大兴安岭大洋山钼矿区侵入岩年代学、岩石地球化学特征及岩石成因

本文研究了黑龙江省大兴安岭东北部大洋山钼矿区中生代侵入岩的年代学和岩石地球化学特征,探讨了研究区中生代侵入岩的形成时代、岩石成因及构造背景。采用电感耦合-等离子体质谱仪(LA-ICP-MS)锆石U-Pb定年方法,获得细中粒二长花岗岩加权平均年龄分别为(177.3±2.6)Ma和(176.5±1.6)Ma,为早侏罗世;闪长玢岩加权平均年龄为(158.0±2.7)Ma,为晚侏罗世。岩石地球化学研究表明:细中粒二长花岗岩具高Si,富K和贫Fe、Mn、Mg等特征,大离子亲石元素Rb、K和LREE富集,高场强元素Nb、Zr、P、Th和HREE亏损,具有显著的Eu负异常(δEu=0.39),结合其低Cr、Ni、Co质量分数和低Mg#值(Mg#为27.25),指示壳源岩浆特征;闪长玢岩偏碱,富K和Na, Ca、Ti、Mg等元素质量分数中等,大离子亲石元素Rb、K、Sr相对富集,高场强元素Nb、Ta、Ti、Th和HREE相对亏损,具俯冲带弧岩浆岩的特征。综合研究表明,细中粒二长花岗岩和闪长玢岩的形成均受到北部蒙古—鄂霍茨克洋俯冲作用的影响,蒙古—鄂霍茨克洋残留部分在大兴安岭东北部俯冲闭合时间为晚侏罗世—早白垩世期间。

西北太平洋不同区域海平面变化特征分析

重点研究西北太平洋长期验潮站海平面变化的季节、年际和年代际变化特征。所选站点多年平均变化速率为1.71mm/a。结果表明,近岸区、大洋沿岸区、大洋区主要周期均为12个月;近岸区、大洋沿岸区、大洋区部分低纬度站点存在6个月周期;所有站点都存在明显的年际和年代际周期信号;中高纬度地区年代际信号强于年际信号,热带地区年际信号强于年代际信号;近岸区、大洋沿岸区、大洋区站点年际和年代际变化具有明显的地域性;热带地区受ENSO影响强于中高纬度地区,热带大洋区受ENSO影响强于大洋沿岸区,热带大洋沿岸区受ENSO影响强于近岸区;受PDO影响较明显的站点位于25°N～40°N的中纬度地区。1993—2010年间,近岸区、大洋沿岸区、大洋区验潮站、大洋区T/P的主要周期均为12个月,但变化速率和季节变化振幅各不同,大洋区验潮站滞后其他区近1个月达到极值。

观三大洋风云变幻,看海鸟儿翱翔聚散 中国远洋科学考察任务的主力科考船“大洋一号”

1872年12月21日,“挑战者”号海洋调查船从英国朴次茅斯港启程驶向浩瀚的大西洋,科学家在此次考察中发现了海底的多金属结核,揭开了100多年后人类寻找深海矿产资源的序幕。在世界新一轮“蓝色圈地运动”的浪潮中,我国以“大洋一号”为代表的远洋科考船走上了世界深海资源勘探和研究的国际舞台,追赶着世界的脚步,其航行的足迹也见证了中国大洋科考广度的拓展。

Interdecadal variability of summer precipitation in the Three River Source Region: Influences of SST and zonal shifts of the East Asian subtropical westerly jet

Summer precipitation in the Three Rivers Source Region(TRSR)of China is vital for the headwaters of the Yellow,Yangtze,and Lancang rivers and exhibits significant interdecadal variability.This study investigates the influence of the East Asian westerly jet(EAWJ)on TRSR rainfall.A strong correlation is found between TRSR summer precipitation and the Jet Zonal Position Index(JZPI)of the EAWJ from 1961 to 2019(R=0.619,p<0.01).During periods when a positive JZPI indicates a westward shift in the EAWJ,enhanced water vapor anomalies,warmer air,and low-level convergence anomalies contribute to increased TRSR summer precipitation.Using empirical orthogonal function and regression analyses,this research identifies the influence of large-scale circulation anomalies associated with the Atlantic–Eurasian teleconnection(AEA)from the North Atlantic(NA).The interdecadal variability between the NA and central tropical Pacific(CTP)significantly affects TRSR precipitation.This influence is mediated through the AEA via a Rossby wave train extending eastward along the EAWJ,and another south of 45°N.Moreover,the NA–CTP Opposite Phase Index(OPI),which quantifies the difference between the summer mean sea surface temperatures of the NA and the CTP,is identified as a critical factor in modulating the strength of this teleconnection and influencing the zonal position of the EAWJ.

