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1.
在流体包裹体显微冷热台系统观测基础上,通过显微激光拉曼探针揭示出兰坪中—新生代盆地内金顶及外围矿床成矿主阶段原生流体包裹体含烃富CO_2,成分变化大。流体成分的耦合关系研究,并配合O、C同位素分析认为成矿流体中部分CO_2来自地幔,部分是沉积地层中碳酸盐岩和有机质分解成因,H_2O和烃主要起源于大气成因盆地卤水和地层有机质。地幔源CO_2对贱金属元素的搬运可能贡献突出,而烃类对金属元素的沉淀意义重大。成矿流体成分具有幔源(富CO_2和金属元素)和壳源(盆地流体富烃类和H_2O)两种流体混合的特征,暗示不同性质流体的混合可能是成矿作用基本方式。  相似文献   

2.
右江盆地含油气成矿流体性质及其成藏-成矿作用   总被引:10,自引:5,他引:5  
右江盆地含油气成矿流体是一种多组分、多相态的不混溶体系,成藏流体具低温(多为90~160℃)和低盐度(多小于6wt%NaCl)的特征,其主要组分是有机质、CO2和H2O;金矿成矿流体以中低温(多集中于150~250℃)和低盐度(0.4~6.7wt%NaCl)为特征,其主要组分为H2O和CO2,次为烃类有机组分。盆地内古油藏与金矿床在空间上密切共存,在成藏和成矿流体活动时限上基本一致,在成因上一脉相承,表明两者均为盆地有机成矿流体演化的产物。加里东晚期至印支中期,"盆-台相间"的沉积构造格局为成矿和成藏奠定了物质基础,盆地有机成矿流体的活动使油气和金属分别聚集形成油气藏和金属矿床。印支晚期至燕山早期,伴随褶皱造山作用的盆地流体活动使油气的原始分布格局发生改变,并造成了油气和金属矿床的空间分带。燕山中晚期强烈的构造抬升剥蚀,使油气藏和金属矿床遭受强烈的破坏与改造。  相似文献   

3.
碳酸盐岩的H2CO3溶蚀产生岩溶碳汇,占整个岩石风化碳汇的 94%。西南岩溶区硫酸型酸雨严重,硫酸型酸雨广泛参与碳酸盐岩的溶蚀。H2SO4参与的碳酸盐岩风化是一个大气CO2净释放过程,具有减汇作用巨大。另一方面,岩溶区石灰土壤和地下水具有较高的pH值及盐基饱和度,对H+有巨大的缓冲作用,大气酸沉降在碳酸盐岩地区可能并不会造成地下水的HCO3-和pH降低;相反,较高浓度的SO42-所产生的盐效应和SO2-4与各种阳离子形成的离子对会增大方解石、白云石溶解度,可增强H2CO3对碳酸盐的溶蚀,这可能会使岩溶作用产生更大的碳汇效应。因此,硫酸型酸雨参与碳酸盐岩风化的减汇效应不仅可能被高估,硫酸型酸雨还可能增强碳酸盐岩的H2CO3溶蚀,具有增加岩溶碳汇效应的作用。应结合石灰土壤对大气酸沉降的缓冲容量和阈值及大气酸沉降的H+与土壤中盐基离子的交换量,并综合考虑盐效应、离子对作用、同离子效应,客观评价硫酸型酸雨流经石灰土壤层后对碳酸盐岩溶蚀吸收大气/土壤CO2的影响   相似文献   

