右江盆地含油气成矿流体性质及其成藏-成矿作用

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。     

Physical properties of the triassic host strata and their relations with gold mineralization in Youjiang Rift, South China

Micro-fine disseminated gold deposits are hosted in the Triassic Baipeng Formation (argillaceous siltstone and arenaceous mudstone)in the Youjiang Rift,South China.Physical properties(grain size,specific surface,porosity and permeability)of the host rocks are studied with respect to ore-fluid cirulation,water-rock reaction and the effective volume from which ore-components could be extracted.On this basis,it is considered that the ore-fluid and oremetals were extracted mainly from the strata and hydrothermal solutions,tending to move to wards low-energy sites,depositing their gold in fault zones at the margins of the basin and in the circle fracture systems around underwater uplifts.The gold deposits resulted from the deepcirculation of hydrothermal solutions,Probably aided by multi-stage superimposition The quantites of ore-fluid necessary to form the deposits were estimated.     

鄂尔多斯盆地生烃过程与流体流动及铀矿化关系

鄂尔多斯盆地是我国有机能源矿产重要产区,作为铀成矿省的重要性备受关注。鄂尔多斯盆地铀矿化与烃类的关联性不断被认知,但从盆地流体动力学角度开展的研究鲜见。先前的研究表明,铀矿化在侏罗系上部地层的优先定位机制与还原渗出流和氧化渗入流两种流体系统的混合界面密切相关,混合界面的位置受控于流体超压力与地势差的相互作用。流体超压力...     

江西省金山金矿有机流体与金矿关系

对江西省金山金矿流体包裹体研究表明,矿区发育的包裹体有：①气－液两相盐水溶液包裹体,占包裹体总量８０％～８５％;②纯有机烃类包裹体,占包裹体总量１０％～１５％;③含盐类子矿物多相包裹体,占包裹体总量１％左右;④纯ＣＯ２包裹体（含液态ＣＯ２三相包裹体）,占包裹体总量１％以下。流体时空演化表明,成矿前深大断裂引发深部流体上侵,带来了深部的纯ＣＯ２流体和岩浆期后高盐度流体,伴随后期构造活动,大量向下循环的大气水,不仅温度升高,而且在水－岩交换过程中带来地层中的有机质。在对流体包裹体深入研究的基础上,对成矿流体种类、流体的时空演化,特别是有机流体在成矿中的作用等进行了有益的探索     

Genetic link between Mississippi Valley-Type (MVT) Zn-Pb mineralization and hydrocarbon accumulation in the Nanmushu,northern margin of Sichuan Basin,SW China

The coexistence of Zn-Pb deposits and oil/gas reservoirs demonstrates that a close genetic link between them. The Nanmushu is a large Mississippi Valley-Type (MVT) Zn-Pb deposit discovered on the northern margin of the Yangtze block in recent years. The deposit is hosted in the Ediacaran Dengying Formation dolostone, accompanied by large amount of bitumen in the orebodies. The MVT Zn-Pb deposit overlaps with the paleo-oil/gas reservoir horizontally, and sandwiched in the paleo-oil/gas reservoirs at depth. The Cambrian Guojiaba Formation may have provided not only the oil for paleo-oil/gas reservoirs, but also ore metals for the Zn-Pb mineralization. With increasing burial depth, the Guojiaba Formation may have become more mature to form metal-rich fluids, and the metals migrated and accumulated with hydrocarbons to form a paleo-oil reservoir. Large-scale Zn-Pb mineralization may have occurred in the destruction process of paleo-gas reservoir. With the deep burial of paleo-oil reservoir, the paleo-oil reservoir may have transformed into a paleo-gas reservoir. Decoupling of metals and hydrocarbons during the paleo-gas reservoir formation may have provided the ore metals. Thermal sulfate reduction (TSR) during the paleo-oil/gas reservoirs formation may have provided the hydrogen sulfide for mineralization. Decompression and cooling during the paleo-gas reservoir destruction may have formed extensive metal sulfide precipitation and mineralization.     

