北极斯瓦尔巴、高亚洲和阿尔卑斯山冰川物质平衡对比研究     

何海迪  李忠勤  叶万花  梁鹏斌  牟建新  张明军 《冰川冻土》2018,40(2):205-213

基于冰川物质平衡和平衡线高度数据,对北极斯瓦尔巴、高亚洲和阿尔卑斯山的冰川物质平衡变化和平衡线高度空间分布特征进行了对比分析,得出以下结论：（1）阿尔卑斯山冰川年均负物质平衡值最大,为-907 mm;斯瓦尔巴为-431 mm;高亚洲最小,为-264 mm。（2）高亚洲和斯瓦尔巴冰川物质平衡年振幅较小,年际变化较小;阿尔卑斯山冰川物质平衡年振幅较大,年际变化较大。斯瓦尔巴冰川物质平衡趋向正平衡,阿尔卑斯山和高亚洲冰川物质平衡趋向负平衡。（3）斯瓦尔巴内陆的冰川平衡线高度高于沿海地区,高亚洲冰川平衡线高度呈纬向地带性、经向地带性和区域地带性的分布规律,阿尔卑斯山的冰川平衡线高度主要受冰川所处海拔的影响。  相似文献   

混积岩分类命名体系探讨及对混积岩储层评价的启示——以渤海海域混积岩研究为例   总被引：1，自引：0，他引：1  

叶茂松  解习农  徐长贵  杜晓峰  宋章强  杜学斌 《地质论评》2018,64(5):1118-1131

混积岩是一种普遍而重要的岩石组合类型。然而长期以来,对混积岩的岩石学分类与命名一直存在诸多争议,且尚未有统一的分类体系与命名规则。本文结合渤海海域混积岩岩石薄片组分鉴定、岩石储层物性分析等最新研究成果,并与相关文献结合,最终确立以陆源碎屑物、生物成因碳酸盐颗粒、化学沉淀碳酸盐为三组分端元的一套新的混积岩岩性分类体系,并将混积岩分为4大类、16亚类。通过讨论混积岩混积层系及混积岩组构界定的问题,进一步完善了混积岩定义。利用新的岩石学分类方案,可为储层评价研究提供指导。以渤海海域为例,建立起研究区不同岩性相与储层物性的对应关系,并在岩性分类体系中划分出差储层、中等储层及优质储层三个储层区。  相似文献   

冰川底部富铁溶液氧化沉淀:塔里木北缘新元古界库鲁克赛铁矿床的成因   总被引：1，自引：1，他引：0  

高丙飞  吴昌志  李伟强  杨涛  叶辉  雷如雄  刘倩 《矿床地质》2018,37(1):1-26

新元古代沉积变质铁矿床是继大氧化事件(GOE)后,沉积间断10亿年(~1800 Ma至~750 Ma)之后,再次大规模出现的一种沉积铁建造类型。这类铁建造与新元古代冰碛岩密切伴生,是新元古代雪球地球事件的重要证据。文章选择与新元古代雪球地球事件有关的沉积变质赤铁矿床—库鲁克赛铁矿进行研究,通过锆石U-Pb定年和区域地层对比工作限定其形成时代为新元古代青白口纪末期—南华纪早期。锆石年龄谱值对比和岩相学研究表明,铁矿床中的碎屑物质主要来自于青白口系下部独断山组石英砂岩地层。主、微量元素研究表明,库鲁克赛铁矿形成于相对富氧或者从贫氧向富氧变化的环境,其成矿元素应主要与陆源物质风化有关,可能有少量成矿元素来自于低温海底热液或海水。笔者认为,库鲁克赛铁矿的形成与成冰纪冰水沉积作用有关,来自冰下水体、从冰下通道中流出的富铁缺氧水溶液与富氧的表层海水混合时,成矿元素快速氧化沉淀,胶结冰水中的近源砾石,进而形成了此种富铁砾岩型铁矿。  相似文献   

