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1.
长江经济带包括上海、江苏、浙江、安徽、江西、湖北、湖南、四川、重庆、云南和贵州11个省(直辖市),是我国重要的经济发展区域,油气资源长期安全可靠的储存对于该区经济可持续发展至关重要。基于长江经济带战略油气储库基地建设规划布局的需求,在充分收集利用前人地质调查和研究成果的基础上,对区内岩盐矿床进行了综合研究和分析,建立了层次结构模型,评价了盐穴油气储库建设的可行性。长江经济带除上海和贵州外,其余9省(直辖市)均发现了大量的岩盐矿床,主要成盐时代为震旦纪、三叠纪、白垩纪和古近纪; 成盐盆地范围0.29~10 000 km2,盐层累计厚度3~1 050 m,矿体埋藏深度40~3 400 m; 矿石中NaCl含量20%~99.86%; 矿体顶底板及夹层岩石主要为泥岩、粉砂质泥岩及泥质粉砂岩。地质调查揭示出区内大部分地下盐穴远离地震活动带,构造稳定,因此可以改造为石油储库。考虑储气库的密闭性及安全性,江苏金坛盆地等6个盐矿埋深适中,建穴地质条件较好,适合建造储气盐穴库; 江苏淮安等14个盆地的局部地区适合建造天然气储库; 重庆垫江等11个盐矿埋深较大,可以建造储气盐穴库,但建造成本较高; 湖南澧县等21个盐矿埋藏偏浅,应选择更深部的盐层空间建造油气储库。建议在江苏金坛、淮安、赵集和丰县,江西清江和会昌,湖北云应、天门小板和潜江等盐矿地区优先开发利用盐穴。  相似文献   
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The development of thermodynamic models for tonalitic melt and the updated clinopyroxene and amphibole models now allow the use of phase equilibrium modelling to estimate P–T conditions and melt production for anatectic mafic and intermediate rock types at high‐T conditions. The Permian mid‐lower crustal section of the Ivrea Zone preserves a metamorphic field gradient from mid amphibolite facies to granulite facies, and thus records the onset of partial melting in metabasic rocks. Interlayered metabasic and metapelitic rocks allows the direct comparison of P–T estimates and partial melting between both rock types with the same metamorphic evolution. Pseudosections for metabasic compositions calculated in the Na2O–CaO–K2O–FeO–MgO–Al2O3–SiO2–H2O–TiO2–O (NCKFMASHTO) system are presented and compared with those of metapelitic rocks calculated with consistent end‐member data and a–x models. The results presented in this study show that P–T conditions obtained by phase equilibria modelling of both metabasic and metapelitic rocks give consistent results within uncertainties, allowing integration of results obtained for both rock types. In combination, the calculations for both metabasic and metapelitic rocks allows an updated and more precisely constrained metamorphic field gradient for Val Strona di Omegna to be defined. The new field gradient has a slightly lower dP/dT which is in better agreement with the onset of crustal thinning of the Adriatic margin during the Permian inferred in recent studies.  相似文献   
4.
