共查询到20条相似文献，搜索用时 171 毫秒
1.
青岛崂山碱性花岗岩的元素地球化学研究 总被引：1，自引：0，他引：1
本文报道了青岛崂山碱性花岗岩的稀土元素和微量元素地球化学特征。利用仪器中子活化分析了崂山碱性花岗岩的稀土元素和微量元素含量,并依此讨论了崂山碱性花岗岩的成因和物质来源。 相似文献
2.
为了解三亚近岸海域沉积物地球化学特征,测定了331个站位的表层沉积物23种微量元素含量;利用多元统计法进行相关性及R型因子分析,探讨研究区元素的来源、分布特征及其控制因素。微量元素含量测定结果表明,Sr、Ba、Zr、Rb元素平均值比其他元素高;Be、Cr、Co、Ni、Cu、Zn、Cd、Sb、Pb、U、Zr、Ba、Sc、V、Ga等15种元素含量与海南岛水系沉积物、表层土壤、深层土壤接近,推测沉积物主要来自海南岛。各元素在研究区的空间分布比较复杂,在中部和东部,以Li为代表的15种微量元素随离岸距离增加含量增大;Cd、Sb、Zr、Ba、Rb、Sr、As、Hg的分布特征与其他微量元素相比差异明显。Li等15种元素来源与分布主要受陆源黏土矿物吸附作用控制,Sr主要受海洋生源沉积作用的控制,Zr主要受重矿物的控制,Ba和Rb主要受研究区地质背景控制,而Cd和As的来源与分布则与人类活动有关。 相似文献
3.
莱州湾东部滨海水域砂金分布特征 总被引：1，自引：0，他引：1
通过对莱州湾东部滨海水域地球物理和地质钻综合调查，业已查明该海区地质的构造和古地理环境特征，并发现区内砂金分布较普遍，本文从砂金分布的地貌单元，沉积物类型，砂金成因类型，物质来源，古气候，构造作用，砂金成因等诸方面，研究了该海域内砂金特征。 相似文献
4.
以成因矿物学的理论和方法，运用电子探针、中子活化、常规化学分析和稳定同位素分析等多种地球化学实验测试技术，较系统地研究了太平洋三区四地热液烟囱物的地球化学组成和变化，揭示了研究区不同热液喷发类型中的地球化学标型特征。高温热液类型的硫化物，由高温热液矿物组成，除本身富合Fe，Zn，Cu，Pb等金属元素外，氧同位素换算温度也表现最高或中高；中低温热液类型的烟囱物，金属元素合量较低，氧同位素换算温度也表现较低。由此论证了不同标型特征的热液矿物地球化学特征与热液喷发环境之间相互依存的紧密关系。 相似文献
5.
6.
天然气水合物与资源和全球环境变化等重大科学问题密切相关.前期关于甲烷渗漏区地球化学特征的研究主要集中于浅表层沉积物(<20 m),而浅层沉积物(>20 m)地球化学特征知之甚少.为探讨海洋浅层沉积物微量元素特征与天然气水合物勘探的相关关系,对南海神狐海域沉积物进行了4个站位的钻探取样,分析了样品主、微量元素和有机碳地球... 相似文献
7.
南海海盆扩张成因质疑 总被引：9，自引：4，他引：9
从板块构造学、地球物理学和地球动力学等角度,结合南海中央海盆及其周边的地质、地球物理资料进行综合分析论证,对南海“扩张成因”模式提出质疑.认为南海“扩张成因说”不能成立,其中的几个核心问题是:(1)数学理论模型的边界参数选取存在多解性,其结果与地质地球物理资料不符或相去甚远;(2)无法解释海盆区地球物理探测和研究所表明的地壳结构及岩性特征,也无法解释海盆区的断裂分布和岩浆活动特征;(3)地球动力学诸方面难以支持南海“扩张成因说”成立;(4)南海海盆周边不存在与南海“扩张成因”相关的相互强烈作用的地球物理和地质构造特征;(5)南海海盆不具备大规模扩张的空间.南海“扩张成因说”已严重阻碍对南海和周边的地质与地球物理研究工作的深入和发展,应该放弃. 相似文献
8.