4.
Leaking hydrocarbon and associated fluids produce a reduced environment which initiates diagenetic reactions in the rocks and soils overlying hydrocarbon reservoirs. This article introduces mineralogical and geochemical alterations induced by hydrocarbon seepages in the Gachsaran evaporite Formation, Masjed Soleiman, Zagros Folded Belt, SW Iran, using various geochemical methods. X-ray diffraction (XRD) analysis revealed two dominant groups of mineralogical changes in the anomalous zone including: (1) spotty occurrences of jarosite, natroalunite, and sulfur; (2) simultaneous decrease of sulfate and increase of carbonate. The δ13C values of carbonate phases vary between −8.9‰ and −32.3‰ which support a partial contribution of hydrocarbon in these phases. pH measurements of rock samples indicated that hydrocarbon seepage causes decrease of pH, though not very significantly. However, pH in areas that show ongoing sour hydrocarbon seepage among rarely pure gypsum beds decrease to −0.09 which produces acid sulfate soil. Trace element concentrations indicated that Cr, Co, Ni, V, Cd, U, Cu, and Zn increase in various patterns around the hydrocarbon seepages excepting the areas with very low pH.  相似文献   

5.
石膏在有机物厌氧分解中的固碳效应   总被引:2,自引:0,他引:2  
本文以牛肉膏蛋白胨为厌氧微生物的营养源,研究了石膏对厌氧微生物生化系统中甲烷释放量和有机物矿化的影响.根据溶液中总有机碳(TOC)、总无机碳(TIC)、硫酸根、硫化物、pH值以及气体中CO2,CH4和H2S的释放量的观测,以及固体产物的扫描电镜(SEM)、能谱(EDS)、X-射线衍射(XRD)分析结果,探讨了石膏对抑制...  相似文献   

6.
X-ray diffractometer analysis and SEM investigation confirmed the occurrence of jarosite and alunogen minerals in the Quaternary siliciclastic sabkha sediments of northern Kuwait within the Bahrah oilfield area, Arabian Gulf. Jarosite is relatively abundant in a near-surface whitish sticky tidal muddy sand layer about 60 cm thick that overlies the ferruginous sandstone of the Oligo-Miocene Ghar Formation. Jarosite occurs as clusters of euhedral pseudo-cubes of about 1 μm in size and as agglomerated nanoglobules of 250 nm in size. A hypogenetic origin related to the reaction of sulfuric acid produced by the oxidation of H2S associated with hydrocarbon gas seepages with K and Fe leachates is suggested. The restricted occurrence of jarosite within near-surface sabkha sediments may be attributed to limited tidal inundation and prevalence of arid climatic conditions.  相似文献   

7.
油气田微磁异常成因及性质研究的近期进展   总被引:1,自引:0,他引:1  
微磁测量是80年代出现的一种成功的非常规油气勘探方法,它所检测的是与油气渗漏相关的次生磁性矿化作用。近期的大量研究表明,油气田上方的微磁乒常具有复杂多样的成因:(1)从烃类获得代谢能的硫酸盐还原茵的作用;(2)烃类的微生物降解作用;(3)硫化环境中形成的磁黄铁矿;(4)泥质岩中富铁粘土的自生菱铁矿化;(5)与油气源岩露头或油气藏渗漏有关的自燃变质带。此外,烃类在陆相红层中的磁效应可以受到赤铁矿溶离的干扰,使其磁化强度出现数量级的下降。  相似文献   

