北京西山煤田滑脱构造的遥感研究

本文利用多种遥感资料提供的大量的新的构造信息,对北京西山煤田已有的地质认识和成果进行了重要补充和修改,划分出推覆型和滑型两种基本类型的滑脱构造,并详细研究了各个滑脱构造系统的影像特征、展布规律、几何形态、成因机制、演化历史以及控煤作用。     

末次冰期黄河解体事件初探

７０年代末，水文地质部门在华北平原上打下了大量第四系钻孔，１９９３年对其中近百个钻孔的沉积相和测年资料重新进行分析，发现在该区全新统之下、上更新统上部普遍发育了一层细砂层，埋深一般为２０－４０ｍ，厚度约为５－２０ｍ，平面分布连续而稳定。     

Impacts of coastal reclamation on tidal and sediment dynamics in the Rui’an coast of China

Ocean Dynamics - Coastal reclamation projects have been extensively constructed along the coastline of the East China Sea over the past decades. To investigate the impact of reclamations on the...     

Analysis of runoff characteristics in midstream of Yinma River

To use the water resources reasonably in the midstream of Yinma River is of great significance to Changchun City which is short of water. With the runoff data of physical measuring, the paper analyses the characteristics surface rmoff of the area, by means of the groundwater flow numerical simulation, and represents the characteristics of the groundwater runoff in the area. Based on combination analyses of the two runoffs, the authors point out the problem of the water resources use in this area and bring forward a resolution of conjunctive regulation and storage of the surface water and groundwater.     

Geological and geochemical characteristics of the Baogudi Carlin-type gold district (Southwest Guizhou,China) and their geological implications

The newly discovered Baogudi gold district is located in the southwestern Guizhou Province, China, where there are numerous Carlin-type gold deposits. To better understand the geological and geochemical characteristics of the Baogudi gold district, we carried out petrographic observations, elemental analyses, and fluid inclusion and isotopic composition studies. We also compared the results with those of typical Carlin-type gold deposits in southwestern Guizhou. Three mineralization stages, namely, the sedimentation diagenesis, hydrothermal (main-ore and late-ore substages), and supergene stages, were identified based on field and petrographic observations. The main-ore and late-ore stages correspond to Au and Sb mineralization, respectively, which are similar to typical Carlin-type mineralization. The mass transfer associated with alteration and mineralization shows that a significant amount of Au, As, Sb, Hg, Tl, Mo, and S were added to mineralized rocks during the main-ore stage. Remarkably, arsenic, Sb, and S were added to the mineralized rocks during the late-ore stage. Element migration indicates that the sulfidation process was responsible for ore formation. Four types of fluid inclusions were identified in ore-related quartz and fluorite. The main-ore stage fluids are characterized by an H₂O–NaCl–CO₂–CH₄ ± N₂ system, with medium to low temperatures (180–260 °C) and low salinity (0–9.08% NaCl equivalent). The late-ore stage fluids featured H₂O–NaCl ± CO₂ ± CH₄, with low temperature (120–200 °C) and low salinity (0–7.48% NaCl equivalent). The temperature, salinity, and CO₂ and CH₄ concentrations of ore-forming fluids decreased from the main-ore stage to the late-ore stage. The calculated δ¹³C, δD, and δ¹⁸O values of the ore-forming fluids range from − 14.3 to − 7.0‰, −76 to −55.7‰, and 4.5–15.0‰, respectively. Late-ore-stage stibnite had δ³⁴S values ranging from − 0.6 to 1.9‰. These stable isotopic compositions indicate that the ore-forming fluids originated mainly from deep magmatic hydrothermal fluids, with minor contributions from strata. Collectively, the Baogudi metallogenic district has geological and geochemical characteristics that are typical of Carlin-type gold deposits in southwest Guizhou. It is likely that the Baogudi gold district, together with other Carlin-type gold deposits in southwestern Guizhou, was formed in response to a single widespread metallogenic event.

