An Review of International Climate Change Conference and Analysis on Recent Hot Issues

The international climate change negotiation has been carried out over 20 years. The issue of climate change has shifted from a scientific question into a complex political matter which is related to the sustainable development of mankind. Based on the overview of major processes and stages of international climate conferences, this paper analyzed the key measures that major countries have taken to address climate change, as well as the primary tasks of Paris climate conference and recent international actions. The recent international climate policy issues were also analyzed in order to provide suggestions for China’s activel participation in the development of a new round of international climate change system.     

Geochemical characteristics of island-arc volcanic rocks in the Nan-Nam Pat-Phetchabun zone,northern Thailand

Late Permian-Early Triassic (P₂-T₁) volcanic rocks distributed on the eastern side of ocean-ridge and oceanic-island basalts in the Nan-Uttaradit zone were analyzed from aspects of petrographic characteristics, rock assemblage, REE, trace elements, geotectonic setting, etc., indicating that those volcanic rocks possess the characteristic features of island-arc volcanic rocks. The volcanic rock assemblage is basalt-basaltic andesite-andesite. The volcanic rocks are sub-alkaline, dominated by calc-alkaline series, with tholeiite series coming next. The chemical composition of the volcanic rocks is characterized by low TiO₂ and K₂O and high Al₂O₃ and Na₂O. Their REE patterns are of the flat, weak LREE-enrichment right-inclined type. The trace elements are characterized by the enrichment of large cation elements such as K, Rb and Ba, common enrichment of U and Th, and depletion of Nb, Ta, Zr and Hf. The petrochemical plot falls within the field of volcanic rocks, in consistency with the plot of island-arc volcanic rocks in the Jinsha River zone of China. This island-arc volcanic zone, together with the ocean-ridge/oceanic island type volcanic rocks in the Nan-Uttaradit zone, constitutes the ocean-ridge volcanic rock-island-arc magmatic rock zones which are distributed in pairs, indicating that the oceanic crust of the Nan-Uttaradit zone once was of eastward subduction. This work is of great significance in exploring the evolution of paleo-Tethys in the Nan-Uttaradit zone.     

东海陆架盆地伸展率和压缩率及构造跃迁

东海陆架盆地位于欧亚板块的东南缘和西太平洋活动大陆边缘,本文选取了东海陆架盆地主要凹陷的17条地震剖面,采用平衡剖面技术,计算了主要凹陷新生代不同演化阶段的伸展率和压缩率。分析表明,东海陆架盆地构造演化总体由西向东跃迁。晚白垩世至晚古新世东海陆架盆地裂陷中心在西部坳陷带,始新世东迁至东部坳陷带,上新世东迁至东海陆架盆地东侧的冲绳海槽盆地。古新世中后期东海陆架盆地西部坳陷带北侧昆山凹陷反转;中新世东部坳陷带的西湖凹陷反转。东海陆架盆地西部坳陷带与东部坳陷带构造演化不同,证明了东海陆架盆地的东西分带。西部坳陷带北部的长江坳陷和南部的台北坳陷构造演化不同,东部坳陷带北部的西湖凹陷和南部的钓北凹陷构造演化不同,证明了东海陆架盆地的南北分块。     

金选矿厂含氰废水中氰化物降解及其环境风险评价

对陕西凤县四方金矿选矿过程中氰化物的迁移转化和降解进行了研究,结果表明,其尾矿库外排含氰废水氰化物浓度达到国家规定的排放标准。在此基础上对氰化物环境风险进行评价,为同类项目尾矿浆和尾矿水环境风险评价提供可信的基础数据。     

苏北平原MIS 3阶段海侵事件的沉积记录

MIS 3阶段的气候与环境是古气候与古环境研究的热点,该阶段中国沿海地区的海侵过程是沿海平原环境演化的重要事件。根据苏北平原宝应By1钻孔的 14 C年代结果和沉积特征、微体生物组合特点,确认苏北平原MIS 3阶段存在明显的海侵事件,潮滩与泻湖相沉积层的厚度约7m,深度在By1孔19~26m,海相层位于长江三角洲地区的典型末次冰盛期的硬粘土层之下,14 C年代在距今26~39ka之间,属于MIS 3阶段的沉积,岩芯沉积物的沉积构造以水平的薄层砂质粉砂沉积为主。沉积物中大量的海相有孔虫壳体在研究的岩芯段中是最丰富的; 此外,还发现咸水环境下的Sinocytheridea impressa (Brady),Spinileberis pulchra与Spinileberis furuyaensis,Neomonoceratina chenae Zhao,Keijella bisanensis (Okubo)等形类壳体; 该段岩芯中的植物残体、碳屑也很丰富,有机质含量丰富,显示比较封闭的弱动力环境,指示了潮滩、泻湖沉积环境。     