榍石作为副矿物在哀牢山-红河剪切带新生代富碱侵入岩中广泛存在。原位获取榍石矿物内部微量元素、U-Pb年龄和Sm-Nd同位素的空间变化对获取矿物和岩石的成因演化信息具有重要意义。本文使用四级杆/多接收电感耦合等离子体质谱(Quadrupole/Multi-Collector Inductively Coupled Plasma Mass Spectrometry,Q/MC-ICP-MS)与激光剥蚀系统(Laser Ablation,LA)联用,对哀牢山-红河剪切带5个富碱侵入岩体(桃花岩体、宁蒗-永胜岩体、哈播岩体、铜厂岩体和十里村岩体)中榍石开展了微区原位微量元素、U-Pb年代学和Sm-Nd同位素研究。微量元素分析结果表明,三江富碱侵入岩中榍石为岩浆成因,亏损Rb、Ba、Pb、Sr等大离子亲石元素,富集Th、U、Nb、Ta、Zr、Hf等高场强元素。榍石的稀土配分图均表现为明显右倾,不具有或具有弱的Eu负异常。与云南北衙、马厂箐矽卡岩矿床中的热液榍石相比,本文榍石在稀土元素组成上,具有较高的稀土元素总量、较高的Th/U、LREE/HREE和Ce/Ce*比值,具有较低的Eu/Eu*、Nb/Ta、Zr/Hf比值。微区原位LA-Q-ICP-MS U-Pb定年结果表明,研究区富碱岩体中榍石结晶年龄在32.5~37.9Ma之间,代表了岩体形成时代,与三江地区哀牢山-红河剪切带及其附近新生代富碱岩浆活动高峰期(~35Ma)一致,属于青藏高原晚碰撞期岩浆作用的产物。榍石微区原位LA-MCICP-MS Sm-Nd同位素分析结果显示,榍石颗粒的Nd同位素组成均一,表明榍石结晶过程中寄主岩浆的Nd同位素组成没有发生明显变化。各个富碱岩体之间的榍石Nd同位素组成变化范围在-6.8~-2.1之间,与全岩的同位素特征一致,表明榍石的原位微区Sm-Nd同位素可以作为富碱侵入岩研究中有效的示踪手段之一。  相似文献   
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The West Coast dusky kob Argyrosomus coronus is a commercially exploited fish with a distribution confined to the Angola–Benguela Frontal Zone (ABFZ) of the southeastern Atlantic Ocean. A previous study revealed that during a recent period of local warming the species extended its distribution into Namibian waters, where it hybridised with the resident and congeneric Argyrosomus inodorus. Environmental changes are a major threat to marine biodiversity and when combined with overfishing have the potential to accelerate the decline of species. However, little is known regarding the evolutionary history and population structure of A. coronus across the ABFZ. We investigated genetic diversity, population structure and historical demographic changes using mtDNA control region sequences and genotypes at six nuclear microsatellite loci, from 180 individuals. A single, genetically homogeneous population was indicated across the distributional range of A. coronusST = 0.041, FST = 0.000, D = 0.000; p > 0.05). These findings imply that the oceanographic features within the ABFZ do not appear to significantly influence population connectivity in A. coronus, which simplifies management of the species. However, reconstruction of the demographic history points to a close link between the evolutionary history of A. coronus and the environmental characteristics of the ABFZ. This outcome suggests the species’ vulnerability to the rapid environmental changes being observed across this region, and highlights a pressing need for transboundary management to mitigate the impacts of climate change in this global hotspot of seawater temperature changes.  相似文献   
6.
舒小超  刘琰  李德良  贾玉衡 《岩石学报》2019,35(5):1372-1388
霓长岩化作用是指碳酸岩(或碱性岩)流体对围岩的交代蚀变,它是碳酸岩型稀土(REE)矿床常见的蚀变类型,其所形成的岩石即为霓长岩。对霓长岩的深入研究可以鉴别碳酸岩体的存在,厘定碳酸岩岩浆(或流体)的地球化学性质及源区特征,这对于找寻碳酸岩相关的矿产资源(尤其是REE)以及剖析矿床成因机制有着重要的地质意义。川西冕宁-德昌稀土矿带是中国最重要的轻稀土矿带之一,包括牦牛坪超大型、大陆槽大型、木落寨和里庄中小型REE矿床以及一系列矿点。REE矿化与碳酸岩-碱性岩杂岩体密切相关,受一系列新生代走滑断裂的控制。该矿带广泛发育霓长岩化蚀变带,尤以大陆槽及里庄矿床为显著。岩相学分析表明,大陆槽和里庄霓长岩中的矿物多呈他形粒状结构,主要由长石、黑云母、霓辉石以及少量副矿物组成;主微量元素分析表明,霓长岩的碱质(K_2O+Na_2O)、MgO、Fe_2O_3T含量较高,且富集REE、Sr、Ba等微量元素;电子探针分析表明,霓长岩中的霓辉石Fe OT含量较高,长石Na_2O及K_2O含量较高,Ca O含量极低。An-Ab-Or三角图解显示长石主要为透长石和钠长石,属碱性长石系列;黑云母的地球化学成分图解表明云母的成因类型为交代型且具有相对富镁、贫铁等特征,属镁质黑云母。霓长岩化作用的交代流体含有较高的CO_2组分,且富含碱质、Mg、Fe及REE、Sr、Ba等元素。对比霓长岩与原岩的主微量元素发现:相比于正长岩原岩,在主量元素中,霓长岩的Fe、Mg、Ca等元素含量增加,Si、Al等元素含量降低;微量元素中,霓长岩的REE及Sr、Ba等元素显著增加。这意味着交代流体含有的Fe_2O_3T、MgO、CaO等组分在霓长岩化过程中被带进了围岩,而SiO_2和Al_2O_3等从围岩中被逐出。大陆槽及里庄矿区发育的角砾岩指示了矿区曾经历过频繁的角砾岩化事件,这提高了霓长岩作用的强度,并且为矿脉的穿插及REE矿物的沉淀提供了空间。在霓长岩化过程中,流体-围岩的组分交换反复发生,这削弱了REE络合物的稳定性,伴随多期次的热液活动及构造事件,最终完成REE活化→迁移→沉淀的过程。  相似文献   
7.
