台特玛湖湿地保护研究

台特玛湖位于塔里木盆地东北隅,属新疆若羌县,是现塔里木河和车尔臣河的归宿地。它是由阿尔金山山前平原和塔里木河及车尔臣河冲积平原交汇处的低地积水形成的,过去曾与罗布泊相通。湖泊沉积物以细沙为主,在强劲的东北风吹蚀下,极易就地起沙。1982~1998年曾连续干涸17年,使湖西岸发展成强度沙漠化,若长期干涸,将会演变成一片沙海。这将会严重威胁218国道和将要修建的环塔里木盆地铁路以及新疆至青海铁路,对塔里木盆地东部重镇若羌的发展带来很大的影响。保护台特玛湿地,还可为候鸟迁徙提供栖息地,并可发展养鱼和育苇。湖面应保持最小面积为10~30km2,根据水面蒸发系数计算约需3000×104~4500×104m3的水量。入湖水量由塔里木河和车尔臣河各承担一半。要求塔里木河每年从大西海子下泄水量2.3×108m3,除维护下游绿色走廊生态用水外,可有1500×104~2500×104m3的水量入湖。车尔臣河向台特玛湖输水方便快捷,其上游不宜修建大型水库,使中下游水量达到1.5×108~2.0×108m3,保证所分担的水量不成问题,并通过对其下游三角洲整治,还可增加向台特玛湖的输水量,使之成为台特玛湖的主要补给水源。     

Field Test Research on Embankment Supported by Plastic Tube Cast-in-place Concrete Piles

The plastic tube cast-in-place concrete pile (TC pile) with a small diameter consists of pre-driven plastic tube filled with concrete. Based on the case of TC pile-reinforced embankment on soft ground, and according to the monitoring data of the TC pile-reinforced embankment system, the treatment effect and reinforcement characteristics for this system were analyzed. The field monitoring results indicates that the critical height of embankment is about 1.1 times the pile net spacing, and the small-spacing arranged TC piles can be applied to low embankment engineering; the load share rate can reflect the degree of soil arching more better and steadily and exceeds 70 % at the end of monitoring period; the settlements of pile cap and soil between piles mainly occurs in the embankment construction period; the different settlement between pile cap and soil approaches the maximum and then reduces gradually when the embankment height is about 2.2 times the pile net spacing. The variation of layered settlement and pore water pressure illustrates that the embankment settlement is mainly caused by the compression of soils within pile length, which is about 90 % of the total settlement; the influence depth of pore water pressure is about 1/3 pile length.     

Major element geochemistry of purple soils/rocks in the red Sichuan Basin, China: implications of their diagenesis and pedogenesis

Major element compositions and chemical weathering features of the purple soils and their corresponding rocks in the Red Sichuan Basin, China were studied in this paper to infer the diagenetic features of the purple rocks and the pedogenetic features of the purple soils. The results showed that all of the rock and soil samples, except those from Yibin, have strongly similar major element compositions and the distribution patterns of their major element compositions are similar to those of the upper continental crust. Chemical index of alteration, chemical index of weathering and Na₂O/K₂O indicate that the purple soils and rocks have similar chemical weathering intensities, whereas the Al₂O₃–CaO* + Na₂O–K₂O (A–CN–K) relationship, suggests that chemical weathering was strong during diagenesis of the purple rocks, but weak during pedogenesis of the purple soils. Variations in major element compositions of the purplish rock samples, except that from Yibin, do not primarily reflect differences in compositions of the sediment source, sediment recycling and potassium metasomatism, and therefore the effects of chemical weathering on the major element compositions were mainly dependent on climate condition and the residence time of material exposed to chemical weathering. Chemical weathering of the purple rocks reached only moderate degrees under the general influence of warm and humid climate during Jurassic and Cretaceous. Warmer and more humid climate conditions partly resulted in stronger chemical weathering of rocks in the southern region of the basin than in the central and western region, whereas shorter residence time of material in upslope position partly resulted in weaker chemical weathering of rocks in the eastern region than in the central and western region. The same climate and stable tectonic setting led to comparable chemical weathering intensities of rocks in the Ziliujing and Jiaguan Formations. Gradually colder and dryer climate from Early Jurassic to Middle Jurassic then to Late Jurassic and shorter residence time in tectonically active setting of Middle Jurassic and late Late Jurassic resulted in the following order of chemical weathering intensity of the purple Jurassic rocks: Ziliujing Formation ? Shaximiao Formation ≈ Suining Formation > Penglaizhen Formation.     

区域资源定量评价中面金属量法的应用

地球化学方法被普遍应用于矿产资源评价,但多数方法都只是基于地球化学数据本身而进行的,较少考虑除成矿物质来源之外的诸如构造、地层等地质环境的影响。文章运用面金属量法,在充分研究地质因素的基础上,确定了预测单元及地球化学背景值,在一定程度上屏蔽了虚假资源量,对东天山地区铜的资源量进行了定量评价。预测认为,东天山地区铜的资源潜力巨大。     