两广云开大山地区开合旋回转换与金成矿作用的关系

开合构造是总结地壳或岩石圈水平扩张和压缩运动规律的一种大地构造观点,开合构造旋回代表了地壳或岩石圈的汇聚、离散和平移等宏观构造运动形式,以及由此引发的壳幔物质相互作用、沉积作用、变形与变质作用、熔融或重熔的岩浆活动、构造流体运移的过程。因此,开合构造运动促使地球表层成矿物质活化、迁移、聚集和成矿。对于多数内生金属矿床而言,特别是贵金属矿床,其主成矿期发生在开合构造由压缩向扩张快速过渡转变的时期,油气等非金属矿产则形成于扩张时期。成矿与容矿主断层多数都属于压性或压扭性向张性转换的复杂断层。云开地区自新元古代以来经历了多旋回的开合构造运动,产生了一系列不同期次、不同类型的金银矿床。     

盆地形成及成矿与地幔流体间的成因联系

文中共讨论以下5个问题:(1)盆地起源于幔壳溃变和膨隆,后者是地幔流体(超临界态(>375℃)HACONS流体,简称幔汁)上涌、渗入、交代、富化、致熔的产物。地幔流体造成油气盆地深部的高热流、异常超高压、伊利水云母化、硅化和地层有机碳的加氢成油作用。(2)盆地成矿可分两大阶段,先是沉积时的同生成矿;地层沉积后还有众多的后生成矿。两者组成“盆地矿套”(杜乐天,2002)。成矿无论同生还是后生,其分布均受断裂控制,都和地幔流体活动有关。(3)黑色页岩的实质是碳-硅-泥三元岩系,和热液成矿中的碳酸盐-硅质-泥质蚀变三元完全相当。此类岩系中总是有几十种亲壳亲幔亲气元素的特殊富集。奇异的是,石油、油页岩、沥青及砂岩型铀矿彼此有完全类似的继承性元素特殊富集。此等元素群不可能都是来自盆地之外蚀源区岩体的风化。研究证明,相当多的元素是地幔流体携带上来的。(4)盆地地层中广泛发育由地幔流体衍生的热液作用。(5)盆地实质上是气盆,全盆地排气。许多气田是地幔流体排气形成的。沙漠(原地型)和天然气田的共生很值得注意,两者皆源于地球强烈排气,导致地下和大气增温,过度蒸发,不易降雨,长期干旱而形成沙漠。     

Ore-forming fluids associated with granite-hosted gold mineralization at the Sanshandao deposit, Jiaodong gold province, China

The Sanshandao gold deposit, with total resources of more than 60 t of gold, is located in the Jiaodong gold province, the most important gold province of China. The deposit is a typical highly fractured and altered, disseminated gold system, with high-grade, quartz-sulphide vein/veinlet stockworks that cut Mesozoic granodiorite. There are four stages of veins that developed in the following sequence: (1) quartz-K-feldspar-sericite; (2) quartz-pyrite±arsenopyrite; (3) quartz-base metal sulfide; and (4) quartz-carbonate. Fluid inclusions in quartz and calcite in vein/veinlet stockworks contain C-O-H fluids of three main types. The first type consists of dilute CO₂–H₂O fluids coeval with the early vein stage. Molar volumes of these CO₂–H₂O fluid inclusions, ranging from 50–60 cm³/mol, yield estimated minimum trapping pressures of 3 kbar. Homogenization temperatures, obtained mainly from CO₂–H₂O inclusions with lower CO₂ concentration, range from 267–375 °C. The second inclusion type, with a CO₂–H₂O±CH₄ composition, was trapped during the main mineralizing stages. These fluids may reflect the CO₂–H₂O fluids that were modified by fluid/rock reactions with altered wallrocks. Isochores for CO₂-H₂O±CH₄ inclusions, with homogenization temperatures ranging from 204–325 °C and molar volumes from 55 to 70 cm³/mol, provide an estimated minimum trapping pressure of 1.2 kbar. The third inclusion type, aqueous inclusions, trapped in cross-cutting microfractures in quartz and randomly in calcite, are post-mineralization, and have homogenization temperatures between 143–228 °C and salinities from 0.71–7.86 wt% NaCl equiv. Stable isotope data show that the metamorphic fluid contribution is minimal and that ore fluids are of magmatic origin, most likely sourced from 120–126 Ma mafic to intermediate dikes. This is consistent with the carbonic nature of the fluid, and the cross-cutting nature of those deposits relative to the host Mesozoic granitoid.Editorial handling: R.J. Goldfarb     