四川西昌盆地白垩纪恐龙足迹群的新发现     

童馗  邢立达  姜巽  彭光照  叶勇  江山  丑春永  李轲  李智武 《地质通报》2018,37(10):1771-1776

四川西昌盆地白垩系小坝组尚未发现骨骼化石记录,其白垩系恐龙动物群的信息全赖于足迹化石。2017年,在喜德县洛甘发现小坝组迄今最大型的恐龙足迹群。该足迹点保存了大量的兽脚类足迹。足迹保存条件较差,但具备了基本的形态学特征。总体来看,兽脚类足迹具有尺寸较小(8~13cm),中等中趾前凹(0.5~0.6)和第Ⅱ趾和第Ⅳ趾间较宽趾间角(70°~100°)的特征;少量足迹保存了跖骨垫。初步分析认为,洛甘兽脚类足迹与四川盆地夹关组的兽脚类足迹Eubrontes和Grallator形态类型相似,为两地在白垩纪中期具有类似的恐龙动物群的观点提供了新的证据。该发现对于西昌盆地的古气候、古地理和地层对比都具有重要的意义,足迹详细分类还有待进一步研究。  相似文献   

塔里木陆块西北缘萨热克砂岩型铜矿床构造-流体演化对成矿的制约     

王伟  李文渊  高满新  熊中乙  李天虎  宿晓虹  郭周平  孟勇  全守村  刘增仁  叶雷  陈传庆  唐小东 《地质通报》2018,37(7):1315-1324

塔里木陆块西北缘萨热克砂岩型铜矿床构造演化、流体演化与成矿之间具有密切关系,处于一个统一系统中。矿床成岩期方解石中包裹体水的δD值为-65.3‰~-99.2‰,改造成矿期石英包裹体水的δD值为-77.7‰~-96.3‰,成岩成矿期成矿流体δ~(18)OH_2O变化范围为-3.22‰~1.84‰,改造成矿期成矿流体δ~(18)OH_2O变化范围为-4.26‰~5.14‰,指示萨热克铜矿成岩期、改造期成矿流体主要为中生代大气降水及其经水岩作用而成的盆地卤水。矿石中辉铜矿δ~(34)S值为-24.7‰~-15.4‰,指示硫主要源自硫酸盐细菌与有机质还原,部分源于有机硫。构造与成矿流体演化对砂岩铜矿成矿起关键制约作用。盆地发展早期强烈的抬升运动使盆地周缘基底与古生界剥蚀,为富铜矿源层的形成提供了丰富物源,至晚侏罗世盆地发展晚期,长期演化积聚的巨量含矿流体在库孜贡苏组砾岩胶结物及裂隙中富集,在萨热克巴依盆地内形成具有经济意义的砂岩型铜矿床。  相似文献   

基于水化学的沂源盆地地热田成热模式探讨          下载免费PDF全文

薄本玉  王韶霞  马鹏飞  叶倩  谭肖波  谢峰 《山东国土资源》2022,38(7)

沂源盆地地热田为低温水热型岩溶热储地热系统,盖层为古近系、白垩系、石炭系,热储层为寒武纪、奥陶纪碳酸盐岩,区内发育的深大断裂如上五井断裂、韩旺断裂、傅家庄断裂等为沟通深部热源的良好通道。为掌握地热田热水的补给来源、热源、地热水年龄,进一步分析其形成机理,采集地热水样品进行了地热水水文地球化学分析、气体及其同位素分析。结果表明,该地热田地热水水化学类型为HCO3·Cl·SO4Na·Ca型、HCO3Ca·Mg型,矿化度小于1g/L;地热水补给来源为大气降水,具深循环特征;热源以壳源为主;地热水年龄10.51ka B.P.,为古地下水。结合地下水循环机理,将其地热水形成机理总结为小型断陷盆地深循环承压型。  相似文献   

利用背景噪声研究滇西北波速异常与M≥5.0地震关系     

杨建文  叶泵  高琼  陈佳  王军 《大地测量与地球动力学》2022,42(2):165-171

提出基于背景噪声波速测量的综合预测指标法,将测震资料更好地应用于震情跟踪和地震短临预报。利用滇西北5个台站2012-01~2020-11宽频带连续波形资料,基于背景噪声互相关及傅立叶变换等方法,提取10个台站对当天经验格林函数与参考经验格林函数的直达瑞利波走时偏移时间序列,设定±1.5倍标准差作为异常阈值,并以其间发生的6次M≥5.0地震为样本,采用R值评分法对每个台站对的映震能力进行效能检验,最后基于自适应加权综合预测方法提取适合于滇西北地区的地震短临异常识别指标（综合指标）。结果表明,利用该综合指标对滇西北2012年以来发生的6次M≥5.0地震进行90 d短临预报,异常指标共出现8次,其中准确预报地震5次,漏报1次,虚报4次,预报效能评分R为0.692,R₀为0.475。该综合指标的地震对应率为62.50%,概括率为83.33%。  相似文献   

Phospholipid Compositions in Portunus trituberculatus Larvae at Different Developmental Stages     