杭州湾及其邻近陆架区沉积物中有机碳、氮、磷和硅的地球化学 总被引：1，自引：0，他引：1
本文通过对杭州湾及其邻近陆架区29个表层沉积物样中有机碳、全氮、全磷和全硅的资料分析,及与水文、地质、矿物等资料的对比研究,详细地探讨了研究区沉积物中有机碳、全氮、全磷和全硅的含量分布、来源及地球化学特征。 相似文献
9.
《海洋地质与第四纪地质》2010,(4)
超压与油气的生成、运移、储集、保存等成藏要素及油气分布均有十分密切的关系,在油气成藏动力学研究中占有非常重要的地位。利用地质、钻井、测井、地球化学等资料及数值模拟技术,分析了珠江口盆地番禺4洼的超压发育特征,探讨了超压成因机制,并重建了超压演化历史。研究表明,番禺4洼深洼区文昌组现今发育超压,岩性对超压幅度具有明显的控制作用,存在生烃作用和欠压实两种主要成因机制;研究区超压具有较为复杂的演化历史,文昌组超压可划分为早、晚两期,其中早期超压主要形成于文昌组沉积期,为欠压实成因;晚期超压形成于15Ma以来,主要由生烃作用所致。 相似文献
10.
西南印度洋中脊沉积物来源广泛,是区域海洋环境演化的记录器,对其沉积物特征及物源研究是区域古海洋研究的基础。对采自西南印度洋中脊扩张轴部(34.9°S)西翼的重力柱沉积物样品进行总碳、总有机碳、生物硅、主量元素、微量及稀土元素测试,测试结果显示,样品中生物成因组分为沉积物的主要组成,主要包括碳酸盐和二氧化硅;主微量元素除了Ca、Sr与LOI外,其余元素的分布趋势基本一致,且相关系数基本大于0.8。结合不同生物组分特点进行分析计算,获得了沉积物中各生物组分的含量。去除生物成因组分重新计算了非生物成因元素含量,通过潜在物源及相应地球化学指标对比分析,发现非生物成因组分主要由非洲南部风成陆源物质组成,含少量洋中脊硫化物与结壳物质。 相似文献
11.
单颗粒碎屑矿物可减小源区岩石类型、蚀变过程和程度及搬运与沉积过程对物源信息释读的干扰, 已逐渐成为海洋沉积物物源分析的有力工具, 并取得一定的应用成果。目前, 锆石、石榴石、长石、辉石、角闪石、独居石及磁铁矿等均已被成功用于海洋沉积物物源研究, 并主要利用单矿物主量元素、年代学等方法精确识别物源区地质特征和位置, 但单矿物微量元素、同位素及微区结构及多矿物对比研究的应用尚有不足; 因此, 目前对物源信息的释读难免片面, 物源识别方法和技术也仍未成熟。随着方法的发展和完善, 将可开展诸多深入研究, 如通过锆石、独居石、云母和磷灰石等不同矿物的年代学研究, 示踪研究物源区的时空变化; 通过建立多矿物定量研究模型, 进而定量研究源区蚀变速率和源汇过程中的物质输运通量和过程等。文章总结单颗粒碎屑矿物在物源识别中的应用现状, 并展望其应用前景, 以期引起同行对此研究方法的关注, 进一步促进该方法在海洋沉积物物源分析中的应用和发展。 相似文献
12.