Hydrothermal alteration and ore-forming fluids associated with gold-tellurium mineralization in the Dongping gold deposit,China

The Dongping gold deposit hosted in syenites is one of the largest hydrothermal gold deposits in China and composed of ore veins in the upper parts and altered zones in the lower parts of the ore bodies. Pervasive potassic alteration and silicification overprint the wall rocks of the ore deposit. The alteration minerals include orthoclase, microcline, perthite, quartz, sericite, epidote, calcite, hematite and pyrite, with the quartz, pyrite and hematite assemblages closely associated with gold mineralization. The phases of hydrothermal alteration include: (i) potassic alteration, (ii) potassic alteration - silicification, (iii) silicification - epidotization - hematitization, (iv) silicification - sericitization - pyritization and (v) carbonation. Mass-balance calculations in potassic altered and silicified rocks reveal the gain of K₂O, Na₂O, SiO₂, HFSEs and transition elements (TEs) and the loss of REEs. Most major elements were affected by intense mineral reactions, and the REE patterns of the ore are consistent with those of the syenites. Gold, silver and tellurium show positive correlation and close association with silicification. Fluid inclusion homogenization temperatures in quartz veins range from 154 °C to 382 °C (peak at 275 °C–325 °C), with salinities of 4–9 wt.% NaCl equiv. At temperatures of 325 °C the fluid is estimated to have pH = 3.70–5.86, log fO₂ = − 32.4 to − 28.1, with Au and Te transported as Au (HS)₂⁻ and Te₂^2 − complexes. The ore forming fluids evolved from high pH and fO₂ at moderate temperatures into moderate-low pH, low fO₂ and low temperature conditions. The fineness of the precipitated native gold and the contents of the oxide minerals (e.g., magnetite and hematite) decreased, followed by precipitation of Au- and Ag-bearing tellurides. The hydrothermal system was derived from an alkaline magma and the deposit is defined as an alkaline rock-hosted hydrothermal gold deposit.     

四川含油气叠合盆地基本特征

随着近年来四川盆地油气勘探的不断突破,重新审视其基本地质特征和油气成藏特点变得迫切而必要.四川盆地是典型的叠合盆地,显生宙以来经历了震旦纪一中三叠世伸展体制下的差异升降和被动大陆边缘(海相碳酸盐岩台地)、晚三叠世-始新世挤压体制下的摺皱冲断和复合前陆盆地(陆相碎屑岩盆地)、渐新世以来的褶皱隆升改造(构造盆地)3大演化阶...     

