用cGPS研究青藏高原南缘现今垂向变动     

方智伟  邹蓉  李志才  王敏  谭凯  杨少敏  王琪 《地球物理学报》2022,65(6):1965-1979

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Diatom Response to Global Warming in Douhu Lake,Southeast China     

LI Jingjing  WANG Luo  CAO Qi  Patrick RIOUAL  LEI Guoliang  CAI Binggui  ZHANG Jiaoyang  ZOU Yafei  YAN Yao  WAN Xiaoqiao  XIAO Jule 《《地质学报》英文版》2021,95(2):638-647

A large number of lacustrine sedimentary records indicate that global warming is the main factor leading to significant changes in diatom communities in lakes of the northern hemisphere.However,due to the intensification of human activities since 1850,some scholars have emphasized that the increasing lake trophic level may be the main reason for the changes in diatom communities.The debate is ongoing.In order to avoid falling into the complex relationship between diatom changes and the seasonal cycle that characterizes lakes in mid and high latitudes,we chose a lake located at a low latitude,where the relationship between diatoms and temperature is not indirect but direct.The diatom record spans the past ca.100 years and reveals that the abundance of Aulacoseira granulata increased from 1900 until 1985, replacing the previously dominant Aulacoseira ambigua.These changes are in agreement with the increasing trend in global temperature.Since 1985,the percentages of the small-celled Discostella stelligera and the benthic diatom Navicula heimansioides have increased,while Aulacoseira granulata has decreased.This latest shift is caused by further global warming.We conclude that warming is the main factor leading to changing diatom communities in Douhu Lake.  相似文献   

黔东北双河重晶石-萤石矿床流体包裹体组合研究及成因     

李敏  邹灏  陈海锋  蒋修未  刘春梅 《矿物岩石地球化学通报》2021,40(4):858-870

黔东北双河重晶石-萤石矿床的矿体主要产于下奥陶统碳酸盐岩中,严格受断裂构造控制,为探讨其成因,采用流体包裹体组合(FIA)方法对成矿流体进行了研究.结果显示,流体包裹体类型分为单相水溶液包裹体和富液相两相水溶液包裹体;成矿早期萤石和晚期萤石的均一温度分别为89～131℃和99～122℃,盐度分别为3.83％～20.84％NaCleqv和5.37％～20.51％NaCleqv;估算的流体密度为0.97～1.11g/cm3.此外,激光拉曼光谱分析表明,成矿流体主要成分是H20,但早期流体含有CH4.综合推断,双河矿床是由于温度降低同时受到大气降水及建造水影响形成的低温热液矿床.结合前人对该地区其他萤石矿床的研究,推断该矿床与川东南地区的萤石矿床应具有相同的成矿流体场.  相似文献   

结合地理国情监测的宁波市生态环境评价指标体系的构建     

项志勇  邹小玲  陈江平 《测绘通报》2018,(6):98-103

基于地理国情监测数据的特点和生态环境评价的需求,结合压力-状态-响应模型,提出了宁波市生态环境评价的指标体系,并基于宁波市的地理国情监测数据对本文提出的指标体系进行了计算,得到宁波市的生态环境状况、压力和状态指数。结果表明,宁波市的生态环境压力高于浙江省均值,其生态状况和生态保护大致与浙江省平均水平持平,说明现阶段宁波市的生态环境状态处于较为适中的状态,宁波市的生态保护较浙江省平均水平略低。  相似文献   

长直轨道精密准直测量方案研究与应用     

杨义辉  邹进贵  聂海滨  李方 《测绘工程》2018,(4):49-53,59

针对长直轨道设备安装中的准直问题,提出一种结合全站仪和激光跟踪仪的简易准直测量方案。在仅有轴线首尾端控制点的情况下,无需建立三维控制网,仅利用高精度全站仪建立两端短直线基准,并以此确定激光跟踪仪坐标基准,实现直线中间段准直测量。实验结果表明,对于长约110m的实验轨道,该准直测量方案的平面直线精度优于0.2mm,满足精密安装的要求,且安装效率和可靠性相应提高。  相似文献   

An Analysis of the Discontinuity in Chinese Radiosonde Temperature Data Using Satellite Observation as a Reference     

Yanjun GUO  Chengzhi ZOU  Panmao ZHAI  Guofu WANG 《Journal of Meteorological Research》2019,(2):289-306

Reconciling upper-air temperature trends derived from radiosonde and satellite observations is a necessary step to confidently determine the global warming rate. This study examines the raw and homogenized radiosonde observations over China and compares them with layer-mean atmospheric temperatures derived from satellite microwave observations for the lower-troposphere(TLT), mid-troposphere(TMT), upper-troposphere(TUT), and lower-stratosphere(TLS) by three research groups. Comparisons are for averages over China, excluding the Tibetan Plateau, and at individual stations where metadata contain information on radiosonde instrument changes. It is found that major differences between the satellite and radiosonde observations are related to artificial systematic changes. The radiosonde system updates in the early 2000 s over China caused significant discontinuities and led the radiosonde temperature trends to exhibit less warming in the middle and upper troposphere and more cooling in the lower stratosphere than satellite temperatures. Homogenized radiosonde data have been further adjusted by using the shift-point adjustment approaches to match with satellite products for China averages. The obtained trends during 1979–2015 from the re-adjusted radiosonde observation are respectively 0.203 ± 0.066, 0.128 ± 0.044, 0.034 ± 0.039, and –0.329 ± 0.135 K decade^–1 for TLT, TMT, TUT, and TLS equivalents. Compared to satellite trends, the re-adjusted radiosonde trends are within 0.01 K decade^–1 for TMT and TUT, 0.054 K decade^–1 warmer for TLT, and 0.051 K decade^–1 cooler for TLS. The results suggest that the use of satellite data as a reference is helpful in identifying and removing inhomogeneities of radiosonde temperatures over China and reconciling their trends to satellite microwave observations. Future efforts are to homogenize radiosonde temperatures at individual stations over China by using similar approaches.  相似文献   

