鄂尔多斯盆地延安地区山西组山2段储层可动流体赋存影响因素分析

山2段是鄂尔多斯盆地延安地区致密砂岩气生产的重要层段,目前对其流体赋存规律认识明显不足。因此在铸体薄片、扫描电镜、X射线衍射、高压压汞、恒速压汞、核磁共振测试的基础上,分析该储层可动流体的赋存特征及其影响因素。结果表明:山2储层主要为岩屑石英砂岩和岩屑砂岩,溶蚀孔和晶间孔为主要储集空间,粒间溶孔显著发育。山2储层可动流体饱和度为34.74%～91.83%,平均为69.94%,T2谱多为双峰态,呈左低右高型。储层孔隙度、渗透率、孔隙类型、孔喉特征及胶结物影响可动流体饱和度。孔隙为可动流体提供主要空间,平均孔隙半径越大,平均喉道半径越大,孔喉比越小,可动流体饱和度越高。硅质含量越高,粒间孔保存越好,可动流体饱和度越高。铁方解石含量越高,孔隙破坏越明显,可动流体饱和越低。高岭石含量较高,长石溶孔及晶间孔发育较好,有利于流体流动,可动流体饱和度也较高。     

高温高压下水流体pH值测量

高温高压下水流体的pH值是影响矿物-水流体相互作用平衡和动力学过程的一个重要参数。确定高温高压流体pH的方法主要包括电位势测量、化学分析与热力学计算及电导率方法。电位势测量在化学领域应用广泛,也被用来测量了洋中脊的热液流体的pH值。人们尝试了各种形式的电极,如氢电极、钯氢化物电极、金属-金属氧化物电极和钇稳定的氧化锆(YSZ)电极。玻璃电极只取得了有限的成果,通常用来测量常温及低温下的流体的pH值。对金属-金属氧化物电极在较宽的温度范围内进行了研究,但它需要利用合适的参比溶液来校正,与玻璃电极一样都表现出较大的偏移和误差以及不可回测性。陶瓷薄膜电极,如钇稳定的氧化锆(YSZ)电极,为测量相对较高温度下的pH值提供了一个可靠的方法。利用高温淬火水的化学分析和常温下的pH的测量,通过求解络合反应质量平衡与所有组分质量平衡的联立方程,来计算指定温度压力下pH值和水溶液种类的分布,是获得高温pH值的另一个重要而常用的方法,但热力学数据中的数值误差和不确定性以及分析误差能够影响计算出的高温溶液的pH值的精度。对高温高压超临界水流体的电导测量已经取得很大的成就,它被用来作为确定溶液内部离子反应平衡常数的一种最常用的方法,通过获得的这些反应的平衡常数,就可以得到在高温高压下流体的就位物质组成,这个方法可以测量更高温度压力下流体的pH值。     

胶莱盆地蛇窝泊地区白垩纪林寺山组沉积时代与物源特征:来自碎屑锆石U-Pb测年与稀土元素组成的新证据

林寺山组是胶莱盆地莱阳群底部重要的地层单元之一.准确限定其沉积时代与物源性质对于客观重建华北陆块东部晚中生代大地构造格局以及周缘造山带/前寒武纪变质基底晚中生代的折返过程具有重要的制约作用.以莱阳盆地蛇窝泊地区莱阳群林寺山组细砾岩为研究对象,对其开展了野外地质调查、岩相学观察、锆石U-Pb测年与锆石稀土元素分析等综合研...     

再论塔里木板块的归属问题

长期以来，对塔里木板块属于华北板块？扬子板块？还是一个独立的板块？一直存在争议。本文根据塔里木板前寒武纪基底的性质，古生代沉积建造序列，生物古地理区系的面貌和古地磁资料认为：（１）塔里木是属于前寒武纪陆壳基底的独立板块，与周边板块之间的存在不同规模的洋盆；（２）早古生代时，塔里木位于南半球，更接近于扬子板块，而远离华北板块（３）在古生代一中生代时，塔里木板块与周边坡板块先后碰撞，直到三叠纪末，塔里     

哀牢山过山气流的气候效应

本文研讨哀牢山脉北段西南季风与东北季风的过山气候效应。     

萨拉乌苏河流域萨拉乌苏组砂丘砂沉积特征

The Salawusu Formation of Milanggouwan section in Salawusu River Valley includes 7 layers of paleo-mobile dune sands, and 4 layers of paleo-fixed and semi-fixed dune sands. Their structures have been observed and their grain size, surface textural features and several main chemical elements have been analyzed. The results showed that： 1） Some of the aeolian structural characteristics of these dune sands are similar to that of the recent dune sands. 2） They are also similar to the recent dune sands in grain size components, and parameters of Mz,σ, Sk and Kg, as well as in several main chemical components. 3） The scattergrams of Mz-σ and SiO2-Al2O3＋TOFE and the probability curves of grain size showed that these paleo-dune sands are different from paleosols and fluvio-lacustrine facies, but are consistency with recent dune sands. 4） Quartz sands have well roundness and surface textural features such as dish-shaped pits, crescent-shaped pits, pockmarked pits, upturned cleavage plates, siliceous precipitates and siliceous crevasses, indicating that they had been carried for a long time by the wind. As the 11 layers of paleo-dune sands possess the aeolian characteristics in structure, grain size, surface textural features and chemical elements, the origin of their formation should be attributed to eolation.     

