太行山地区铁矿尾矿特点及应用前景

对太行山地区铁矿进行了研究，分析了矽卡岩型铁矿的成因，并对矽卡岩型铁矿尾矿矿物组成及成分进行了分析，指出了此类尾矿的特殊性。还对其应用前景进行了简单的探讨，其中对尾矿还进行了几个方面的工业应用研究。     

Magnetic records of Core MD77-181 in the Bay of Bengal and their paleoenvironmental implications

Located in the low latitude region of the northeastern Indian Ocean, the Bay of Bengal represents one of the largest marginal seas in the world. The Bengal Fan hosts erosional products mostly from Himalayas and is under the influence of the Indian monsoon system. The Bengal Fan has thus been one of the ideal places for studying the uplift of the Tibet Plateau and the history of the Indian monsoon[1―8]. The intensity of the Indian monsoon is controlled by secular variations in insola- ti…     

Abrupt variations of the radiolarian fauna at Mid-Pleistocene climate transition in the South China Sea

Based on a detailed study of the radiolarian fauna, the abundance pattern of planktic foraminifera as well as on isotope and sedimentological records, the Mid-Pleistocene climate transition as a multiple transition phenomenon could be recognized at Core 17957-2 from the South China Sea. Distinct changes in the radiolarian/foraminfera ratio, the coarse fraction and the radiolarian assemblages can be related to the global climate cooling observed at the Mid-Pleistocene revolution (MPR) around 900 ka. A pronounced southward shift of the North Equatorial Current that leads to lower sea-surface temperatures in the South China Sea is documented by the shift of tropical to subtropical radiolarian assemblages at 900 ka. Increasing radiolarian abundance after the MPR can be interpreted as a result of stronger upwelling and nutrient supply. These abrupt variations could result from the northern trade wind system and East Asian monsoon circulation.     

The saproxylic hoverflies (Diptera: Syrphidae) of Serbia

The revision of the saproxylic hoverflies collected in Serbia from 1950 to 2010 has revealed a total of 56 species, of which Sphiximorpha subsessilis (Illiger in Rossi) is new to the Balkan Peninsula and Arctophila superbiens (Muller), Blera fallax (Linnaeus), Brachyopa panzeri Goffe, Brachyopa testacea (Fallén), Brachyopa vittata Zetterstedt and Chalcosyrphus piger (Fabricius) are new to Serbia. According to “Syrph the Net, the database of European Syrphidae”, 16 of the 56 species are threatened with extinction in Europe, while 6 species are “strictly protected” and 13 are “protected” under Serbian legislation. Distribution maps for each species, as well as new data on adult habitats, are provided. The conservation status of the saproxylic hoverflies of Serbia is discussed. The present study attempts to provide a basis for the conservation of the saproxylic hoverflies of this Balkan country.     

北部湾北部近岸全新世沉积环境变化及对8.2 ka小冷期的响应

【目的】北部湾北部是东亚夏季风、印度季风以及蒙古冷高压影响的交汇处,对气候变化敏感,该区沉积物要素在全新世的分布与变化,可反映该区气候波动特征和海岸格局演进之影响因素。【方法】在北部湾北部广西水域依次钻取3孔岩芯并进行粒度、矿物、元素、微体古生物测试鉴定以及~(14) C测年,综合分析对比沉积物要素的垂直分布、变化以及响应特征。【结果】全新世孢粉组合为热带-亚热带山地组合。岩芯粒度波动旋回变化,经历了自河床向浅海湾的变迁,沉积物具有陆源性,元素等几乎与沉积旋回细组分同步变化。早期三角洲盆地钻孔显示为盐沼环境;相对晚更新世或者末期,全新世早期沉积物颗粒粗减细增,有机质增幅超过700%。碎屑矿物种类增加,孢粉和硅藻化石逐步丰富,硅藻属种数也保持增加趋势,沉积速率为全新世平均值的1.36~1.85倍,具有风化较强、水沙丰沛、沉积快、物质分配活跃、生物较为繁盛的特点,与邻区全新世中早期气候适宜期相符合。早期气候仍然波动,可辨认出8.2ka小冷期事件的影响,Sr/Ba比值偏低。【结论】研究区作为东亚低纬度季风区海陆过渡界面,其环境变化与气候变化相联系。     