LU Zhibin  SHI Ce  LIU Lei  MU Changkao  YE Yangfang  WANG Chunlin 《中国海洋大学学报(英文版)》2022,21(1):152-162

Phospholipids are used to improve the growth and survival of Portunus trituberculatus,a widely cultured crab species in China.However,only total phospholipids or several classes are applied in crab diets.In this study,we employed a targeted lipidomic method to investigate the comprehensive phospholipid composition in P.trituberculatus larvae and reveal the changing phospholipid profile over the larval development.Results showed that P.trituberculatus larvae contain 112 phospholipid species belonging to 10 phospholipid classes,in which phosphatidylcholine(PC)and phosphatidylethanolamine(PE)species are the most abundant,and PC,PE,phosphatidic acid,and phosphatidylserine(PS)are with high concentrations.The levels of all phospholipids significantly changed with larval development,which was highlighted by the downward parabolic changes in PE,phosphatidylglycerol,phosphatidylino-sitol,PS,lysophosphatidic acid,and sphingomyelin levels.In addition,nearly all phospholipid species were depleted at the M stage,which probably contributed to the mass mortality of crab larvae.These findings on the composition and alterations of phospholipids in P.trituberculatus larvae provide novel perspectives for the targeted supplementation of phospholipids in crab diets.Our work also highlights the use of targeted UHPLC-MS lipidomics in understanding the changes of phospholipids during crab development.  相似文献   

Effect of Temperature on the Acoustic Reflection Characteristics of Seafloor Surface Sediments     

ZOU Dapeng  YE Guican  LIU Wei  SUN Han  LI Jun  XIAO Tibing 《中国海洋大学学报(英文版)》2022,21(1):62-68

Because the sound speeds of seawater and seafloor sediment both increase with temperature,the influence of tempera-ture on the bottom reflection characteristics of seafloor sediments needs to be investigated.Based on the calculation of the temperature-controlled experimental measurement data of typical seafloor surface sediment samples,the temperature-dependent acoustic characteristics,including acoustic impedance,acoustic impedance ratio between surface sediment and seawater,and reflection coefficient,were analyzed.The effective density fluid model was used to analyze and explain the reflection coefficient variation of surface sediments with temperature and predict the dispersion characteristics.Results show that the acoustic impedance of the seabed sediment increases with temperature,whereas the acoustic impedance ratio and acoustic reflection coefficient slightly decrease.The acoustic impedance,acoustic impedance ratio,and acoustic reflection coefficient of sandy,silty,and clayey sediments vary similarly with tem-perature variation.Moreover,the influence of temperature on these acoustic characteristics is independent of detection frequencies.  相似文献   

Intercomparison of CRA-Interim Precipitation Products with ERA5 and JRA-55     

叶梦姝  姚秀萍  张涛  许小峰  王式功 《热带气象学报(英文版)》2021,27(2):136-147

By using the hourly data from surface meteorological stations in China, the 3-hour precipitation data from CRA-Interim (Chinese Reanalysis-Interim), ERA5 (ECMWF Reanalysis 5) and JRA-55 (Japanese Reanalysis-55) are compared, both on the spatial-temporal distributions and on bias with observation precipitation in China. The results show that: (1) The three sets of reanalysis datasets can all reflect the basic spatial distribution characteristics of annual average precipitation in China. The simulation of topographic forced precipitation in complex terrain by CRA-interim is more detailed, while CRA-interim has larger negative bias in central and East China, and larger positive bias in southwest China. (2) In terms of seasonal precipitation, the three sets of reanalysis datasets overestimate the precipitation in the heavy rainfall zone of spring and summer, especially in southwest China. CRA interim’s location of the rain belt in the First Rainy Season in South China is west by south, the summer precipitation has positive bias in southwest and South China. (3) All of the reanalysis datasets can basically reflect the distribution difference of inter-annual variation of drought and flood, but the overall the CRA-Interim generally shows negative bias, while the ERA5 and JRA-55 exhibit positive bias. (4) For the diurnal variation of precipitation in summer, all the reanalysis datasets perform better in simulating the daytime precipitation than in the night, and bias of CRA-interim is less in southeast and northeast than elsewhere. (5) ERA5 generally performs the best on the evaluation of quantitative precipitation forecast, the JRA-55 is the next, followed by the CRA-Interim. CRA-Interim has higher missing rate and lower threat score for heavy rains; however, at the level of downpour, the CRA-Interim performs slightly better.  相似文献