江汉盆地潜江凹陷地下卤水地球化学特征和分布规律

江汉盆地潜江凹陷潜江组赋存有丰富的地下卤水,因其有较高的经济价值,是江汉盆地油气资源之外的又一种重要的战略资源。然而,长期的油田注水开采也对地下卤水产生了一定的影响,为进一步评估这种影响并探讨地下卤水微量元素的分布情况,通过采集和分析潜江组第一至第四卤水组的地下卤水样品开展其地球化学特征和分布规律的研究。结果表明,潜江凹陷潜江组地下卤水受油田生产影响,虽然普遍发生了淡化,但仍然拥有较高的TDS含量,淡化影响有限。卤水储层从上至下,第一卤水组至第四卤水组,随着深度的增加,硫酸钠亚型卤水和碳酸盐型水逐渐变少,氯化物型水逐渐增多。尽管区内地下卤水普遍经受油田注水生产的影响,但是卤水中Li、B、Br等元素依然保持较高的含量,大部分样品达到或超过边界工业品位,尤其以第二、第三卤水Li、B、Br品位较高,第四卤水组次之,第一卤水组最低。潜江凹陷地下卤水样品的钠氯系数接近于1,具备溶滤卤水特征,属于非海相地层的卤水,氯溴系数分析揭示区内现存地下卤水是溶滤卤水和沉积卤水混合以后的结果,卤水的脱硫系数和钙镁系数反映卤水的储集空间封闭性相对较差,凹陷内从第一至第三下卤水储集体的空间的封闭性逐渐变好,第四卤水组略变差。平面上,Li、B、Br具有相似的分布特征,凹陷内,卤水的浓集中心从下至上具有明显的迁移特征,钟市、浩子口、王场、周矶所围限的区域是高浓度卤水分布中心地带,其分布明显受控于卤水储集体的分布。     

贵州草海近21 ka以来有机地球化学记录反映的古环境变化*

草海位于黔滇交界,主要受印度夏季风的影响,其湖沼沉积物记录了中—晚第四纪的环境变化历史,是研究第四纪环境和季风演变的良好载体。本研究选取的南屯NT03钻孔,岩心长405 cm,在放射性碳同位素(AMS¹⁴C)测年基础上建立了年代序列,并进行了沉积物的色差值(L^*)、烧失量(LOI550)、总有机碳(TOC)、碳氮比(C/N)和有机稳定碳同位素(δ13Corg)等古环境替代指标的测试。实验结果显示,L^*、LOI550和TOC等3个有机碳含量指标同步变化,共同指示该钻孔序列经历了3个沉积环境演变阶段,即末次盛冰期晚期(21—15 cal ka BP)河流—冲积相沉积阶段、冰消期至早中全新世(15—4 cal ka BP)高湖面湖泊—沼泽相沉积阶段和晚全新世(4 cal ka BP以来)洪冲积相沉积阶段。近2万年以来草海湖沼面积经历的收缩→扩张→收缩演变过程与石笋氧同位素变化基本吻合,表明季风降雨是引起草海湖泊水体和周边生态系统变化的主要因素。δ13Corg指标变化范围为-29.28‰~-24.19‰,表明草海盆地周围植被组成在末次盛冰期以来C4草本虽然略有增加,但均以C3植物为主。同时,TOC和δ13Corg指标证明了B/A冰消期暖事件对盆地边缘区的湿地泥炭富集起到关键作用,而多指标揭示了近4 ka以来水域变浅并发展成为冲积环境的过程,也可能与石笋记录的夏季风减弱所带来的降水量减少有关。     

Activity–composition relations for the calculation of partial melting equilibria in metabasic rocks

A set of thermodynamic models is presented that, for the first time, allows partial melting equilibria to be calculated for metabasic rocks. The models consist of new activity–composition relations combined with end‐member thermodynamic properties from the Holland & Powell dataset, version 6. They allow for forward modelling in the system NaO–CaO–KO–FeO–MgO–AlO–SiO–HO–TiO–FeO. In particular, new activity–composition relations are presented for silicate melt of broadly trondhjemitic–tonalitic composition, and for augitic clinopyroxene with Si–Al mixing on the tetrahedral sites, while existing activity–composition relations for hornblende are extended to include KO and TiO. Calibration of the activity–composition relations was carried out with the aim of reproducing major experimental phase‐in/phase‐out boundaries that define the amphibolite–granulite transition, across a range of bulk compositions, at ≤13 kbar.     