8.
四川盆地东北部三叠系飞仙关组存在广泛的硫酸盐还原作用,同时地层中也存在锶含量异常高的成岩流体。研究表明:热化学硫酸盐还原作用(TSR)和(或)细菌硫酸盐还原作用(BSR)造成的SO42-离子的消耗对成岩孔隙流体中SrSO4溶解度的改变是三叠系中高Sr成岩流体的形成机制之一,该机制使得孔隙流体从白云石化作用和碳酸盐矿物的新生变形作用中获得的Sr在流体中以高浓度的Sr2+形式存在,并使之在流体中极度富集,这也是四川盆地东北部三叠系中大型和超大型天青石矿床的形成机制之一。H2S和CO2是硫酸盐还原作用的重要产物,不同温度条件下溶于水中的H2S和CO2,与不溶于水的气体分子之间的平衡反应H2S(aq)H2S(g)和CO2(aq)CO2(g)的平衡常数和吉布斯自由能增量计算表明,当温度从25℃升高至220℃时,两个反应的平衡常数分别大致从10增至240和从20增至500,两个反应的平衡常数都始终大于1,说明H2S和CO2更趋向于以气体形式存在,同时温度越高,系统中以气体形式存在的H2S和CO2会越多,溶解于水中的H2S和CO2会越少,因而在深埋藏的高温条件下,H2S和CO2对碳酸盐矿物的溶解能力可能相对很小。相对低温的成岩环境、高温流体的向上和侧向运移、构造抬升、富氧流体与含有H2S流体的混合以及金属硫化物的沉淀是提高含H2S和(或)CO2流体对碳酸盐矿物溶解能力的五个途径。因此,与较早成岩阶段相对浅埋藏环境的碳酸盐溶解作用有关的H2S和CO2流体可能与细菌硫酸盐还原作用(BSR)关系更为密切;断层或其它流体运移通道是高温含有H2S和CO2流体向上运移的基础条件,具有原生孔隙度和渗透率的礁、滩相高能沉积物也是流体发生侧向运移的先决条件;大幅度的构造抬升造成的地层温度降低是提高含H2S和(或)CO2地层流体对碳酸盐矿物溶解能力的重要因素,地壳抬升至近地表造成的古喀斯特作用也可以为H2S的氧化提供良好的地质环境。在有关的勘探中应注意:在断层等流体运移通道造成高温含H2S和CO2流体向上运移的条件下,与之有关的构造低点应该是主要的勘探目标;在燕山运动导致的地层抬升并导致深部热流体降温的条件下,与之有关的构造高点应该是主要的勘探目标,应分别对待。  相似文献   

9.
The Madoonga iron ore body hosted by banded iron formation (BIF) in the Weld Range greenstone belt of Western Australia is a blend of four genetically and compositionally distinct types of high-grade (>55 wt% Fe) iron ore that includes: (1) hypogene magnetite–talc veins, (2) hypogene specular hematite–quartz veins, (3) supergene goethite–hematite, and (4) supergene-modified, goethite–hematite-rich detrital ores. The spatial coincidence of these different ore types is a major factor controlling the overall size of the Madoonga ore body, but results in a compositionally heterogeneous ore deposit. Hypogene magnetite–talc veins that are up to 3 m thick and 50 m long formed within mylonite and shear zones located along the limbs of isoclinal, recumbent F1 folds. Relative to least-altered BIF, the magnetite–talc veins are enriched in Fe2O3(total), P2O5, MgO, Sc, Ga, Al2O3, Cl, and Zr; and depleted in SiO2 and MnO2. Mafic igneous countryrocks located within 10 m of the northern contact of the mineralised BIF display the replacement of primary igneous amphibole and plagioclase, and metamorphic chlorite by hypogene ferroan chlorite, talc, and magnetite. Later-forming, hypogene specular hematite–quartz veins and their associated alteration halos partly replace magnetite–talc veins in BIF and formed during, to shortly after, the F2-folding and tilting of the Weld Range tectono-stratigraphy. Supergene goethite–hematite ore zones that are up to 150 m wide, 400 m long, and extend to depths of 300 m replace least-altered BIF and existing hypogene alteration zones. The supergene ore zones formed as a result of the circulation of surface oxidised fluids through late NNW- to NNE-trending, subvertical brittle faults. Flat-lying, supergene goethite–hematite-altered, detrital sediments are concentrated in a paleo-topographic depression along the southern side of the main ENE-trending ridge at Madoonga. Iron ore deposits of the Weld Range greenstone belt record remarkably similar deformation histories, overprinting hypogene alteration events, and high-grade Fe ore types to other Fe ore deposits in the wider Yilgarn Craton (e.g. Koolyanobbing and Windarling deposits) despite these Fe camps being presently located more than 400 km apart and in different tectono-stratigraphic domains. Rather than the existence of a synchronous, Yilgarn-wide, Fe mineralisation event affecting BIF throughout the Yilgarn, it is more likely that these geographically isolated Fe ore districts experienced similar tectonic histories, whereby hypogene fluids were sourced from commonly available fluid reservoirs (e.g. metamorphic, magmatic, or both) and channelled along evolving structures during progressive deformation, resulting in several generations of Fe ore.  相似文献   