四川含油气叠合盆地基本特征

随着近年来四川盆地油气勘探的不断突破,重新审视其基本地质特征和油气成藏特点变得迫切而必要。四川盆地是典型的叠合盆地,显生宙以来经历了震旦纪—中三叠世伸展体制下的差异升降和被动大陆边缘（海相碳酸盐岩台地）、晚三叠世—始新世挤压体制下的褶皱冲断和复合前陆盆地（陆相碎屑岩盆地）、渐新世以来的褶皱隆升改造（构造盆地）3大演化阶段以及晚三叠世（被动大陆边缘→前陆盆地、海相碳酸盐岩—海相碎屑岩、海相碎屑岩→陆相碎屑岩）、晚白垩世（前陆盆地沉降中心的迁移、秦岭构造域→青藏构造域、沉积→部分隆升剥蚀）、始新世（外流盆地→内流盆地、沉积盆地→地貌盆地、沉积→整体隆升剥蚀）3大关键构造变革/沉积转换期。印支期以来,四川盆地受周边多个方向造山带（北缘秦岭造山带、东缘雪峰陆内构造系统、西南缘青藏高原）多期活动影响,形成多组、多期构造的复合—联合叠加。现今盆山构造格局呈现明显的三分性（地貌、基底和构造形迹）,发育突变型和渐变型两类盆山边界。按盆地不同区域盆山结构特征、定型时间和主控因素,可将四川盆地划分为5大盆山结构区： Ⅰ区： 川北突变型盆山结构区（秦岭构造控制域）; Ⅱ区： 川西突变型盆山结构区（青藏构造控制域）; Ⅲ区： 川东渐变型盆山结构区（雪峰构造控制域）; Ⅳ区： 川西南渐变型盆山结构区（青藏—雪峰—基底构造联合控制域）和Ⅴ区： 川中原地隆起—盆地区（基底构造控制域）。四川盆地是我国西部重要的含油富气盆地,勘探潜力巨大。这是由充足的烃源和良好的保存条件所决定的。首先,多阶段盆地叠合演化造就了5套重要的烃源层,总厚度可达1500～2500 m,有机碳含量高,生烃量大,成气率高。其次,中下三叠统膏盐岩的发育对海相油气起了重要的封闭作用,而冲断带—前陆盆地二元结构和隆升剥蚀作用较弱的特点大大增强了突变型盆山结构区的保存条件。此外,晚白垩世以来的隆升作用使古气藏（储气中心）发生调整或破坏的同时,也为现今气藏（保气中心）的形成创造了条件,隆升作用还造成流体跨层流动和天然气爆发式成藏。叠合盆地演化的多阶段性、多组多期构造的复合—联合作用、储层的非均质性和天然气的活动性决定了四川盆地油气勘探的复杂性、长期性和曲折性,同时说明不能用单一的勘探思路、勘探方法和成藏理论来指导整个盆地的油气勘探,即勘探策略也应多样化。     

右江盆地油气成藏与金成矿的时代耦合：Sm-Nd同位素制约

右江盆地二叠系生物礁古油藏的三期油气注入时间分别为237.5～235 Ma、232.5～230 Ma和227.5～185 Ma，其中第三期裂缝充填方解石的Sm-Nd等时线年龄为（182±21） Ma，微细浸染型（卡林型）金矿床成矿流体的活动时限为267～172 Ma。金矿床与古油藏在空间上密切共生、在成矿成藏时间上大致吻合、在成因上一脉相承，它们同是盆地有机成矿流体演化的产物。     

Relationship between the hydrogeochemical environment and sandstone-type uranium mineralization in the Ili basin, China

This paper describes the occurrence and distribution of U within groundwater of the Ili basin in Xinjiang, China. Dissolved major ions, dissolved gases, pH, Eh and salinity in groundwater were employed to distinguish different hydrogeochemical environments and associated processes affecting U transport within the aquifer. The results show that dissolution and deposition of U by groundwater are closely related to reactions with organic C and minerals such as sulfides, carbonates and silicates along groundwater flow paths. Different chemical reactions predominate and account for changes in the occurrence of U in the rock and water of the oxidized zone, the redox transition zone, and the reduced zone. Knowledge of these associations between U and hydrogeochemical environments could enhance the understanding of relationships of groundwater circulation and U mineralization and could have implications for prospecting for sandstone-type U deposits.     