塔里木盆地北部上震旦统葡萄状白云岩的发现及成因探讨*

“皮壳—葡萄状”白云岩是一种非常特殊结构的白云岩。文中报道了塔里木盆地西北缘东二沟及塔北星火101井上震旦统奇格布拉克组中皮壳—葡萄状白云岩特征,并对其成因进行了探讨。皮壳状—葡萄状白云石中发育明、暗纤状白云石或纹层条带的含少量细晶的纤状—细粒状白云石以及肾状和葡萄状粉细晶白云石;由球形、杆形、孢子形等蓝细菌构成泡沫状结构;明暗、环带状橙红色光或中等橙红色光、核部发光较暗或不发光;与基质白云石相比,葡萄—皮壳状白云石δ13CPDB相似;但δ18OPDB正偏, ⁸⁷Sr/⁸⁶Sr 相对高(0.70887~0.70939)、但与震旦纪海水(0.7087~0.7094)相似,从皮壳边缘、暗色(蓝细菌)至核部,微区δ18OPDB、δ13CPDB显示了环带内变化较小、环带外的强烈负漂移;云化程度的增加,δ18OPDB、δ13CPDB负偏明显, ⁸⁷Sr/⁸⁶Sr 增加。皮壳—葡萄状白云岩中Al₂O₃ 、Fe₂O₃ 、MnO、LREE/HREE值均低于基质泥粉晶云岩对应值、稀土总量介于基质与粉细晶云岩之间,而Na₂O+K₂O、P₂O₅、 Sr、Hg、Cu、Sr/Ba、Sr/Mn、δCe值均高于基质泥粉晶云岩对应值;且随着云化程度的提高,总体呈现出Mn含量增加,Al₂O₃ 、Fe₂O₃ 、Na₂O+K₂O、P₂O₅、Sr/Ba、Fe/Mn等值递减的趋势;由此判断皮壳状—葡萄状白云石可能是弱还原、保存较好的海水中形成,或在成岩早期或浅埋藏孔隙海水为主的流体中形成、部分经历了较强的大气水作用改造。     

Raman Quantitative Measurements for Carbon Isotopic Composition in CO2-Rich Fluid Inclusion: A Preliminary Study

Carbon dioxide is a common and important component in fluid inclusions. Because carbon isotopic ratio of CO₂ in fluid inclusion can provide geochemical characteristics of source rocks, many works have been conducted to measure the carbon isotopic ratio (¹³C/¹²C) of CO₂. In general, carbon isotopic composition (¹³C/¹²C) of CO₂ fluid inclusions are measured by mass spectroscopy. However, mass spectroscopy is a destructive analytical technique, and can not be applied to measure single inclusion. Raman spectroscopy is an efficient non-contact and non-destructive method, and has been widely employed in many research fields. In fact, due to the difference of carbon atom mass, the Femi resonance of ¹³CO₂ is lower than that of ¹²CO₂, so they can be identified in Raman spectrum. In principle, the carbon isotopic composition (¹³CO₂/¹²CO₂) in CO₂ is closely related to the Raman intensity ratio between ¹³CO₂ and ¹²CO₂ (I+13/I+12). Therefore, Raman spectroscopy can theoretically be utilized to measure the carbon isotopic composition (¹³CO₂/¹²CO₂) of CO₂. However, this method is seriously hampered by the poor measurement accuracy and precision. In this study, based on the theoretical analysis, and in combination with previous Raman studies on carbon isotopic composition in CO₂, a preliminary research on Raman quantitative measurement for carbon isotopic composition in CO₂ was carried out.     

