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1.
试论火山岩油气藏成藏机理 总被引：24，自引：3，他引：21
全球100多个国家/地区在火山岩内或其周围发现了油气藏或油气显示,展示了火山岩油气藏勘探的广阔前景。火山岩已从油气勘探的"禁区"转变为了"靶区",成为油气勘探的新目标。火山岩储集物性较好,其本身可直接作为储层,各类侵入体与围岩相互作用还可形成与火成岩有关的圈闭。火山岩油气藏的烃源包括有机成因和无机成因两种。火山作用可以明显提高烃源岩内有机质的成熟度,加快烃的产生,促进油气运移,并为无机成因烃提供合成原料(CO_2和H_2等)和运移通道。虽然火山岩在盆地早期尤为发育,约占盆地充填体积的1/4,但是目前火山岩油气储量仅占世界油气探明储量的1%左右,勘探潜力巨大。中国沉积盆地内发育不同时代火山岩,火山岩储层与烃源岩匹配较好,无机成因气来源丰富,火山岩油气藏正在成为我国油气勘探的重要领域之一。 相似文献
2.
新疆北部早石炭世沉积建造及其形成的大地构造环境 总被引：1，自引：0，他引：1
张琴华 《大地构造与成矿学》1991,15(2):128-136
本文详细地研究了新疆北部早石炭世发育的三类沉积建造:碳酸盐建造、陆屑建造和火山-沉积建造,并进行了建造区的划分,据此论述了早石炭世新疆北部的大地构造环境及其分区。 相似文献
3.
燕山中段 (主要是指北京市平谷县内 )大红峪组火山岩 ,在火山活动的间歇期 ,存在古风化现象。古风化使火山岩的成分、结构遭受改变 ,以致影响对岩石岩性的确定及同位素年龄的测定等。不同的地质环境 ,其风化情景不同。文中论述了火山岩的三种风化带及其不同的风化环境特征 ,并与现代风化带进行了对比。研究大红峪组的古风化现象 ,有利于更好地认识当时的地质环境。 相似文献
4.
突出山铜铁矿床赋存于上石炭统底坎尔组火山岩中, 地质特征表明矿床成因为火山热液交代型。矿区玄武岩具有高Al、Na, 贫K、P、Ti的特点, 属于钙碱性系列火山岩。岩石具有轻稀土元素、大离子亲石元素相对富集和高场强元素相对亏损的特点。微量元素特征表明岩石与俯冲带流体作用有关, 经历了橄榄石(±辉石)和铬铁矿的结晶分异作用, 形成于石炭纪弧后盆地环境, 指示铁矿床的成矿环境为弧后盆地环境。矿区闪长岩和钾长花岗岩的锆石LA-ICP-MS U-Pb谐和年龄分别为326.2±1.6 Ma与318.2±2.5 Ma, 均为石炭纪岩浆活动的产物。根据闪长岩、钾长花岗岩、矿体与底坎尔组火山岩的穿插关系, 限定矿床的铁成矿作用时间为底坎尔组火山岩的形成时代, 早于闪长岩的形成时代(326 Ma), 而铜成矿作用时间与闪长岩的形成时代相近或稍晚。 相似文献
5.
《International Geology Review》2012,54(11):1027-1047
New geological and petrological data on the range of magmatic complexes and formations of the Eastern Sayan show two primary magmas: basic and granitoid. These magmas were formed through melting hard deep-seated layers of the earth crust: basaltic and sialic. During the geosynclinal stage the development of magmas belonging to the Archean, Proterozoic, and Salair [Cambrian] volcanic cycles proceeded consecutively from ultrabasic and basic formations formed in a pre-orogenic or earlier-orogenic geosynclinal development stage to granitoids set up in a synorogenic or later-synorogenic development stage. During the platform stage middle Paleozoic (Lower Devonian) and Mesozoic-Cenozoic cycles of magmatism proceeded directly, without the geosynclinal preparatory stage. Their development, accompanied by faulting, proceeded in reverse order from acidic and alkalic intrusions to predominantly basic eruptives. A further development of deep-seated basic and granitoid magmas was determined first by magmatic differentiation and later by assimilation phenomena which took place during the magma's passage into upper structural layers. The granitoids of geosynclinal magmatic complexes correspond petrochemically to the intermediate types of calc-alkalic rocks of the Pacific Ocean belt. The granitoids and alkalic rocks of the Lower Devonian platform magmatic complex resemble those of the Cenozoic East-Asia alkalic province. The composition of the granitoid magma belonging to the volcanic cycle is conditioned initially chiefly by the sial environment and geosynclinal strata. Magmatic complexes and formations are characterized by definite endogenic mineralizations. Chromium, nickel, cobalt, platinum, diamond, asbestos and other deposits are genetically connected with Proterozoic basic and ultrabasic rocks; gold, muscovite and tin-rare metal pegmatite with upper Proterozoic granitoids. Copper, galenaite and gold-ore occurrences are related to the postmagmatic manifestations of Salair granitoids. Deposits of pyrochlore carbonatites, molybdenite, graphite and others belong to Lower Devonian acidic and alkalic granitoids. — Auth. English summ. 相似文献
6.