国际油轮运输市场:运价反弹乏力

9月,油轮市场需求疲软,交易量下滑;运价缺乏上涨动能,维持低位震荡。亚洲原油进口大国印度进入疫情暴发期,墨西哥湾炼油厂在飓风过后减产,两大洋区运价双双下跌。考虑到多地疫情反弹拖累能源需求前景,OPEC月报进一步调低了全球能源需求前景,原油轮运价在月初中东出货增加而略有修复后,月中再次遭遇打压,继续低位盘整。成品油市场需求随着美国驾驶季的结束而收缩,运价随着下滑。

国际油轮运输市场:震荡上行

11月,油轮市场先扬后抑。原油轮市场,月初为护航中期选举,美国拜登政府持续释放原油战略储备抵抗通胀,刺激出口增加,支撑运价上涨。月中,中国政府优化疫情防控工作的二十条措施出台,政策调整有效缓解了市场对中国能源需求前景的担忧。欧盟对俄原油禁运令将于12月生效,抢运潮下运价继续上涨。月末,受宏观经济前景黯淡拖累,运价有所回调。2022年10月,欧佩克原油产量2949万桶/天,环比下降0.7%,同比增长7.6%。中国原油进口量4324万吨,环比上升7.2%。成品油轮市场,取暖旺季叠加补库存需求,两大洋区运价均大幅上涨。

国际干散货运输市场:冲高回落

10月,国际干散货市场呈冲高回落走势。月初在矿商集中出货的支撑下延续升势,10月6日BCI创下2019年9月以来的最高4208点,带动BDI同步创下13个月以来的高位2097点。随着两大洋区铁矿石密集出货势头的减弱以及中国禁止进口澳大利亚煤炭,好望角型船市场快速下行;巴拿马型船也受到澳煤运量明显减少的冲击震荡下跌;菲律宾雨季影响镍矿出口,灵便型船小幅波动。截至10月27日,10月BDI均值1680点,环比上涨19.1%,同比下跌8.4%;1-10月BDI均值1036点,同比下跌22.6%。

国际油轮运输市场:呈倒N型走势

5月,油轮市场呈倒N型走势。原油轮市场,月初OPEC继续减产,美欧相继加息引发经济衰退与能源需求下降担忧,运价承压下行。月中,中国“五一”假期旅客出行量激增,带动经济复苏和能源需求回升,运价止跌反弹。月末,亚洲炼厂进入维护期后开工率下降,炼油利润疲软进一步打击了原油进口热情,运价再度回落。今年4月,欧佩克原油产量2860万桶/日,环比下降0.7%,同比下降0.3%;中国原油进口量4241万吨,环比下降18.9%。1至4月,中国原油进口量1.79亿吨,同比上升4.6%。成品油轮市场,两大洋区走势分化。太平洋区后半月受亚洲炼厂检修影响,运价先扬后抑;大西洋区后半月迎来出游旺季,运价先抑后扬。

全球干散货运输市场

8月份国际干散货市场呈震荡回升走势。BDI在连续下跌16个交易日后,在好望角型船和巴拿马型船市场回升的带动下,8月10日,BDI再度回升。中国对澳大利亚和巴西铁矿石进口需求支撑好望角型运价升至5周来新高;小宗矿产品支持两大洋区的贸易活跃,小灵便型船租金涨至11个月以来最高。8月BDI均值671点,环比下跌4.6%,同比下跌37.1%。1-8月份BDI平均537点,同比下跌25.8%。