湖北省罗田县陈林沟金矿床地质特征及矿床成因          下载免费PDF全文

邹院兵  刘兴平  范玮  李俊  蔡立元 《地质找矿论丛》2018,33(4):527-533

陈林沟金矿床矿体呈脉状赋存于近EW向断裂构造中,矿石类型以石英脉型矿石为主,蚀变岩型矿石为次;矿化从浅部向深部出现由金矿化向金银多金属矿化转变,矿体规模逐渐变大,矿化强度逐渐变强;成矿年龄约为130 Ma±,其形成与燕山期岩浆作用具有时空和成因联系,矿床成因类型为中低温岩浆热液型金矿床。  相似文献   

青海省俄昌公仁地区尕笛考组火山岩地球化学特征及构造环境          下载免费PDF全文

王光辉  加永泽巴  邹建  宋福生 《地质找矿论丛》2018,33(3):417-424

俄昌公仁地区地处西金乌兰—金沙江构造混杂岩带与北羌塘—昌都地体的交汇部位。文章通过对乌丽—开心岭尕笛考组火山岩岩石学、主量元素、稀土元素、微量元素等地质地球化学研究表明:尕笛考组火山岩为典型的钙碱性岩石组合,推断尕笛考组火山岩属于与板块俯冲作用有关的岩浆岛弧带的产物,形成于与板块俯冲作用有关的岛弧构造环境;锆石U-Pb同位素年代为258.5 Ma±4.6 Ma,属晚二叠世早期。  相似文献   

贵州务-正-道地区二叠纪铝土矿沉积环境地球化学证据   总被引：1，自引：0，他引：1  

金中国  刘辰生  邹林  郑明泓  张力  韩英 《地质学报》2018,92(4):817-827

黔北务-正-道地区铝土矿形成于早二叠世大竹园期,属古风化壳沉积型。沉积环境是该类型铝土矿形成的重要因素,本文通过对反映沉积环境比较敏感的B、Ga、Sr、Ba、Th元素含量变化及B/Ga、Sr/Ba、Sr/Cu、Th/U、V/Ni、V/Cr、Ni/Co、Rb/K比值特征分析研究,认为含矿岩系大竹园组主要形成于陆相滨浅湖环境,其底部沉积时期曾遭受海侵影响,具海相→海陆过渡相→陆相沉积特点;深时气候主要为古赤道附近的热带-亚热带温湿气候;氧化还原条件以相对开放的氧化环境为主,局部区域存在相对封闭的贫氧-厌氧环境;铝土矿形成经历了风化早期的强氧化、碱性介质环境→风化中后期的氧化、酸性介质环境→风化物迁移、搬运阶段的弱氧化、弱酸-中性介质环境→沉积成岩成矿期的氧化-弱氧化,弱酸-弱碱性介质环境(局部为贫氧-厌氧环境)→次生淋滤改造富集阶段的氧化、酸性介质环境。铝土矿工业矿体的形成与次生淋滤改造作用密切相关。  相似文献   

赣南浅变质岩岩石地球化学特征及稀土成矿潜力研究   总被引：2，自引：1，他引：1  

王臻  赵芝  邹新勇  陈振宇  涂雪静 《岩矿测试》2018,37(1):96-107

赣南地区浅变质岩系分布广泛,且风化壳发育,查明浅变质岩的岩石学及地球化学特征对分析离子吸附型稀土矿床的成矿潜力具有重要作用,而目前关于变质岩离子吸附型稀土矿的研究资料较少。本文对区内广泛发育的新元古代—寒武纪浅变质岩进行采样,通过岩相学、岩石地球化学等方法对赣南浅变质岩进行分类研究。结果表明:赣南浅变质岩时代跨度大,从青白口系至泥盆系以及少量侏罗系均有出露,以新元古代面积最广,主要类型有变砂岩类、变质凝灰岩类、板岩类、千枚岩类及片岩类。其中,变砂岩类和变质凝灰岩类的稀土含量高(∑REEs平均值分别为302μg/g和246μg/g),LREEs/HREEs=2.68~5.43,目前查明的稀土矿物主要为独居石和磷钇矿。区内变质凝灰岩类产出厚度较大,稀土含量较高,风化壳发育,是良好的离子吸附型稀土矿的成矿母岩类型。千枚岩类和片岩类的平均稀土含量(∑REEs224μg/g)次之,但由于岩石风化难度较大,形成稀土风化壳型矿体可能性偏低。本研究是对变质岩离子吸附型稀土矿成矿的初步探讨,旨在为今后进一步的研究和找矿工作提供基础资料和依据。  相似文献