准噶尔盆地腹部地区生烃增压定量化评价——东道海子北凹陷为例          下载免费PDF全文

于春勇郭小文  任战利任文波 杨桂林 《地质科学》2018,(1):207-220

目前准噶尔盆地腹部地区超压演化过程仅提供了相对时间、概念、定性的认识,并未达到定量化。本文以东道海子北凹陷为例,基于流体包裹体、单井一维和剖面二维烃源岩成熟生烃史模拟技术,采用生烃增压模型定量化评价了侏罗纪八道湾组顶部和底部烃源岩的生烃增压演化过程。研究结果表明侏罗纪八道湾组为东道海子北凹陷主力烃源岩,具有幕式排烃的特点。八道湾组底部烃源岩经历了3 次超压增加和两次超压释放的过程,顶部烃源岩经历了两次超压增加和一次超压释放的过程。八道湾底部烃源岩3 次超压增加的时间分别为距今170～70 Ma、55～23 Ma、10～0 Ma,对应最大压力系数均为2.0,最大剩余流体压力50 MPa,两次超压释放的时间分别为70～55 Ma、23～10 Ma;八道湾组顶部烃源岩两次超压增加的时间分别为130～40 Ma、23～0 Ma,对应流体最大压力系数最大亦可达2.0 左右,最大剩余流体压力44 MPa,超压释放的时间为40～23 Ma。  相似文献   

Dunites of the Inagli massif (Central Aldan), cumulates of lamproitic magma     

I.F. Chaika  A.E. Izokh 《Russian Geology and Geophysics》2018,59(11):1450-1460

We consider a hypothesis for the origin of PGE-bearing ultramafic rocks of the Inagli massif (Central Aldan) through fractional crystallization from ultrabasic high-potassium magma. We studied dunites and wehrlites of the Inagli massif and olivine lamproites of the Ryabinovy massif, which is also included into the Central Aldan high-potassium magmatic area. The research is focused on the chemistry of Cr-spinels and the phase composition of Cr-spinel-hosted crystallized melt inclusions and their daughter phases. Mainly two methods were used: SEM-EDS (Tescan Mira-3), to establish different phases and their relationships, and EPMA, to obtain precise chemical data on small (2-100 μm) phases. The obtained results show similarity in chromite composition and its evolutionary trends for the Inagli massif ultramafites and Ryabinovy massif lamproites. The same has been established for phlogopite and diopside from crystallized melt inclusions from the rocks of both objects. Based on the results of the study, the conclusion is drawn that the ultramafic core of the Inagli massif resulted from fractional crystallization of high-potassium melt with corresponding in composition to low-titanium lamproite. This conclusion is consistent with the previous hypotheses suggesting an ultrabasic high-potassium composition of primary melt for the Inagli ultramafites.  相似文献   

Natural ring structures on the Baikal ice cover: Analysis of experimental data and mathematical modeling     

N.G. Granin  I.B. Mizandrontsev  V.V. Kozlov  E.A. Tsvetova  R.Yu. Gnatovskii  V.V. Blinov  I.A. Aslamov  K.M. Kucher  V.G. Ivanov  A.A. Zhdanov 《Russian Geology and Geophysics》2018,59(11):1514-1525

Hydrophysical studies and mathematical modeling of ring structures during ice cover on Lake Baikal have shown that their existence at the stage of ice cover degradation is due to anticyclonic currents. Such currents can be generated as a result of local upwelling, which we associate with the rise of methane hydrates from the top layer of bottom sediments and their dissociation. Analysis of satellite images shows that the radii of ice rings range from 1300 to 2400 m, which is close to the baroclinic Rossby radius. The measured ice thicknesses in the area of the rings are in agreement with model calculations. Deep water renewal in Lake Baikal can also be associated with the rise of hydrates.  相似文献   

