A Report of the Newly Discovered Cu–Ni Ore Deposit in the West of East Tianshan, North Xinjiang, China

Objective The Early Permian mafic-ultramafic intrusions （298- 270 Ma, Mao et al., 2008）, which are widely distributed in different tectonic domains in North Xinjiang, host magmatic sulfide ore deposits, making North Xinjiang the second most important region for Ni resources in China. The bulk of Cu-Ni ore deposits in East Tianshan, making up a large portion of Ni resources in North Xinjiang, were concentrated in the east of East Tianshan （the Huangshan- Jing＇erquan region） （Feng Yanqing, et al., 2017）, while no any analogue was discovered in the west of East Tianshan until the Lubei Cu-Ni （Co） ore deposit （90°21＇E, 42°10rN） was identified by Xinjiang Geological Survey in 2014. The Lubei Cu-Ni （Co） ore deposit is a medium- to large- sized deposit with Ni and Cu grades in the range 0.2%- 7.76% and 0.2%-2.30%, respectively. This work has initiated the prospection for a large-sized Cu-Ni ore deposit in the west of East Tianshan.

LONG AND DEEP DIVERSION TUNNELS OF 1^(ST) STAGE PROJECT IN WEST ROUTE OF SOUTH-NORTH WATER TRANSFER PROJECT

West Route of South-North Water Transfer Project,situated in southeastern Qinghai-Tibet Plateau,is a giant project,which will deliver 17 billion m3 of water from the main stream and tributaries upstream of the Yangtze River to the upper reaches of the Yellow River. It is to be constructed in 3 stages, of which the 1st stage project includes delivering 4 billion m3 of water by gravity from two tributaries of Yalong River and three tributaries of Dadu River. The project consists of 5 dams,7 tunnels and a channel in series,with the dam height of 63～123 m and water transfer length of 260.3 km,of which the tunnels measure 244.1 km. The special climatic,environmental and geologic conditions make the project much more complicated in construction,especially 3 tunnels with the length longer than 50 km each create challenges to the technical requirements of engineering survey,design and construction.

3D Velocity Structure and Its Tectonic Implications in the East China Sea and Yellow Sea

3D structure of the crust and upper mantle in the studied area has been analyzed from surface wave tomography. The velocity distribution in the uppermost crust is symmetrical on two sides of the central line of the sea, and coincides with the structure of crystalline basement. The essential difference in tectonics between the East China Sea and the Yellow Sea mainly lies in that the velocity structures of their lower crust and upper mantle are identical to those of South China and North China respectively. In the upper mantle there exists a high-velocity zone with a nearly EW strike from the Hangzhou Bay, China, to the Tokara Channel, Japan, along about the latitude of 30°N. It is found that between the East China Sea and the Yellow Sea there are systematical differences in geomorphology, geology, seismicity, heat flow, quality factor and gravity and aeromagnetic anomalies, which is related to both left-lateral shear dislocation and right-lateral tear of the Benioff zone from the Hangzhou Bay to the Tokara Channel.It is inferred that the East China Sea was formed by Cenozoic back-arc extension. The boundary between the North China and South China crustal blocks stretches along the southern piedmont of Mts. Daba-Dabie-Hangzhou Bay-Tokara Channel, and the subduction zone at the Okinawa trench is the eastern boundary of the South China crustal block. The movements of the Pacific plate, Indian plate and upper mantle rather than the Philippine plate subduction have played a dominant role for the modern tectonic movements in East Asia.

Relationship between the simulated East Asian westerly jet biases and seasonal evolu-tion of rainbelt over eastern China

A possible reason for the unreasonable simula- tion of maximum rainfall location, intensity and seasonal evolution over eastern China in CCM3 has been investigated. The analyses focus on the relationship between the simulated East Asian subtropical westerly jet biases and the seasonal evolution of rainbelt over eastern China. Comparisons of the simulated and observed precipitation distributions indicate that the simulated maximum rainfall location, intensity and seasonal evolution are inconsistent with reality. The simu- lated westerly jet center is located to the north of 40°N, which shifts eastward and northward and strengthens, com- pared with NCEP/NCAR reanalysis. The correlation analysis shows that there exists a significant positive correlation be- tween the maximum rainfall amount and zonal wind at 200 hPa over the Great Bend of the Huanghe River. Thus the simulated unrealistic heavy precipitation in the inland area of western China is related to the biases in the location and intensity of the East Asian subtropical westerly jet. Further analysis indicates that the temperature differences from south to north in the lower troposphere and the larger sensi- ble heating over the southeast Tibetan Plateau are responsi- ble for the westerly jet location and intensity biases. There- fore, much more attention should be paid to the accurate simulation of the surface heating near the Tibetan Plateau and the location and intensity of the East Asian subtropical westerly jet for the improvement of precipitation simulation over East Asia.