基于我们布设的探测深俯冲的中国东北地震台阵NECsaids台阵和固定地震台长时段的观测记录及NECESSArray流动台阵共计152个台站数据提取得到的33752条P波接收函数,采用H-κ叠加分析和共转换点(CCP)叠加成像等方法进行统一分析处理,并汇集他人接收函数研究结果得到中国东北东南部地区迄今为止最高分辨率的地壳厚度和平均波速比分布图像.对中国东北东南部地区不同构造体的地壳特征综合分析研究表明:研究区不同陆块的地壳属性存在明显差别,张广才岭地块中南部的地壳厚度和波速比与华北克拉通东北缘相当,地壳厚度同地表地形之间显示有明显的正相关关系;松辽地块东南缘地壳最薄、波速比最高,地壳厚度同壳内波速比之间显示出明显的负相关关系;兴凯地块西部地区的地壳结构表现为稍厚的地壳厚度和研究区内最低的壳内波速比,其地壳厚度同壳内波速比之间亦显示出明显的负相关关系;佳木斯地块西南缘在具有"正常"的壳内波速比同时地壳最厚.研究区内的郯庐断裂带北延段在切穿其下Moho面的同时表现出南北分段的特征:北段(44.4°N—47°N)两分支之下的Moho面整体下凹,而南段(41.5°N—43.3°N)两分支之下的Moho面则整体上隆.长白山天池火山下方表现为Moho面下凹沉落及高壳内波速比特征,推测其壳内岩浆囊很可能存在于火山口东北隅至少10 km的范围内.  相似文献   
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The interactions among surface water, groundwater and seawater are closely related in the coastal area with complex hydrological conditions. A series of impacts from human activities and climate change are also more significant in this region. In order to understand the key knowledge and research status of surface water and groundwater interaction in coastal area, it is a useful method to analyze literatures in this research scope in the core database of Web of Science by using CiteSpace. The research achievements in this field were systematically sorted and potential research hotspots were explored, which may provide references for subsequent researches. The results show the following. The number of highly cited articles and highly burst articles in this research field has increased significantly since 2010. At present, this field is still in the development stage and has a broad research prospect. The United States, Australia, China and Germany have done plenty of researches on this issue and achieved a lot. At present, the number of research achievements supported by National Natural Science Foundation of China is in the lead over the world. Seawater intrusion, submarine groundwater discharge, the relationship between tide and hydrological conditions are the main research direction in this field. Hydrochemistry and isotopic analysis, and numerical simulation are the most important research methods in this field. The potential development directions and breakthroughs in this field include submarine groundwater discharge, the evolution of coastal mangrove wetlands, the migration and transformation of nutrients, the influences of different hydrological factors on coastal areas, and the impact of climate change on coastal areas. Overall, the future development of surface water and groundwater research in coastal areas is inseparable from the cross-integration of various disciplines, mutual verification of multiple methods and the introduction of new technical means.  相似文献   
9.
