基于粒子滤波的行车轨迹路网匹配方法     

郑诗晨  盛业华  吕海洋 《地球信息科学学报》2020,22(11):2109-2117

行车轨迹是一种时间序列的地理空间位置采样数据,而传统的轨迹—路网匹配方法主要以全局或局部寻优的方式建立轨迹—路网匹配关系,影响了时空场景中数据的匹配计算过程的相对独立性。针对这个问题,本文基于粒子滤波（Particle Filter,PF）原理建立行车轨迹与道路网络之间的匹配关系。首先,沿轨迹中车辆运动方向在道路网络中搜索邻近道路节点,在与道路节点拓扑邻接的道路弧段上初始化随机生成粒子,根据轨迹中车辆运动模型将粒子沿所在道路弧段移动;然后,基于PF原理计算各时刻粒子运动状态及与行车轨迹采样点之间的距离误差,根据高斯概率密度函数计算粒子权重并利用随机重采样方法进行粒子重采样,迭代更新粒子运动状态;最后,计算与搜索到的道路节点拓扑邻接的每条道路弧段中累计粒子权重,通过各道路弧段累计权重计算轨迹—路网匹配关系。以行车轨迹进行实验表明,利用本文方法可以通过粒子时空变化反映采样点的移动,行车轨迹—路网匹配结果的正确率大于85%,能够实现行车轨迹和路网的准确匹配。  相似文献   

新疆卡拉麦里地区早泥盆世洋内弧：来自火山岩地球化学及锆石U-Pb 年龄的证据          下载免费PDF全文

黄 岗牛广智  赵平甲王新录 郭 俊 宇 峰 《地质科学》2017,(2):526-544

新疆东准噶尔卡拉麦里地区早泥盆世火山岩由玄武岩和玄武安山岩组成,采用LA-ICP-MS锆石U-Pb定年方法,获得玄武安山岩锆石的U-Pb年龄为404.5±1.9 Ma,表明喷发时代为早泥盆世。岩石地球化学显示早泥盆世火山岩属岛弧拉斑系列,具相对较高的Mg^# 值(41.25～55.32)及较低的Nb(1.11×10^{- 6}～2.42×10^{- 6})、Zr(73.9×10^{- 6}～95×10^{- 6})和ΣREE(81.50×10^{- 6}～121.80×10^-6)含量。富集大离子亲石元素(LILE：K、Rb、Ba)和轻稀土元素(LREE),而亏损Ta、Nb和Ti高场强元素（HFSE：Ta、Nb、Ti）,并显示Eu弱的亏损,这些特征与岛弧火山岩类似,其原始岩浆可能起源于俯冲流体交代的亏损地幔楔的部分熔融。结合区域地质背景,认为早泥盆世火山形成于洋内弧的构造环境,为卡拉麦里古洋盆向北俯冲消减的产物。这是在卡拉麦里地区首次报道的洋内弧火山岩,这一新的发现和认识对研究东准噶尔古生代洋盆演化及区域构造格局均具有重要的意义。  相似文献   

中国东北地区显生宙岩浆作用和洋-陆格局及其与气候演变的关系SCIEI北大核心CSCD     

杨浩  葛文春  纪政  井佳浩  董玉  景妍 《岩石学报》2022,38(5):1443-1459

显生宙期间,地球经历了温室-冰室气候的周期性交替变化。在数百万年的时间尺度,这种古气候的转变被认为是碳源和碳汇过程耦合的结果,但一直以来关于两者贡献程度的认识尚不明确。通过全球统计分析,不同学者提出大陆弧火山脱气模型和热带弧-陆碰撞模型用于解释整个显生宙古气候的演变,分别强调了碳源和碳汇的一级控制作用。为了检验上述模型,更好地理解古气候的转变机制和演化细节,本文系统总结了中国东北地区显生宙岩浆作用-矽卡岩型矿床的时空展布和构造背景,以及弧-陆碰撞的时代、规模和古地理位置,通过数据统计和作图对比,发现东北地区岩浆作用-矽卡岩成矿峰期、弧-陆碰撞缝合带的时空迁移与大气圈CO_(2)浓度和大陆冰川沉积有很好的对应关系,暗示东北显生宙构造-岩浆过程和古气候演变的内在联系。综合东北地区及全球的研究进展,本文提出如下倾向性认识:1)洋-陆俯冲过程中火山-变质脱气的强度决定了CO_(2)排放量,而热带区域弧-陆碰撞缝合带的规模决定了全球硅酸盐风化速率和CO_(2)吸收量,在地质演化过程中两者紧密联动,共同控制了显生宙古气候的演变;2)大陆弧岩浆作用的全球爆发不一定能造成温室气候的出现,如果缺乏充分矽卡岩变质脱碳反应,大陆弧CO_(2)排放通量与岛弧、大洋中脊和板内并无显著区别;3)SO_(2)属于短期效应气体,理论和实例研究均暗示爆发式火山作用难以诱发大冰期的形成,火山作用之于长期气候应该仍是促使地球升温而非变冷。  相似文献   