10.
造山型金矿是全球重要的金矿类型。造山型金矿包含三种类型:产于绿岩带的含金石英碳酸盐脉、产于浊积岩中的含金石英脉和产于条带状铁矿(BIF)中的含金石英脉。造山型金矿的形成受板块构造控制,处于压缩或者转换挤压的造山构造环境。造山型金矿中的绿岩带金矿主要受剪切带、转换断层控制,浊积岩型金矿受褶皱和层间走滑断层控制,而赋存于BIF中的金矿则受剪切带和断层所控制。在这些金矿床中发现了4类流体包裹体:H_2O-CO_2型、富CO_2型、气液包裹体和含Na Cl子矿物的包裹体。所有年代的造山型金矿成矿流体的成分均为低盐度的水溶液和富CO_2的流体,温度在200~400℃范围内。稳定同位素研究表明造山型金矿的成矿流体源自变质流体和岩浆流体。金在成矿流体中的络合物应为Au HS~-或Au H_2S。虽然成矿流体中有丰富的CO_2,但Au在CO_2流体中的溶解度很低,有丰富的CO_2时Au在H_2S中的溶解度增大。流体包裹体研究表明,Au的成矿流体是Na Cl-H_2O-CO_2体系的流体,并在成矿过程中发生了相分离,即Na Cl-H_2O-CO_2流体分成两个流体:H_2O-Na Cl和CO_2-H_2O,Au的沉淀是在这种相分离过程中发生的。  相似文献   

11.
刘铁庚  龚国洪  叶霖 《矿物学报》1995,15(3):286-290
锌水绿矾产于陕西省南部红土石黄铁矿矿床氧化带。集合体呈钟乳状或皮壳状,单晶为短柱状和不规则粒状,极易溶于水。颜色为黄绿色或翠绿色。主要化学成分:ZnO16.35%,FeO8.86%,SO328.30%,H2O44.33%。分子式为(Zn,Fe)SO4·7H2O。主要X射线粉晶谱线是:0.4880(100),0.2739(80),0.5439(30),0.3225(30)和0.2476(30)um。它的化学成分和粉晶数据均与水绿矾(FeSO47H2O)或人工合成的锌水绿矾相似。  相似文献   

12.
Groundwater of the southern Jornada del Muerto Basin, an intermontane basin structure associated with the Rio Grande rift located in south-central New Mexico, USA, was analyzed chemically and microbially. A microbial phospholipid fatty acids (PLFA) analysis revealed a sparse microbial population consisting of relatively simple microorganisms with no major population changes along the flow system. A nucleic acid (DNA) analysis of the groundwater resulted in the identification of ten eubacterial and one archeal species. Chemical analyses revealed that sulfate along with calcium, magnesium, iron, and manganese is removed by about an order of magnitude in concentration from the recharge area to the discharge area. The removal of iron, manganese, magnesium, and to some extent calcium can be explained by oxidation reactions and the precipitation of dolomite. Sulfate and additional calcium are most likely removed by the precipitation of gypsum. Thiobacillus spp. are oxidizing metal sulfides that occur as subsurface sulfide mineral deposits to sulfuric acid, which subsequently reacts with calcium carbonate and water to precipitate gypsum. The presence of these sulfide deposits exposed to oxygenated water in the deep groundwater flow system significantly alters its chemical and bacteriological composition. Electronic Publication  相似文献   

