风险区,冲积平原边缘与西部山地为风险易变区,南部山地与冰川为风险增加滞后区。研究结果可为当地景观生态安全格局优化与生态风险防范或降低提供参考。

东疆地区石炭纪—二叠纪构造古地理与原型盆地演化

石炭纪—二叠纪是东疆地区洋-陆转换的关键构造转折期,期间发生了多次洋壳闭合和陆陆碰撞活动。基于东疆地区洋盆性质、沟-弧-盆俯冲事件和陆陆碰撞的复杂性,目前针对东疆地区盆地晚古生代地层格架对比以及沉积充填特征认识不足。文中以活动论构造古地理思想为指导,复原东疆地区盆山构造带的构造-沉积面貌,厘定各构造地层单元的构造-沉积环境,从沉积充填、构造演化复原、周缘构造环境等角度来综合地、动态地开展原型盆地恢复。研究结果表明:东疆地区经历了早石炭世伸展、早石炭世末期—晚石炭世早期弱伸展、晚石炭世末期挤压、早二叠世早期伸展、早二叠世末期挤压5期伸展聚敛旋回,随后经历了晚二叠世、晚三叠世、晚侏罗世、晚白垩世—古近纪、晚新生代5期构造改造过程。盆山构造复原揭示了石炭纪吐哈盆地南部边界距现今盆山边界向南46~70 km,石炭纪准东盆地北部克拉美丽山距现今向北约30 km,三塘湖盆地北部造山带石炭纪边界距今约55 km。东疆地区沉积环境经历了从石炭纪海相到早二叠世海陆过渡相再到中晚二叠世陆相的沉积演化,石炭纪发育海相的弧相关断陷盆地、裂谷边缘盆地、断陷盆地,早二叠世以发育海相、陆相断陷盆地为主,中二叠世主要发育陆相坳陷盆地,晚二叠世发育挤压型坳陷盆地。解析东疆地区盆山构造格局及石炭纪—二叠纪构造古地理演化,为探究东疆地区主要沉积盆地石炭系—二叠系成藏条件、源-储组合分布奠定良好基础。

塔克拉玛干沙漠北缘发现红沙蚺兼记繁殖数量新纪录

2017年5月—2021年10月,在塔克拉玛干沙漠北缘进行动物学野外实习和项目调研过程中,多次发现并采集到一种中小型蛇类。依据2017、2018年采集固定的2号标本及2020年采集到的母蛇,鉴定为红沙蚺(Eryx miliaris)。2020年采集到的母蛇产子16条。本次在塔克拉玛干沙漠北缘发现红沙蚺及其繁殖数量为其分布和繁殖数量新纪录。标本保存于塔里木大学生命科学与技术学院动物学标本室(R-2017-1,R-2018-1)。

库车坳陷东部阿合组地层水化学特征及其油气响应

【研究目的 】地层水作为油气运移的载体,对油气成藏具有重要意义。塔里木盆地库车坳陷东部侏罗系阿合组油气藏的油水分布关系复杂,地层水特征及其与油气藏的关系缺少系统研究。【研究方法 】为了明确地层水化学特征及其与油气藏之间的关系,在对地层水样品筛选的基础上,对库车东部阿合组的地层水测试数据进行分析,研究地层水的水型、矿化度、离子比例系数的分布特征及其油气意义。【研究结果 】阿合组的地层水主要为NaHCO_(3)型,其次为CaCl_(2)型和MgCl_(2)型,矿化度相对较低。地层水的矿化度、离子比例系数具有受构造控制的特点:在构造的开启区、地层的尖灭区,地层水主要为低矿化度的NaHCO_(3)型,钠氯系数、脱硫酸系数较高且变质系数为负值,而封闭性的地层中地层水具有相反的化学特征。【结论 】地层水化学特征与油水层的平面分布特征有较好的耦合关系,以迪北油气藏为例,依奇克里克断裂以北虽经历过油气的充注,但已经生成的油气沿着断裂逸散,低矿化度、高钠氯系数、高脱硫酸系数、低变质系数及高高岭石含量表明地层受到了沿断裂进入大气降水的影响;而断裂以南相反的地层水化学特征及高岭石含量反映地层封闭性较好,受大气降水影响小,对应了气藏的分布。地层水的化学特征与油气藏的分布关系为后续致密油气藏的勘探开发和评价提供一定依据。