北大巴山逆冲推覆构造带前缘构造特征及变形年代学研究

在北大巴山推覆构造带前缘,北—北东倾斜的城口断裂和南—南西倾斜的高桥断裂形成一背冲式逆冲推覆体系,以两断层为界,其间为一巨型冲起构造。该冲起构造因边界断裂的产状特征、活动强度沿走向的差异,而表现出明显的分段性:其北西段为双向逆冲的"正花状"结构;而南东段为反向逆冲为主的"半花状"结构。同构造低温变质绢云母40Ar-39Ar年龄显示,城口断裂在燕山期(约143.3Ma)存在一次强烈的构造活动,导致北大巴构造带进一步逆冲扩展和强烈隆升。在逆冲-推覆向前扩展过程中,受锋缘外侧阻抗的影响,沿前缘部位形成一系列反向逆冲断层,从而形成巨型冲起构造。     

秦岭商丹断裂带的构造样式与变形分析

商丹断裂带作为扬子板块与华北板块的缝合带,在秦岭造山带中占据重要的地位。对其进行精细的构造研究,是了解扬子板块与华北板块相互作用过程的关键。研究工作在商丹断裂带东段展开,对该带进行了详细的野外观察、显微构造观察、糜棱岩化过程中温度的估算、有限应变测量、差异应力的计算以及糜棱岩化过程中运动学涡度的计算。变形温压条件指示糜棱岩形成于中-高绿片岩相到低角闪岩相变质条件。差异应力计算结果指示商丹带具备大型构造动力特征。涡度分析表明该断裂带的变形以纯剪切作用占据主导作用,但包含有简单剪切的分量,从而证明了扬子板块与华北板块之间具有以碰撞挤压为主的斜向汇聚方式。     

巨晶普通辉石的M1位分裂

巨晶普通辉石的Ｍ１位分裂李一良，支霞臣，李玉芝，李铁，张裕恒（中国科学技术大学，合肥２３００２６）关键词巨晶辉石，Ｍ１位分裂，面积约束法，近邻边效应，Ｔ位铁单斜辉石的穆斯堡尔谱学研究历时已久。但由于其晶体结构和成份的复杂性、化学不均一性及出溶现象等［...     

Stratigraphy of the upper cretaceous and lower tertiary strata in the Tethyan Himalayas of Tibet (Tingri area,China)

The 1500-m-thick marine strata of the Tethys Himalaya of the Zhepure Mountain (Tingri, Tibet) comprise the Upper Albian to Eocene and represent the sedimentary development of the passive northern continental margin of the Indian plate. Investigations of foraminifera have led to a detailed biozonation which is compared with the west Tethyan record. Five stratigraphic units can be distinguished: The Gamba group (Upper Albian - Lower Santonian) represents the development from a basin and slope to an outer-shelf environment. In the following Zhepure Shanbei formation (Lower Santonian - Middle Maastrichtian), outer-shelf deposits continue. Pebbles in the top layers point to beginning redeposition on a continental slope. Intensified redeposition continues within the Zhepure Shanpo formation (Middle Maastrichtian - Lower Paleocene). The series is capped by sandstones of the Jidula formation (Danian) deposited from a seaward prograding delta plain. The overall succession of these units represents a sea-level high at the Cenomanian/Turonian boundary followed, from the Turonian to Danian, by an overall shallowing-upward megasequence. This is followed by a final transgression — regression cycle during the Paleocene and Eocene, documented in the Zhepure Shan formation (?Upper Danian - Lutetian) and by Upper Eocene continental deposits. The section represents the narrowing and closure of the Tethys as a result of the convergence between northward-drifting India and Eurasia. The plate collision started in the Lower Maastrichtian and caused rapid changes in sedimentation patterns affected by tectonic subsidence and uplift. Stronger subsidence and deposition took place from the Middle Maastrichtian to the Lower Paleocene. The final closure of remnant Tethys in the Tingri area took place in the Lutetian.     

帕米尔东北缘地区构造变形特征与盆山结构

帕米尔东北缘乌泊尔地区是正确认识帕米尔北缘盆山结构和构造变形特征非常关键的地区,本文利用连续电磁剖面(CEMP)资料和地震资料,并结合野外地质调查资料和钻井资料,对帕米尔东北缘乌泊尔地区的盆山结构和构造变形特征进行了研究。认为帕米尔东北缘及其以北地区的盆山结构表现为帕米尔造山带向北冲断和南天山向南冲断所形成的对冲结构; 帕米尔山前为基底卷入式构造,古生界—中生界沿高角度的逆冲断层推覆到新近系和第四系之上,形成山前的古生界—中生界逆冲推覆带; 北侧由受乌泊尔断裂控制的深部隐伏冲断体系和浅部的第四纪背驮盆地所构成。研究区的新生代构造变形时间开始于上新世晚期,并持续变形至今,形成了下更新统西域组（Q1x）与下伏上新统、Q2与Q1和Q3 4与Q2之间的不整合。研究区最小构造缩短量为486 km,缩短率为481％。