大兴安岭火山喷发带北段中性、中酸性火山岩地球化学特征及其地质意义 总被引：11，自引：0，他引：11
通过对大兴安岭北段晚侏罗世吉祥峰组中酸性火山岩的岩石地球化学研究,发现其中存在高Sr低Y型火山岩,即文献上所称的埃达克质岩,笔者认为中酸性火山岩的岩浆起源于下地壳玄武质岩浆,为玄武质岩浆底辟上侵引起地热梯度增加、下地壳中-基性变质火成岩石部分熔融的之混合岩浆,是古太平洋板块向西伯利亚板块斜向俯冲过程中,蒙古-鄂霍次克海槽封闭,陆壳碰撞使地壳加厚,形成兴蒙造山带时所引起的一系列构造岩浆活动。其形成时的构造环境应是在滨太平洋构造域背景下受古亚洲构造域的影响和限制,并非是滨太平洋构造活动带的单一活动所致。早白垩世上库力组酸性火山岩属陆壳重熔型(S型)火山岩,其形成可能与印度-澳大利亚板块朝北偏东方向推挤运移、中国东部岩石圈拉张引起的下地壳拆沉作用有关。 相似文献
7.
沱沱河盆地是冻土天然气水合物潜在分布区之一,其内发育下—中二叠统开心岭群九十道班组、上二叠统乌丽群那益雄组、上三叠统结扎群巴贡组、中—渐新统雅西措组4套烃源岩以及不同类型的火山岩。研究表明,火山岩岩石类型主要为玄武岩、玄武安山岩、安山岩、玄武质粗面安山岩和粗面安山岩。火山岩主量元素低TiO_2,Al_2O_3含量较高,K_2O含量较低,K_2ONa_2O;火山岩的稀土元素配分模式为轻稀土富集型;微量元素配分模式呈锯齿状,Ta、Nb、P_2O_5、TiO_2、Y、Yb以及铁族元素Sc、Cr、Ni亏损,综合判断青海南部沱沱河地区火山岩形成于岛弧环境。结合火山岩的地球化学特征,推断火山活动可以加快烃源岩的热成熟,进而促使有机质裂解,产生热解气,为水合物的生成提供气源条件。同时,火山岩的气孔构造发育,连通性较好,有可能成为水合物的储层。火山热液具有的高压使周围的烃源岩产生裂隙,这些裂隙不仅是水合物气源的运移通道,还可以为水合物提供形成场所和储存空间。 相似文献
8.
V. F. Saltykov 《Lithology and Mineral Resources》2009,44(4):339-347
Distribution of polymorphs of aluminum hydroxides within an ore lode of allophone-gibbsite rocks of the Volga region has been studied and compared with the results of experimental research on the behavior of aluminum in diluted solutions. The XRD study of morphology and crystallinity of gibbsite confirmed trends noted by Ershova et al. (1979) for the lateritic-sedimentary bauxite series. In these rocks, bayerite and nordstrandite are typically secondary minerals with respect to gibbsite. In the rocks studied, bayerite and nordstrandite form at the early diagenetic stage that leads to decrease of gibbsite crystallinity. The crystallization model of minerals during the formation of the allophone-gibbsite rocks of the Volga region is proposed. 相似文献
9.
《International Geology Review》2012,54(12):1537-1543
Granitic magmas result from refusion of sedimentary rocks. Metals associated in gold ore formations are mobilized by magmatic and etamorphic activity from volcanic and sedimentary rocks of a geosynclinal series. The comportment of metals during the processes of mobilization, transfer, and deposition is ruled by their atomic structure and electromagnetic properties. Ionic density (di) and concentration coefficient (Cs/Cv) of the metals are chosen as coordinates for plotting the associations of metals of different gold ore formations. The degree of complexity of the associations is a consequence of the degree of heterogeneity of the geosynclinal rock series and of the intermittence or telescoping of the ore deposition process. — B.V. Brajnikov. 相似文献
10.