An Ocean Reanalysis System for the Joining Area of Asia and Indian-Pacific Ocean

An ocean reanalysis system for the joining area of Asia and Indian-Pacific Ocean (AIPO) has been developed and is currently delivering reanalysis data sets for study on the air-sea interaction over AIPO and its climate variation over China in the inter-annual time scale.This system consists of a nested ocean model forced by atmospheric reanalysis,an ensemble-based multivariate ocean data assimilation system and various ocean observations.The following report describes the main components of the data assimilation system in detail.The system adopts an ensemble optimal interpolation scheme that uses a seasonal update from a free running model to estimate the background error covariance matrix.In view of the systematic biases in some observation systems,some treatments were performed on the observations before the assimilation.A coarse resolution reanalysis dataset from the system is preliminarily evaluated to demonstrate the performance of the system for the period 1992 to 2006 by comparing this dataset with other observations or reanalysis data.

North Atlantic forcing of autumn drought in Southwest China

Drought often lasts long and is thus closely related to slowly varying external forcing such as sea surface temperature(SST).Here,based on observed precipitation and SST data along with NCEP-DOE reanalysis data,the possible impacts of North Atlantic SST on drought formation in Southwest China are investigated.Results show that northeast-southwest-orientated dipole SST anomalies in the mid-high latitudes of the North Atlantic are closely related to autumn drought in Southwest China;the linear correlation coefficient between them reaches 0.48 during 1979-2020,significant at the 0.001 level.The dipole SST anomalies trigger southeastward-propagating Rossby waves and induce barotropic cyclonic circulation anomalies over India and the western Tibetan Plateau.This enhances the upward motion in northern India and the western Tibetan Plateau and causes a compensating downdraft,reduced precipitation,and consequent drought formation in Southwest China.

Abrupt Climate Changes of Holocene

This paper is a review of studies of abrupt climate changes(ACCs) during the Holocene published during the past ten years.North Atlantic cold events are indicators of ACCs.As indicated by North Atlantic ice-rafted debris(IRD),there were nine confirmed cold events during the Holocene,occurring at 11.1 kyr,10.3 kyr,9.4 kyr,8.1 kyr,5.9 kyr,4.2 kyr,2.8 kyr,1.4 kyr,and 0.4 kyr respectively according to most representative results from Bond et al.(1997).However,the identification of chronology has been made with some uncertainties.Considerable climatic proxy data have shown that,during the cold events,substantial climate abnormalities have occurred widely across the globe,particularly in the areas surrounding the North Atlantic.These abnormalities were in the form of high-latitude cold in the both hemispheres,expansion of the Westerlies to low latitudes,drought in the monsoon regions,recession of summer monsoons,and intensification of the winter monsoons.Studies have indicated that the four ACCs occurring in the early Holocene may be related to freshwater pulses from ice melting in the northern part of the North Atlantic,and the other five ACCs that occurred during the middle and late Holocene may be related to the decreased solar activity.

Bioclimatic Urbanism and Regional Design in Portugal： The Atlantic and the Mediterranean Contexts

The subject of the present work is the study of the relationship between the city shape and its geographical and climatic context. This is a very important feature of the Portuguese city. The Iberian Peninsula comprised by Spain and Portugal belongs to very different environments： the Atlantic and Mediterranean sea. This position is responsible for a series of highly contrasted regions. The external forces presented in each region, influence the shape, location and orientation, not only of individual buildings but of whole villages in such a way that we can identify pattems of construction in different natural regions. There is in fact, a remarkable correspondence between climate and urban type which is useful to identify for planning the different regions. The legacy of industrial city, as in other parts of the world, has changed this close connection between geography and architecture, with consequences not only in environment but especially for the identity of urban spaces. Bioclimatic urbanism is not just a question of sustainability or survival. It is also a question of local identity and variety. There is in fact a relationship between cultural process and environment responsive which we can learn from the structures of the past -- the pre-industrial city. We believe that the reinterpretation of the traditional city pattems forms a language which can be used as a design process for recovering urban landscape.