13.
伊梨盆地512层间氧化带型砂岩铀矿床是中国第一个工业化规模开发的地浸铀矿床,作者简要地介绍了其地质特征和地浸开发工艺,并利用较新的Gibbs自由能和平衡常数数据,对该矿床地浸处理中铀的地球化学行为进行了定量研究。首先,通过标准电动势(E^o),氧化-还原电位(Eh)的计算和分析,阐明了H2O2、硝酸盐、大气中自由氧都能提升溶液的Eh值,从而加速矿物相U^4 的氧化溶解,为了节约地浸氧化剂成本,对于U^4 /U^6 比值不太高的矿床来说,建议充分利用大气中自由氧化氧化剂,然后,通过化学平衡计算,推导出了地下水和硫酸浸出液中铀存在形式的计算公式,计算结果表明:(1)512铀矿床矿体所赋存的含矿层地下水中,铀主要以碳酸铀酰类络合物形式存在,并且以UO2(CO3)^4-3和UO2(CO3)^2-2形式为主,并随着pH从7.31升高到8.20,UO2CO3从3.80%降低到0.06%,UO2(CO3)^2-2从21.91%降低到3.12%,而UO2(CO3)^4-3则从74.28%升高到96.82%,(2)512铀矿床硫酸浸出液中,铀主要以硫酸铀酰类络合物形式存在,其中,UO2SO4占63.28%~ 63.86%,UO2(SO4)^2-2占16.55%~21.36%,UO^2 2占15.04%~19.62%,从推导出的计算公式可以看出,硫酸浸出液中铀的存在形式随溶液pH、总SO^2-4含量的变化而变化,并呈非线性关系,为了提高离子交换树脂的吸附性能,可利用文中推导出的公式进行计算,以使调节溶浸液的pH和总SO^2-4含量,从而达到浸出液中铀存在形式的最佳比例关系,最后,因热力学数据对化学反应平衡计算的影响呈指数关系,在进行热力学数据计算时,必须采用较新、较准确的数据。  相似文献   

14.
Hypogenic caves, developed by sulphuric acid speleogenesis, are known all over the world among which the Santa Cesarea Terme caves have been included. They are four submerged caves, located along a coastal carbonate sector in Southern Italy and hosting the outflow of coastal springs of thermal mixed waters (from 21 to 33 °C). These waters derive from the mixing of three water end members: the fresh pure groundwater of a wide karstic aquifer, the deep sulphur thermal water and the seawater. This cave system represents an almost unique case of hypogenic sea caves in carbonate environment. The thermal mixed waters have a different effect on the surrounding rocks of the caves, influencing the sulphuric acid speleogenetic process within the whole cave system. To understand the complex and overlapping natural processes acting on the development of these coastal caves, a multidisciplinary study has been carried out. This study has integrated all the data resulting from different methods and technologies, merging morphology, structural geology, hydrogeology, hydrogeochemistry and mineralogy. This multidisciplinary study has allowed to define the main geochemical processes acting within these caves, including the cave development and the formation of the mineral concretions. After the introduction of H2S in the thermal waters, formed by the reduction of sulphates in the sedimentary deposits crossed at depth in the offshore, the oxidation occurs within the caves, producing sulphuric acid. Favoured by upwelling deep-seated thermal flows, this acid dissolves the limestone, with condensation corrosion process that involve replacement of limestone rock with gypsum. This process has resulted to be more active and remarkable within the Gattulla Cave, one of the Santa Cesarea Terme sea caves.  相似文献   

