印尼西婆罗洲早白垩世Mensibau花岗岩类的成因及构造意义

婆罗洲西部(印尼)在中生代期间处于特提斯构造域和古太平洋构造域交汇地带,是全球少有的多重板块动力学体制既有先后叠加又有同时复合的独特大地构造单元。因此,该区相关花岗岩类成因及构造背景的研究对揭示东南亚构造—岩浆演化历史及多重构造体制叠合造山作用下的岩浆演化机制至关重要。笔者等对西婆罗洲Mensibau岩基的花岗岩类进行了锆石U-Pb年代学、元素地球化学和Sr-Nd-Hf同位素分析。其中,石英二长岩和钾长花岗岩样品的LA-ICP-MS锆石U-Pb同位素年龄分别为126.9±2.1 Ma和141.8±2.6 Ma,表明岩体形成于早白垩世,岩浆活动至少持续了15 Ma。Mensibau花岗岩类具有高SiO₂(67.5%～73.3%)、高K₂O (4.3%～5.4%)和低P₂O₅(0.07%～0.14%)的元素含量特征,铝饱和指数(A/CNK)为0.92～1.06,并且含角闪石,属准铝质—弱过铝质I型花岗岩类。这些花岗岩类具有轻稀土元素(LREEs)富集和重稀土元素(HREEs)亏损,弱的负铕异常(δEu=...     

Magmatic evolution and rare earth element enrichment of Saima alkaline complex,Liaoning, ChinaSCIEI北大核心CSCD

赛马碱性杂岩体位于我国辽东半岛,是一个典型的铀-铌和稀土多金属矿化杂岩体,富含重稀土,其复杂的演化过程和稀土元素富集机制仍没有得到有效约束。本文对该碱性杂岩体中角闪辉石正长岩、正长岩、黑云正长岩、云霓霞石正长岩和异霞正长岩5类岩石及锆石的元素地球化学特征进行了系统研究,并开展了特征矿物包裹体的显微岩相学研究,旨在限定杂岩体母岩浆的演化路径,揭示稀土元素的富集机制。研究结果显示,赛马碱性杂岩体的母岩浆经历了由钾质碱性(角闪辉石正长岩、正长岩和黑云正长岩),到钾质过碱性(云霓霞石正长岩),向钠质过碱性(异霞正长岩)的充分演化。在演化过程中赛马碱性杂岩体母岩浆的体系状态发生了明显变化,碱性岩浆演化受流体不饱和的纯岩浆体系的控制,而过碱性岩浆岩则形成于流体过饱和的岩浆体系,且异霞正长岩母岩浆流体的饱和程度明显高于云霓霞石正长岩的母岩浆。研究还显示,钾质碱性岩浆稀土元素的地球化学行为主要受控于磷灰石等矿物的分离结晶,而成矿的钠质过碱性岩浆稀土、锆和铌等元素的富集成矿则主要受富CO_(2)的高盐度岩浆热液的控制。     

Formation conditions and reservoir-forming models of the Ordovician buried hill reservoirs in the Jizhong depression

The buried hill in the Jizhong depression contains abundant petroleum reserves and are important production areas. The Ordovician buried hill has restricted the discovery of new oil and gas exploration targets because of its strong reservoir heterogeneity and complex reservoir-controlling factors. Based on a large volume of core, thin section, logging, seismic, and geochemical data and numerous geological analyses, the reservoir-forming conditions and modes were systematically analyzed to guide the exploration and achieve important breakthroughs in the Yangshuiwu and Wen’an slope buried hills. The study revealed that three sets of source rocks of the third and fourth members of the Shahejie Formation from the Paleogene and Carboniferous-Permian were developed in the Jizhong depression, providing sufficient material basis for the formation of buried hill oil and gas reservoirs. The reservoir control mechanism involving the three major factors of “cloud-karst-fault” was clarified, and karst cave, fracture fissure-pore, and cloud pore type reservoir models were established, thereby expanding the exploration potential. Controlled by the superposition of multi-stage tectonic processes during the Indosinian, Yanshanian, and Himalayan, two genetic buried hill trap types of uplift-depression and depression-uplift were formed. Based on the analysis of reservoir-forming factors of the Ordovician buried hill, three buried hill oil and gas reservoir-forming models were identified: low-level tectonic-lithologic composite quasi-layered buried hill, medium-level paleo-storage paleo-block buried hill, and high-level paleo-storage new-block buried hill. Comprehensive evaluations indicate that the reservoir-forming conditions of the low-level tectonic-lithologic composite quasi-layered buried hill in the northern portion of the Jizhong depression are the most favorable and that the Sicundian and Xinzhen buried hills are favorable areas for future exploration.     

Energy dissimilation characteristics and shock mechanism of coal-rock mass induced in steeply-inclined mining: comparison based on physical simulation and numerical calculation

Acta Geotechnica - In recent years, as the Urumqi mining area deepens, rockbursts induced by the instability of the coal-rock mass are becoming more serious in steeply-inclined coal seam mining....     