Horizontal layered structure with heterogeneity beneath continents and island arcs from particle orbits of long-period P waves     

Takeshi Nishimura 《Geophysical Journal International》1996,127(3):773-782

We investigate the particle orbits of long-period (about 20 s) P waves observed with the global seismic network. By analysing 84 three-component seismograms recorded at 25 stations from 60 earthquakes occurring beneath 300 km, we quantitatively evaluate the orbits by three sets of eigenvalues and eigenvectors, using a covariance matrix method. The eigenvalues for P waves recorded at stations located on continents are explained by the standard horizontal layered structure model (iasp91). On the other hand, the orbits observed at stations close to island arcs are affected not only by the horizontal layered structure but also by heterogeneity due to subducting plates, mantle diapirs and so on. On the basis of a single-scattering model for a plane P wave, we quantify the heterogeneities by an isotropic scattering coefficient g0. Fitting the theoretical eigenvalues to the observed ones, we estimate g0 for the crust and upper mantle beneath continents to be less than 0.0005 km^-1, and the mean g₀ for the structure beneath island arcs to be about 0.0015 to 0.003 km^-1.  相似文献   

Iron oxide-copper-gold deposits: an Andean view   总被引：22，自引：2，他引：20  

Richard?H.?SillitoeEmail author 《Mineralium Deposita》2003,38(7):787-812

Iron oxide-copper-gold (IOCG) deposits, defined primarily by their elevated magnetite and/or hematite contents, constitute a broad, ill-defined clan related to a variety of tectono-magmatic settings. The youngest and, therefore, most readily understandable IOCG belt is located in the Coastal Cordillera of northern Chile and southern Peru, where it is part of a volcano-plutonic arc of Jurassic through Early Cretaceous age. The arc is characterised by voluminous tholeiitic to calc-alkaline plutonic complexes of gabbro through granodiorite composition and primitive, mantle-derived parentage. Major arc-parallel fault systems developed in response to extension and transtension induced by subduction roll-back at the retreating convergent margin. The arc crust was attenuated and subjected to high heat flow. IOCG deposits share the arc with massive magnetite deposits, the copper-deficient end-members of the IOCG clan, as well as with manto-type copper and small porphyry copper deposits to create a distinctive metallogenic signature.The IOCG deposits display close relations to the plutonic complexes and broadly coeval fault systems. Based on deposit morphology and dictated in part by lithological and structural parameters, they can be separated into several styles: veins, hydrothermal breccias, replacement mantos, calcic skarns and composite deposits that combine all or many of the preceding types. The vein deposits tend to be hosted by intrusive rocks, especially equigranular gabbrodiorite and diorite, whereas the larger, composite deposits (e.g. Candelaria-Punta del Cobre) occur within volcano-sedimentary sequences up to 2 km from pluton contacts and in intimate association with major orogen-parallel fault systems. Structurally localised IOCG deposits normally share faults and fractures with pre-mineral mafic dykes, many of dioritic composition, thereby further emphasising the close connection with mafic magmatism. The deposits formed in association with sodic, calcic and potassic alteration, either alone or in some combination, reveal evidence of an upward and outward zonation from magnetite-actinolite-apatite to specular hematite-chlorite-sericite and possess a Cu-Au-Co-Ni-As-Mo-U-(LREE) (light rare earth element) signature reminiscent of some calcic iron skarns around diorite intrusions. Scant observations suggest that massive calcite veins and, at shallower palaeodepths, extensive zones of barren pyritic feldspar-destructive alteration may be indicators of concealed IOCG deposits.The balance of evidence strongly supports a genetic connection of the central Andean IOCG deposits with gabbrodiorite to diorite magmas from which the ore fluid may have been channelled by major ductile to brittle fault systems for several kilometres vertically or perhaps even laterally. The large, composite IOCG deposits originated by ingress of the ore fluid to relatively permeable volcano-sedimentary sequences. The mafic magma may form entire plutons or, alternatively, may underplate more felsic intrusions, as witnessed by the ore-related diorite dykes, but in either case the origin of the ore fluid at greater, unobserved depths may be inferred. It is concluded that external 'basinal' fluids were not a requirement for IOCG formation in the central Andes, although metamorphic, seawater, evaporitic or meteoric fluids may have fortuitously contaminated the magmatic ore fluid locally. The proposed linkage of central Andean and probably some other IOCG deposits to oxidised dioritic magmas may be compared with the well-documented dependency of several other magmatic-hydrothermal deposit types on igneous petrochemistry. The affiliation of a spectrum of base-metal poor gold-(Bi-W-Mo) deposit styles to relatively reduced monzogranite-granodiorite intrusions may be considered as a closely analogous example.Editorial handling: B. Lehmann  相似文献   