Hydrachemical Characteristics at the Seismic Stations in Songyuan District,Jilin Province

The hydrochemical types and origins of underground water in Songyuan and vicinity, Liaoning Province were discussed based on the hydrochemical composition, δD and δ¹⁸O. The water samples from eight wells were collected 4 times during 2014 to 2015. The main ion concentrations of water were analyzed with an Ion Chromatography. Isotopic compositions of hydrogen and oxygen were analyzed with the Liquid Water Isotope Analyzer. The mineralization (TDS) of the water ranged from 125.4 mg/L to 19 350.9 mg/L. Values of δD and δ¹⁸O ranged from -71.7‰ to -98.1‰ and from -9.0‰ to -12.5‰, respectively. The isotopic data indicated that the water originated from meteorological precipitation. The chemical compositions of Taolaizhao phreatic water were influenced by the human activity while the other water samples collected from artesian well were less affected by the human activity. Water in Changling, Dongdashi, Taohaotai, Qianan and Ningjiang were characterized by HCO₃-Na with low TDS values. Such chemical types of water with fluctuations of Na⁺, SO42- and δ¹⁸O drift were resulted from dissolving silicate minerals and adding surfactant during oil exploitation. Fresh water in Fuyu well was Cl-Na type, which was influenced by acid injection during oil exploitation. Water in Qianguo well was characterized by Cl-Na type with TDS up to 19 350.9 mg/L, the obvious fluctuations of hydrogen and oxygen isotopes and increasing ion concentrations in the Qianguo well may be caused by the earthquakes that occurred in the sampling duration. The results will provide the background of hydrochemistry, and will be of benefit to monitoring earthquake and certificating seismic-chemical anomalies in the future.     

混合岩溶流域碳酸盐岩溶蚀速率与岩溶碳汇——以漓江流域上游为例

碳酸盐岩矿物的化学风化速率要显著高于硅酸盐岩矿物,碳酸盐岩和硅酸盐岩混合流域中碳酸盐岩矿物风化对河流水化学的贡献占主导。为研究混合岩溶流域碳酸盐岩风化及岩溶碳汇特征,在漓江流域上游大溶江、小溶江、灵渠3个混合岩溶流域选取了24个点放置标准溶蚀试片并测试对应的土壤理化性质。基于雨季和全年试片溶蚀量和土壤理化特征,分析试片溶蚀量的主控因素及季节差异,定量评估大溶江、小溶江和灵渠流域岩溶碳汇强度。结果表明:空中试片溶蚀量主要受控于降雨,植被会部分遮挡降雨,使试片溶蚀量显著下降,而地表和土下碳酸盐岩溶蚀受降雨和水文过程共同控制;雨季碳酸盐岩溶蚀更快,空中试片溶蚀量主要受控于降雨,而地表和土下试片主要受控于土壤水分的变化;基于溶蚀试片法,大溶江、小溶江和灵渠流域岩溶碳汇强度分别为0.75、0.30和2.92 tC?km-2 ?yr-1。      

Observations on the extended Matsuoka–Nakai failure criterion

The equivalent Mohr–Coulomb (M‐C) friction angle ? (J. Geotech. Eng. 1990; 116 (6):986–999) of the extended Matsuoka–Nakai (E‐M‐N) criterion has been examined under all possible stress paths. It is shown that ? depends only on the ratio of cohesion to confining stress c^′/σ and the frictional angle ?, where ? is the friction angle measured in triaxial compression (or extension) to which the E‐M‐N surface is fitted. It is also shown that ? is independent of c^′, when σ=0 and of σ when c^′=0, with the former representing an upper bound and the latter a lower bound of ? for any particular stress path. The closest point projection method has also been implemented successfully with the E‐M‐N criterion, and plane strain and axisymmetric element tests performed to verify some theoretical predictions relating to failure and post‐yielding behavior. Finally, a bearing capacity problem was analyzed using both E‐M‐N and M‐C, highlighting the conservative nature of M‐C for different friction angles. Copyright © 2009 John Wiley & Sons, Ltd.     