Degrading river network due to urbanization in Yangtze River Delta

Evolution of river systems under the background of human activities has been a heated topic among geographers and hydrologists. Spatial and temporal variations of river systems during the 1960s–2010s in the Yangtze River Delta (YRD) were investigated based on streams derived from the topographic maps in the 1960s, 1980s and 2010s. A list of indices, drainage density (Dd), water surface ratio (WSR), ratio of area to length of main streams (R), evolution coefficient of tributaries (K) and box dimension (D), were classified into three types (quantitative, structural, and complex indices) and used to quantify the variations of stream structure. Results showed that: (1) quantitative indices (Dd, WSR) presented decreasing trend in the past 50 years, and Dd in Wuchengxiyu, Hangjiahu and Yindongnan have decreased most, about 20%. Structurally, the Qinhuai River basin was characterized by significant upward R, and K value in Hangjiahu went down dramatically by 46.8% during the 1960s–2010s. Decreasing tendency in D was found dominating across the YRD, and decreasing magnitude in Wuchengxiyu and Hangjiahu peaks for 7.8% and 6.5%, respectively in the YRD. (2) Urbanization affected the spatial pattern of river system, and areas with high level of urbanization exhibited least Dd (2.18 km/km²), WSR (6.52%), K (2.64) and D (1.42), compared to moderate and low levels of urbanization. (3) Urbanization also affected the evolution of stream system. In the past 50 years, areas with high level of urbanization showed compelling decreasing tendency in quantitative (27.2% and 19.3%) and complex indices (4.9%) and trend of enlarging of main rivers (4.5% and 7.9% in periods of the 1960s–1980s and the 1980s–2010s). In the recent 30 years, areas with low level of urbanization were detected with significant downward trend in Dd and K. (4) Expanding of urban land, construction of hydraulic engineering and irrigation and water conservancy activities were the main means which degraded the river system in the YRD.     

云南昭通盆地降雨侵蚀性与土壤可蚀性的初步研究

通用土壤流失公式已被广泛用于坡地土壤流失量的估算方面, 而此公式中降雨侵蚀性因子 （ Ｒ 值） 与土壤可蚀性因子 （ Ｋ 值） 因地域差异而不同, 必须结合各地和水文与土壤条件进行修正。以云南昭通坝区昭鲁河新泉水文站１０ 年的观测资料为基础, 分析计算了各种降雨参数的单因子和复合因子, 分别与土壤流失量之间的相关关系, 结果表明, 适合于昭通坝区的降雨侵蚀力 Ｒ 指标为Σ Ｅ· Ｉ１５, 昭通坝区年平均降雨侵蚀力 Ｒ 值为 １８４１４。同时, 根据对本区水稻土、紫色土和山地黄壤机械组成和有机碳含量的分析结果, 计算出这些土壤的可侵蚀性因子 Ｋ 值。最后提出, 鉴于本区降雨侵蚀性因子 Ｒ 值和土壤可蚀性因子 Ｋ 值均较高的情况, 应加强地表植被和表土层的保护, 防止水土流失。     

卫星遥感反演土壤水分研究综述

土壤水分是影响地表过程的核心变量之一。精准地测量土壤水分及其时空分布,长期以来是定量遥感研究领域的难点问题。简要回顾基于光学、被动微波、主动微波和多传感器联合反演等卫星遥感反演土壤水分的主要反演算法、存在的难点和前沿性研究问题,介绍了应用土壤水分反演算法所形成的3种主要全球土壤水分数据集,包括欧洲气象业务卫星（ERS/MetOp）数据集、高级微波扫描辐射计（AMSR-E）数据集、土壤湿度与海洋盐分卫星（SMOS）数据集,并结合目前存在的问题探讨卫星遥感反演土壤水分研究的发展趋势。     

硫酸参与的长江流域岩石化学风化速率与大气CO2消耗

流域的岩石化学风化过程是全球碳循环中的重要环节。以往的流域水化学碳汇通量估算大多是基于碳酸的风化作用。而实际上,硫酸和碳酸一样,也参与了流域碳元素的地球化学循环,从而对全球碳循环过程产生影响。长江流域水体近几年出现酸化现象,大部分河段SO42-和Ca2+含量增高,其对应的岩石风化过程和大气CO2消耗速率也发生变化。文章对长江干流及主要支流2013年不同季节的离子组成进行监测,利用水化学平衡法和Galy估算模型,对长江流域岩石化学风化速率和CO2消耗通量进行了估算,对硫酸参与下的长江流域岩石风化和碳循环过程进行了分析。结果表明,长江流域水体离子主要来源于硅酸盐岩风化和碳酸盐岩风化。其中碳酸盐岩风化对河水离子贡献率为92%。在硅酸盐岩广泛分布的赣江流域,碳酸盐岩风化离子贡献也达85%。分析表明,硫酸参与了长江流域的岩石风化过程,对水体中离子产生一定影响。硫酸的参与加快了碳酸盐岩的化学风化速率,平均提高约30%,但是使流域大气CO2消耗速率降低。在不考虑蒸发岩溶蚀作用下,平均从516×103 mol/km2·a降至356×103 mol/km2·a,降低约31%。在各支流中,硫酸对乌江流域碳酸盐岩的风化和碳循环的影响最大,而对雅砻江的影响最小,这与乌江流域的含煤地层、矿床硫化物及大气酸沉降有关。