KOSMA 12CO(2–1) and (3–2) observations toward Infrared Dark Clouds     

Dalei Li  Jarken Esimbek  Jianjun Zhou  Willem Baan  Gang Wu  Xindi Tang  Weiguang Ji  Ye Yuan  Yuxin He  Toktarkhan Komesh 《Astrophysics and Space Science》2016,361(7):220

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华北克拉通东缘金岭杂岩体岩浆源区及构造背景:来自岩相学、岩石地球化学及年代学的证据          下载免费PDF全文

高继雷周永刚  张振飞高明波赵体群  田振环朱振宏 《地质科学》2021,56(1):253-271

金岭杂岩体由细粒黑云角闪闪长岩、中细粒黑云角闪闪长岩、中细粒黑云角闪二长闪长岩和细粒角闪二长闪长岩组成,是鲁西地区典型矽卡岩型富铁矿(金岭铁矿)控矿岩体。本次研究对细粒黑云角闪闪长岩和细粒角闪二长闪长岩进行了锆石LA‐ICP‐MS U‐Pb定年,其结果分别为129.2±3.2 Ma和132.8±1.2 Ma,表明该杂岩体的侵位时代为早白垩世。样品SiO2、K2O和Na2O含量分别介于54.17%~63.73%、1.92%~4.76%和3.10%~5.41%之间,K2O/Na2O为0.58~0.94,A/CNK为0.60~0.93,具有轻稀土富集,重稀土亏损的右倾型稀土配分模式,轻、重稀土分馏程度中等((La/Yb)N=9.94~23.49),Eu异常不明显(δEu=0.84~1.10),具中—弱负Ce异常(δCe=0.56~0.92)。样品以富集大离子亲石元素(Ba、K、U、Pb等)、亏损高场强元素(Nb、Ta、Ti)以及高Sr/Y为特征。金岭杂岩体为燕山晚期岩浆活动产物,属准铝质高钾钙碱性系列,岩浆主要来源于富集岩石圈地幔的部分熔融,并在岩浆上升侵位的过程中有地壳物质的同化混染。燕山晚期华北克拉通在古太平洋板块俯冲后后撤引起的板内伸展环境下,增厚陆壳减薄阶段,岩浆上侵就位形成金岭杂岩体。  相似文献   

Drought prediction using in situ and remote sensing products with SVM over the Xiang River Basin,China     

Zhu  Qian  Luo  Yulin  Zhou  Dongyang  Xu  Yue-Ping  Wang  Guoqing  Tian  Ye 《Natural Hazards》2021,105(2):2161-2185

Natural Hazards - Droughts have caused many damages in many countries and might be aggravated around the world. Therefore, it is urgent to predict and monitor drought accurately. Soil moisture and...  相似文献   

青海茫崖石棉矿区变质超基性岩的蚀变演化序列：岩石化学及矿物学证据     

周志强 《地质与勘探》2021,57(5):981-993

青海茫崖石棉矿区超基性岩体是由原岩以纯橄岩、辉橄岩和橄辉岩为主体组成的富镁质超基性岩体,经历自变质和后期多期热液的叠加变质蚀变作用,经蛇纹石化后形成蚀变完全的蛇纹岩岩体,其中部分蛇纹岩又进一步发生滑石化及碳酸盐化蚀变为滑石菱镁片岩、菱镁滑石片岩、滑石片岩和菱镁岩等。本文在野外地质调查基础上,在室内通过镜下岩矿综合鉴定、全岩化学成分分析以及电子探针成分分析等手段进行了岩石化学特征、矿物学特征及其蚀变演化过程研究。结果表明,该变质超基性岩体蛇纹岩主要特征组合矿物为蛇纹石(利蛇纹石、叶蛇纹石、纤蛇纹石)、磁铁矿、菱镁矿、滑石、水镁石、铬铁矿,变余矿物有斜方辉石、单斜辉石和铬铁矿,滑石菱镁片岩类主要组成矿物为菱镁矿、滑石、蛇纹石及磁铁矿,局部可见石英脉。该地区变质超基性岩体较完整地记录了橄榄岩水化、滑石化及碳酸盐化作用过程的各个阶段,超基性岩蚀变演化过程主要有两个作用阶段:(Ⅰ)橄榄石、辉石类矿物的蛇纹石化作用及蛇纹石绿泥石化作用;(Ⅱ)富Ca、CO2流体交代蛇纹石、滑石及水镁石的碳酸盐化作用。蛇纹石化等变质蚀变作用促进了Si、Mg及Fe元素化学活动性,使元素发生富集与迁移,对于次生矿物的形成与演化起到了一定的催化作用。多期不同组成流体热液的交代作用过程,清晰地展示了利蛇纹石、纤蛇纹石和叶蛇纹石的演化序列,以及滑石、水镁石、铬铁矿和磁铁矿的形成过程及标形特征。  相似文献   

