论中国古代地缘战略制定中的“权衡”——以《盐铁论》为例   总被引：3，自引：1，他引：2  

王丰龙  刘云刚 《地理科学》2019,39(9):1407-1415

《盐铁论》是记录汉朝时期关于盐铁酒榷均输及对匈奴关系的辩论的一部重要著作,能够较典型地反映中国古代地缘战略制定中的“权衡”过程。构建中国古代地缘战略制定中的“权衡”理论分析框架,继而基于该分析框架对《盐铁论》中的地缘战略辩论进行详细解读。《盐铁论》中辩论双方“权衡”的要点包含匈奴对汉朝产生的威胁程度、领土扩张所带来的收益大小和相应地缘战略的合法性3个方面。从思想、方法、目的等比较中西方地缘政治研究差异,指出“权衡”思想为西方主导的地缘政治理论提供新视角。  相似文献   

A synthesis of iron deposits in the eastern Tianshan,NW China     

《地学前缘(英文版)》2020,11(4):1271-1287

The northern Xinjiang region is one of the most significant iron metallogenic provinces in China.Iron deposits are found mainly within three regions:the Altay,western Tianshan,and eastern Tianshan orogenic belts.Previous studies have elaborated on the genesis of Fe deposits in the Altay orogenic belt and western Tianshan.However,the geological characteristics and mineralization history of iron deposits in the eastern Tianshan are still poorly understood.In this paper I describe the geological characteristics of iron deposits in the eastern Tianshan,and discuss their genetic types as well as metallogenic-tectonic settings,Iron deposits are preferentially distributed in central and southern parts of the eastern Tianshan.The known iron deposits in the eastern Tianshan show characteristics of magmatic Fe-Ti-V(e.g.,Weiya and Niumaoquan),sedimentary-metamorphic type(e.g.,Tianhu),and iron skarn(e.g.,Hongyuntan).In addition to the abovementioned iron deposits,many iron deposits in the eastern Tianshan are hosted in submarine volcanic rocks with well-developed skarn mineral assemblages.Their geological characteristics and magnetite compositions suggest that they may belong to distal skarns.SIMS zircon U-Pb analyses suggest that the Fe-Ti oxide ores from Niumaoquan and Weiya deposits were formed at 307.7±1.3 Ma and 242.7±1.9 Ma,respectively.Combined with available isotopic age data,the timing of Fe mineralization in the eastern Tianshan can be divided into four broad intervals:Early Ordovician-Early Silurian(476-438 Ma),Carboniferous(335-303 Ma),Early Permian(295-282 Ma),and Triassic(ca.243 Ma).Each of these episodes corresponds to a period of subduction,post-collision,and intraplate tectonics during the Paleozoic and Mesozoic time.  相似文献   

Arsenic accumulation in the roots of Helianthus annuus and Zea mays by irrigation with arsenic-rich groundwater: Insights from synchrotron X-ray fluorescence imaging     

《Chemie der Erde / Geochemistry》2015,75(2):261-270

The aim of this study was to investigate the accumulation of arsenic (As) in and on roots of Zea mays (maize) and Helianthus annuus (sunflower) by means of synchrotron-based micro-focused X-ray fluorescence imaging (μ-XRF). Plant and soil samples were collected from two field sites in the Hetao Plain (Inner Mongolia, China) which have been regularly irrigated with As-rich groundwater. Detailed μ-XRF element distribution maps were generated at the Fluo-beamline of the Anka synchrotron facility (Karlsruhe Institute of Technology) to assess the spatial distribution of As in thin sections of plant roots and soil particles. The results showed that average As concentrations in the roots (14.5–27.4 mg kg⁻¹) covered a similar range as in the surrounding soil, but local maximum root As concentrations reached up to 424 mg kg⁻¹ (H. annuus) and 1280 mg kg⁻¹ (Z. mays), respectively. Importantly, the results revealed that As had mainly accumulated at the outer rhizodermis along with iron (Fe). We therefore conclude that thin crusts of Fe-(hydr)oxides cover the roots and act as an effective barrier to As, similar to the formation of Fe plaque in rice roots. In contrast to permanently flooded rice paddy fields, regular flood irrigation results in variable redox conditions within the silty and loamy soils at our study site and fosters the formation of Fe-(hydr)oxide plaque on the root surfaces.  相似文献   