武夷山成矿带及邻区上地幔速度结构及其对燕山期岩浆-成矿活动的启示

武夷山成矿带燕山期岩浆-成矿活动的深部动力学机制一直是学者们研究的热点。已有的研究结果表明,武夷山成矿带及邻区的上地幔存在着显著的低速异常,可能与地表的岩浆-成矿活动存在着密切的联系。本研究利用分布在华夏地块98个固定地震台站以及59个流动地震台站所记录到的278个远震事件,采用远震层析成像方法构建了武夷山成矿带及邻区上地幔三维P波速度结构模型。成像结果表明,武夷山成矿带及其东侧的上地幔存在着显著的低速异常,代表了热物质富集的地幔楔,且上地幔的热物质在这些地幔楔间进行着横向流动。东南沿海的地幔过渡带存在着一个显著的低速异常,推测为新生代欧亚板块与菲律宾海板块碰撞俯冲的产物。南岭成矿带下方的低速异常从上地幔一直向上延伸到上地壳,可能指示了一个热物质上涌的通道。结合已有的研究结果,本研究认为武夷山成矿带燕山期岩浆-成矿活动可能与古太平洋板块的俯冲和后撤所引起的热物质上涌有关。

     

An approach for estimating sustainable yield of karst water in data sparse regions

This study presents an approach for transferring the qualitative analysis of groundwater sustainability for development to quantitative evaluation by an analogy of two similar regions. A concept of groundwater exploitation sustainability (GES), which is an evaluation index based on water supply capability, eco-geo-environment maintaining capability and the harmony between water and society, is put forward. The fuzzy analytic hierarchy process method is applied to calculate the GES for the Xiangshan and Dianchang karst groundwater sources in the Huaibei city, Anhui Province, China. The GES of the Xiangshan karst system was calculated to be 0.53 and represents medium exploitation sustainability, while that for the Dianchang is relatively high with a value of 0.70. These two karst systems are separate units but have similar hydrogeological conditions. The Dianchang area had limited groundwater observation data, while the Xiangshan area had long series of observation data, which enabled the computation of the sustainable yield. The sustainable yield of the Xiangshan karst area was used to calibrate the GES, and develop a linear equation between the GES and sustainable yield, which was used to calculate the sustainable yield of the Diangchang karst area as 40.4 million m³.     

赤峰西部地区金矿床成矿时代及其成矿机制的新认识

赤峰西部地区产华北板块与兴蒙造山带拼合部位南侧的板块北部边缘带上，为著名的赤峰－朝阳金矿集中区重要金矿产地之一。本区金矿床包括两种类型：柴胡栏子金矿床为蚀变岩型金矿床为蚀变岩型金矿；莲花山和红花沟金矿床属石英脉型。诸多地质事实表明这些矿床的形成均与中基性岩浆活动密切相关。野外观察和同位素年代学资料说明中基性岩浆活动发生在印支期。因此，笔者提出本区金矿成矿时代为印支期的新认识，否定了以往一些研究者提出本区金成矿作用是发生在燕山期或海西期的看法。同时，在综合分析基础上，提出本区金矿床是在印支期构造－岩浆活动作用下、区域隆起的过程中形成的产物，从而对本区金矿床的形成机制做出了新的解释。     

Quantitative monitoring of gravity erosion using a novel 3D surface measuring technique: validation and case study

Natural Hazards - Gravity erosion is one of the most remarkable natural hazards in mountainous regions, especially on the Loess Plateau of China. Nevertheless, the measurement of failure mass is...     

云南兰坪北部铜多金属矿化区成矿流体流动与矿化分带——流体包裹体和稳定同位素依据

滇西兰坪盆地北部发育了一类受逆冲推覆构造控制的浅成热液Cu—Ag—Pb-Zn矿化，形成了白秧坪、富隆厂、吴底厂、麻栗坪及金满、科登涧等大-中型矿床和矿点，并存在矿化分带。文章利用这些矿化脉体的流体包裹体和热液方解石的碳氧同位素组成资料，研究成矿流体与矿化分带的关系。结果表明，成矿流体主要属于NaCl-H2O成分体系，盐度ω(NaCleq)为2％～11％，形成温度为170～300℃，形成于1．8～3．8km深度内，这些相似性说明这类矿化的发生具有相似的流体性质和沉淀机制。热液方解石在δ^13C-δ^18O图解中呈近水平线展布的型式，指示流体源自地壳浅部的地下水系统，与海相灰岩等围岩作用形成了溶解碳以[HCO3^]-为主的成矿流体，流体与岩石的相互作用可能是成矿流体沉淀的主要机理。从西到东，流体包裹体的盐度-温度由高到低变化与矿化分带和逆冲推覆构造的根带→中带→锋带相配套，显示重力驱动流动可能是主要的流体流动机制。成矿流体在不同构造部位流动的通畅及流体．岩石系统的封闭-开放程度等流体流动性质与矿化发生的强度和规模有关，兰坪北部逆冲推覆构造中带的流体通畅地流动及沉淀时处于相对开放状态，有利于该区形成较大规模的浅成热液多金属矿化。     

Quasi-hydrostatic compression of ruby to 500 Kbar

Measurements of the cell parameters of ruby to 500 Kbar under quasi-hydrostatic conditions in a diamond-anvil cell show a practically isotropic compression, the ratio c/a of the hexagonal cell parameters remaining constant. These results are consistent with previous single-crystal measurements below 100 Kbar as well as with ultrasonic elastic-constant measurements. There is no evidence for significant differences between the bulk moduli of ruby and corundum, and a review of compression and ultrasonic data yield Ko = 2.53±0.01 Mbar and Ko = 5.0 ± 0.4. Good agreement with the experimental values is found for compressions calculated from empirically or theoretically determined elastic properties.