15.
The ~2,752-Ma Weld Range greenstone belt in the Yilgarn Craton of Western Australia hosts several Fe ore deposits that provide insights into the role of early hypogene fluids in the formation of high-grade (>55 wt% Fe) magnetite-rich ore in banded iron formation (BIF). The 1.5-km-long Beebyn orebody comprises a series of steeply dipping, discontinuous, <50-m-thick lenses of magnetite–(martite)-rich ore zones in BIF that extend from surface to vertical depths of at least 250 m. The ore zones are enveloped by a 3-km-long, 150-m-wide outer halo of hypogene siderite and ferroan dolomite in BIF and mafic igneous country rocks. Ferroan chlorite characterises 20-m-wide proximal alteration zones in mafic country rocks. The magnetite-rich Beebyn orebody is primarily the product of hypogene fluids that circulated through reverse shear zones during the formation of an Archean isoclinal fold-and-thrust belt. Two discrete stages of hypogene fluid flow caused the pseudomorphic replacement of silica-rich bands in BIF by Stage 1 siderite and magnetite and later by Stage 2 ferroan dolomite. The resulting carbonate-altered BIF is markedly depleted in SiO2 and enriched in CaO, MgO, LOI, P2O5 and Fe2O3(total) compared with the least-altered BIF. Subsequent reactivation of these shear zones and circulation of hypogene fluids resulted in the leaching of existing hypogene carbonate minerals and the concentration of residual magnetite-rich bands. These Stage 3 magnetite-rich ore zones are depleted in SiO2 and enriched in K2O, CaO, MgO, P2O5 and Fe2O3(total) relative to the least-altered BIF. Proximal wall rock hypogene alteration zones in mafic igneous country rocks (up to 20 m from the BIF contact) are depleted in SiO2, CaO, Na2O, and K2O and are enriched in Fe2O3(total), MgO and P2O5 compared with distal zones. Recent supergene alteration affects all rocks within about 100 m below the present surface, disturbing hypogene mineral and the geochemical zonation patterns associated with magnetite-rich ore zones. The key vectors for identifying hypogene magnetite-rich Fe ore in weathered outcrop include textural changes in BIF (from thickly to thinly banded), crenulated bands and collapse breccias that indicate volume reduction. Useful indicators of hypogene ore in less weathered rocks include an outer carbonate–magnetite alteration halo in BIF and ferroan chlorite in mafic country rocks.  相似文献   

16.
Calcite/opal deposits (COD) at Yucca Mountain were studied with respect to their regional and field geology, petrology and petrography, chemistry and isotopic geochemistry, and fluid inclusions. They were also compared with true pedogenic deposits (TPD), groundwater spring deposits (GSD), and calcite vein deposits (CVD) in the subsurface. Some of the data are equivocal and can support either a hypogene or pedogenic origin for these deposits. However, Sr-, C-, and O-isotope, fluid inclusion, and other data favor a hypogene interpretation. A hypothesis that may account for all currently available data is that the COD precipitated from warm, CO2-rich water that episodically upwelled along faults during the Pleistocene, and which, upon reaching the surface, flowed downslope within existing alluvial, colluvial, eluvial, or soil deposits. Being formed near, or on, the topographic surface, the COD acquired characteristics of pedogenic deposits. This subject relates to the suitability of Yucca Mountain as a high-level nuclear waste site.  相似文献   

17.
The Arabshah kaolin deposit (Takab geothermal field, NW Iran) is the product of alteration of Miocene dioritic rocks. According to mineralogical data, the rock-forming minerals in this deposit include kaolinite, quartz, muscovite-illite, pyrophyllite, accompanied by lesser amounts of rutile, chlorite, anatase, albite, gypsum, nontronite, and pyrite. Consideration of elemental ratios and geochemical indices such as TiO2, Nb + Cr, Ti + Fe, Sr + Ba, and La + Ce + Y demonstrated that both hypogene and supergene processes played a significant role in the development of this deposit. The mass change calculations revealed that elements like Zr, Ga, Hf, REEs, and Th which are normally immobile in ordinary alteration processes had both incremental and decremental trends during the development of this deposit. The Eu and Ce anomaly values (normalized to chondrite) in kaolinized samples vary within the range of 0.65–1.13 and 0.91–1.05, respectively. It seems that the variation of negative Eu anomaly values was controlled by kaolinization of feldspars by hypogene solutions and by scavenging of this element by Fe oxides and hydroxides (formed during oxidation of hypogene pyrite by supergene solutions). Variation of Ce anomalies also unravels the effective role of reducing hypogene fluids and to some extent of supergene solutions during kaolinization. Combination of the results obtained from mineralization considerations, mass change calculations of elements, and correlation coefficients illustrate that distribution and concentration of major, minor, and rare earth elements during kaolinization at Arabshah were affected by the function of factors such as changes in physico-chemical conditions of altering solutions (e.g., Eh and pH), adsorption, accessibility to complex-forming ligands, water-rock ratios, existing in resistant (to alteration) mineral phases, and scavenging by Fe and Mn oxides.  相似文献   