新疆阿尔泰巴特巴克布拉克铁矿床成矿作用研究   总被引：2，自引：0，他引：2       下载免费PDF全文

杨俊杰  柴凤梅  杨富全  张志欣 《地质科学》2015,(3):879-897

巴特巴克布拉克铁矿床赋存于上志留-下泥盆统康布铁堡组变质火山-沉积岩系中, 近矿围岩为石榴子石矽卡岩、角闪斜长变粒岩和浅粒岩。矿体总体顺层分布, 呈似层状、透镜状及不规则状, 空间上与矽卡岩密切相关。流体包裹体研究表明, 矽卡岩阶段形成的石榴子石中发育纯气体包裹体、气体包裹体、液体包裹体、含子矿物包裹体及熔融包裹体; 退化蚀变阶段发育液体包裹体和少量气体包裹体; 石英-硫化物阶段主要发育液体包裹体、含液体CO₂的三相包裹体及少量纯气体包裹体、气体包裹体和含子矿物包裹体。矽卡岩阶段均一温度变化为217 ℃~499 ℃, 在255 ℃出现峰值, 盐度(NaCl_eq)变化为8.68%~22.65%; 退化蚀变阶段均一温度变化为181 ℃~432 ℃, 在225 ℃出现峰值, 盐度变化为12.85%~22.65%; 石英-硫化物阶段均一温度变化为140 ℃~482 ℃, 在155 ℃出现峰值, 盐度变化为0.18%~42.40%。石榴子石、石英和方解石的 δ¹⁸ O_SMOW 变化为1.8‰~7.1‰, δ¹⁸Ο_Η2Ο为 -4.79‰~4.57‰, δD_SMOW 为 -128‰~-84‰, 表明矽卡岩阶段成矿流体主要为岩浆水, 混合少量大气降水; 石英-硫化物阶段大气降水所占比例明显增加。方解石δ¹³ C_V-PDB 变化为 -3.2‰~-2.0‰, 表明流体中的碳来自深部或地幔。  相似文献   

磁测资料在宁芜地区（江苏部分）矿产资源潜力评价中的应用          下载免费PDF全文

魏邦顺  黄建平  金永念 《江苏地质》2011,35(1):64-72

利用宁芜地区(江苏部分)地质资料,结合磁场特征,重点对该区侵入岩体、断裂等地质构造进行了推断,编制了1:5万磁法推断地质构造图,为铁矿预测提供了地质构造等综合信息要素。采用RGIS2008软件2.5D人机交互拟合方法,累计估算铁磁性矿体资源量84642.6万t并分级。通过已知矿床的分布特征分析,结合磁测资料解释应用的成果,对宁芜地区(江苏部分)铁矿资源潜力进行了探讨和预测。  相似文献   

山东省莱州-安丘铁成矿带特征及找矿方向   总被引：1，自引：0，他引：1  

徐洪岩  董银峰  徐伟祥  田晓留  张德明 《山东地质》2011,(3):8-12

莱州-安丘铁成矿带位于沂沭断裂带东侧,胶北隆起的西南部。成矿带呈NE向展布,长约100 km,宽10~20km。已知区内铁矿类型主要有沉积变质型、岩浆熔离型和岩浆期后热液型,成矿除受地层控制外,还与构造、岩浆活动关系密切。通过对地质和重、磁物理场的分析,确定不同成因类型铁矿的分布范围,并且划分出不同磁异常特征,指出今后的找矿方向。  相似文献   

Expected and observed conditions during the SAGE iron addition experiment in Subantarctic waters     

Mark G. Hadfield 《Deep Sea Research Part II: Topical Studies in Oceanography》2011,58(6):764-775