Interannual Meridional Displacement of the East Asian Upper-tropospheric Jet Stream in Summer

On the interannual timescale, the meridional displacement of the East Asian upper-tropospheric jet stream (EAJS) is significantly associated with the rainfall anomalies in East Asia in summer. In this study, using the data from the National Centers for Environmental Prediction-Department of Energy (NCEP/DOE) reanalysis-2 from 1979 to 2002, the authors investigate the interannual variations of the EAJS's meridional displacement in summer and their associations with the variations of the South Asian high (SAH) and the western North Pacific subtropical high (WNPSH), which are dominant circulation features in the upper and lower troposhere, respectively. The result from an EOF analysis shows that the meridional displacement is the most remarkable feature of the interannual variations of the EAJS in each month of summer and in summer as a whole. A composite analysis indicates that the summer (June-July-August, JJA) EAJS index, which is intended to depict the interannual meridional displacement of the EAJS, is not appropriate because the anomalies of the zonal wind at 200 hPa (U200) in July and August only, rather than in June, significantly contribute to the summer EAJS index. Thus, the index for each month in summer is defined according to the location of the EAJS core in each month. Composite analyses based on the monthly indexes show that corresponding to the monthly equatorward displacement of the EAJS, the South Asian high (SAH) extends southeastward clearly in July and August, and the western North Pacific subtropical high (WNPSH) withdraws southward in June and August.

Revisiting the Second EOF Mode of Interannual Variation in Summer Rainfall over East China

The second EOF（EOF2） mode of interannual variation in summer rainfall over East China is characterized by inverse rainfall changes between South China（SC） and the Yellow River-Huaihe River valleys（YH）.However,understanding of the EOF2 mode is still limited.In this study,the authors identify that the EOF2 mode physically depicts the latitudinal variation of the climatological summer-mean rainy belt along the Yangtze River valley（YRRB）,based on a 160-station rainfall dataset in China for the period 1951-2011.The latitudinal variation of the YRRB is mostly attributed to two different rainfall patterns：one reflects the seesaw（SS） rainfall changes between the YH and SC（SS pattern）,and the other features rainfall anomalies concentrated in SC only（SC pattern）.Corresponding to a southward shift of the YRRB,the SS pattern,with above-normal rainfall in SC and below-normal rainfall in the YH,is related to a cyclonic anomaly centered over the SC-East China Sea region,with a northerly anomaly blowing from the YH to SC;while the SC pattern,with above-normal rainfall in SC,is related to an anticyclonic anomaly over the western North Pacific（WNP）,corresponding to an enhanced southwest monsoon over SC.The cyclonic anomaly,related to the SS pattern,is induced by a near-barotropic eastward propagating wave train along the Asian upper-tropospheric westerly jet,originating from the mid-high latitudes of the North Atlantic.The anticyclonic anomaly,for the SC pattern,is related to suppressed rainfall in the WNP.

Estimation and analysis of the ratio of transpiration to evapotranspiration in forest ecosystems along the North-South Transect of East China

The ratio of transpiration to evapotranspiration (T/ET) is a key parameter for quantifying water use efficiency of ecosystems and understanding the interaction between ecosystem carbon uptake and water cycling in the context of global change.The estimation of T/ET has been paid increasing attention from the scientific community in recent years globally.In this paper,we used the Priestly-Taylor Jet Propulsion Laboratory Model (PT-JPL) driven by regional remote sensing data and gridded meteorological data,to simulate the T/ET in forest ecosystems along the North-South Transect of East China (NSTEC) during 2001-2010,and to analyze the spatial distribution and temporal variation of T/ET,as well as the factors influencing the variation in T/ET.The results showed that:(1) The PT-JPL model is suitable for the simulation of evapotranspiration and its components of forest ecosystems in Eastern China,and has relatively good stability and reliability.(2) Spatial distribution of T/ET in forest ecosystems along NSTEC was heterogeneous,i.e.,T/ET was higher in the north and lower in the south,with an averaged value of 0.69;and the inter-annual variation of T/ET showed a significantly increasing trend,with an increment of 0.007/yr (p<0.01).(3) Seasonal and inter- annual variations of T/ET had different dominant factors.Temperature and EVI can explain around 90%(p<0.01) of the seasonal variation in T/ET,while the inter-annual variation in T/ET was mainly controlled by EVI (53%,p<0.05).