南海南-北陆缘盆地地层沉积发育特征及其对油气成藏的差异性控制

南海作为西太平洋最大的边缘海,油气资源丰富,油气赋存规律的南北差异性大。本文在系统梳理南海中—新生代地层、沉积相发育特征的基础上,对南海南北典型含油气盆地的石油地质条件进行了对比分析。结果认为南海打开过程对古南海沉积地层的改造,使得现有残余地层南北分离,主要分布于北部的珠江口盆地—台西南盆地和南部的礼乐盆地中,推测发育“自生自储”、“新生古储”或“古生新储”的中—新生界油气成藏模式。南海新生代油气藏在“北张、南挤”的构造应力背景下,古近纪以来的古水系控制了大型碎屑岩油气藏的分布;区域构造运动和海平面变化控制了中新世碳酸盐岩油气藏的发育;早新生代以来的古地貌控制的深水峡谷、深海扇、扇三角洲沉积体系孕育了潜在深水油气藏。总之,南海南北地层沉积各有特色,油气成藏条件各有优势,但均有良好的油气勘探前景,本文以期为未来南海油气勘探战略部署和选区提供参考。     

南秦岭旬阳盆地下古生界热水沉积成矿地球化学

新近在南秦岭旬阳盆地志留系中发现重要铅锌矿化,含矿岩系主要是下、中志留统弱变质含炭细碎屑岩和新发现识别出的热水沉积炭硅质岩、钠长石岩等;矿体呈层状与志留系整合产出,含矿层中有热水沉积硅质岩和铁碳酸盐岩.矿床REE地球化学反映铅锌矿石、硅质岩和钠长石岩的形成物质可能来自盆下源深处,成岩成矿作用具有热水沉积性质;岩矿石稳定同位素组成指示成矿流体为深部来源,成矿流体中富含CO2(18.656～35.063mol%),成矿温度135～297℃;矿石S和Pb同位素组成反映S来源于深部,Pb来自盆地基底和沉积地层.受地幔热点控制的扬子北缘古生代伸展海盆中,热水沉积是旬阳盆地志留系铅锌成矿的基本方式.     

CO2-CH4流体与金成矿作用:以阿尔泰山南缘和穆龙套金矿为例

造山型金矿的成矿作用与 H_2O-CO_2流体有着密切的联系。然而对阿尔泰山南缘和穆龙套金矿的流体包裹体研究表明,无水的 CO_2-CH_4流体在中亚成矿域中一些金矿床中具有同样重要意义。阿尔泰山南缘萨热阔布金矿包裹体的 X_(CH_4)达0.20～0.23,穆龙套金矿的 X_(CH_4)为0.07～0.23。CH_4扩大了流体不混溶的范围,有利于对 Au 的富集沉淀。CO_2流体在 Au 成矿中的重要作用至少包括了三方面的意义,即:缓冲流体 pH 值范围、提高流体中的 Au 含量并使其维持与还原硫的络合作用进行迁移;扩大超临界流体的温度范围;增加流体不混溶的区域。CH_4的加入扩大了流体不混溶的范围,有利于对 Au 的富集沉淀。     

Fluid origin and structural enhancement during mineralization of the Jinshan orogenic gold deposit, South China

The Jinshan orogenic gold deposit is a world-class deposit hosted by a ductile shear zone caused by a transpressional terrane collision during Neoproterozoic time. Ore bodies at the deposit include laminated quartz veins and disseminated pyrite-bearing mylonite. Most quartz veins in the shear zone, with and without gold mineralization, were boudinaged during progressive shear deformation with three generations of boudinage structures produced at different stages of progressive deformation. Observations of ore-controlling structures at various scales indicate syn-deformational mineralization. Fluid inclusions from pyrite intergrown with auriferous quartz have ³He/⁴He ratios of 0.15–0.24 Ra and ⁴⁰Ar/³⁶Ar ratios 575–3,060. δ¹⁸O_fluid values calculated from quartz are 5.5–8.4‰, and δD values of fluid inclusions contained in quartz range between −61‰ and −75‰. The δ¹³C values of ankerite range from −5.0‰ to −4.2‰, and ankerite δ¹⁸O values from 4.4‰ to 8.0‰. The noble gas and stable isotope data suggest a predominant crustal source of ore fluids with less than 5% mantle component. Data also show that in situ fluids were generated locally by pervasive pressure solution, and that widespread dissolution seams acted as pathways of fluid flow, migration, and precipitation. The in situ fluids and fluids derived from deeper levels of the crust were focused by deformation and deformation structures at various scales through solution-dissolution creep, crack-seal slip, and cyclic fault-valve mechanisms during progressively localized deformation and gold mineralization.     