Andrew Morton Claire Hallsworth Dominic Strogen Andrew Whitham Mark Fanning 《Marine and Petroleum Geology》2009
An integrated provenance study using provenance-sensitive heavy mineral ratios, mineral chemistry and U/Pb dating of detrital zircons has revealed significant changes in sediment provenance during deposition of the Early to Middle Jurassic succession in the Heidrun Field, offshore Mid-Norway. The variations result from the interplay of two source regions, one of which was located on the Norwegian landmass and the other on the conjugate East Greenland margin. Sediment sourced from central East Greenland is distinguished by high garnet:zircon, high rutile:zircon, low chrome spinel:zircon, garnet assemblages rich in low-Ca, high-Mg varieties, and zircon populations that include an Archean group, a diverse range of Early–Middle Proterozoic grains, and an Early Paleozoic group. These features indicate derivation from a high-grade (granulite facies) metasedimentary terrain together with Archean basement and Early Paleozoic granitoids. Norwegian-sourced sandstones differ by having lower garnet:zircon and rutile:zircon, variable chrome spinel:zircon, garnet assemblages scarce in low-Ca, high-Mg varieties, and zircon populations that lack an Archean group. Derivation from the Caledonian Nappe Domain, comprising metasediments (predominantly at amphibolite facies), ophiolites and Early Paleozoic granitoids, is indicated. Initially, during deposition of the non-marine lower part of the Åre Formation (Hettangian–Sinemurian), sediment was fed from the west, but in the upper (tidally influenced) part of the Åre Formation (Sinemurian–Pliensbachian), Norwegian-sourced material appears. Greenland-derived material disappears in the subsequent Tilje Formation (Pliensbachian), with the Tilje and subsequent Ror and Ile Formations (Toarcian–Aalenian) being predominantly sourced from the east. The regional regression at the base of the Garn Formation (Bajocian) was accompanied by a switch in provenance, with Greenland-derived material replacing sediment sourced from Norway. Variations in mineralogy offer a framework for correlation on both local and sub-regional scales. 相似文献
13.
Thick Triassic siliciclastic units form major reservoir targets for hydrocarbon exploration on the Barents Shelf; however, poor reservoir quality, possibly associated with variation in provenance, remains a key risk factor in the area. In this study, sandstone dispersal patterns on the southwest Barents Shelf are investigated through petrographic and heavy mineral analysis, garnet and rutile geochemistry and zircon U-Pb geochronology. The results show that until the Early Norian Maximum Flooding Surface, two contrasting sand types were present: (i) a Caledonian Sand Type, characterised by a high compositional maturity, a heavy mineral assemblage dominated by garnet and low chrome-spinel:zircon (CZi) values, predominantly metapelitic rutiles and mostly Proterozoic and Archaean detrital zircon ages, interpreted to be sourced from the Caledonides, and (ii) a Uralian Sand Type, characterised by a low compositional maturity, high CZi values, predominantly metamafic rutiles and Carboniferous zircon ages, sourced from the Uralian Orogeny. In addition, disparity in detrital zircon ages of the Uralian Sand Type with contiguous strata on the northern Barents Shelf reveals the presence of a Northern Uraloid Sand Type, interpreted to have been sourced from Taimyr and Severnaya Zemlya. As such, a coincidental system is inferred which delivered sand to the Northern Barents Shelf in the late Carnian/early Norian. Following the Early Norian Maximum Flooding Surface, a significant provenance change occurs. In response to Late Triassic/Early Jurassic hinterland rejuvenation, supply from the Uralian Orogen ceased and the northern Scandinavian (Caledonian) source became dominant, extending northwards out on to the southwest Barents Shelf. The data reveal a link between reservoir quality and sand type and illustrate how provenance played an important role in the development of clastic reservoirs within the Triassic of the Barents Shelf. 相似文献
14.
盆山沉积耦合原理在定量恢复造山带隆升剥蚀过程中的应用 总被引：4，自引：1，他引：3
造山带的隆升剥蚀过程研究一直是地学界研究的热点和难点,而与造山带毗邻的沉积盆地则真实地记录了造山带隆升剥蚀演化历史。因此,通过对沉积盆地中沉积物的研究可以反演山地隆升剥蚀历史。基于这种思路,介绍了两种定量恢复造山带隆升剥蚀的方法,即裂变径迹热年代学方法和质量平衡法。前者利用样品碎屑单颗粒的裂变径迹年龄的统计分析确定其源区,并量化源区的抬升剥露及热演化历史,但要求对样品的沉积时代有很好的年代学控制,沉积后样品没有遭受热重置。后者则假定在一定时间间隔内,盆山耦合系统中物源区的地形变化总和与沉积区的碎屑沉积质量总和成正比,即隆升过程中产生侵蚀总量与毗邻盆地的沉积总量之间质量守恒,从而通过研究盆地中相应时间段的沉积总量、沉积速度来定量恢复古地形,反演造山带的演化,但盆山系统的界定以及地层定年的精度直接影响到恢复造山带隆升剥蚀过程的可靠性。 相似文献
15.