Tectonic mechanisms associated with P–T paths of regional metamorphism: alternatives to single-cycle thrusting and heating     

John Wakabayashi   《Tectonophysics》2004,392(1-4):193

Metamorphic pressure (P)–temperature (T) paths are commonly used as tools to interpret the tectonic history of orogenic belts, those deformed belts of rocks that record past activity along active plate margins. Many studies and reviews relating P–T path development to tectonics have focused on thrusting–thermal relaxation cycles, with special emphasis on collisional processes. Other studies have assumed that P–T paths resulted from a single tectono-metamorphic event that accounted for the entire burial–exhumation history of the rocks. In many cases, such assumptions may prove invalid.This paper speculates on the relationship of tectonic processes other than thrusting–heating to P–T path development. The processes discussed herein include subduction initiation, triple-junction interactions, initiation and shut off of arc volcanism, subcontinental delamination, and hot spot migration. All of these processes may leave a signature in the metamorphic rock record. Examples are presented from a number of localities, most of which are from the Pacific Rim. Although thrusting–heating cycles have influenced metamorphic evolution in many orogenic belts, the potential impact of other types of tectonic mechanisms should not be overlooked.  相似文献   

Similar V/Sc Systematics in MORB and Arc Basalts: Implications for the Oxygen Fugacities of their Mantle Source Regions   总被引：8，自引：0，他引：8  

AEOLUS LEE  CIN-TY; LEEMAN  WILLIAM P.; CANIL  DANTE; LI  ZHENG-XUE A 《Journal of Petrology》2005,46(11):2313-2336

V/Sc systematics in peridotites, mid-ocean ridge basalts andarc basalts are investigated to constrain the variation of fO₂in the asthenospheric mantle. V/Sc ratios are used here to ‘seethrough’ those processes that can modify barometric fO₂determinations in mantle rocks and/or magmas: early fractionalcrystallization, degassing, crustal assimilation and mantlemetasomatism. Melting models are combined here with a literaturedatabase on peridotites, arc lavas and mid-ocean ridge basalts,along with new, more precise data on peridotites and selectedarc lavas. V/Sc ratios in primitive arc lavas from the Cascadesmagmatic arc are correlated with fluid-mobile elements (e.g.Ba and K), indicating that fluids may subtly influence fO₂ duringmelting. However, for the most part, the average V/Sc-inferredfO₂s of arc basalts, MORB and peridotites are remarkably similar(–1·25 to +0·5 log units from the FMQ buffer)and disagree with the observation that the barometric fO₂s ofarc lavas are several orders of magnitude higher. These observationssuggest that the upper part of the Earth's mantle may be stronglybuffered in terms of fO₂. The higher barometric fO₂s of arclavas and some arc-related xenoliths may be due respectivelyto magmatic differentiation processes and to exposure to large,time-integrated fluid fluxes incurred during the long-term stabilityof the lithospheric mantle. KEY WORDS: vanadium; scandium; oxygen fugacity; mantle; arcs  相似文献   

The Late Jurassic Zedong ophiolite: A remnant of subduction initiation within the Yarlung Zangbo Suture Zone (southern Tibet) and its tectonic implications     

《Gondwana Research》2020

The Zedong ophiolite is the largest ophiolite massif east of Dazhuqu in the Yarlung Zangbo Suture Zone in the southern Tibetan Plateau. However, its age, geodynamic setting and relationship to the Xigaze ophiolite remain controversial. New zircon U–Pb ages, whole-rock geochemical and Nd–Pb isotopic data from ophiolitic units provide constraints on the geodynamic and tectonic evolution of the Zedong ophiolite. U–Pb zircon geochronology of dolerite lavas and late gabbro–diabase dikes yield weighted mean ages of 153.9 ± 2.5 Ma and 149.2 ± 5.1 Ma, respectively. Strong positive ε_Nd(t) and positive Δ7/4Pb and Δ8/4Pb values indicate derivation from a highly depleted mantle source with an isotopic composition similar to that of the Indian MORB-type mantle. The geochemistry of ophiolitic lavas and early dikes are analogous to typical island arc tholeiites whereas late dikes are similar to boninites. The geochemistry of these rock types suggests multi-stage partial melting of the mantle and gradually enhanced subduction influences to the mantle source through time. Combined with the MORB-like 162.9 ± 2.8 Ma Luobusha ophiolitic lavas, we suggest that the Luobusha lavas, Zedong lavas and early dikes originated in an infant proto-arc setting whereas late dikes in the Zedong ophiolite originated in a forearc setting. Together, they represent a Neo-Tethyan subduction initiation sequence. The Late Jurassic intra-oceanic proto-arc to forearc setting of the Zedong ophiolite contrasts with the continental margin forearc setting for the Xigaze ophiolite, which suggests a laterally complex geodynamic setting for ophiolites along the Yarlung Zangbo Suture Zone.  相似文献   

