九寨沟“8.8”地震背景下火花海钙华坝体无损探测分析

为研究震后九寨沟钙华景区的溶洞、裂隙、暗流等地质特性,丰富钙华景区岩溶洞穴无损探测技术,探讨了多物探技术在多孔疏松钙华地区作业的可靠性。首次运用地质雷达法及高密度电法相结合的无损探测技术,在九寨沟景区火花海特定区域进行了现场勘查和无损探测试验。结合对比两种无损探测成果与测区内出露地质剖面3组勘探数据,结果发现:高密度电法与地质雷达法相结合,两者能优劣互补,相互佐证,在解决钙华区域浅部溶洞、暗流、裂隙等工作中,对探测目标体具有极高的识别度。两种方法探测数据与震后出露剖面地质特征保持极高的一致性,验证了两种无损检测方法在多孔疏松介质条件下数据的真实可靠性,解决了多物探技术在多孔疏松介质地区施工的疑点和难点,丰富了工程物探领域技术。      

京津冀地区低层局地大气环流的气候特征研究

本文采用2007-2016年的中尺度数值模拟结果和15个地面气象站观测资料,定义了局地风场表征风速,研究京津冀平原地区局地大气环流日变化的气候特征,并对区域大气污染及其输送的影响进行分析。此外,对2016年12月30日至2017年1月7日北京地区跨年大气重污染过程进行了个例分析。得到结论:京津冀平原地区低空风场变化是天气系统与局地大气环流共同作用的结果,山谷风环流致使太行山和燕山沿线平原地区大气边界层内的长年主导风向为偏北和偏南;太行山和燕山沿线地区山谷风环流本身呈顺时针旋转的日变化特征,夜间至早晨谷风转向山风,午后至夜间山风转向谷风;在午后谷风向山风转向期间,容易形成沿太行山东麓和燕山南麓、自南向东北的"弓形"气流输送通道,此气流输送通道在1月于21时左右形成,持续时间大约3 h,在7月于18时左右形成,持续时间可达9 h;冬季午后至晚间盛行谷风时,受山体的阻挡,污染物容易在山前累积,导致污染浓度增高;夏季同样的情况会发生在后半夜。     

Silurian and Devonian systems

The Ediacara mineral field is situated 30 km W of Beltana on the western margins of the Flinders Ranges, South Australia, and consists of silver‐lead and copper deposits in lower Cambrian carbonate rocks that contain anomalous base‐metal contents throughout the Adelaide Geosyncline. The lower Cambrian rocks, which consist of the basal Parachilna Formation and overlying Ajax Limestone, rest disconformably on the Precambrian, and at Ediacara occupy a shallow N‐S elongate syncline near the hinge zone of the Adelaide Geosyncline. The main primary ore minerals of the silver‐lead mineralization are galena and pyrite, with very minor chalcopyrite and sphalerite, and rare tetrahedrite and pearceite. The gangue consists mainly of silica (both chalcedony and quartz), with minor dolomite and rare barite. The mineralization is stratabound and occurs in conformable zones, the lowest of which commences about 30–50 m above the base of the Cambrian sequence. The host to the silver‐lead mineralization, the Ajax Limestone, can be subdivided into three units which represent a set of lithologies, structures and organic traces indicative of a shallow near‐shore carbonate environment. The silver‐lead mineralization is mainly present in sandy and laminated dolomites which were deposited in an environment ranging from sub‐tidal to bar and channel and tidal flat, respectively. Four types of mineralization have been recognized; disseminated sulphides of syngenetic and/or diagenetic origin and epigenetic concentrations along stylolites, in veins and as breccia fillings. Post‐depositional solution activity has affected a large proportion of the carbonate sequence. The effects of this activity range from stylolites through stylobreccias to solution collapse breccias. The epigenetic concentrations of mineralizations have apparently been formed by the remobilization of the disseminated sulphides during solution activity. The ore and gangue minerals of the epigenetic mineralization display both euhedral forms and distinct colloform banding, and framboidal textures have also been observed in both pyrite and galena. There is evidence of repeated episodic precipitation and no simple paragenetic sequence can be recognized. Fluid inclusions in silica and dolomite associated with the epigenetic mineralization have homogenization temperatures of 159 to 199°C and freezing temperatures that indicate the fluids to be saline brines containing NaCl with CaCl₂ and/or MgCl₂. Sulphur isotope analyses show a range of 8³⁴S values from ‐12.5 to +8.6 per mil, with no evidence of significant differences between the four types of mineralization. The data suggest deposition of the disseminated sulphides as a result of biological reduction of seawater sulphate in a system partially open with respect to sulphate supply. Subsequent remobilization of sulphides apparently involved little or no sulphur isotope fractionation. The Ediacara silver‐lead deposits have many features in common with Mississippi Valley‐type lead‐zinc deposits and appear to have similarities in terms of genesis, in that the epigenetic mineralization has been formed as a result of post‐depositional solution activity during diagenesis in a sedimentary basin. The scale of transport of the metals deposited as the epigenetic mineralization at Ediacara appears, however, to have been very much less than that of the metals in other Mississippi Valley‐type deposits.     