海底沉积物中稀土元素的分布特征受多种影响因子的影响,很难定量分析。北部湾沉积物稀土元素(∑REE)与物源、水动力、沉积物粒度和黏土矿物百分比等关系定性分析显示,本区∑REE的物源主要由陆源岩石控制,弱水动力和细颗粒度都对应较高含量的∑REE。结合北部湾海底沉积物的位置、砾石含量、砂含量、粉砂含量、黏土含量和黏土矿物含量训练出来的BP神经网络在控制变量的情况下定量分析各影响因子与∑REE的关系,获得单个影响因子与∑REE的关系曲线。这些关系曲线揭示了北部湾沉积物中稀土元素与各影响因子的联系,所获结果与定性分析结果基本一致,该方法能够通过自主学习,自动判断并定量计算,有助于识别每一个因子对稀土元素含量影响的大小,是如何控制∑REE的分布,从而根据曲线的变化规律结合实际情况去推断区域的环境变化及地质演变,对稀土元素的富集和分散分析提供有益的理论指导。 相似文献
16.
台湾海峡西岸闽江口和九龙江口沉积物中碎屑锆石铀-铅定年及物源意义 总被引：3，自引：1，他引：2
碎屑锆石能较好保存源区岩石组成的信息,其铀-铅年龄是沉积物源区示踪有效的方法。利用激光剥蚀等离子体质谱和多接收器等离子体质谱联机(LA-MC-ICPMS)技术,对台湾海峡西部闽江口和九龙江口沉积物中的碎屑锆石进行原位铀-铅测年,同时获得锆石的微量元素。研究表明大部分碎屑锆石的钍与铀含量之比值大于0.1,稀土元素球粒陨石标准化配分曲线呈左倾型,并具有明显的铈含量正异常和铕含量负异常,结合阴极发光图像表明这些锆石绝大部分为岩浆成因。闽江口和九龙江口的碎屑锆石具有相同的印支期(峰值为236 Ma)、燕山早期(峰值为155 Ma)和燕山晚期(峰值为110 Ma)等3个峰值,这三期碎屑锆石占主要部分,反映闽江口和九龙江口碎屑沉积物主要来自各流域上游印支期和中下游燕山期岩体,而闽江口碎屑锆石具有明显的加里东期峰(峰值为465 Ma)和前寒武纪(553~2 765 Ma)较多的碎屑锆石,这些碎屑物质可能来自上游武夷山地区加里东期和前寒武纪基底的物质。对比闽江口碎屑锆石铀-铅年龄与台湾岛西部海滨沙滩(苗栗-新竹、嘉义-台南)中的独居石年龄具有相似的谱峰特征,表明台湾岛西部海滨沙滩碎屑物质可能有部分来自闽江。闽江口碎屑物质明显区别于福建的九龙江和浙江的瓯江,这为判别台湾海峡沉积物的物质来源提供可靠的依据。 相似文献
17.