Correction to: Mapping method of rainfall-induced landslide hazards by infiltration and slope stability analysis

Landslides - A Correction to this paper has been published: https://doi.org/10.1007/s10346-021-01642-4     

Discrete element method analysis of non‐coaxial flow under rotational shear

This study focuses on non‐coaxial flow behavior of cohesionless soil undergoing cyclic rotational shear, with a special interest in the effects of particle‐scale characteristics. To this end, we perform a series of 2D discrete element simulations with various particle shapes, inter‐particle coefficient of friction, initial density, and stress ratios. The validity and efficacy of the numerical model is established by systematically comparing numerical simulation results with existing laboratory testing results. Such comparison shows that the numerical simulations are capable of capturing mechanical behavior observed in laboratory testing under rotational shear. We further demonstrate and quantify a strong yet simple relationship between the deviatoric part of the normalized strain increment and the non‐coaxial angle, denoted by and ψ, respectively. This quantitative correlation between ψ and is independent of applied stress ratio, initial and current void ratio, and the number of cycles applied, but dependent on the principal stress orientation and particle‐scale characteristics. At the same , specimens with higher inter‐particle friction angle or smaller particle aspect ratio show greater non‐coaxial angles. A simple model is able to fit this ψ‐ relationship well, which provides a useful relationship that can be exploited in developing constitutive models for rotational shearing. Copyright © 2014 John Wiley & Sons, Ltd.     

Correction to: Development of efficient and robust Eikonal solver variants for first-arrival seismic modeling

Computational Geosciences - A Correction to this paper has been published: https://doi.org/10.1007/s10596-020-10022-1     

Correction to: Finite Element Solvers for Biot’s Poroelasticity Equations in Porous Media

Mathematical Geosciences - A correction to this paper has been published: https://doi.org/10.1007/s11004-021-09942-0     

Correction to: Extreme waves induced by cyclone Nargis at Myanmar coast: numerical modeling versus satellite observations

Natural Hazards - A correction to this paper has been published: https://doi.org/10.1007/s11069-021-04687-9     

Correction to: Effect of time and space partitioning strategies of samples on regional landslide susceptibility modelling

Landslides - A Correction to this paper has been published: https://doi.org/10.1007/s10346-021-01646-0.     

四川巴塘县茶洛地区温泉及间歇喷泉水化学特征和成因分析

温泉的水化学和成因研究对地热资源的开发利用有重要意义。四川巴塘县茶洛温泉的分布受茶洛—松多断层带的控制,沿北东—南西向的河流两岸出露,附近出露三叠系灰岩、砾岩和燕山期花岗岩。在温泉区出露有近20个泉眼,对其中10个泉眼进行采样测试。受出露点冷水混入的影响,东北部的两个泉眼温度为45~51 ℃,中西部地区的泉眼温度为77~89 ℃,部分为沸泉泉眼;各泉眼流量为0.01~1.8 L/s;pH值为6.1~8.1,矿化度为0.39~1.06 g/L,F^-含量为15~22 mg/L,偏硅酸含量为69~356 mg/L。泉水主要阳离子为Na⁺、K⁺和Ca²⁺,主要阴离子为 {\mathrm{CO}}_3^{2-}、 {\mathrm{HCO}}_3^{-}、Cl^-和 {\mathrm{SO}}_4^{2-},水化学类型为HCO₃-Na型。氢氧同位素数据表明,研究区地下热水来源于大气降水,补给高程约为4 400~4 800 m,补给区年均气温在-10 ℃左右。利用SiO₂温标估算茶洛温泉热储层温度约为150~200 ℃,热水循环深度约为2 810~3 480 m。茶洛温泉为大气降水入渗后在地下深循环过程中被大地热流加热,再沿断层带在河谷涌出地表而形成的温泉。在河流西北岸分布有灰岩,地下水溶蚀形成空洞,来自浅处的冷水和来自深部的热水在空洞中混合并被加热至沸点,导致热水间歇性上升喷出地面,形成间歇喷泉。     