山区年、月平均温度推算方法的研究

本文提出了山区年、月平均温度空间分布的推算方法,并提供了相应的小地形温度订正值。该方法在福建省沙溪流域山区实际应用的结果表明,能有效地揭示山区年、月平均温度空间分布的宏观与微观变化,效果满意,精度较高。     

北京市北山泥石流分布规律及形成过程

北京北山泥石流的分布受构造控制，呈北东方向展布。其分布在时间上和空间上均有一定的规律可寻。一条泥石流沟谷的形成从开始到结束，概括分为形成、位移和堆积。区内泥石流的形成主要有三种形式：以水力侵蚀为主，以坡面侵蚀为主和以沟源崩、滑塌形式触发沟床物质活动而形成的泥石流。     

川西南干热河谷赤按人工林生物量和营养元素含量

用林木生物量回归方程，求得川西南干热河谷五年生赤桉纯林中乔木层生物量１３１３３．９ｋｇ／ｈａ（年平均生长量８０７９．７ｋｇ／ｈａ），草本层生物量５５２．０ｋｇ／ｈａ（枯落物现存量５９１．６ｋｇ／ｈａ）；赤桉与山毛豆混交林林分生物量２７１８６．９ｋｇ／ｈａ，其中赤桉生物量１６４９４．３ｋｇ／ｈａ（年平均生长量６６２０．２ｋｇ／ｈａ），灌木层生物量１０３６３．６ｋｇ／ｈａ，草本层生物量３２９．０ｋｇ／ｈａ（枯落物现存量１２６４．３ｋｇ／ｈａ）．混交林中赤桉生长好于纯林中赤桉的生长。林分营养元素含量不同植物差别很大，同种植物各器官也有所差别．各器官中营养元素含量顺序一般为：ｃａ＞Ｎ＞Ｍｇ＞Ｋ＞Ｐ，Ｐ是林地土壤缺乏的元素。     

云南元谋干热河谷土地退化及其防治对策*

本文探讨了云南元谋干热河谷土地退化的特点、分布及其危害,提出了加强基础教育、控制人口增长、改革耕作制度、继续农业基础设施建设、因地制宜发展林业和农业等于热河谷土地退化防治对策。     

云南省元谋干热河谷的土壤系统分类

应用土壤系统分类的原理和方法，研究了元谋干热河谷主要土壤的土壤铁铝特性、弱腐殖质化（层）特性、变性特征、岩性特征等诊断特性。据此提出了当地高级分类单元的土壤系统分类（草案）。分析了主要土壤的剖面特征和理化性状，并对亚类以下分类问题提出了看法。     

黄河流域旱涝年地面热量收支变化特征

根据北京、郑州３年热量平衡观测资料，建立波文（Ｂｏｗｅｎ）比计算模式。并用此模式及辐射计算式等估计黄河流域８年５－８月地面月辐射收支、蒸发耗热、湍流热交换量和土壤热交换量，并比较分析旱涝年它们的差异以及随旱涝（用降水距平表示）的变化。      

云南三江一河典型地区河谷第四系发育特征

三江一河（金沙江、怒江、澜沧江、红河是流经云南境内的４条主体水系，将上述４条河流河谷第四系的野外观察加以总结得出；金沙江河谷局部发育早一中更新世的湖相层和河湖相层，常形成晚期阶地的基座，晚更新世至全新世冲积层构成四级阶地；怒江河谷第四系发育较差，在六库的上游河谷中冲积层极不发育，只有局部地方有少量的河漫滩砂砾层（全新世），在六库至过街河段中，尤其是过街盆地，发育有中更新世至全新世的冲积层和洪积层，前者构成五级阶地，后者形成巨大的洪积扇分布在河流右岸的谷底或苍坡上；澜沧江除景洪、勐罕（橄榄坝）盆地外，其它河段主要为峡谷，第四系很少，在景洪盆地中发育有第二、第一级阶地和河漫滩冲积层；红河的第四系有中更新世至全新世的冲积层，并构成五级阶地。基于上述第四系特点，简要地讨论了这４条河流的形成时代。