Contemporary crustal deformation of the Chinese continent and tectonic block model

We obtain the preliminary result of crustal deformation velocity field for the Chinese continent by analyzing GPS data from the Crustal Motion Observation Network of China (CMONOC), particularly the data from the regional networks of CMONOC observed in 1999 and 2001. We delineate 9 technically active blocks and 2 broadly distributed deformation zones out of a dense GPS velocity field, and derive block motion Euler poles for the blocks and their relative motion rates. Our result reveals that there are 3 categories of deformation patterns in the Chinese continent. The first category, associated with the interior of the Tibetan Plateau and the Tianshan orogenic belt, shows broadly distributed deformation within the regions. The third category, associated with the Tarim Basin and the region east of the north-south seismic belt of China, shows block-like motion, with deformation accommodated along the block boundaries only. The second category, mainly associated with the borderland of the Tibetan Plateau, such as the Qaidam, Qilian, Xining (in eastern Qinghai), and the Diamond-shaped (in western Sichuan and Yunnan) blocks, has the deformation pattern between the first and the third, i.e. these regions appear to deform block-like, but with smaller sizes and less strength for the blocks. Based on the analysis of the lithospheric structures and the deformation patterns of the regions above, we come to the inference that the deformation modes of the Chinese continental crust are mainly controlled by the crustal structure. The crust of the eastern China and the Tarim Basin is mechanically strong, and its deformation takes the form of relative motion between rigid blocks. On the other hand, the northward indentation of the Indian plate into the Asia continent has created the uplift of the Tibetan Plateau and the Tianshan Mountains, thickened their crust, and raised the temperature in the crust. The lower crust thus has become ductile, evidenced in low seismic velocity and high electric conductivity observed. The brittle part of the crust, driven by the visco-plastic flow of the lower crust, deforms extensively at all scales. The regions of the second category located at the borderland of the Tibetan Plateau are at the transition zone between the regions of the first and the third categories in terms of the crustal structure. Driven by the lateral boundary forces, their deformation style is also between the two, in the form of block motion and deformation with smaller blocks and less internal strength.     

内陆河流生态环境需水量定量研究

在有限的水资源中,必须维持合理的生态环境需水量,以满足国民经济持续发展和生态平衡维护的需要,以内陆河流为对象,以生态学理论和水环境容量理论为基础,从维持河流系统水生生物生存、维持水体一定量稀释自净能力以及防止河流水面净蒸发损失的角度出发,分析计算了河流系统的生态环境需水量,以期为水资源合理配置提供科学依据。     

地震资料约束下大地电磁资料反演

应用地震资料约束下大地电磁资料反演古潜山或基底内部结构的新方法. 首先利用地震及井资料,反演得到古潜山或基底之上各层的厚度及电阻率,建立了古潜山或基底以上的地电模型;并利用大地电磁一维反演资料,建立了古潜山或基底及其以下的地电模型. 在初始模型建立的基础上,应用高效快速的二维大地电磁正演算法——模式匹配方法,进行正演计算. 利用共扼梯度迭代方法,进行正反演迭代计算. 通过对胜利油田南北618剖面反演, 基底以下在地震资料没有显示的构造信息,在反演结果中得到了较好地反映.     

不同地下水流系统模式渗流场和温度场的互相影响

在地热资源丰富的地区,需要研究不同地下水流系统发育模式下渗流场和温度场的互相影响.基于二维潜水盆地多源汇的数值模拟和室内砂箱实验,改变降雨入渗强度,通过砂箱底部加温研究上下边界不同温度差条件下的渗流场和温度场的变化.研究结果表明:①随着降雨入渗强度加大,地下水流速增大,地下水流系统由单一区域系统向复杂的局部+区域、局部...     

The initial impoundment of the Baihetan reservoir region (China) exacerbated the deformation of the Wangjiashan landslide: characteristics and mechanism

Landslides - Reservoir landslides greatly threaten reservoir safety. Understanding the deformation characteristics and mechanism of reservoir landslides can help evaluate their stability and...     

Study on Rationality of Large Diameter Pressure Relief Drilling Parameters Under Different Coal Seam Conditions

Geotechnical and Geological Engineering - To study the influence of changes in the coal seam mechanical characteristics at depth on the stress relief effect of a borehole, this paper established...     

Zircon U-Pb dating of intermediate-acid intrusive rocks in the middle section of Ningzhen district and their metallogenic implicationsEI北大核心CSCD

The Ningzhen metallogenic district is an important part of the Middle-Lower Yangtze River Valley metallogenic belt. LA-ICP-MS zircon U-Pb dating of the three intermediate-acid intrusions, i.e., Anjishan, Xinqiao, and Shima, in the central part of the Ningzhen district, indicates that those intrusions were emplaced in the Late Early Cretaceous, with ages of 107.0±1.1 Ma-108.0±1.6 Ma, 108.0±1.3 Ma, and 102.5±1.1 Ma, respectively. Combined with the molybdenite Re-Os isotope age (106-108 Ma) of porphyry copper deposit in this regions, the Ningzhen district exists an intensively magmatic-metallogenic-thermal event at 102.5-108.0 Ma. The age of this event is similar with the age of the third period of large scale mineralization in South China, however obviously later than the magmatic activity of other ore field (124-148 Ma) in the Middle-Lower Yangtze River Valley metallogenic belt. It is suggested that the tectonic-magmatic-thermal events in the Ningzhen area is formed under regional lithospheric extension environment, which is also consistent with the tectonic background of the third period of large scale mineralization in South China. The zircon U-Pb ages of the intrusions and the Re-Os ages of molybdenites from the porphyry deposits in the study area demonstrate that the Ningzhen district underwent intensive magmatism and hydrothermal mineralization during the period from 102.5 to 108.0 Ma, which is consistent with the third pulse of large scale mineralization in the South China. ©, 2015, Science Press. All right reserved.     

云南省乡镇农村地震灾害直接经济损失研究

根据1993-2003年30余次云南省地震的损失评估调查资料,建立了云南省农村乡镇各烈度区房屋建筑物损失与受灾人口的定量关系,初步建立了各烈度区水利设施损失、生命线工程损失与房屋建筑物损失的关系。以云南地区2004年-2005年4次地震为实例,用以上计算方法估算了4次地震的直接经济损失,并与地震现场评估的结果作比较,结果表明,该计算模型实用性强,对一般性地震的模拟误差平均值在30％左右。     

综合RS与GIS方法提取青藏高原冲川变化信息：以布喀塔格峰为例

冰川变化的常规观测方法在高原的大部分地区无法实施。遥感与地理信息系统技术的发展为研究冲川变化提供了有效的手段,本文以位于昆仑山脉中段的布喀塔格山峰冰川为例,利用１９７３年至１９９４年的ＲＢＶ,ＭＳＳ和ＴＭ遥感资料为信息源,综合目视判读与统计分析方法提取冰川界限,形成冰川边界图,并规一化坐标系统,以ＧＩＳ为工具分析该冲川群的变化情况,计算冲川进退变化速率。     

半荒漠风沙区土地沙漠化生物整治技术的研究

试验证明,土地沙漠化生物整治技术能在半荒漠风沙区取得显著的作用和效果。在柠条、毛条、花棒、杨柴、沙木蓼等灌木树种的适生立地上营造防风固沙林,林后3~4年,灌木就可郁闭成林,流动沙丘完全被控制变为固定沙丘;林下植被结构得以改善,优良品种增多,如能合理开发其饲料等用途,还具有十分可观的经济效益。