Cui Yuchi Shao Lei Qiao Peijun Pei Jianxiang Zhang Daojun Tran Huyen 《Marine Geophysical Researches》2019,40(2):223-235
Provenance studies of the Central Canyon, Qiongdongnan Basin has provided significant insights into paleographic and sedimentology research of the South China Sea (SCS). A suite of geochemical approaches mainly including rare earth elemental (REE) analysis and detrital zircon U–Pb dating has been systematically applied to the “source-to-sink” system involving our upper Miocene–Pliocene Central Canyon sediments and surrounding potential source areas. Based on samples tracing the entire course of the Central Canyon, REE distribution patterns indicate that the western channel was generally characterized by positive Eu anomalies in larger proportion, in contrast to the dominance of negative values of its eastern side during late Miocene–Pliocene. Additionally, for the whole canyon and farther regions of Qiongdongnan Basin, the number of samples bearing negative Eu anomalies tended to increase within younger geological strata. On the other hand, U–Pb geochronology results suggest a wide Proterozoic to Mesozoic age range with peak complexity in Yanshanian, Indosinian, Caledonian and Jinningian periods. However in detail, age combination of most western samples displayed older-age signatures than the eastern. To make it more evidently, western boreholes of the Central Canyon are mainly characterized with confined Indosinian and Caledonian clusters which show great comparability with mafic-to-ultramafic source of Kontum Massif of Central Vietnam, while eastern samples largely bear with distinguishable Yanshanian and Indosinian peaks which more resemble with Hainan Island. Based on geochemistry and geochronology analyses, two significant suppliers and sedimentary infilling processes are generated: (1) the Indosinian collision orogenic belt in central-northern Vietnam, Indochina has ever played significant role in Central Canyon sedimentary evolution, (2) Hainan Island once as a typical provenance restricted within eastern Central Canyon, has been enlarging its influence into the whole channel, even into the farther western regions of Qiongdongnan Basin.
相似文献18.
河口地层独居石Th(U)-Pb年龄对长江贯通时限的约束 总被引：6，自引：0，他引：6
新生代长江水系调整、东西贯通时限是国内外学者共同关注的问题。长江发展演化的复杂性在近一个世纪的河流沉积地貌学研究中得到充分的认识,但在贯通时限问题上难以形成共识。河口地层中碎屑独居石的电子探针Th(U)-Pb年龄较好地限定长江东西贯通的时间在2.58MaBP前后。随着碎屑矿物微区分析技术的发展,锆石、独居石年代学和微区特征将成为研究流域演化、构造运动的主要手段。 相似文献
19.
There are many large-scale Cenozoic sedimentary basins with plentiful river deltas, deep-water fans and carbonate platforms in the southern South China Sea. The Crocker Fan was deposited as a typical submarine fan during the late Eocene–early Miocene, and stretches extensively across the entire Sarawak–Sabah of the northern Borneo area. However, systematic analyses are still lacking regarding its sediment composition and potential source suppliers. No consensus has been reached yet on the provenance evolution and sedimentary infilling processes, which seriously impeded the oil-and-gas exploration undertakings. By combining with sedimentary-facies identification, heavy mineral assemblages, elemental geochemistry and detrital zircon U-Pb dating, this paper aims to generalize an integrated analysis on the potential provenance terranes and restore source-to-sink pathways of the Crocker Fan. In general, the Crocker Fan was initially formed over the Cretaceous–lower/middle Eocene Rajang Group by an angular Rajang unconformity. The continual southward subduction of the proto-South China Sea resulted in magmatic activities and subsequent regional deformation and thrusting along the Lupar Line in the northern Borneo. The lowermost Crocker sequence is featured by a thick conglomerate layer sourced from in-situ or adjacent paleo-uplifts. From the late Eocene to the early Miocene, the Crocker Fan was constantly delivered with voluminous detritus from the Malay Peninsula of the western Sundaland. The Zengmu Basin was widely deposited with delta plain and neritic facies sediments, while the Brunei-Sabah Basin, to the farther east, was ubiquitously characterized by turbiditic sequences. The Crocker Fan successions are overall thick layers of modest-grained sandstones, which formed high-quality reservoirs in the southern South China Sea region. 相似文献
20.
Jinshui Liu Shuai Li Kaifei Liao Yuchi Cui Lei Shao Peijun Qiao Yi Lu Yuanli Hou Thian Lai Goh Yongjian Yao 《海洋学报(英文版)》2023,42(3):89-100
Both Pinghu and Huagang formations are important hydrocarbon reservoirs of the Xihu Depression in the East China Sea Shelf Basin. Clarifying the source suppliers and restoring source-to-sink transport routes are of great significance to the future petroleum and gas undertakings. Previous researchers were largely confined by either limitation of geological records, highly dependence on a singular method or low-precision dating techniques. Our study integrated heavy mineral assemblages, geochemica... 相似文献