A preliminary study on the intermediate water masses in the tropical West Pacific

Based on the CTD data of China's first WOCE cruise in winter of 1991, and those of the first and second Chinese TOGA cruises in the winters of 1985 and 1986, we apply the classical method of T-S diagram analysis to identify intermediate water masses in the tropical West Pacific and study their distribution feature. Results of these analyses show that there are mainly two kinds of intermediate water masses, namely, the mouth Pacific intermediate Water (SPIW) and the North Pacific intermediate Water (NPIW) in the tropical West Pacific. The NPIW extends from north to south with its southern boundary generally at about 8° N. However, it is westwards intensified near the coast of Mindanao Island where it extends further south to about 5° N with more distinctive characteristics of low salinity and low temperature. The SPIW extends from south to north with its northern boundary at about 12° N. In the zonal area between 0° and 4° N various intermediate waters interact. The analysis also shows the existence of interannual variations of NPIW in the tropical West Pacific.

Petrography and Geochemical Characterization of Dolerites from Figuil (Northern Cameroon) and Léré(Southwestern Chad)

This work presents the petrographic and geochemical data of the dolerite dykes crosscutting the Pan-African basement of Figuil (North-Cameroon) and Léré (South-West Chad) in order to approach their petrogenesis and their emplacement context. Two groups of dolerites have been highlighted by petrographic and geochemical studies. These groups were discriminated by their TiO2, Fe2O3, REE, Ba, Nb, Zr, La and Hf contents which are relatively higher in group I;group II, on the other hand, has higher MgO, Mg#, Sc, Ni and Cr contents. The mineralogical assemblage of these dolerites is made up by plagioclases, pyroxenes, olivine, oxides, amphibole, biotite and sometimes pyrite, calcite, apatite, epidote and chlorite. The behaviour of the major and trace elements suggest that studied dolerites have an evolution dominated by fractional crystallization. Most dolerite samples show higher REE concentrations and (La/Yb)N > 8.7, (Tb/Yb)N > 1.9 and Dy/Yb > 2 ratios characterizing a garnet-bearing mantle. The difference in incompatible elements between the two groups is explained by the degree of partial melting of the same source which becomes more important over time. Low (Ce/Yb)N values (3.3 - 11.58) also suggest relatively low partial melting degree of the source. Fractional crystallization process was possibly combined with minor crustal contamination as shown by enrichment of Th/Yb from group II to Group I that might be due to turbulent magma emplacement. The chemical compositions of these dolerites are similar to that of continental tholeiites with slightly moderate negative Nb-Ta anomalies which are attributed to crustal contamination of magmas. As other dolerites of Cameroon, continental tholeiitic signature of the studied dolerites is evidenced in geotectonic discrimination diagrams with Group II dolerite compositions falling within the field of tholeiitic basalts and group I within the field of alkali basalts.

DEFINITING AND ITS GEOLOGIC MEANING OF SOUTH-NORTH TREND FAULTED STRUCTURE BELT IN QIANGTANG BASIN, NORTH PART OF TIBET

There were more expounding to north—west (west) trend fault and north\|east trend fault within Qiangtang Basin, North Part of Tibet, in the past literature. With increasing of geophysical exploration data, nearly east\|west trend structure began to be taken note to. Since the year of 1995, by a synthetic study to geophysical and geological data, that south\|north trend faulted structures are well developed. These structures should be paid much more attention to, because they have important theoretical meaning and practical significance.1 Spreading of south\|north faulted structure belt According to different geological and geophysical data, the six larger scale nearly south\|north faulted structure belt could be distinguished within the scope of east longitude 84°～96° and near Qiangtang Basin. The actual location of the six belts are nearly located in the west of the six meridian of east longitude 85°,87°,89°,91°,93°,95° or located near these meridian. The six south\|north faulted structure belts spread in the same interval with near 2° longitude interval. The more clear and much more significance of south\|north trend faulted structure belts are the two S—N trend faulted structure belts of east longitude 87° and 89°. There are S—N trend faulted structure belts in the west of east longitude 83°,81°, or near the longitudes. The structure belts spreading features,manifestation,geological function and its importance, and inter texture and structure are not exactly so same. The structure belts all different degree caused different region of geological structure or gravity field and magnetic field. There is different scale near S—N trend faulted structure belt between the belts.

