淮河流域平原区高铁锰地下水环境健康风险评估

基于近期获得的水文地球化学分析数据,应用指示克立格法开展了淮河流域平原区高铁、锰地下水环境健康风险评估,并分析了高铁、锰地下水的形成原因。结果表明:铁、锰是影响研究区地下水质量的主要化学组分,铁、锰在地下水中的空间分布上表现出明显的变异性。铁、锰超标概率峰值具有相似的空间分布格局,铁、锰高风险地区呈岛状分布,深层地下水的环境健康风险明显降低。含铁浅层地下水高风险地区面积为1 257.15 km2,面积占比0.07％;含铁深层地下水高风险地区面积为476.93 km2,面积占比0.03％。含锰浅层地下水高风险地区面积为35 883.16 km2,面积占比19.19％;含锰深层地下水高风险地区面积为1 269.30 km2,面积占比0.07％。淮河流域高铁锰地下水是原生成因,铁、锰离子主要来源于含水层中含铁、锰矿物的还原性溶解。高铁锰地下水的风险评价结果,可为区域供水区划提供指导。     

郴州市玛瑙山铁锰多金属矿床地质特征

玛瑙山铁锰多金属矿床产于棋梓桥组底部层位中，矿体呈似层状。除铁、锰、铅外，伴生有银、铟。由泥盆纪沉积期成岩成矿作用和燕山期岩浆热液叠加成矿作用所形成的沉积改造—岩浆热液叠加型铁锰多金属矿床。     

Geological and geophysical characteristics of hotspots of the Amur region

This study presents models of inactive and currently active hotspots of the Amur region that were developed based on the results obtained from seismogravitational modeling and a large–scale aeromagnetic survey in combination with other geological and geophysical data. The study considers the mechanisms triggering the evolutionary changes in the deep structure of the hotspots and the Maya—Selemdzha plume, as well as some characteristics of related ore–bearing regions.     

江汉平原东北部地区高铁锰地下水成因与分布规律

肖港地区位于江汉平原东北部,属于大别山连片贫困区和贫水区,地下水资源较贫乏,且地下水水质不佳,水中铁锰离子含量普遍超过了国家饮用水标准。为查明高铁锰地下水成因及空间分布规律,服务区内地下水开发利用及安全供水问题,系统采集区内岩石、土壤和地下水样品,测试岩土与地下水中铁锰的含量,分析地下水中铁锰含量与含水层沉积物的铁锰含量、地下水的氧化还原条件和酸碱度之间的关系。结果表明:江汉平原东北部地区地下水中铁锰超标现象普遍存在,其中锰的超标率大于铁,第四系孔隙潜水超标最严重,铁锰最大浓度分别达到44.88 mg/L和19.21 mg/L。研究区岩土中铁锰氧化物为地下水中铁锰提供了物质来源,弱酸性、强还原环境为沉积物中铁锰的溶解释放提供了有利条件,总体上从研究区东西两侧（补给、径流区）向中部第四系孔隙潜水含水层（排泄区）,沿地下水流向Eh值、pH值逐渐减小,铁锰含量逐渐增大,形成北北东向带状分布的高铁锰地下水区。     

水城徐家寨锰矿床地质特征及成矿模式

贵州水城徐家寨锰矿是该地区的一个重要锰矿典型矿床,通过对该矿床的基本地质特征及成矿进行研究、分析,初步总结出成矿模式。徐家寨锰矿最终定位于开阔台地沉积相的沉积-风化锰帽型矿床。     

Microelements in fractions of bottom sediments of the Amur River

The grain size distribution and fraction composition of bottom sediments (BS) in the Amur River are studied. The total composition of sediments, their clay subfractions—water-peptizable (WPC) and aggregated (AC) clays—and residue after clay elutriation were analyzed. It has been established that contents of Fe, Mn, Zn, and Cu in the clay subfractions are 2–4 times higher than in common bottom sediments and their residue left after the extraction of clay subfractions, confirming a significant role of clay minerals in the accumulation of elements mentioned above. It is shown that diatom algae participate in the accumulation and transport of Fe, Mn, Zn, and Cu in the river water-suspended matter-bottom sediments (clay minerals) system. It has been established that high Zr concentrations in bottom sediments are related to the presence of zircon therein.     

江汉平原东北部浅层高铁锰地下水环境特征

铁、锰元素是影响江汉平原东北部浅层地下水质量的主要因素.为了查明该地区地下水中铁锰的分布特征及地下水环境特征,选择典型研究区,采集了13件地下水样品,测试了地下水中铁锰的含量以及酸碱度、矿化度和氧化还原条件,分析了上述条件对铁锰含量的影响,并与江汉平原腹地高铁锰地下水环境进行对比.结果表明,本研究区地下水以HCO3-Ca、HCO3-Ca·Mg型为主,高铁锰水主要分布于研究区东部和南部沿江地带,与江汉平原腹地地下水化学类型一致,铁锰的含量相对偏低.研究区上部土层中铁锰的氧化物为地下水中的铁锰提供了丰富的来源,地下水的酸碱度、矿化度和氧化还原环境是影响铁锰迁移的主要因素.研究区高铁锰地下水多呈弱酸性,矿化度较高,地下水中铁锰的含量与溶解氧具弱负相关,与氨氮具强烈正相关,表明相对还原的环境有利于铁锰释放到地下水中,江汉平原腹地处于更加还原的环境,是地下水中铁锰高于本研究区的主要原因.     