桂林西北郊光明山峰丛坡地土壤210Pb与226Ra分布与迁移规律研究

利用单一210Pb技术来估算岩溶区土壤侵蚀、水土流失和泥沙来源等还存在一定问题。岩溶区土层厚度不一,难以准确地确定支持性210Pb放射比活度是制约该方法应用的一大关键问题。文章选取桂林西北郊光明山岩溶峰丛坡地的4个土壤剖面,测试了土壤剖面210Pb与226Ra放射性比活度,探讨其分布规律及影响因素,初步确定土壤中支持性210Pb放射性比活度。测试结果表明4个土壤剖面中210Pb垂向分布服从指数衰变规律, 226Ra放射性比活度随土壤深度增加基本不变。光明山峰丛山坡土壤中约95%的210Pbex主要聚集在0~10 cm深度处,地表20~30 cm以下基本为支持性210Pb。土壤中支持性210Pb放射性比活度约为56.60±11.97 Bq?kg-1,与226Ra放射性比活度值64.93±8.83 Bq?kg-1在误差范围内一致。进一步研究发现,土壤剖面中210Pb受研究区大气干湿沉降、植被覆盖类型、地形条件、土壤特性（特别是有机质）的影响。此外,研究区土壤剖面226Ra的差异主要与土壤特性和植被类型有关。      

Correction to: Perceived and actual risks of drought: household and expert views from the lower Teesta River Basin of northern Bangladesh

Natural Hazards - A correction to this paper has been published: https://doi.org/10.1007/s11069-021-04825-3     

Correction: A parsimonious approach for large-scale tracer test interpretation

Hydrogeology Journal - A Correction to this paper has been published: https://doi.org/10.1007/s10040-021-02380-6     

Correction: Geochemical and isotopic evidence for upward flow of saline fluid to the Mississippi River Valley alluvial aquifer,southeastern Arkansas,USA

Hydrogeology Journal - A Correction to this paper has been published: https://doi.org/10.1007/s10040-021-02350-y     

川中地区茅口组两期流体叠合控制下的白云石化模式

岩相学特征、地化分析揭示:川中地区下二叠统茅口组白云岩存在三种白云石:①平直晶面细晶白云石(δ13C_PDB=3.06‰,δ18O_PDB=-6.81‰;Fe:1×10-6,Mn:未检出,Sr:150×10-6);②非平直晶面粗晶鞍状白云石(δ13C_PDB=3.22‰,δ18O_PDB=-7.82‰;Fe:149×10-6,Mn:185×10-6,Sr:85×10-6);③非平直晶面细晶白云石(δ13C_PDB=3.49‰,δ18O_PDB=-9.45‰;Th=123℃,S=133~139‰NaCl;Fe:58×10-6,Mn:59×10-6,Sr:76×10-6)。研究结果表明存在两期白云石化流体:①早期压实作用形成的埋藏白云石化流体(T=37.4℃;S=29.8‰NaCl);②晚期受构造控制的热液白云石化流体(Th=114.8℃;S=153~226‰NaCl)。明确了三种白云石的成因:平直晶面细晶白云石是由早期埋藏流体交代泥晶基质形成的;非平直晶面细晶白云石是平直晶面细晶白云石在受到热液流体改造后所形成的;而非平直晶面粗晶鞍状白云石则是由热液流体直接沉淀出的。基于研究结果建立了相应的白云化模式。