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821.
邱晓璐  刘根友  曲绍杰 《北京测绘》2021,35(10):1343-1347
针对北斗卫星导航系统(BeiDou Navigation Satellite System,BDS)/全球卫星导航系统(Global Positioning System,GPS)载波相位定位的病态性,提出采用伪距观测来改善上述问题,并对比分析了在我国8个地面站不同精度伪距观测量的引入对载波相位定位病态性的改善效果,这种病态特征可以通过伪距与载波相位联合观测得到的法方程条件数表示.实验结果表明:伪距观测对载波相位定位的病态性有很大程度的改善,且BDS系统的改善程度比GPS更大;伪距观测精度越高,联合定位的病态性程度越弱;在较短的观测时间内,伪距观测量的引入,对载波相位定位病态性的改善效果非常明显.  相似文献   
822.
以收集到的挪威中部陆架最新地质基础资料和油气田资料为依据,归纳总结该区的烃源岩、储集层、生储盖组合及油气运移特征,分析其勘探潜力,为相关公司介入本区的油气勘探提供依据。综合研究结果认为,挪威中部陆架烃源岩主要为下侏罗统re组三角洲平原相泥页岩及煤层和上侏罗统Spekk组海相泥页岩,其中上侏罗统Spekk组海相泥页岩是主力烃源岩;储层主要为白垩系—新近系浊积砂岩和中侏罗统裂谷期Fangst群滨浅海相砂岩,其中主力储层为中侏罗统裂谷期滨浅海相砂岩;发育裂谷期下生上储(正常)和上生下储两种组合模式;油气通过裂缝、疏导层及断层等作短距离汇聚,通过地层不整合面或连通砂体作长距离运移。该区油气成藏条件优越,资源潜力巨大,储量约为73×108桶油当量,待发现油气田约36个,随着油气勘探的逐步展开,挪威中部陆架必将还有重大油气发现。  相似文献   
823.
鸡冠子山二长花岗岩LA—ICP—MS单颗粒锆石U—Pb测试年龄为245±1 Ma,说明其形成于早三叠世。岩石地球化学研究表明,岩体具有高Si、富K、贫Ti、Ca、Fe、Mg的特点;A/KNC1.1,显示出S型花岗岩特点;固结指数(SI)为1.68~1.88,分异指数(DI)为93.94~94.25,说明岩体经历了较高程度的分异演化作用;稀土元素总量较低(∑REE=80.10×10-6~145.06×10-6),轻稀土明显富集,重稀土相对亏损,Eu负异常,大离子亲石元素Rb、K较富集,表明鸡冠子山二长花岗岩属于高钾钙碱性、过铝质S型花岗岩。结合前人相关的研究成果,推测鸡冠子山二长花岗岩是华北板块和西伯利亚板块碰撞作用形成的同碰撞型花岗岩。  相似文献   
824.
辉钼矿中Re、Os含量高且几乎不含普通Os,通常被认为是开展金属矿床定年的理想对象。然而,在一些矿床中辉钼矿常以浸染状产出,矿物颗粒微小,挑纯难度较大,本文尝试使用含辉钼矿的岩石样品进行测年实验。选择研究程度较高、年龄数据较多的德兴斑岩铜矿田朱砂红矿床的4件含辉钼矿岩石样品进行了Re_Os同位素定年,结果获得等时线年龄为172.6±2.6 Ma,与前人已获得的年龄数据基本一致,说明该年龄数据可靠,样品中的硅酸盐矿物对定年结果没有影响。德兴斑岩铜矿田中3个矿床的辉钼矿Re_Os年龄与花岗闪长斑岩的锆石U_Pb年龄相一致,表明其矿化与斑岩侵入体直接相关。而前人获得的Rb_Sr年龄及K_Ar年龄与近年得到的Re_Os、U_Pb年龄数据存在差别的原因可能是后期热液蚀变及热事件破坏或重置了Rb_Sr和K_Ar同位素体系。  相似文献   
825.
曲跃  曹成润  张武  张宜 《地质通报》2015,34(203):419-424
最近在辽宁本溪牛毛岭剖面上的上石炭统(宾夕法尼亚亚系)本溪组新洞沟段(本溪组中段)的煤系地层中发现了大量鳞木化石。现有资料证明,在牛毛岭剖面本溪组复洲湾段(本溪组上段)灰岩中发现了属于晚石炭世莫斯科期的牙形石,而在牛毛岭剖面邻近地区本溪组湖田段(本溪组下段)中则发现了属于早石炭世(密西西比亚纪)的亚鳞木、大脉羊齿和贝叶。由此认为,新发现的牛毛岭剖面本溪组新洞沟段(本溪组中段)的鳞木化石,应晚于早石炭世,早于晚石炭世莫斯科期,即应属巴什基尔期。鳞木是辽宁东部第一次成煤期滨海沼泽相成煤植物群中的代表性植物。  相似文献   
826.