秦苏保 《大地构造与成矿学》1989,13(3):250-257
研究表明,本区现阶段的构造分区为:天山地洼区,准噶尔地洼区和阿尔泰地洼区,各区演化、发展各具特征,表明地壳演比的不平衡性和差异性,石炭—二叠纪分别处于地槽发展前期和后期,二者无论在沉积环境、古地理条件,还是在构造型式、岩浆活动强度上都存在明显的差异。前期形成的聚煤盆地属海相环境,受近东西、北西西向地槽构造系的控制,火山话动强烈,系典型的优地槽沉积;后期形成的聚煤盆地属海陆交替相、陆相环境,为山间坳陷型盆地,受地槽褶皱山系的控制,以快速升降运动和快速堆积为特色,盆地中沉积了巨厚的磨拉式建造。石炭—二叠纪的沉积环境和构造条件不利于聚煤作用的发生和持续进行,致使海盆边缘和陆盆中未能形成良好的含煤岩系。因此,新疆北部地槽区与华北地合区相反,石炭—二叠纪不是理想的成煤时期,地槽期的海盆和地槽褶皱带期的山间坳陷也不是理想的聚煤盆地,这为该区的大地构造条件所决定。 相似文献
11.
鞍山、本溪地区鞍山群变质岩岩石化学研究及条带状铁矿的成矿条件 总被引：3，自引：0，他引：3
通过对鞍山群变质岩石及条带状铁矿的岩石化学研究,探讨了鞍本地区太古宙老变质岩(正变质岩为斜长角闪岩及中酸性变粒岩等;副变质岩主要为泥质—泥灰质岩及硅铁质胶体化学沉积岩石)岩石学特征,并恢复变质前之原岩建造。太古宙条带状铁矿石的化学成分较单一;SiO_2、Fe_2O_3、FeO之和为85—95％,是一种成分很纯的磁铁矿石。作者从矿体的产状呈层;与围岩之间基本整合;条带状构造所显示的原生层理;铁矿石成分简单以及在世界上的分布情况表明它是海底火山沉积矿床。本文基于铁矿成因和与原岩建造的关系,进而讨论了铁矿的赋存 相似文献
12.
1. The division of main tectonic regions and their minerogenetic belts. In quite a few fold zones of geosynclinal systems, such as Altay, Junggar, Tianshan, Kunlun and Beishan Mountains, there exist ore zones of rare metals, muscovite, Fe, Cr, Mn, Au, P, asbestos, nonferrous metals, etc., whereas in Tarim platform, Fe, Al, Zn, Cr, P, S, Cu and coal minerogenetic belts have already been found. 2. Minerogenetic relations between major types of ore deposits and magmatic series, sedimentary formation, or metamorphic facies. Cr, Cu, Ni, Co, Fe and rare metals of magmatic type are related to magnesian ultrabasic, ferruginous basic-ultrabasic or acid-alkaline rocks, nonferrous and noble metals, Fe and asbestos of hydrothermal type are found associated with acid, intermediate-acid intrusive rocks generally rich in alkali; rare metals and muscovite of pegmatitic type are genetically in connection with acid-alkaline rocks, Fe of volcanic type has to do with alkali-rich acid to basic eruptive rocks, coal, Fe, Mn, Al, Cu, Pb, Zn, P and S of sedimentary type occur mostly in clastic carbonate-rocks, siliceous carbonate rocks, detrital rocks, red beds, salt-bearing or coal-bearing formations, Fe, P of sedimentary-metamorphic type are preserrt: within such metamorphic facies as ferro-siliceous hornblendite, green schist-marble or siliceous-magnesian carbonatite. 3. Regularity of the formation and distribution of ore deposits. The formation and distribution of ore deposits are generally characterued by zoning, fault-controlling, polycycles, stratabinding, inheritance, regeneration, ore combination, equidistance, migration and superimposition, with individual ore deposit having its specific characteristics. 相似文献
13.
中国石炭纪铝土矿的地质特征与成因 总被引：8，自引：0，他引：8
世界石炭纪铝土矿主要产于中国,其形成条件因当时处于湿热的热带地区,构造长期稳定,准平原化排水条件好,强烈的化学及生物风化后产物经水流短程搬运,成胶体及碎屑不同程度兼有的混合沉积;往往经多次的震荡运动或地震活动成内碎屑浊流沉积;还遭受成岩、后生、表生及后期风化作用等的改造,而富集成矿。其中硬水铝石及地开石一般不形成于氧化的风化壳,主要是还原的成岩后生作用转变的,固相转化的氧同位素组成仍可具有“红土性质”或“风化壳性质”的保存性。 相似文献
14.