Subseasonal reversal of haze pollution over the North China Plain

中国近几十年来频受雾霾污染问题困扰,其中华北平原作为排放最密集的区域之一,常遭遇不同尺度的严重雾霾污染本文利用30余年的能见度和颗粒物(PM_(2.5))观测数据,发现了华北平原地区在秋季和早冬时雾霾污染在次季节尺度上“跷跷板式”反向变化的关系.研究发现,当9-10月污染较轻(重)时,11-12月的污染倾向于加重(减轻).这种突然的变化与局地和大尺度环流的反向变化有关,污染较重的月份常伴随有更高的相对湿度,更低的边界层高度和近地面风速以及低层的南风异常,均不利于污染的垂直和水平扩散和传输,从而导致了次季节尺度上霾污染的加重,进一步的研究发现环流场的突然转向与在次季节尺度上活跃的中纬度波列的传播密切相关,而此波列可能主要与大西洋海温转变及引起的EA/WR遥相关型有关,这一次季节反向变化为霾污染多尺度变率预测提供了新的理解,同时为华北地区年度空气质量达标的短期目标提供了具有可行性的参考方法.

气候变化对南水北调西线工程的影响及建议

南水北调工程是国家水网的重要组成部分,其西线工程建设是缓解我国西北、华北地区水资源短缺的重要举措。气候变化下西线工程引水区和受水区水资源情势直接关系到工程的规划建设与运行方式。基于历史实测资料和气候模式情景,采用数理统计与水文模拟相结合的途径分析了气候变化对南水北调西线工程引水区和受水区水资源的影响。结果表明:1)1961—2020年西线调水区和受水区气候变化以暖湿化为主要特征,调水区年径流量整体稳定略增,受水区年径流量显著性减少。2)未来中期(2035年)和远期(2050年),调水区和受水区气温继续显著升高,降水多呈非显著增加;未来中期、远期调水区年径流量较基准期(1961—2000年)分别增加1.42%和2.08%,受水区年径流量分别减少1.02%和0.28%。3)未来气候变化下,调水区年径流量相对稳定,能够满足调水需求,受水区年径流量略减,对跨流域调水需求有所增加。为确保南水北调西线工程的长期稳定运行,建议加强气候变化及其影响的不确定性研究,制定科学合理的应对措施,以应对未来可能的水资源短缺的挑战。

南水北调西线工程上线水源区大型底栖动物群落结构及环境驱动因子

为评估南水北调西线工程上线水源区大型底栖动物群落结构及环境驱动因子,于2022年7月(汛期)和11月(非汛期)开展监测采样工作。采用生物多样性指数和丰度-生物量比较曲线(ABC曲线)作为大型底栖动物群落特征参数,分析大型底栖动物群落在水源区的结构,并对其进行多元排序和Pearson相关性分析。结果表明:共采集45种大型底栖动物,隶属于4门5纲10目32科44属,其中优势种8种,所有优势物种出现频率均大于50%,水源区大型底栖动物群落结构一致性较高;水源区Margalef丰富度指数、Shannon-Wiener多样性指数和Pielou均匀度指数均值分别为4.01、1.68、0.61;多数采样区域大型底栖动物的ABC曲线呈纠缠态势,其丰度和生物量累积百分比的差值面积在0附近波动,群落以小个头物种为主;优势种以耐污值低的敏感种类为主,说明河流几乎不受污染,水体清洁;pH值是影响水源区大型底栖动物群落结构的主要环境驱动因子。

基于多方法综合比较的南水北调西线工程水源区生态需水研究

针对南水北调西线工程调水需求,以方法比选、目标修正、可行性验证为主线,提出了一套多方法综合确定水源区生态需水过程的思路,并制定了10个坝址断面枯水期和非枯水期的生态基流、敏感生态需水及年生态水量目标。结果表明:水源区坝址断面枯水期生态基流在多年平均流量中的占比约为20%,非枯水期占比约为40%;3—6月为鱼类集中产卵敏感期,需要每月发生一次脉冲流量过程,每次至少持续10 d,脉冲流量在多年平均流量中的占比为48%~73%;各坝址断面年均生态水量在多年平均径流量中的占比约为70%,其中丰水年、一般偏枯年、枯水年生态水量占比分别为68%~78%、66%~75%和61%~70%;研究结果符合长江流域现有管控要求,具备较好的现实可达性。

