熊耳山地区内生金矿床成矿系列

按容矿空间和控矿因素,可将熊耳山地区内生金矿床划分为角砾岩型、构造破碎带蚀变岩型、石英脉型及由不同控矿因素复合控制的复合类型等。空间上不同类型之间具有密切的共生过渡关系。太华群原岩中的金在变质热液作用下被活化迁移至有利的构造部位,发生局部富集,形成"矿胚"或"矿胚"的发展,并为后期岩浆热液再次搬运,参与成矿。燕山中晚期钙碱性岩浆岩具较大的成矿能力,是本区金矿床的主要矿源。不同类型矿床稳定同位素及包裹体特征具相似的变化特点,分析表明,成矿流体主要源自岩浆,在成矿早期和晚期,不同地区可能有不同程度的变质水或大气水加入。作者认为,区内不同类型的金矿床是在统一的大地构造环境和成矿背景中形成的,有统一的矿质和介质来源,具相同或相似的成因,以发育角砾岩型金矿床为特点,以构造破碎带蚀变岩和角砾岩型为主要矿床类型,形成一个特定的矿床组合,即熊耳山地区内生金矿床系列。     

Source analysis and risk evaluation of heavy metal in the river sediment of polymetallic mining area: Taking the Tonglüshan skarn type Cu-Fe-Au deposit as an example,Hubei section of the Yangtze River Basin,China

In this paper, 25 sampling points of overlying deposits in Tonglushan mining area, Daye City, Hubei Province, China were tested for heavy metal content to explore pollution characteristics, pollution sources and ecological risks of heavy metals in sediments. A geo-accumulation index method was used to evaluate the degree of heavy metal pollution in the sediment. The mean sediment quality guideline quotient was used for evaluating the ecological risk level of heavy metal in the sediment. And a method of correlation analysis, clustering analysis, and principal component analysis was used for preliminary analysis on the source of heavy metal in the sediment. It was indicated that there was extremely heavy metal pollution in the sediment, among which Cd was extremely polluted, Cu strongly contaminated, Zn, As, and Hg moderately contaminated, and Pb, Cr, and Ni were slightly contaminated. It was also indicated by the mean sediment quality guideline-quotient result that there was a high ecological risk of heavy metals in the sediment, and 64% of the sample sites had extremely high hidden biotoxic effects. For distribution, the contamination of branches was worse than that of the main channel of Daye Dagang, and the deposition of each heavy metal was mainly influenced by the distance from this sample site to the sewage draining exit of a tailings pond. The source analysis showed that the heavy metals in the sediment come from pollution discharging of mining and beneficiation companies, tailings ponds, smelting companies, and transport vehicles. In the study area, due to the influence of heavy metal discharging from these sources, the ecotoxicity of heavy metals in the sediment was extremely high, and Cd was the most toxic pollutant. The research figured out the key restoration area and elements for ecological restoration in the sediment of the Tonglüshan mining area, which could be referenced by monitoring and governance of heavy metal pollution in the sediment of the polymetallic mining area.©2022 China Geology Editorial Office.     

Geoelectrical survey over perched aquifers in the northern part of Upper Sakarya River Basin,Türkiye

In this study, a groundwater exploration survey was conducted using the DC Resistivity (DCR) method in a hydrogeological setting containing a perched aquifer. DCR data were gathered and an electrical tomography section was recovered using conventional four-electrode instruments with a Schlumberger array and a two-dimensional (2D) inversion scheme. The proposed scheme was tested over a synthetic three-dimensional (3D) subsurface model before deploying it in a field situation. The proposed method indicated that gathering data with simple four-electrode instruments at stations along a line and 2D inversion of datasets at multiple stations can recover depth intervals of the studied aquifer in the hydrogeological setting even if it has a 3D structure. In this study, 2D inversion of parallel profiles formed a pseudo-3D volume of the subsurface resistivity structures and mapped out multiple resistive (>25 ohm·m) bodies at shallow (between 50–100 m) and deep sections (>150 m). In general, the proposed method is convenient to encounter geological units that have limited vertical and spatial extensions in any direction and presents resistivity contrast from groundwater-bearing geologic materials.     

基于Plücker直线的机载LiDAR点云与航空影像的配准

机载LiDAR点云与航空影像的配准是地物提取的关键。本文提出了基于Plücker直线的机载LiDAR点云与航空影像的配准模型。基于三维线空间线变换Plücker直线方程,确定点云和影像中的同名直线间的相对位姿关系,建立Plücker直线共面条件方程,通过影像上的Plücker直线在三维线空间中的螺旋运动,实现像点到其对应LiDAR点的坐标变换。结果表明,Plücker直线共面条件配准模型简洁,将旋转和平移统一处理,避免了两者间的耦合误差,提高了配准精度,为获取高质量的地球三维空间信息提供了技术支持。     

贡嘎山东坡亚高山森林系统植被光合作用——双裂蟹甲草（Cacalia davidii）净光合速率对生态因子的响应

以双裂蟹甲草(Cacaliadavidii)为材料，研究其净光合速率对生态因子的响应。结果表明，双裂蟹甲草净光合速率(P     

米仓山西段地质研究新进展

通过米仓山西段１∶５万区域地质调查研究，从元古界火地垭群中解体出后河岩群，属太古－早元古代。认为前震旦纪变质基底以穹盆构造、叠加褶皱、多期面理置换、韧性剪切带为特色，确立了光雾山推覆构造，提出盖层变形以层滑褶皱为主。对岩浆杂岩成功地进行了解体，认为侵入岩具多种成因类型并具多旋回演化特点，指出地台边缘的层序地层有别于陆棚边缘经典模式。     