Atsuyuki Ohta Noboru ImaiShigeru Terashima Yoshiko TachibanaKen Ikehara Hajime KatayamaAtsushi Noda 《Applied Geochemistry》2010
In all, 53 elements were analyzed in 1406 coastal sea sediment samples collected from an area off Hokkaido and the Tohoku region of Japan during a nationwide marine geochemical mapping project. The spatial distribution patterns of the elemental concentrations in coastal seas along with the existing geochemical maps in terrestrial areas were used to define natural geochemical background variation and mass transport processes. The terrestrial area is covered by mafic volcanic rocks and accretionary complexes associated with ophiolite, which has small amounts of felsic volcanic rocks and granite. The spatial distribution patterns of elements enriched in mafic lithologies such as Fe (Total Fe2O3) and Sc in marine environments are influenced by adjoining terrestrial materials. The spatial distribution patterns of Cr and Ni concentrations, which are highly abundant in ultramafic rocks on land, are used to evaluate the mass transport from land to the sea and the dispersive processes caused by oceanic currents. The scale of mass transport by oceanic currents occurs up to a distance of 100–200 km from the coast along the coastal areas. The regional differences of elements rich in felsic lithologies such as K (K2O), Nb and La in marine sediments are determined mainly by the relative proportion of minerals and lithic fragments enriching felsic materials to those associated with mafic materials. The spatial distribution of elemental concentration is not always continuous between the land areas and coastal sea areas. That difference is interpreted as resulting from (1) transportation of marine sediments by oceanic currents and storm waves, (2) contribution of volcanic materials such as tephra, (3) occurrence of shell fragments and foraminifera tests and (4) distribution of relict sediments of the last glacial age and early transgression age. Contamination with Cu, Zn, Cd, As, Mo, Sn, Sb, Hg, Pb and Bi was not observed in marine environments because the study area has little anthropogenic activity. Terrestrial materials are the dominant source for these metals. The Mo, Cd, Sn, Sb, Hg, Pb and Bi are abundant in silty and clayey sediments locally because of early diagenetic processes, authigenic precipitation and organic substances associated with these elements. The spatial distribution of As concentration shows exceptions: it is concentrated in some coarse and fine sands on the shelf. The enrichment is explained by adsorption of As, sourced from a coal field, to Fe hydroxide. 相似文献
15.
对升平气田白垩系营城组火山岩岩石学与物性特征、储集空间类型及其形成和演化等研究结果表明,火山岩岩石类型主要有火山碎屑岩、火山熔岩和沉火山岩,以流纹岩为主,少量英安岩、安山岩。火山岩气藏储集空间以次生溶孔(洞)为主,其次为原生孔隙和裂缝。火山岩的演化过程可划分为前期和后期两个阶段。前期阶段以火山自身活动为主,主要形成气孔和火山角砾间孔为主的原生孔隙;后期阶段包括火山熔岩的冷凝作用与火山岩的后生成岩作用,是火山岩储集空间形成的主要时期。研究区风化剥蚀面、断层与裂缝是天然气成藏的主要运移通道,也是有利的储集空间。 相似文献
16.
四川石棉-冕宁地区之伸展构造 总被引：1，自引：0，他引：1
研究区在中生代造山过程中,以穹隆状变形变质体发育为特征。可分为岩浆核杂岩和变质核杂岩。前者位于地槽区,具前造山期隆—滑构造变形、造山期和后造山期的收缩及伸展变形的演化,与碲矿关系密切后者位于地台区,经历了伸展滑脱、逆冲—推覆和平移剪切变形过程,对区内金矿的形成、分布起重要控制作用。 相似文献
17.
山西本溪组铝土矿成矿条件及成矿规律探讨 总被引：3，自引：0，他引：3
通过对山西石炭系本溪组铝土矿,即华北G层铝土矿形成的构造背景、古地理环境及铝土矿床的分布分析,指出了山西铝土矿矿床主要分布在各古陆、古岛边缘的成矿盆地中,且成矿盆地的封闭性越好越有利于成矿.古陆上广泛出露的铝硅酸盐岩经过风化分解,其中的K、Na、Ca、Mg等元素大多数被淋失,Fe、Al、Ti、Si等元素相对富集,残留在红土风化壳中,经海侵短距离机械搬运至沉积盆地沉积.通过对铝土矿成分及其围岩物质组分的分析,进一步确认沉积在古陆边缘的原始铝土矿层埋藏于潜水面以下的还原环境中,经地下水、地表水等酸性溶液的淋滤脱硅后沉积成矿,后经地壳抬升,通过对原始铝土矿的渗流作用、氧化改造而达到铝土矿的富集,且铝土矿多分布在靠近古陆边缘的缓坡一侧,在沟谷两侧的高山低洼处矿体较富,而埋藏越深越则不利于成矿. 相似文献
18.