Marine and Inland Water Resources in Eneolithic Communities. New Data from Sardinia （Italy）

This paper presents research aimed at identifying the methods with which prehistoric man interacted with marine and inland water environments. The objective is to determine the degree to which resources from these environments influenced the socio-economic organization of these peoples. The coastline around Cagliari and its hinterland （southern Sardinia, Italy） were chosen as the subject, on the basis of the presence of both the sea and several ponds. The territory is noted as being home to both Neolithic and Eneolithic settlements. Among these the archaeological excavation of the village of Su Coddu/Canelles produced a large quantity of malacofauna. Data has been processed from part of the settlement that gave radiocarbon dating from the period between 3640 and 2900 cal. BC, and in which it was possible to carry out the level of sampling that was necessary to complete the research. In particular this interdisciplinary project, which aims to make an overall study of the settlement, the data relating to the geography of the area, the archaeological documentation, the fauna and shell artefacts will be extrapolated. Numerous methods are applied above all in reference to the marines and ponds resources. Additionally, the morphological anatomical-comparative analysis （in order to determine the typology of the faunal remains and to identify each individual species） and the technological analysis of the manufactured shells （so as to detect the selection and the transformation type of raw materials） are accomplished. The research has led to the identification of a settlement model in which agriculture formed the primary means of subsistence, that was complemented by the rearing of livestock, through hunting and gathering. The exploitation of marine and inland waters resources, as food source, have to be important because 99% of the faunal remains are shells. Different shell species are recognized, among those the Ostrea edulis provides the raw material to produce bevelled objects, which are documented inside the settlement in considerable number. Some plant species, typical of the lagoon ecosystem, were used for building and craft production.

NUMERICAL SIMULATION OF SSTA IMPACTS OVER THE GLOBAL OCEAN ON THE ANOMALOUS CIRCULATION OVER EURASIA IN JANUARY 2008

In this paper, we discussed the features of atmospheric circulations over Eurasia as a response to sea surface temperature anomalies （SSTAs） over the tropical Indian Ocean, the equatorial Pacific, Kuroshio and the North Atlantic. Our results are shown as follows： （1） CAM3.0, driven by the combined SSTAs over the four oceanic regions, can simulate well the features of anomalous atmospheric circulations over Eurasia in January 2008, indicating that the effects of the SSTAs over these four regions were one of the key causes of the anomalous systems over Eurasia. （2） The SSTAs over each key region contributed to the intensification of blocking over the Urals Mountains and a main East Asian trough. However, the influence of the SSTAs over individual oceanic regions differed from one another in other aspects. The SSTAs over the North Atlantic had an impact on the 500-hPa anomalous height （Z500A） over the middle-high latitudes and had a somewhat smaller effect over the low latitudes. For the warm SSTAs over Kuroshio, the subtropical high was much stronger, spread farther north than usual, and had an anomalous easterly that dominated the northwest Pacific Ocean. The warm SSTAs over the tropical Indian Ocean could have caused a negative Z500A from West Asia to Middle Asia, a remarkably anomalous southwesterly from the Indian Ocean to the south of China and an anomalous anticyclone circulation over the South China Sea-Philippine Sea region. Because of the La Nifia event, the winter monsoon was stronger than normal, with an anomalously cooler northerly over the southeastern coastal areas of China. （3） The combined effects of the SSTAs over the four key regions were likely more important to the atmospheric circulation anomalies of January 2008 over Eurasia than the effects of individual or partly combined SSTAS. This unique SSTA distribution possibly led to the circulation anomalies over Eurasia in January 2008, especially the atmospheric circulation anomalies over the subtropics, which were more similar to those of the winter E1 Nifio events than to the circulation anomalies following La Nifia.

Object-Based Method Outperforms Per-Pixel Method for Land Cover Classification in a Protected Area of the Brazilian Atlantic Rainforest Region

Conventional image classification based on pixels hinders the possibilities to obtain information contained in images, while modern object-based classification methods increase the acquisition of information about the object and the context in which it is inserted in the image. The objective of this study was to investigate the performance of different classification methods for land cover mapping in the vicinity of the Alto Ribeira Tourist State Park, a Brazilian Atlantic rainforest area. Two classification methods were tested, including i） a hybrid per-pixel classification using the image processing software ERDAS Imagine version 9.1 and ii） an object-based classification using the software eCognition version 5. In the first method, six different classes were established, while in the second method, another two classes were established in addition to the six classes in the first method. Accuracy assessment of the classification results presented showed that the object-based classification with a Kappa index value of 0.8687 outperformed the per-pixel classification with a Kappa index value of 0.2224. Application of the user＇s knowledge during the object-based classification process achieved the desired quality; therefore, the use of inter-relationships between objects, superelasses, subclasses, and neighboring classes were critical to improving the efficiency of land cover classification.