天山乌鲁木齐河流域冰川地貌与冰期研究的回顾与展望

乌鲁木齐河源于天山北列喀拉乌成山的北坡,区内保存着形态多样、较为清晰的第四纪冰川侵蚀与沉积地形.经过老中青数代人的考察研究,取得如下研究成果:1)查清了河源区冰川地形的分布与特征,运用冰川沉积学与地貌地层学原理对乌鲁木齐河出山口处的扇形地进行了冰川与非冰川成因的鉴别;2)基于地衣法、常规14 C与AMS14 C、TL、ESR、CRN(10Be)等多种定年方法的测年结果,并结合地貌地层学原理,建立了乌鲁木齐河流域小冰期、新冰期、末次冰期(MIS 2～4)、MIS 6与MIS12较完整的冰川演化序列,为我国第四纪冰川研究树立了一个典型范例.展望未来,乌鲁木齐河源区的冰川地貌演化模拟与古环境重建等需作进一步研究,喀拉乌成山南坡的冰川地形有待进行综合定年;若以乌鲁木齐河源流域冰期序列为参照,冰川发育与天山的构造抬升以及东、中与西段天山冰川发育是否具有一致性,天山地区是否保存有更老冰碛等科学问题尚待深入探讨.     

伊利石结晶度Kübler指数的校正与近变质带的确定

就像用"砝码"标定"称"来测量物质质量一样,伊利石结晶度的测量也需要这样的"砝码"标定它的测量工具——衍射仪,从而能够进行伊利石结晶度的测量和对比。这个砝码就是伊利石结晶度标样或称伊利石结晶度国际标样。第2届Kübler-Frey国际研讨会伊利石结晶度圆桌会议就伊利石结晶度标样和近变质带的确定的问题进行了深入的讨论。会议一致认为,用伊利石结晶度标样校正X射线衍射仪是极为重要和必要的,没有进行标样校正的伊利石结晶度数据将被拒绝发表,经过伊利石结晶度国际标样校正后的伊利石结晶度数据才可用于近变质带的划分和国际对比。本文就伊利石结晶度测量的有关衍射仪类型与差别,衍射仪系统,测量条件,样品的影响和国际标样对仪器的校正等问题进行了分析研究。结果表明不同型号仪器,同型号仪器不同测量条件与状态,样品的不同制备方法都将影响伊利石结晶度Kübler指数的测量。指出只有使用国际标样才可校正测量的伊利石结晶度Kübler指数,从而达到消除偏差准确划分近变质带的标准和进行国际对比的目的。     

云南元谋县黄瓜园花岗岩锆石LA-ICP-MSU-Pb定年和岩石地球化学及其地质意义

康滇地区是我国南方元古宇地层集中出露的地区,元古宙岩浆活动频繁,是研究扬子陆块早期地质构造演化的窗口,也是最近研究的热点。近年本项目组在南北走向的元谋-绿汁江深大断裂北部、云南元谋县黄瓜园地区识别出了中元古代晚期的片麻状花岗岩。花岗岩锆石的LA-ICP-MS U-Pb年龄为1069.4±6.9Ma(MSWD=0.47,n=18)。岩石化学表现为较高的SiO_2(平均值高达72.79%)和中等Na_2O+K_2O(平均为6.62%),低TiO_2(平均0.26%)、低CaO(平均0.79%)、低MgO(平均0.52%,Mg#平均值22.13)和高Al_2O_3(平均12.84%,A/CNK平均值为1.33)含量,总体表现为亚碱性花岗岩的特征。微量元素分析显示稀土元素总量(∑REE)为132.96×10~(-6)~278.72×10~(-6),平均237.00×10~(-6),稀土配分曲线明显呈轻稀土富集、重稀土亏损的特点;δEu在0.38~0.49之间;微量元素配模式明显亏损Ba、Ta、Nb、Sr、P和Ti,相对富集Rb、Th、U、K等大离子亲石元素和La、Zr、Hf、Y等元素。岩石地球化学特征显示本区花岗岩属于A2亚类,可能源于下地壳基性岩部分熔融,为板块碰撞后伸展构造背景下的产物。花岗岩锆石U-Pb定年和地球化学特征表明在中元古代末期,康滇地区除了发生过南北向的块体汇聚外,可能还可能发生过较大规模东西向的汇聚过程,为全球性格林威尔造山运动的组成部分。此外,该区花岗岩的时代与邻近拉拉IOCG矿床中辉钼矿的Re-0s年龄高度一致,表明拉拉铜铁矿床成矿物质的最终定位富集与中元古代晚期康滇地区微陆块东西方向汇聚后的伸展运动密切相关。     

天山乌鲁木齐河源1号冰川1959-2009年物质平衡变化过程及特征研究

以天山乌鲁木齐河源1号冰川1958/1959—2008/2009年度物质平衡资料为基础,研究了冰川的物质平衡变化过程及特征.结果表明:51a来1号冰川物质平衡经历了9次负平衡波动和9次正平衡波动,负平衡年与正平衡年之比为35∶16,负平衡年平均物质平衡-450mm,正平衡年平均物质平衡130mm,多年平均物质平衡-267mm.1997—2008年,该冰川连续12a的物质平衡观测结果均为负平衡年,并且总体上处于数值很大的强负平衡,直至2008年出现了历史上最大的负平衡,物质平衡量为-999mm.1959—2009年,累积亏损达-13 646mm(约-2 402.6×104 m3),即冰川平均较之1959年减薄了15.2m,这种长时期连续物质亏损状态对1号冰川是一个严峻的考验.