《Applied Geochemistry》1997,12(2):119-131
Only small, low grade occurrences of bauxite are known in Nigeria, associated with ferricretes on the Jos Plateau. Widespread bauxite has been discovered on the Mambilla Plateau. Laterite is developed on gneisses and basalt, while on trachytic parent rocks low-silica bauxite occurs with a thickness of more than 5 m and covering an area of at least 1 km2. This bauxite consists of gibbsite and goethite.In contrast to the ferricretes of the Jos Plateau, weathering on the Mambilla Plateau led to the formation of stone line profiles. Ferricretes were developed on the Upper Jurassic Gondwana surface under contrasting climate and are preserved as relicts in the southern part of the Mambilla Plateau where weathered Precambrian basement occurs in a highly uplifted position. Dismantling of these ferricretes is attributed to a gradual change of paleoclimate towards more humid conditions. After the extrusion of volcanic rocks in the northern part of the plateau, presumably during Lower to Mid Miocene, these volcanics underwent intense chemical weathering. Bauxite and laterite formed depending on the type of parent rock. Weathering profiles are mostly truncated and overlain by reworked material. Allochthonous components occur both within and also below the stone-line. This is shown by mineralogical indicators such as ilmenite or quartz and by a shift in the Zr/Ti-ratio. Similar profiles are missing further north on the Jos plateau, where ferricretes formed instead. This is attributed to regional differences in paleoclimatic conditions which were more humid at Mambilla while Jos was under the influence of dryer conditions.The widespread formation of laterite on different parent rocks on the Mambilla Plateau could be related to a global Mid-Miocene climatic optimum, which led to a general intensification of chemical weathering processes. 相似文献
19.
The investigation was conducted within highly and moderately separated highlands and high plateaus where glaciers, stone streams, solifluction, and glacial and fluvio-glacial deposits are widely developed. A capping of Miocene basalts remains in the divides over the Au ore deposits and their oxidation zones. Young water-filled fractures traverse the ore-bearing structures and control the direction of the glacial and river valleys, as well as the location of the lakes, springs, and icings.Gold occurs in small- to average-sized sulphide-Au-quartz veins and in a sulphidized black shale series of Precambrian and Paleozoic age. Both mechanical and hydromorphic dispersion of Au are exhibited clearly in the highlands. The latter is due to the processes of modern oxidation of the Au-bearing sulphide minerals. The anomalies of Au in streams and small lakes are related to supra- and sub-ice waters. In the water of streams Au is present in three forms; colloidal, dissolved, and sorbed. Gold in colloidal form comprises the most ample and contrasty anomalies. The truly dissolved Au is more local and manifests itself close to the source of the stream. Gold sorbed on suspended matter is evident because of a significant removal from the source into the solution. Migration of Au and formation of long (up to 2.5 km) and contrasty dispersions in waters of low dissolved solids is favoured by the presence of organic matter and argillaceous and ferruginous suspensions as well as other sorbents. The anomalies of Au in water either coincide with anomalies in stream sediments over mineralized zones or indicate new mineralized areas not reflected in stream sediments. 相似文献
20.
采用电感耦合等离子体发射光谱法（ICP-OES）测定铝土矿中的稀土氧化物时,酸溶往往造成溶样不彻底,高温碱熔时大量的熔剂会降低稀土元素的发射强度,同时由于稀土氧化物含量（0.0010%~0.050%）较低,存在铝、铁等基体干扰,难以准确测定。本文采用氢氧化钠熔融铝土矿样品,熔融物用热水浸取,三乙醇胺溶液掩蔽铝和铁,乙二胺四乙酸二钠溶液络合钙、镁等干扰元素,稀土氢氧化物留存于沉淀中,沉淀经盐酸溶解进入待测液,从而将稀土元素与熔剂和基体元素分离。实验结果表明：标准溶液无需基体匹配,各稀土氧化物标准曲线的线性相关系数均不小于0.9999,检出限在0.0002%~0.0015%之间;按照实验方法分析实际样品中稀土氧化物的含量,测定结果的相对标准偏差（RSD,n=6）为2.0%~4.6%,回收率为85.2%~104.4%。本方法与电感耦合等离子体质谱法（ICP-MS）相比,两种方法的测定结果无显著性差异。 相似文献