新疆巴里坤湖9.0 cal ka BP以来沉积物地球化学元素分布特征与古气候环境演化

根据中国西北干旱区巴里坤湖BLK-1剖面沉积物的地化元素分析,采用SPSS因子分析法提取了对沉积环境变化敏感的地化元素和氧化物组分.在R、Q型因子分析的基础上,结合沉积物的硅铁铝率(SiO2/(Al2O3+Fe2O3))、淋失系数(SiO2/(MgO+K2O))、CaO/MgO以及腐殖化度等指标,提取出古气候环境信息.初步研究结果表明:近9.0 cal ka BP以来,巴里坤湖地区气候环境仍以干旱化为主,全新世期间出现过多次不同程度的干湿变化,经历了5个气候阶段:9.0—7.5 cal ka BP期间,气候干旱;7.5—5.8 cal ka BP期间,气候温暖湿润,为研究区全新世最佳适宜期;5.8—3.0 cal ka BP期间,气候干旱;3.0—1.0 cal ka BP期间,气候湿润;1.0—0 cal ka BP期间,气候干旱.     

Environmental evolution of Xingkai （Khanka） Lake since 200 ka by OSL dating of sand hills

Crossing the Sino-Russian boundary, Xingkai Lake is the largest freshwater lake in Northeast Asia. In addition to the lakeshore, there are four sand hills on the north side of the lake that accumulated during a period of sustainable and stable lacustrine trans gression and were preserved after depression. Analysis of well-dated stratigraphic sequences based on 18 OSL datings combined with multiple index analysis of six sites in the sand hills revealed that the north shoreline of Xingkai Lake retreated in a stepwise fashion since the middle Pleistocene, and that at least four transgressions (during 193-183 ka, 136-130 ka, 24-15 ka and since 3 ka) and three depressions occurred during this process. The results of this study confirmed that transgressive stages were concur- rent with epochs of climate cooling, whereas the period of regression corresponded to the climatic optima. Transgressions and regressions were primarily caused by variations in the intensity of alluvial accumulation in the Ussuri River Valley and fluctuations in regional temperature and humidity that were controlled by climatic change. Moreover, one obvious transgressive process that occurred in MIS3 may have been related to enhanced precipitation that was reportedly widespread in the west of China, while shortterm fluctuations in the lake level might well be a direct response to regional precipitation variations on the millennial scale.     

Interpretation and preliminary simulation of the 40 ka periodicity of the Quaternary glaciation

More and more proxy records approved that the periodicity of the glacial cycles is about 40 ka before MPT (middle Pleistocene transition) as early as late Tertiary from 3.0 Ma to 0.9 Ma,whereas it changes to about 100 ka after MPT. Summer insolation at high latitude in Northern Hemisphere,usually consid-ered as the main external force for the ice age,is dominated by the 23 ka precession period,which does not match the period of the glacial cycles. In this paper,we define an energy index C and its threshold Ct that indicate the net energy supply and the overall response of the climate system. The difference between these two parameters determines whether the ice sheet melts or not,and accordingly the start and termination of the interglacial stages,as well as the periodicity of glacial oscillations. Based on the energy threshold hypothesis,the preliminary simulation experiments are made to test the period of the glacial cycles and driven factors from a conceptual model. The results indicate that energy index C and threshold Ct can interpret not only the 40 ka periodicity before MPT,but also the quasi-100 ka perio-dicity after MPT to some extent,and the 40 ka is the basic period of the glacial cycles,which discloses the inherent continuity of climatic change before and after MPT.     

Evidence and modeling study of droughts in China during 4―2 ka BP

Four periods with predominated droughts are identified in 4-2 ka BP according to documentary data, namely 3.6-3.5, 3.1-3.0, 2.8-2.7, and 2.45-2.35 ka BP. Palaeo-environmental data indicated that droughts were predominated in 4-2 ka BP in the south of Northeast China, Inner-Mongolia, east of Qinghai-Tibetan Plateau, and South China. Modeling study shows that precession may be responsible for the occurrence of droughts in 4-2 ka BP, integrating the GCM with forcing of insolation.