18.
Hydrocarbons, native sulfur, Mississippi Valley-type (MVT) deposits, and sulfuric acid karst in the Delaware Basin, southeastern New Mexico, and west Texas, USA, are all genetically related through a series of sulfur redox reactions. The relationship began with hydrocarbons in the basin that reacted with sulfate ions from evaporite rock to produce isotopically light ( 34S = -22 to -12) H2S and bioepigenetic limestone (castiles). This light H2S was then oxidized at the redox interface to produce economic native sulfur deposits ( 34S = -15 to +9) in the castiles, paleokarst, and along graben-boundary faults. This isotopically light H2S also migrated from the basin into its margins to accumulate in structural (anticlinal) and stratigraphic (Yates siltstone) traps, where it formed MVT deposits within the zone of reduction ( 34S = -15 to +7). Later in time, in th zone of oxidation, this H2S reacted with oxygenated water to produce sulfuric acid, which dissolved the caves (e.g., Carlsbad Cavern and Lechuguilla Cave, Guadalupe Mountains). Massive gypsum blocks on the floors of the caves ( 34S = -25 to +4) were formed as a result of this reaction. The H2S also produced istopically light cave sulfur ( 34S = -24 to -15), which is now slowly oxidizing to gypsum in the presence of vadose drip water.  相似文献   

19.
对浙江遂昌地区所发现的金(银)矿床之矿物包裹体研究表明,其均一化温度多集中在140~260℃,成矿压力(0.2~0.6)×102MPa,气液比在5%~27%。成矿流体为液态,矿液中主要有Au,Ag,Cu,Pb,Zn,Bi,K,Na,Ca,Si.Mg,H2O,CO2.Cl,F,S,Mn,Li.Ti,Cr,Co,Ni等组分。成矿时的含矿流体呈弱酸性─中性(pH4.56~5.14),盐度较高(NaCl(20~32)wB%).根据这些特征,并综合其产出的大地构造环境及成矿地质条件,认为该区所产出的金(银)矿床在成因上属地洼型火山─次火山中(─低)温热液矿床。  相似文献   

20.
玄武岩油气藏储层一方面含有大量可与CO2 反应生成碳酸盐的造岩矿物,另一方面又有枯竭油气藏的良好储(储集
空间)、运(运移通道)、盖(盖层条件)和保(保存能力)等 CO2 封存优势,是潜力大、实施易、成本低和安全性高的碳
汇靶区。该文选取了位于松辽盆地东北部的徐家围子断陷玄武岩气藏开展CO2 封存潜力研究,在对该气藏地质特征和储层
发育特征详细描述的基础上,结合玄武岩矿物组成和化学成分的鉴定分析结果,探讨该气藏的矿物固碳能力和油气储层固
碳能力,并对其封存CO2 的可行性进行了初步评价。研究表明,徐家围子断陷玄武岩气藏有着良好的储集空间,且易碳酸
盐化,其盖层可阻止所充注CO2 的逸散,稳定的圈闭条件可保证所充注CO2 的安全性,因而是CO2 封存的理想靶区。初步的
定量计算结果表明,徐家围子断陷玄武岩油气藏的矿物固碳潜力约为89.33×108 t,油气储层的封存能力约为6.2×108 t,总
计约95.53×108 t,具有十分可观的固碳潜力。  相似文献   

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