基于随机森林模型的中国中老年人群HDL-C环境影响因素研究     

裴泽华  葛淼  李浩  何进伟  王聪霞 《地球信息科学学报》2022,24(7):1286-1300

高密度脂蛋白胆固醇（HDL-C）可以有效促进人体内胆固醇的代谢外排,其水平的高低与患心血管疾病的风险呈负相关关系,是心血管疾病的预防与保护因素。厘清我国中老年人群HDL-C水平的地理分异特征及环境影响因素,对我国心血管疾病防治工作的开展有重要意义。论文基于中国中老年人纵向追踪调查,利用全局空间自相关、冷热点分析等方法阐释中国中老年人群HDL-C水平的空间分异特征及变化趋势,同时对比引入随机森林回归模型及多元线性回归方法探讨HDL-C水平空间分布的环境影响因素及其指示作用。结果表明：中国中老年人群HDL-C水平表现为女性高于男性、农村高于城镇,具有明显的地域差异性,整体呈现出“北低南高,中间过渡”的分布格局,且北方出现了以内蒙古、河北、辽宁为代表的低值聚集区,南方出现了以广东、广西、云南为代表的高值聚集区;SO₂、NO₂、降水、气压、PM₁₀和PM_2.5是影响中老年人群HDL-C水平差异分布的主要环境因素,其中高浓度的空气污染物是造成HDL-C值较低的危险因素,充沛的降水和低压环境是防治HDL-C值较低的保护因素。因此,今后关于HDL-C血脂异常防控工作在全国各地应注重其空间分布规律,重点加强对HDL-C低值区的监测,以达到因地制宜、精准防控的目的。  相似文献   

造山型金矿中富CO_(2)高内压流体包裹体完全均一温度的有效测定实验研究——以东天山玉峰金矿床为例SCIEI北大核心CSCD     

于立栋  李胜虎  张静  何西恒  于学峰  单伟  迟乃杰 《岩石学报》2022,38(1):267-280

形成于中-深成条件下的造山型金矿的成矿流体属于H_(2)O-NaCl-CO_(2)体系,金矿化阶段的石英中发育大量的富CO_(2)流体包裹体。长期以来,用常规冷热台对其进行显微测温热力学研究时,较高的内压力会造成绝大多数CO_(2)充填度>0.4的包裹体在尚未达到完全均一状态前就发生爆裂或泄露,导致所测的完全均一温度值明显偏离真实值,甚至无法测得完全均一温度,这制约了对造山型金矿床成矿条件的认知。针对该问题,本文以东天山玉峰金矿床富金矿石中的H_(2)O-NaCl包裹体(A型)和H_(2)O-NaCl-CO_(2)包裹体(AC型)为研究对象,介绍了利用最新型热液金刚石压腔(HDAC-VT型号)测试富CO_(2)高内压的AC型包裹体完全均一温度的实验流程与结果,并将实验数据与Linkam THMSG600冷热台测得的A型、AC型包裹体的完全均一温度进行了对比分析。实验结果表明,热液金刚石压腔能够有效阻止富CO_(2)流体包裹体在升温过程中发生爆裂、泄露等非弹性体积改变现象的发生,从而获得有效的完全均一温度。同时,本文还提出了一个新的压力-温度拟合线两线相交法,对热液金刚石压腔所测富CO_(2)流体包裹体的完全均一温度数据进行校正,以最大程度上减少外压力造成的影响,获得更为接近真实成矿流体的完全均一温度。基于此,获得玉峰金矿床的成矿温度和成矿压力分别为312~343℃和181~268 MPa。本文的实验研究工作显示了热液金刚石压腔在中-深成造山型金矿富CO_(2)成矿流体的研究领域具有重要应用前景。  相似文献   

河南省煤层气钻井技术发展历程及展望          下载免费PDF全文

张晓昂  刘国卫  齐治虎  张留彬  胡向志  王立峰 《探矿工程》2022,49(5):86-93

河南省地勘队伍自2003年开展煤层气钻井施工以来,积极开展技术创新研究,先后研发了大直径绳索取心机具、射流式扩孔掏穴器等专用器具,率先开展了煤层气参数井、水平井、采动井、穿采空井等施工技术研究和实践,形成了涵盖各类煤层气井型的钻井施工技术体系,积累了丰富的实战经验,促进了我国煤层气产业的发展。本文在总结了河南地勘单位在煤层气钻井技术方面取得的成果的基础上,结合国内煤层气开发深度逐渐增加、采空区覆盖面积逐渐增大、构造煤煤层气未实现突破等行业发展需求,提出了开展高效煤层气水平井钻井技术、气动定向钻井技术及构造煤开发钻井关键技术等方面研究的建议。  相似文献   