Decadal variations in the season advancement of spring water cycle over Eastern China

Spring is the critical period for atmospheric circulation transition from winter to summer. The spring water cycle is very im- portant to agriculture in planting crop and the initial growth of crop. Note that there was a significant abrupt decadal change in the water budget increase during early spring over eastern China in the late 1970s. Studied here are the decadal variations of water budgets over the key regions and the associated change of water cycle over East Asia and atmospheric circulation over Asia-West Pacific region in early spring, using the observed （OBS） precipitation, the ECMWF （ERA） and NCEP/NCAR rea- nalysis （NRA）, and the Mantua＇s Pacific decadal oscillation index （PDOI）. The water budget increments from March to April exhibited a sharp decrease over the key region around Huaihe River basin （HHR） （111°-120°E; 31°-36°N） after year 1978. Before 1977 the water vapor flux through south boundary of the HHR region increased greatly during March to April by 1.52 mm d^-1 in ERA and 1.88 mm d^-1 in NRA. Concurrently the moisture convergence and precipitation over the region also in- creased greatly. The increment for the moisture convergence was 1.11 mmd^-1 in ERA and 1.22 mm d^-1 in NRA, and for the precipitation was 1.05 mm d^-1 in observation and 1.05 mm d^-1 in ERA. April was the time that the water budgets over HHR increased most rapidly before 1977. But after 1978 the water budgets decreased conversely from Mach to April. The water vapor flux increment through the south boundary was -0.03 mmd^-1 in ERA and 0.01 mm d^-1 in NRA, the moisture conver- gence increment was -0.91 mm d^-1 in ERA and -0.53 mm d^-1 in NRA, and precipitation increment was -0.08 mm d^-1 in ob- servation and -0.15 mm d^-1 in ERA. Further investigation has shown that the large-scale atmospheric circulation in the early spring has correspondingly changed significantly after the late 1970s. During March to April, the weakening of the trough over East Asia became significantly slower, and the strengthening of the ridge over the west China became significantly faster in the middle troposphere after the late 1970s. At the same time, in the lower troposphere, the strengthening and northward extending of the west pan of the subtropical high and the weakening of the trough over the southwest part of the Aleutian low in the early spring became slower, and the weakening of the main part of Asian high became slower, but the strengthening of its west part became faster. This significant decadal change of circulation caused a sharp decrease in the northward extending speed of wa- ter vapor transport, and in the water budgets increasing speed over the southeastern China during early spring after the late 1970s.

Mantle-derived magmas:intraplate,hot-spots and mid-ocean ridges

Primary or parental magmas act as probes to infer eruption and source temperatures for both mid-ocean ridge （MOR） and‘hot-spot＇ magmas （tholeiitic picrites）. The experimental petrogenetic constraints （＇inverse＇ experiments） argue for no significant temperature differences between them. However, there are differences in major, minor and trace elements which characterise geochemical, not thermal, anomalies beneath ‘hot-spots＇. We suggest that diapiric upwelling from interfaces （redox contrasts） between old subducted slab and normal MOR basalt source mantle is the major reason for the observed characteristics of island chain or ‘hot-spot＇ volcanism. Intraplate basalts also include widely distributed volcanic centres containing lherzolite xenoliths, i.e. mantle-derived magmas. Inverse experiments on olivine basalt, alkali oli- vine basalt, olivine basanite, olivine nephelinite, olivine melilitite and olivine leucitite （lamproite） determined liquidus phases as a function of pressure, initially under anhydrous and CO2-absent conditions. Under C- and H-absent conditions, only tholeiites to alkali olivine basalts had O1 ＋ Opx 4-Cpx as high-pressure liquidus phases. Addition of H20 accessed olivine basanites at 2.5-3 GPa, ,- 1,200 ℃, but both CO2 and H20 were necessary to obtain saturation with O1, Opx, Cpx and Ga at 2.5-3.5 GPa for olivine nephelinite and olivine melilitite. The forward and inverse experimental studies are combined to formulate a petrogenetic grid for intraplate, ‘hot-spot＇ and MOR magmatism within the plate tectonics paradigm. The asthenosphere is geochemically zoned by slow upward migration of incipient melt. The solidus and phasestabilities of lherzolite with very small water contents （〈3,000 ppm） determine the thin plate behaviour of the oceanic lithosphere and thus the Earth＇s convection in the form of plate tectonics. There is no evidence from the parental magmas of MOR and ‘hot-spots＇ to support the ＇deep mantle thermal plume＇ hypothesis. The preferred alternative is the presence of old subducted slabs, relatively buoyant and oxidised with respect to MORB source mantle and suspended or upwelling in or below the lower asthenosphere （and thus detached from overlying plate movement）.