《China Geology》2020,3(3):385-401
Recently, continuous breakthroughs have been made about deep gold prospecting in the Jiaodong gold province area of China. Approximately 5000 t of cumulative gold resources have been explored in Jiaodong, which has thus become an internationally noteworthy gold ore cluster. The gold exploration depth has been increased to about 2000 m from the previous <1000 m. To further explore the mineralization potential of the Jiaodong area at a depth of about 3000 m, the Shandong Institute of Geological Sciences has drilled an exploratory drillhole named “Deep drillhole ZK01” to a depth of 3266 m. Hence, as reported herein, the mineralization characteristics of the Jiaojia metallogenic belt have been successfully documented. ZK01 is, to date, the deepest borehole with an gold intersect in China, and constitutes a significant advance in deep gold prospecting in China. The findings of this study further indicate that the depth interval of 2000 m to 4000 m below the ground surface in the Wuyi Village area incorporates 912 t of inferred gold resources, while the depth interval of 2000 m to 4000 m below the surface across the Jiaodong area possesses about 4000 t of inferred gold resources. The Jiaojia Fault Belt tends to gently dip downward, having dip angles of about 25° and about 20° at vertical depths of 2000 m and 2850 m, respectively. The deep part of the Jiaojia metallogenic belt differs from the shallow and moderately deep parts about fracturing, alteration, mineralization, and tectonic type. The deep zones can generally be categorized from inside outward as cataclastic granite, granitic cataclasite, weakly beresitized granitic cataclasite, beresitized cataclasite, and gouge. These zones exhibit a gradual transitional relation or occur alternately and repeatedly. The mineralization degree of the pyritized cataclastic granite-type ore in the deep part of the Jiaojia metallogenic belt is closely related to the degree of pyrite vein development; that is, the higher the pyrite content, the wider the veins and the higher the gold grade. Compared to the shallow gold ores, the deep-seated gold ores have higher fineness and contain joseite, tetradymite, and native bismuth, suggesting that the deep gold mineralization temperature is higher and that mantle-sourced material may have contributed to this mineralization. ZK01 has also revealed that the deep-seated ore bodies in the Jiaojia metallogenic belt are principally situated above the main fracture plane (gouge) and hosted within the Linglong Granite, contradicting previous findings indicating that the moderately shallow gold ore bodies are usually hosted in the contact zone between the Linglong Granite and Jiaodong Group or meta-gabbro. These new discoveries are particularly significant because they can help correct mineralization prospecting models, determine favorable positions for deep prospecting, and improve metallogenic prediction and resource potential evaluation.  相似文献   
10.
长江口盐度梯度下不同形态碳的分布、来源与混合行为   总被引:1,自引:0,他引:1  
河口碳的生物地球化学过程是全球碳循环的重要组成。通过测定溶解无机碳(DIC)及其稳定同位素丰度(δ13CDIC),溶解有机碳(DOC),有色溶解有机物(CDOM),颗粒有机碳(POC)及其稳定同位素丰度(δ13CPOC)与元素比值(N/C)及相关指标,研究了2014年7月长江口盐度梯度下不同形态碳的分布、来源和混合行为。结果表明,DIC浓度、DOC浓度、POC含量分别为1 583.2~1 739.6 μmol/L,128.4~369.4 μmol/L和51.2~530.8 μmol/L,这些不同形态碳及CDOM的荧光组分的分布模式相似,均是从口内到口外,整体呈现先增大后减小的趋势,并与盐度呈现非保守混合行为。添加作用主要发生在在口门处最大浑浊带附近。与含量相反,从口内到口外,δ13CDIC和δ13CPOC均呈现逐渐减小再增大的趋势,在口门附近达到最低值,分别为-9.7‰和-26.7‰。在口门附近不同形态碳含量上升及δ13CDIC、δ13CPOC的降低可能主要与沉积物再悬浮及微生物作用有关。基于蒙特卡洛模拟的三端元混合模型的结果显示,河口内外POC来源变化明显,口内POC以陆源有机碳贡献为主,平均为62.3%,口外海源贡献逐渐增加。CDOM相关参数结果表明长江口CDOM主要来自陆源输入,海源及人类活动等也对其产生影响。  相似文献   
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