     

渤海湾盆地北塘凹陷古近系湖相白云岩 地质特征及古环境意义

湖相白云岩是渤海湾盆地北塘凹陷古近系沙河街组三段发现的一种特殊油气储层类型。根据钻井岩心、古生物、薄 片、扫描电镜及电子探针等分析,确定了该套白云岩的主要岩石类型及矿物特征,并通过地球化学特征分析,对白云岩的 形成环境进行了探讨。北塘凹陷白云岩常与泥岩和方沸石岩呈互层状产出,其次为均匀块状;矿物成分主要有白云石、方 沸石、粘土矿物等。通过X射线衍射、主微量元素地球化学分析,对白云岩形成时的古盐度、古温度、水深、氧化还原条 件等进行了研究,认为研究区白云岩沉积于高盐度、较高水体温度和较高PH值的半咸水湖湾还原环境。海水的侵入使湖水 的含盐度增大,提供了有利的物理化学条件,促进了白云岩的形成。     

袖阀管注浆在人工填土暗挖施工中的应用

阜石路分洪暗涵某暗挖段,浅涵暗挖洞身大部位于人工填土内,部分区域洞底人工填土厚度仍达2m。人工填土松散,自稳能力差,易发生塌落现象,不易成洞,施工难度大。为避免暗挖施工期间人工填土产生安全隐患并减少后期隧道变形,采用了袖阀管注浆技术对填土地层进行注浆加固,以确保工程施工安全及隧道工程质量&根据工程实施效果可见,袖阀管注浆加固对在人工填土中进行暗挖隧道开挖的沉降、变形控制的效果较好。     

中国环境考古学的兴起、发展和展望

环境考古学是一门介于考古学与第四纪环境学(或古地理学)之间的边缘学科。它出现于20世纪之初,经过近1个世纪的摸索和实践,在理论和方法上日趋成熟。中国环境考古学出现较晚,但发展迅速,已经形成以人类生态系统理论为依据,以聚落和遗址古环境分析为主要手段,以探讨古代人类行为及其文化的形成、发展和演变的环境背景为目标的新型交叉学科。目前,它已经逐渐得到了中国考古学家的广泛认同,并成为考古学研究的重要组成部分,在涉及人类起源、MIS3阶段旧石器晚期文化革命、旧—新石器文化过渡以及农业起源、文明起源等一系列关键问题的研究中发挥着重要作用。     

宿南矿区不同时期塌陷塘水环境质量评价

以宿南矿区不同时期形成的采煤塌陷塘(芦岭塘、朱仙庄#1塘和#2塘)为研究对象,于2017年先后采集夏季和冬季水样,运用piper三线图、相关性分析、改进模糊综合评价法等,对其水环境质量进行分析评价与比较,得到以下结论:①芦岭塘、朱仙庄#1塘夏、冬两季水化学类型均为HCO_3―Na·Mg型,朱仙庄#2塘为SO_4―Na·Mg·Ca型。②三个塌陷塘水的TDS、pH、EC变化趋势为朱仙庄#1塘>朱仙庄#2塘>芦岭塘,其季节变化趋势均为夏季>冬季; ORP变化趋势为朱仙庄#2塘>芦岭塘>朱仙庄#1塘,其季节性变化趋势为冬季>夏季。③改进的模糊综合评价结果表明,三个塌陷塘夏季水质较差,主要受人为污染影响;冬季芦岭塘、朱仙庄#1塘水质良好,受污染小;朱仙庄#2塘冬季水质与夏季相近,均较差,主要受投加鱼食料的影响。     

Energy flux partitioning and evapotranspiration in a sub‐alpine spruce forest ecosystem

In this study, we examined the year 2011 characteristics of energy flux partitioning and evapotranspiration of a sub‐alpine spruce forest underlain by permafrost on the Qinghai–Tibet Plateau (QPT). Energy balance closure on a half‐hourly basis was H + λE = 0.81 × (R_n ? G ? S) + 3.48 (W m^?2) (r² = 0.83, n = 14938), where H, λE, R_n, G and S are the sensible heat, latent heat, net radiation, soil heat and air‐column heat storage fluxes, respectively. Maximum H was higher than maximum λE, and H dominated the energy budget at midday during the whole year, even in summer time. However, the rainfall events significantly affected energy flux partitioning and evapotranspiration. The mean value of evaporative fraction (Λ = λE/(λE + H)) during the growth period on zero precipitation days and non‐zero precipitation days was 0.40 and 0.61, respectively. The mean daily evapotranspiration of this sub‐alpine forest during summer time was 2.56 mm day^?1. The annual evapotranspiration and sublimation was 417 ± 8 mm year^?1, which was very similar to the annual precipitation of 428 mm. Sublimation accounted for 7.1% (30 ± 2 mm year^?1) of annual evapotranspiration and sublimation, indicating that the sublimation is not negligible in the annual water balance in sub‐alpine forests on the QPT. The low values of the Priestley–Taylor coefficient (α) and the very low value of the decoupling coefficient (Ω) during most of the growing season suggested low soil water content and conservative water loss in this sub‐alpine forest. Copyright © 2013 John Wiley & Sons, Ltd.