The SAGE iron addition experiment was conducted from R.V. Tangaroa east of South Island, New Zealand, in late March-early April 2004. A desktop survey of climatological data was completed before the experiment, providing information to inform site selection and experiment design. The desktop survey is presented here in updated and enhanced form in order to explain the site selection and describe the conditions expected at the site during the experiment in comparison with those actually encountered.The experiment site was in Subantarctic waters between the Subtropical and Subantarctic Fronts. These waters are characterised by high surface macronutrient concentration, low iron concentration and low chlorophyll. The preferred site based on the desktop survey was in the vicinity of 173.5°E, 47.5°S, in Southern Bounty Trough. The actual release location was chosen immediately before the release and was 112 km to the northwest of this at 172°32′E, 46°44′S. The surface water here has typically come from the southwest (over the northern Campbell Plateau) or the southeast (through Pukaki Gap) and the mean current is directed towards ENE at ∼0.1 m s⁻¹. The release location is well removed from regions of high eddy kinetic energy to the east (where the Subantarctic Front reaches its northern limit) and the west (where fine-scale instabilities develop on the Southland Front, which flows along the continental shelf). Typical conditions at the release site at the end of March are: surface temperature 12 °C; mixed layer depth 40 m; surface chlorophyll concentration ∼0.3 mg m⁻³; surface photosynthetically active radiation (PAR) 23 E m⁻² d⁻¹; surface nutrient concentrations 8-10 mmol m⁻³ (nitrate), 0.5-0.8 mmol m⁻³ (phosphate), 1-2 mmol m⁻³ (silicate) and 0.1-0.5 nM (iron); 99th percentile wind speed 19-21 m s⁻¹. At this time of year, surface PAR is well below its summer maximum, the mixed layer is beginning its seasonal deepening and the silicate concentration is at its seasonal minimum. These factors may have limited the phytoplankton response to iron addition and were compounded in March-April 2004 by strong winds early in the experiment (substantially exceeding the 99th percentile in speed), lower than the average SST, larger than the average mixed layer depth, silicate concentration at the bottom end of the expected range and initially low PAR.  相似文献   

Grazing suppression of dimethylsulphoniopropionate (DMSP) accumulation in iron-fertilised, sub-Antarctic waters     

S.D. Archer  K. SafiA. Hall  D.G. CummingsM. Harvey 《Deep Sea Research Part II: Topical Studies in Oceanography》2011,58(6):839-850

The impact of in situ iron fertilisation on the production of particulate dimethylsulphoniopropionate (DMSPp) and its breakdown product dimethyl sulphide (DMS) was monitored during the SOLAS air-sea gas exchange experiment (SAGE). The experiment was conducted in the high nitrate, low chlorophyll (HNLC) waters of the sub-Antarctic Southern Ocean (46.7°S 172.5°E) to the south-east of New Zealand, during March-April, 2004. In addition to monitoring net changes in the standing stocks of DMSPp and DMS, a series of dilution experiments were used to determine the DMSPp production and consumption rates in relation to increased iron availability. In contrast to previous experiments in the Southern Ocean, DMS concentrations decreased over the course of the 15-d iron-fertilisation experiment, from an integrated volume-specific concentration in the mixed layer on day 0 of 0.78 nM (measured values 0.65-0.91 nM) to 0.46 nM (measured values 0.42-0.47 nM) by day 15, in parallel with the surrounding waters. DMSPp, chlorophyll a and the abundance of photosynthetic picoeukaryotes exhibited indiscernible or only moderate increases in response to the raised iron availability, despite an obvious physiological response by the phytoplankton. High specific growth rates of DMSPp, equivalent to 0.8-1.2 doublings d⁻¹, occurred at the simulated 60% light level of the dilution experiments. Despite the high production rates, DMSPp accumulation was suppressed in part by microzooplankton grazers who consumed between 61% d⁻¹ and 126% d⁻¹ of the DMSPp production. Temporal trends in the rates of production and consumption illustrated a close coupling between the DMSP-producing phytoplankton and their microzooplankton grazers. Similar grazing and production rates were observed for the eukaryotic picophytoplankton that dominated the phytoplankton biomass, partial evidence that picoeukaryotes contributed a substantial proportion of the DMSP synthesis. These rates for DMSPp and picoeukaryotes were considerably higher than for chlorophyll a, indicating higher cycling rates of the DMSP-producing taxa than for the bulk phytoplankton community. When compared to the total phytoplankton community, there was no evidence of selection against the DMSP-containing phytoplankton by the microzooplankton grazers; the opposite appeared to be the case. SAGE demonstrated that increased iron availability in the HNLC waters of the Southern Ocean does not invariably lead to enhanced DMS sea-air flux. The potential suppression of DMSPp accumulation by grazers needs to be taken into account in future attempts to elevate DMS emission through in situ iron fertilisation and in understanding the hypothesised link between levels of Aeolian iron deposition in the Southern Ocean, DMS emission and global albedo.  相似文献   