四川省黑水县四美沟锰矿床地质特征及成因

四美沟锰矿处于瓦钵梁子—四美沟复式背斜西段北翼,次级北西向指状罗白背斜核部中段的两翼。矿区包括多瓦矿点和各百窝矿点。该矿床的含矿层位为菠茨沟组中段,已在多瓦矿点中发现锰矿体10条,其中工业矿体3条;在各百窝矿点中锰矿体4条,其中工业矿体1条。经对该矿床成因及成矿演化的分析认为,该矿床属沉积变质型矿床,有六条找矿标志。     

四川省黑水县四美沟锰矿床地质特征及成因

四美沟锰矿处于瓦钵梁子—四美沟复式背斜西段北翼,次级北西向指状罗白背斜核部中段的两翼。矿区包括多瓦矿点和各百窝矿点。该矿床的含矿层位为菠茨沟组中段,已在多瓦矿点中发现锰矿体10条,其中工业矿体3条;在各百窝矿点中锰矿体4条,其中工业矿体1条。经对该矿床成因及成矿演化的分析认为,该矿床属沉积变质型矿床,有六条找矿标志。     

四川黑水县徐古锰矿徐古矿段成矿地质特征及成因

徐古锰矿属扬子地台西缘之松潘-甘孜地槽南缘拗陷盆地边缘沉积,分为红岩、卡门和徐古三个矿段,徐古矿段位于矿区的东部。该矿段有高精度磁异常6处,目前已发现1个锰矿层,2个矿化层,均赋存于下三叠统菠茨沟组地层中。在区域地质成矿背景和矿床特征研究基础上,对矿床成因进行了分析,认为该矿属沉积变质型锰矿床,成矿过程大致经历了铁锰的第一次富集、第二次富集等阶段,并提出了五种找矿标志。     

Moisture tension in fine-grained reconstituted soils at high initial water contents

Acta Geotechnica - The reclamation of land filled with high water content dredged clays is an important geological and geo-environmental issue. When designing such reclaimed land, the yield...     

Photosynthetic capability and Fe,Mn, Cu,and Zn contents in two Moraceae species under different phosphorus levels

The strong adaptability of Broussonetia papyrifera (L.) Vent. to low phosphorus (P) conditions can be attributed to the large amount of root-exuded organic acids and the high efficiency of P extraction. However, microelement contents are influenced by low-P stress, and their effects on the photosynthetic capability of B. papyrifera remain unknown. In this study, we investigated the effects of low-P treatment on net photosynthetic rate (P _N); chlorophyll a fluorescence (ChlF) characteristics; and Fe, Mn, Cu, and Zn contents of B. papyrifera and Morus alba L. seedlings. Results show that B. papyrifera exhibited better photosynthetic capability under moderate P deficiency (0.125, 0.063, and 0.031 mmol/L P treatments), whereas the photosynthetic capability of M. alba decreased under moderate and severe P deficiency (0.016 and 0 mmol/L P treatments). Under moderate P deficiency, the decrease in Cu and Zn contents in B. papyrifera was lower than that in M. alba. Under severe P deficiency, a considerable decrease of photosynthetic capability in B. papyrifera and M. alba was associated with low Cu and Zn contents. The P _N of the two Moraceae species exhibited a better correlation with Cu and Zn contents than with Fe or Mn content. P deficiency could not only decrease cyclic photophorylation and photosynthetic efficiency, but could also affect the stability of thylakoid membrane structure and electron transport efficiency by influencing the contents of Cu or Zn, thereby affecting photosynthesis.     

Distribution and sources of pre-anthropogenic lead isotopes in deep ocean water from FeMn crusts

The lead isotope composition of ocean water is not well constrained due to contamination by anthropogenic lead. Here the global distribution of lead isotopes in deep ocean water is presented as derived from dated (ca. 100 ka) surface layers of hydrogenetic Fe-Mn crusts. The results indicate that the radiogenic lead in North Atlantic deep water is probably supplied from the continents by river particulates, and that lead in Pacific deep water is similar to that characteristic of island and continental volcanic arcs. Despite a short residence time in deep water (80–100 a), the isotopes of lead appear to be exceedingly well mixed in the Pacific basin. There is no evidence for the import of North Atlantic deep water-derived lead into the Pacific ocean, nor into the North Indian Ocean. This implies that the short residence time of lead in deep water prohibits advection over such long distances. Consequently, any climate-induced changes in deep-water flow are not expected to result in major changes in the seawater Pb-isotope record of the Pacific Ocean.     

张家山锰矿地质特征及找矿标志

四川张家山锰矿是近年来新发现的锰矿床,位于松潘—甘孜推覆造山带和扬子陆块的结合部位。在成矿地质背景及矿区地质特征系统研究的基础上,对矿床成因及找矿标志做了探讨,确立其成因类型为海相沉积型锰矿床。张家山锰矿地质特征、成因及找矿标志探讨,对于研究该地区沉积型锰矿床不仅具有理论研究价值,而且对于实践指导找矿有一定的借鉴意义。     

四川黑水徐古锰矿床成矿地质特征及找矿标志

四川黑水徐古锰矿位于日嘎希—瓦钵梁子复背斜西段北翼。铁锰矿赋存于下三叠统菠茨沟组浅海相泥质—碳酸盐类的混合沉积物中,地层、岩性控矿明显。矿体呈层状、似层状产出,沿走向、倾向延伸比较稳定。属沉积变质类型,具有7种找矿标志。