Infant intra-oceanic arc magmatism due to initial subduction induced by oceanic plateau accretion: A case study of the Bangong Meso-Tethys,central Tibet,western China     

《Gondwana Research》2020

The Meso-Tethyan oceanic plateaus are becoming conspicuous as giant units on the oceanic floor and have played important roles in both continental marginal orogenesis and Tethys oceanic evolution. In this study, we present mineralogical, geochronological, geochemical and Sm–Nd isotopic data for basaltic lavas from the Namco ophiolite and a high-Mg pillow lava–dyke–gabbro association from the Pengco ophiolite in central Tibet. Zircon U–Pb and Ar–Ar dating reveals that the Namco lavas erupted at ∼181 Ma while the Pengco boninitic association formed at ∼164 Ma. The Namco lavas display nearly flat rare-earth element (REE) patterns with no Nb–Ta depletions as well as high ε_Nd values, characteristic of oceanic plateau lava. In contrast, the Pengco high-Mg rocks exhibit low REE concentrations below the normal mid-ocean ridge basalt (N-MORB), ubiquitous Nb–Ta depletions and low ε_Nd values, and the dykes and gabbros are characterized by U-shape REE patterns, indicating that they could have derived from a depleted mantle source that was contaminated by sedimentary flux and marking a mid-Jurassic initial intra-oceanic arc magmatism erupted on the Early Jurassic Meso-Tethyan oceanic plateau represented by the Namco ophiolite. Our Pengco boninitic rocks, along with the literature data, indicate a 167–160 Ma boninitic-like initial intra-oceanic arc within the Bangong Meso-Tethys, running from the Shiquanhe area to the Naqu area with a length of ∼1000 km, which was uniformly built on the Early Jurassic Meso-Tethyan oceanic plateau. Our literature investigation also indicates a ∼175 Ma accretionary orogeny with distinct signature of the oceanic plateau involvements along the southern Qiangtang continental margin, which is manifested by regional metamorphic, magmatic and depositional records. We thus suggest that the accretion of the Early Jurassic Meso-Tethyan oceanic plateau onto the southern Qiangtang continental margin resulted in the extensive orogeny along the continental margin, jammed the subduction zone at ∼175 Ma and induced intra-oceanic subduction initiation as well as the intra-oceanic infant arc magmatism in the Meso-Tethys at ∼164 Ma.  相似文献   

Temporal Geochemical Evolution of Neogene Magmatism in the Baguio Gold–Copper Mining District (Northern Luzon, Philippines)     

Mireille Polve    Rene C. Maury    Sebastien Jego    Herve Bellon    Ahmed Margoum    Graciano P. Yumul  Jr  Betchaida D. Payot    Rodolfo A. Tamayo  Jr Joseph Cotten 《Resource Geology》2007,57(2):197-218

Baguio, in the Central Cordillera of Northern Luzon, is a district that displays porphyry copper and epithermal gold mineralization, associated with Early Miocene–Pliocene–Quaternary calc‐alkaline and adakitic intrusions. Systematic sampling, K‐Ar dating, major and trace elements, and Sr, Nd, Pb isotopic analyses of fresh magmatic rocks indicate three magmatic pulses: an Early Miocene phase (21.2–18.7 Ma), a Middle–Late Miocene phase (15.3–8 Ma) and finally a Pliocene–Quaternary event (3–1 Ma). The first phase emplaced evolved calc‐alkaline magmas, essentially within the Agno Batholith complex, and is thought to be related to the westward‐dipping subduction of the West Philippine Basin. After a quiescence period during which the Kennon limestone was deposited, magmatic activity resumed at 15.3 Ma, in connection with the start of the subduction of the South China Sea along the Manila Trench. It emplaced first petrogenetically related and relatively unradiogenic low‐K calc‐alkaline lavas and intermediate adakites. Temporal geochemical patterns observed from 15.3 to 1 Ma include progressive enrichment in K and other large ion lithophile elements, increase in radiogenic Sr and Pb and corresponding decrease in radiogenic Nd. These features are thought to reflect the progressive addition to the Luzon arc mantle wedge of incompatible elements largely inherited from South China Sea sediments. The origin of the long quiescence period, from 8 to 3 Ma, remains problematic. It might represent a local consequence of the docking of the Zambales ophiolitic terrane to Northern Luzon. Then, magmatic activity resumed at 3 Ma, emplacing chemically diversified rocks ranging from low K to high K and including a large proportion of adakites, especially during the Quaternary (dacitic plugs). The authors tentatively relate this diversity to the development of a slab tear linked with the subduction of the fossil South China Sea ridge beneath the Baguio area.  相似文献