Qinling orogen is one of the five main repository distribution provinces of large scale graphite resources. Graphite occurrence strata are multitudinous including Neo Archaean group to Neopaleozoic. Mineral deposit types are complete consisting of crystal flaky graphite deposit and aphanitic graphite deposit, ore types of the former are main graphite gneiss, graphite schist and graphitized marble, and ore types of the latter are main graphite layer metamorphosised from coal bed and graphitic carbargilite. At present, most graphite deposits with low research degree only implement preliminary investigations of the graphite resource, which has a good prospect. Based on the basic material of dozens of graphite deposits, spots and plays discovered in the Qinling orogen, this paper applied geologic multidisciplinary analysis method to disclose the graphite deposit types of the Qinling orogen, mainly through outdoors geologic survey and specimen examination with analysis of some typical deposits: regional metamorphism crystal graphite deposits and thermo-contact metamorphic aphanitic graphite deposits, with the control of latitudinally trending regional tectonic, graphite deposits of the Qinling orogen distribute sublatitudinally trending three large ore belts: I the Neoarchean–Proterozoic basement crystal graphite enrichment deposits zone along the south margin of North China plate; II the Carboniferous intermountain basin group aphanitic graphite enrichment deposits zone near the Shangdan suture of the West Qinling; III Paleozoic crystal graphite enrichment deposits zone in the Qinling paleomicroplate of the west part of the East Qinling.Conclusions are reached from multiple inquiries: Qinling multi-cycle complex continental collision orogen zone has experienced multiple tectonic framework transformation and polyphase tectonic thermal event from Neo Archean Erathem adjointing multiple graphite tectonic mineralization cycle. In the light of chief control of mineralization and ore types, each of the three large graphite deposits belts of the Qinling orogen has its own genesis: I graphite deposits enriched metallogenetic zone is that regional tectogenetic movement from Neo Archaean caused polyphase metapepsis, which superimposed up and reconstructed Neo Archean Erathem to Proterozoic basement, forming regional metamorphic big flake crystal graphite deposits; II graphite deposits enriched metallogenetic zone is that polyphase regional tectogenetic movement associated with multiple heating caused by multiphase igneous intrusion, which resulted in original coal layers emerging multiple thermo-contact metamorphisms and formed thermo-contact metamorphic aphanitic graphite deposits. III graphite deposits enriched metallogenetic zone is that Palaeozoic cap–rock experienced polyphase metapepsis, forming regional metamorphic finely flake crystal graphite deposits. Comprehensive research of metallogenetic mechanism in graphite deposits and its associated profitable deposits of the Qinling orogen is importance for future exploration.  相似文献   
827.
<正>There is a large Mesoproterozoic rift at the northern margin of North China Craton(NCC),and one of China’s most important metallogenic belts,the Langshan-Zhaertai Shan-Bayan Obo mesoproterozoic metallogenic belt is just located in this rift.This metallogenic belt contains some large or ultra-large ore deposits,such as the Bayan Obo iron deposits and ultra-large rare earth deposits,and the large Dongshengmiao Cu-Pb-Zn sulphide deposits.The Zhaertai Group is composed of a set of metamorphic rocks,interbedded with thin ferruginous  相似文献   
828.
为了研究酸性条件下碳酸盐岩的溶蚀表面特征及机理,以南堡凹陷及周边凸起区10个典型碳酸盐岩样品为研究对象,进行乙酸和盐酸溶液的溶解实验,并通过扫描电镜观察样品的溶蚀特征。结果显示,岩石结构和矿物成分的选择性溶蚀,是碳酸盐岩溶蚀过程中的主要作用形式;方解石和白云石均存在特有的溶蚀现象,即"溶蚀晶锥"方解石和"蜂窝状"白云石,为晶体选择性溶蚀的产物;表生条件下,灰岩中少量白云石的加入能够增加方解石的溶解度,白云石的含量上限为13%,超过该界限,随白云石含量的增加,溶蚀作用减弱。  相似文献   
829.
信息化时代不可避免地来临,随着地质数据的数据量的飞速增长,地质数据也正式归类到了大数据中。应势,国土资源部地质信息技术重点实验室建设了地学大数据技术研究实验平台GeoBDA,用以解决地质大数据的存储和管理等问题。  相似文献   
830.
This study, using laboratory experiments and scaling analysis, evaluates the influence of geothermal heating on global oceanic circulation. Upon a well-developed large-scale convective flow, an additional heat flux perturbation δF/F is employed. The increments of flow and thermal properties, including eddy diffusivity KT, flow velocity V and bottom temperature Tb, are found to be independent of the applied heat flux F. Together with the scaling analysis of convective flow at different configurations, where the flow is thermally driven in the relatively low or extremely high turbulent thermal convections or the horizontal convection, the variances of flow properties, δKT/KT and δV/V, are found to be close to 0.5% and 0.75% at δF/F=2%. This means that the small heat flux perturbation plays a negligible role in the global convective flow. However, δTb/ΔT is found to be 1.5% at δF/F=2%, which would have a significant effect in the local region. The results might provide a clue to understanding the influence of geothermal heating on global oceanic circulation. It is expected that geothermal heating will contribute less than 1% in turbulent mixing and volume flux to global oceanic circulation, so its influence can be negligible in this situation. However, when it comes to the local environment, the influence of geothermal heating cannot be ignored. For example, temperature increases of about 0.5°C with geothermal heating would have a significant effect on the physical environments within the benthic boundary layer.  相似文献   
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