夏季南亚高压东-西振荡过程中青藏高原及周边上对流层水汽的分布和传输特征

夏季南亚高压的“双模态”分布对应着其中心位置在10~20天准双周时间尺度上的东—西振荡,对青藏高原及周边上对流层的水汽分布和传输有显著影响。本文利用夏季7~8月逐日的ERAI再分析资料,通过基于南亚高压东—西振荡指数的位相合成分析发现,当南亚高压呈青藏高原模态时,青藏高原(伊朗高原)地区上对流层水汽含量异常偏高(低),伊朗高原模态时则相反;伴随南亚高压中心位置由青藏高原向西移至伊朗高原上空,上对流层水汽含量正异常中心亦自青藏高原东侧向西逐渐传播到伊朗高原以西地区。进一步诊断表明,除了在青藏高原北侧和南侧水汽经向绝热输送异常有抵消作用外,两高原地区上对流层水汽倾向异常主要由水汽纬向绝热输送异常及其辐合辐散异常所贡献,而青藏高原地区对流活动引起的垂直非绝热输送异常在上对流层则主要与剩余项(水汽的凝结和蒸发)相抵消。因此,青藏高原(伊朗高原)上对流层为水汽含量正异常时对应着青藏高原上空的对流活动异常偏弱(强)。而南亚高压中心位置和上对流层水汽含量正异常中心自青藏高原向伊朗高原移动的过程,对应着青藏高原地区的对流活动异常和垂直向上的水汽非绝热输送异常不断增强,同时上对流层水汽凝结异常也不断增强。此外,南亚高压向西移动过程中,上对流层水汽绝热辐合(辐散)异常主要发生在其西(东)侧,这是造成水汽含量异常中心纬向传播的主要原因。

中国东部冬季气温变化的主要区域空间模态及其与大气环流的关系

本文利用1956—2017年我国519个站点逐日气温资料,通过旋转经验正交函数分析方法得到了近62年我国冬季气温变化主要的区域空间模态,研究了其与大气环流的关系,并进一步使用2018—2023年上述站点冬季气温资料进行验证分析。结果表明,我国冬季气温变化有两个较为稳定的区域空间模态:第一模态主要表现为南方大部分地区出现异常低温,低温极值区位于华南和东南沿海区,称之为南方型;第二模态的气温异常信号主要集中在东北地区,称之为东北型。其中,南方型模态与赤道中太平洋的海温呈显著负相关关系,与东亚冬季风的“南北反向”模态呈显著正相关。当冬季赤道中太平洋海温异常偏冷时,东亚南部地区表现为强烈的低层偏北风距平,北方则无显著偏北风距平,造成南方大部分地区出现异常低温。冬季北极涛动与东北型低温模态有显著联系,当北极涛动呈负位相时,冷高压主要集中在极区,高压东侧盛行东北风,造成东北地区冬季气温异常偏低。近6年中,2018年与2021年冬季呈东北型低温模态,其关键环流系统接近北极涛动负位相,验证了该结论。

南水北调东线工程典型供排闸站施工导流分析研究

南水北调东线工程南起扬州长江,经13个梯级提水入东平湖后,穿黄北送等,线路总长1466.5 km。鉴于南水北调输水干线上水工建筑物的功能多样,加固改造时供排水导流工况复杂,选取输水干线典型闸站即沙集闸站,分功能、分时段、分规模、分方案地进行导流,充分保障施工期工程原供排水充分效益发挥。

A quantitative research for present-time crustal motion in Fujian Province, China and its marginal sea── Synthetical analysis of GPS measurement, fault deformation survey, leveling and focal mechanism solution

Based on the Chinese mainland GPS network (1994~1996), Fujian GPS network (1995~1997), cross fault deformation network (1982-1998), precise leveling network (1973~1980) and focal mechanism solutions of the recent several tens years, we synthetically and quantitatively studied the present-time crustal motion of the southeast coast of Chinese mainland-Fujian and its marginal sea. We find that this area with its mainland together moves toward SE with a rather constant velocity of 11 .2±3.0 mm/a. At the same time, there is a motion from the Quanzhou bay pointing to hinterland, with a major orientation of NW, extending toward two sides, and with an average velocity of 3.0±2.6 mm/a. The faults orienting NE show compressing motions, and the ones orienting NW show extending motions. The present-time strain field derived from crustal deformation is consistent with seismic stress field derived from the focal mechanism solutions and the tectonic stress field derived from geology data. The principal stress of compression orients NW (NWW) - SE (SEE). Demarcated by the NW orienting faults of the Quanzhou bay and Jinjiang-Yongan, the crustal motions show regional characteristics f the southwest of Fujian and the boundary of Fujian and Guangdong are areas of rising, the northeast of Fujian are areas of sinking. The horizontal strain rate and the fault motion of the former are both greater than the later. The side-transferring motion of Hymalaya collision zone and the compression of the west pacific subduction zone affect the motion of the research area. The amount of motion affected by the former is larger than the later, but the former is homogeneous and the later is not, which indicates that the events of strong earthquakes in this region relate more directly with western pacific subduction zone.

高速铁路与城市群发展社会经济效应探究

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