春季黄、渤海沉积物中CH4和N2O的垂向分布特征研究     

李思琦  陈烨  尹霞  臧昆鹏  甄毓 《地学前缘》2022,29(5):35-46

本研究分别利用顶空平衡法与qPCR技术测定了2018年春季黄、渤海5个典型站位柱状沉积物中甲烷(CH₄)和氧化亚氮(N₂O)浓度及产甲烷菌与硫酸盐还原菌功能基因拷贝数,并分析了其与间隙水中相关环境因子的关系。沉积物上方水文条件的差异以及其中复杂的碳氮生物地球化学过程使得CH₄和N₂O浓度呈现出明显的空间和垂直变化。结果显示,沉积物中CH₄浓度为0.23~0.92 μmol·kg^-1,N₂O浓度为18.90~104.96 nmol·kg^-1。总体来说,渤海沉积物中CH₄和N₂O平均浓度高于黄海。垂向分布上,CH₄浓度均随深度增加逐渐升高, $\text{SO}_{4}^{2-}$浓度随深度增加逐渐降低,并与CH₄浓度呈镜像关系,产甲烷菌与硫酸盐还原菌的丰度也遵循着同样规律,这表明沉积物中产甲烷作用受$\text{SO}_{4}^{2-}$浓度的抑制。 mcrA基因拷贝数平均值为渤海低于黄海。除3500-7站外,沉积物中mcrA基因拷贝数随深度增加而升高。各站位mcrA 基因丰度与CH₄浓度均无显著相关性,且mcrA丰度与$\text{SO}_{4}^{2-}$浓度之间也未检测到显著相关性。dsrB基因拷贝数远高于mcrA基因拷贝数,且两者相差至少两个数量级。 dsrB基因拷贝数随深度逐渐增加,直至10 cm左右,随后至沉积物底部逐渐减少。各站位dsrB基因拷贝数与CH₄浓度剖面略有镜像关系,但均未检测到显著负相关性。以上结果均表明沉积物中存在着同时消耗沉积物中$\text{SO}_{4}^{2-}$与CH₄的其他作用。N₂O浓度随深度增加先降低,在深度30 cm以下逐渐升高。间隙水中$\text{NO}_{3}^{-}$和$\text{NO}_{2}^{-}$浓度均随深度减小,同时$\text{NH}_{4}^{+}$浓度与其呈相反趋势。沉积物中N₂O与$\text{NO}_{2}^{-}$及$\text{NO}_{3}^{-}$浓度均呈正相关,且前者相关性较高,说明反硝化作用是沉积物中N₂O产生的主要过程。这些结果为进一步了解近岸陆架海域沉积物中CH₄和N₂O的来源、分布及碳氮生物地球化学循环提供了参考资料。  相似文献   

Genesis of the Maoling gold deposit in the Liaodong Peninsula: Constraints from a combined fluid inclusion,C-H-O-S-Pb-He-Ar isotopic and geochronological studies     

《地学前缘(英文版)》2022,13(4):101379

The large tonnage Maoling gold deposit (25 t @ 3.2 g/t) is located in the southwest Liaodong Peninsula, North China Craton. The deposit is hosted in the Paleoproterozoic metamorphic rocks. Four stages of mineralization were identified in the deposit: (stage I) quartz-arsenopyrite ± pyrite, (stage II) quartz-gold- arsenopyrite-pyrrhotite, (stage III) quartz-gold- polymetallic sulfide, and (stage IV) quartz-calcite-pyrrhotite. In this paper, we present fluid inclusion, C-H-O-S-Pb-He-Ar isotope data, zircon U-Pb, and gold-bearing sulfide (i.e. arsenopyrite and pyrrhotite) Rb-Sr age of the Maoling gold deposit to constrain its genesis and ore-forming mechanism. Three types of fluid inclusions were distinguished in quartz-bearing veins, including liquid-rich two-phase (WL type), gas-rich two-phase (GL type), and daughter mineral-bearing fluid inclusions (S type). Fluid inclusions data show that the homogenization at temperatures 197 to 372 °C for stage I, 126 to 319 °C for stage II, 119 to 189 °C for stage III, and 115 to 183 °C for stage IV, with corresponding salinities of 3.7 to 22.6 wt.%, 4.7 to 23.2 wt.%, 5.3 to 23.2 wt.%, and 1.7 to 14.9 wt.% NaCl equiv., respectively. Fluid boiling was the critical factor controlling the gold and associated sulfide precipitation at Maoling. Hydrogen and oxygen stable isotopic analyses for quartz yielded δ¹⁸O = ?5.0‰ to 9.8‰ and δ D = ?133.5‰ to ?77.0‰. Carbon stable isotopic analyses for calcite and ankerite yielded δ¹³C = ?2.3‰ to ?1.2‰ and O = 7.9‰ to 14.1‰. The C-H-O isotope data show that the ore-forming fluids were originated from magmatic water with meteoric water input during mineralization. Hydrothermal inclusions in arsenopyrite have ³He/⁴He ratios of 0.002 Ra to 0.054 Ra, and ⁴⁰Ar/³⁶Ar rations of 1225 to 3930, indicating that the ore-forming fluids were dominantly derived from crustal sources almost no mantle input. Sulfur isotopic values of Maoling fine-grained granite range from 6.‰1 to 9.8‰, with a mean of 7.7‰, δ³⁴S values of arsenopyrite from the mineralized phyllite (host rock) range from 8.9‰ to 10.6‰, with a mean of 10.0‰, by contrast, δ³⁴S values of sulfides from ore vary between 4.3‰ and 10.6‰, with a mean of 6.8‰, suggesting that sulfur was mainly originated from both the host rock and magma. Lead radioactive isotopic analyses for sulfides yielded ²⁰⁶Pb/²⁰⁴Pb = 15.830–17.103, ²⁰⁷Pb/²⁰⁴Pb = 13.397–15.548, ²⁰⁸Pb/²⁰⁴Pb = 35.478–36.683, and for Maoling fine-grained granite yielded ²⁰⁶Pb/²⁰⁴Pb = 18.757–19.053, ²⁰⁷Pb/²⁰⁴Pb = 15.596–15.612, and ²⁰⁸Pb/²⁰⁴Pb = 38.184–39.309, also suggesting that the ore-forming materials were mainly originated from the host rocks and magma. Zircon U-Pb dating demonstrates that the Maoling fine-grained granite was emplaced at 192.7 ± 1.8 Ma, and the host rock (mineralized phyllite) was emplaced at some time after 2065.0 ± 27.0 Ma. Arsenopyrite and pyrrhotite give Rb–Sr isochron age of 188.7 ± 4.5 Ma, indicating that both magmatism and mineralization occurred during the Early Jurassic. Geochronological and geochemical data, together with the regional geological history, indicate that Early Jurassic magmatism and mineralization of the Maoling gold deposit occurred during the subducting Paleo-Pacific Plate beneath Eurasia, and the Maoling gold deposit is of the intrusion-related gold deposit type.  相似文献   