南海北部—东海南部中生代盆地演化与油气资源潜力

目前的勘探成果表明,南海北部到东海南部的广阔海域普遍发育中生代地层,但是除了在台西南盆地发现工业油气藏之外,其他地区的中生界尚未有大的勘探突破。本次研究将中生代南海北部—东海南部作为一个整体,开展大地构造背景分析,厘清各构造时期盆地的性质及其形成演化机制,探讨油气资源潜力。结果表明:南海北部—东海南部从晚三叠世到白垩纪整体为一个大型盆地,盆地的演化受其周围板块相互运动所控制;晚三叠世(T₃)主要受特提斯构造域控制,发育被动陆缘边缘海沉积盆地;从早侏罗世(J₁)到早白垩世均受古太平洋板块(伊泽奈崎板块)向欧亚板块俯冲机制的控制,其中早—中侏罗世(J_1-2)发育弧前坳陷盆地,晚侏罗—早白垩世(J₃—K₁)盆地性质为弧后断陷盆地;晚白垩世(K₂)受太平洋板块、欧亚板块和印度板块的联合控制,性质依然为弧后断陷盆地,与前期相比,裂陷强度加大;海水由东南方向侵入,地层垂向上由海相向陆相逐渐过渡,由东南向西北和东北方向,水体逐渐变浅,亦由海相向陆相逐渐演变;中生界在南海北部潮汕坳陷等地区发育深海相和海湾相泥岩,在东海南部基隆坳陷也发育良好的海湾相泥岩,生烃潜力大,具有形成大型油气藏的物质基础和地质条件,勘探潜力巨大。本次研究结果可以为南海北部—东海南部中生界的油气资源勘探提供依据。     

山东夏甸金矿烃类组分特征与幔源流体成矿作用探讨

烃类是成矿流体中的重要气相组分之一,与其他气态组分相比烃类则具有组分多元化和性质稳定的特点,同时烃类各组分间的相关特征和配分规律是成矿流体演化过程(氧化-还原条件、温度、压力等环境因素)的重要参数,因此烃类组分宏观和微观特征可以作为成矿物质来源、成矿流体演化以及流体间混合叠加规律的研究工具和手段.宏观上烃类组分在夏甸金矿不同类型地质体中的含量值差异明显滦家河型花岗岩和硅质岩烃类含量很高,而胶东群变质岩、脉岩、金矿体及矿化蚀变带烃类含量明显偏低;通过烃类组分相关性、配分及比值特征等微观规律研究,可以推测夏句金矿的成矿作用与滦家河型花岗岩不存在直接关系,而与胶东群变质岩和深源的中.基性脉岩具有密切联系,表现出不同类型流体之间的叠加、改造特征,反映了夏甸金矿床乃至整个胶东矿集区具有地幔流体参与并和壳源流体发生不同程度混合,促进成矿物质运移并在合适的条件和构造空间沉淀富集的成矿特点.     

右江盆地含油气流体的物理化学特征

通过对右江盆地二叠系生物礁古油藏流体包裹体的研究,探讨含油气流体的物理化学性质和油气演化程度。结果表明,含油气流体是一种多成分、多相态的不混溶体系,主要组分是有机质、CO2和H2O。成藏流体的温度变化于73~200℃,主要集中于90~160℃,与我国碳酸盐岩生油最佳温度或生油高峰温度一致。含油气流体的盐度低(多小于6%NaCl),密度中等(0.90~1.02 g/cm3),压力为4.2~65.4 MPa,有机组分中CH4占绝对优势,次为C2H6。从含油气流体的演化程度和物理化学特征来看,生物礁型油气藏应是右江盆地油气勘探的重点对象。