内蒙古平安地元古代构造混杂岩的发现与地质意义     

杨月后  王继春  张海平  周飞  苏银春  钱程  汪岩  郭永烈  顾新雨  寇帅 《地质论评》2021,67(Z1):67z1157-67z1159

正研究区位于内蒙古东部天山镇西平安地地区,古生代大地构造位置由南向北可划分为华北板块、白乃庙岛弧和索伦—林西缝合带(图1)。Xiao等(2015)和Jian等(2012)等认为温都尔庙—柯丹山—西拉木伦蛇绿混杂岩带是华北板块和西伯利亚板块的缝合带,研究区则位于该混杂岩带以南白乃庙岛弧一侧。  相似文献   

Failure and Acoustic Emission Characteristics of Jointed Rock Masses with Different Joint Inclination Angles and Combination Mode     

Zhang  Qinghao  Tang  Xinbao  Zhou  Yan  Ma  Depeng 《Geotechnical and Geological Engineering》2021,39(8):5971-5981

Geotechnical and Geological Engineering - In order to analyze the characteristics of the mechanical property, failure mode and acoustic emission of the columnar jointed rock masses,...  相似文献   

Identifying rainfall threshold of flash flood using entropy decision approach and hydrological model method     

Lin  Kairong  Zhou  Jiaqi  Liang  Ruhao  Hu  Xiaozhang  Lan  Tian  Liu  Meixian  Gao  Xin  Yan  Denghua 《Natural Hazards》2021,108(2):1427-1448

Natural Hazards - Flash flood disaster, with strong suddenness and tremendous destructiveness, is one of the most severe natural disasters in China that seriously threaten the lives and property...  相似文献   

Rapid forecasting of urban flood inundation using multiple machine learning models     

Hou  Jingming  Zhou  Nie  Chen  Guangzhao  Huang  Miansong  Bai  Guangbi 《Natural Hazards》2021,108(2):2335-2356

Natural Hazards - Urban flood inundation is worsening as the number of short-duration rainstorms increases, and it is difficult to accurately predict urban flood inundation over a long lead time;...  相似文献   

Geologic hazards of the Ocoña river valley,Peru and the influence of small-scale mining     

Santi  P.  Manning  J.  Zhou  W.  Meza  P.  Colque  P. 《Natural Hazards》2021,108(3):2679-2700

Natural Hazards - The Ocoña River Valley, in the Arequipa Department in southern Peru, extends over 150 km from the Pacific coast to its headwaters in the Andes Mountains. While...  相似文献   

Direct Tensile Tests of Red Sandstone Under Different Loading Rates with the Self-developed Centering Device     

Zhang  Yue  Zhang  Qiang-Yong  Zhou  Xin-Yu  Xiang  Wen 《Geotechnical and Geological Engineering》2021,39(2):709-718

To study the tensile strength of rock under different loading rates, direct tensile test is the most accurate method. However, the eccentric tension in the process of rock direct tensile test has a significant influence on the test results. In this paper, firstly, a self-developed centering device for rock direct tensile test is introduced, which can effectively eliminate the eccentric tension in the process of rock direct tensile test. Then, with the aid of the self-developed centering device, the direct tensile tests of red sandstone under the loading rates of 0.001 mm/s, 0.01 mm/s and 0.1 mm/s are successfully carried out. After tests, both the macro failure characteristics and the scanning electron microscope micrograph show that the fracture pattern of the rock is caused by pure tensile loading. The stress-strain curves of the direct tensile test of the red sandstone show that the process of the direct tensile test can be roughly divided into four stages. With the increase of loading rate, both of the tensile strength and the peak tensile strain of the rock increase obviously. The direct tensile test of the red sandstone shows obvious loading rate effect.

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