Identification of functionally active aerobic methanotrophs and their methane oxidation potential in sediments from the Shenhu Area,South China Sea     

Jing Li  Chang-ling Liu  Neng-you Wu  Xiao-qing Xu  Gao-wei Hu  Yan-long Li  Qing-guo Meng 《China Geology》2022,5(2):285-292

Large amounts of gas hydrate are distributed in the northern slope of the South China Sea, which is a potential threat of methane leakage. Aerobic methane oxidation by methanotrophs, significant methane biotransformation that occurs in sediment surface and water column, can effectively reduce atmospheric emission of hydrate-decomposed methane. To identify active aerobic methanotrophs and their methane oxidation potential in sediments from the Shenhu Area in the South China Sea, multi-day enrichment incubations were conducted in this study. The results show that the methane oxidation rates in the studied sediments were 2.03–2.36 μmol/gdw/d, which were higher than those obtained by sediment incubations from other areas in marine ecosystems. Thus the authors suspect that the methane oxidation potential of methanotrophs was relatively higher in sediments from the Shenhu Area. After the incubations family Methylococcaea (type I methanotrophs) mainly consisted of genus Methylobacter and Methylococcaea_Other were predominant with an increased proportion of 70.3%, whereas Methylocaldum decreased simultaneously in the incubated sediments. Collectively, this study may help to gain a better understanding of the methane biotransformation in the Shenhu Area.©2022 China Geology Editorial Office.  相似文献   

超临界态甲烷密度研究     

张新宾  宋党育  李云波  齐永安  范顺利 《煤田地质与勘探》2021,49(1):137-142,150

超临界甲烷密度不仅是非常规天然气资源量计算与吸附能力测定的重要参数,同时也是衡量超临界甲烷扩散效率与溶解有机物能力的主要指标。通过对比分析各种气体状态方程的适用性,认为基于亥姆霍兹能量基本状态方程可以准确计算0~30 MPa、270~360 K条件下甲烷的密度。利用Microsoft Office Excel编写了甲烷密度的计算程序,与NIST （美国国家标准与技术研究院）商业软件计算结果相比,误差小于0.05%。分析了0~100 MPa、270~360 K范围内甲烷密度的变化规律。结果表明,甲烷密度随压力增大而增大,在低于30 MPa时增速较大且对温度的敏感性较强,高于30 MPa时增速逐渐变缓,且敏感性减弱。在煤层原位条件下随着埋深的增大,甲烷密度随温度升高而减小,随压力增大而增大;在温度与压力共同作用下,甲烷密度呈先增速不变、近似线性增加,后增速逐渐减小、凸曲线形增加的变化规律。游离态甲烷密度受温度的影响比吸附态甲烷小,是深部煤层气资源增量的主要贡献者。研究结果为深部煤层气赋存及其潜力预测提供了基础参数。   相似文献