Anthropogenic Aerosol Pollution over the Eastern Slope of the Tibetan Plateau

In this study, a combination of satellite observations and reanalysis datasets is used to analyze the spatiotemporal distribution, classification and source of pollutants over the eastern slope of the Tibetan Plateau(ESTP). The aerosol optical depth(AOD) over the ESTP is extremely large and even larger than some important industrialized regions and deserts. The main aerosol component over the ESTP is sulfate, followed by carbonaceous and dust aerosols. Local emissions related to human activity directly contribute to the accumulation of sulfate and carbonaceous aerosols over the Sichuan Basin. In addition, in spring, abundant carbonaceous aerosols emitted from forest, grassland and savanna fires in Southeast Asia can be transported by the prevailing southwesterly wind to southern China and the ESTP. The dust AOD over the ESTP peaks in spring because of the transport from the Taklimakan and Gobi deserts. Additionally, the high aerosol loading over the ESTP is also directly related to the meteorological background. Due to the special topography, the terrain-driven circulation can trap aerosols in the Sichuan Basin and these aerosols can climb along the ESTP due to the perennial updraft. The aerosol loading is lowest in summer because of effective wet deposition induced by the strong precipitation and better dispersion conditions due to the larger vertical temperature gradients and ascending air movement enhanced by the plateau heat pump effect. In contrast,the aerosol loading is greatest in winter. Abundant anthropogenic aerosols over the ESTP may generate some climatic and environmental risks and consequently greatly influence the downstream regions.     

安康及石泉水库入库流量变化特征及汛期预测

利用安康及石泉水库2000—2011年逐日入库流量及对应时段安康及石泉流域观测站逐日降水资料,分析了安康及石泉水库入库流量的变化特征及其与流域面雨量的关系。结果发现,安康及石泉入库流量主要集中在7到10月,极端入库流量在7—9月的出现频率最大;入库流量变化与其流域面雨量关系密切,其中6—10月,逐日入库流量与面雨量呈显著正相关;随着面雨量的增长,入库流量呈阶段性增长趋势,安康水库入库流量分别在流域面雨量达到20 mm和40 mm时显著增加,石泉水库入库流量则分别在流域面雨量达到15 mm和30 mm时大幅增加;建立了引入降水累积效应的汛期安康及石泉水库入库流量预测模型,经检验表明模型能较好地模拟入库流量的实际变化,对电力部门汛期水量调度有参考价值。     

山西省冰雪运动气候适宜性评价

综合考虑温度、降雪量、风等因素,构建冰雪运动气候指数(ice-snow sport climate index,ISCI)评价模型,确定冰雪运动气候适应性分级标准。以山西省为例,定量评价冰雪运动的气候适宜性特征和空间分布状况。结果表明:全省冰雪运动气候指数平均值为5. 03,属于一般适宜等级; 38°N以北的大部分区域均适合发展冰雪运动产业,且未来气候适宜性呈现增强趋势。     

全球变暖背景下青藏高原夏季大气中水汽含量的变化特征

利用中国气象局提供的0. 5°×0. 5°降水和温度的日值资料,联合ERA-Interim、MERRA2(second M odern-Era Retrospective analysis for Research and Applications)和JRA-55(Japanese 55-year Reanalysis)再分析资料以及全球陆面数据同化系统(Global Land surface Data Asimilation System,GLDAS-2. 0)资料,研究了全球变暖背景下青藏高原夏季地表气温及降水的变化特征,以及该地区大气中水汽含量及水汽输送特征。结果表明,1979—1998年期间,高原的地表气温呈增加趋势,降水呈减少趋势;而在全球增温减缓期间(1999—2010年),地表气温及降水较1979—1998年期间呈现更为显著的增加趋势。在青藏高原上空,大气中水汽含量在1979—2010年间整体呈增加趋势;然而,进一步分析表明,在此期间由外界向高原输送的水汽逐年降低,尤其在1998年后,由于西南季风强度的大幅减弱,使得外界向高原的净水汽输送量减少得更为显著;青藏高原地表蒸散量的分析表明,自1998年后,高原地表的蒸散量显著增加,成为高原地区大气中水汽增加的主要原因。     

晚渐新世以来青藏高原北部东昆仑山构造隆升对亚洲内陆干旱化的潜在影响——基于现代地质观测证据

青藏高原的构造隆升—生长过程及其资源环境效应是地球系统科学研究中的一个重要命题。其中,新生代青藏高原构造隆升过程与亚洲内陆干旱化之间的联系是研究的一个热点和难点。本文基于青藏高原从那曲到格尔木沿109国道现代地理要素和景观变化的证据以及大量器测数据和模拟结果讨论了青藏高原具体区域对亚洲内陆干旱化形成演化的重要影响,结果指出东昆仑山对印度季风继续深入内陆具有明显的阻挡作用,是一个重要的水汽屏障。同时本文结合东昆仑山晚渐新世以来主要构造隆升事件与亚洲内陆干旱化关键时间点的高度契合,进一步指出东昆仑山晚渐新世以来的构造隆升对亚洲内陆或者至少柴达木盆地的干旱化事件具有重要的影响,但是~3.6 Ma之后,北半球冰期对内陆盆地的干旱化的影响更大。     

晚渐新世以来青藏高原北部东昆仑山构造隆升对亚洲内陆干旱化的潜在影响 ——基于现代地质观测证据

青藏高原的构造隆升—生长过程及其资源环境效应是地球系统科学研究中的一个重要命题。其中,新生代青藏高原构造隆升过程与亚洲内陆干旱化之间的联系是研究的一个热点和难点。本文基于青藏高原从那曲到格尔木沿109国道现代地理要素和景观变化的证据以及大量器测数据和模拟结果讨论了青藏高原具体区域对亚洲内陆干旱化形成演化的重要影响,结果指出东昆仑山对印度季风继续深入内陆具有明显的阻挡作用,是一个重要的水汽屏障。同时本文结合东昆仑山晚渐新世以来主要构造隆升事件与亚洲内陆干旱化关键时间点的高度契合,进一步指出东昆仑山晚渐新世以来的构造隆升对亚洲内陆或者至少柴达木盆地的干旱化事件具有重要的影响,但是～3.6 Ma之后,北半球冰期对内陆盆地的干旱化的影响更大。