On the geo-basis of river regulation in the lower reaches of the Yellow River

This paper investigates the important scientific problem of river regulation strategies in the lower reaches of the Yellow River, and discusses the "geo-basis" of river regulation. The concept of a geo-basis to river regulation in the lower Yellow River was discussed in terms of subsidence and sedimentation features of the fiver plain; channel features, erosion characteristics of the Loess Plateau and storm-flood features of the middle and lower reaches. The geographic features of the lower Yellow River have gradually changed since the Holocene but there has been no fundamental change. Based on an analysis of the geo-attributes of the lower reaches of the Yellow River, several conclusions on its river regulation were made. The release of sediment should be the first measure of river regulation because of deposition in the lower reaches. The fiver channels should be provided with adequate space for wandering in the lower reaches. The tail river should be also provided with necessary wandering space because of weak marine dynamics in the estuary area and changes in the delta. Because the erosion environ- ment of the Loess Plateau will not fundamentally change, river harnessing of the middle reaches should focus on improving the plateau morphology, which can be done by reducing the fragmentation of terrain and building a planation surface. Eco- remediation should focus on converting farmland to grassland. There may be extreme floods in the future, as has occurred pre- viously, thus an extreme flood defense system should be considered for the lower reaches. A periodic law for regulation in the Yellow River is discussed. We also discuss how the current use of the lower reaches of the Yellow River is unsustainable and it is urgent to research artificial rechanneling and the creation of new flow paths for the lower reaches.

Estimating the geographic range of a threatened shark in a data-poor region： Cetorhinus maximus in the South Atlantic Ocean

The distribution of the planktivorous basking shark Cetorhinus maximus is influenced by zooplankton abundance at small scales and temperature at medium scales in the North Atlantic. Here, we estimate the distribution of basking sharks on South Atlantic continental shelves, and the relative importance of chlorophyll concentration, as a proxy for zooplankton abun- dance, and temperature in determining habitat suitability for basking sharks at large scales. We used maximum entropy （MaxEnt） and maximum likelihood （MaxLike） species distribution modelling to test three hypotheses： the distribution of basking sharks is determined by （1） temperature, （2） chlorophyll concentration, or （3） both chlorophyll and temperature, while considering other factors, such as oxygen and salinity. Off South America, basking shark habitat included subtropical, temperate and cool-temperate waters between approximately 20°S and 55°S. Off Africa, basking shark habitat was limited to cool-temperate waters off Namibia and southern South Africa. MaxLike models bad a better fit than MaxEnt models. The best model included minimum chlorophyll concentration, dissolved oxygen concentration, and sea surface temperature range, supporting hypothesis 3. However, of all variables included in the best model, minimum chlorophyll concentration had the highest influence on basking shark distribution. Unlike the North Atlantic distribution, the South Atlantic distribution of basking sharks includes subtropical and cool-temperate waters. This difference is explained by high minimum chlorophyll concentration off southern Brazil as compared to North Atlantic subtropical areas. Observations in other regions of the world support this conclusion. The highest habitat suitability for basking sharks is located close to nearshore areas that experience high anthropogenic impact [Current Zoology 61 （5）： 811-826, 2015].