Global distributions of Fe,Al, Cu,and Zn contained in Earth's derma layers     

Jason N. Rauch 《Journal of Geochemical Exploration》2011

To improve the usefulness and accuracy of modeling Earth's anthrobiogeochemical metal cycles, global maps at approximately 1° × 1° are produced of the concentrations and masses of Fe, Al, Cu, and Zn contained in continental sediments and soils. The maps generated utilize inverse distance weighting (IDW) and cokriging to generate new estimates for geospatially weighted mean global concentrations for these metallic micronutrients. Sediment metal concentration maps are generated from IDW of sediment samples; global soil maps are produced via cokriging upon an underlying parent rock dataset composed of both surface bedrock and sediment samples. Derived are independent estimates for the global mean concentrations in continental sediments (Fe = 3.1 wt.%, Al = 6.1 wt.%, Cu = 45 μg/g, Zn = 86 μg/g) and soils (Fe = 2.5 wt.%, Al = 3.9 wt.%, Cu = 17 μg/g, Zn = 50 μg/g). While continental sediment concentrations for Cu are within the range of previous estimates, Zn concentrations are relatively higher, ~ 20 μg/g above previous estimates. Fe and Al are slightly depleted (~ 1 wt.%) in continental sediments relative to previous estimates, likely ascribable to sampling bias and error inherent in the comparative methodologies. Besides an estimated global mean, metal concentrations in soils are also broken down by FAO soil group. Metal masses in sediments and soils remain within 30% of previous, non-spatial estimates. These maps also illustrate the discernable spatial variability across the Earth's surface. Despite data gaps, maps of metal mass show regional patterns such as the high quantities of Al in the soils and biomass of the Amazonia and Congo regions. Concentrations of metals are relatively high in the anthrosols of China. Finally, this analysis highlights those areas for which generating and providing publically available geochemical data should be prioritized. For instance, gypsisols, lixisols, and nitisols have little to no analytical data available on metal contents. A sensitivity analysis suggests that the most poorly constrained soil metal concentrations occur in the thick, old tropical soils of central Africa and the anthrosols of eastern China.  相似文献   

Using iron speciation in authigenic carbonates from hydrocarbon seeps to trace variable redox conditions     

《Marine and Petroleum Geology》2015

Seepage of hydrocarbon-rich fluids out of the marine sedimentary column is characterized by temporal changes of flow intensity and resultant spatially variable redox conditions. Authigenic carbonates at marine hydrocarbon seeps provide excellent geological and geochemical archives that serve to explore seepage dynamics over time. In this study, we investigated the potential of Mössbuaer spectroscopy and Fe contents of seep-related authigenic carbonates from the Congo Fan, the Gulf of Mexico, and the Black Sea for reconstructing past redox conditions and fluid seepage activity at cold seeps. The Fe speciation observed by Mössbauer spectroscopy and Fe contents suggest that (1) the Congo Fan carbonates precipitated in a sulfidic environment, (2) the formation conditions of seep carbonates were variable at the Gulf of Mexico seep site, ranging from oxic to suboxic and anoxic and even spanning into the methanogenic zone, and (3) the stratified water column of the Black Sea or suboxic condition resulted in low Fe contents of Black Sea carbonates. The study reveals that Fe speciation can provide constraints on the wide range of redox conditions that imprinted seep carbonates during the life span of seepage. Similarly, Mössbauer spectroscopy – particularly when used in combination with the analysis of redox-sensitive elements – is a promising tool to trace variable redox conditions in marine paleoenvironments other than seeps.  相似文献