泥火山的全球分布和研究进展

本文系统介绍了泥火山的全球分布特征、分类、成矿、成因特征和机制、生物地球化学和地质灾害。泥火山是盆地地层深部含水的泥质物在高压作用下喷出地表形成的锥状沉积体,主要发育在沉积速率较快和有横向挤压构造作用的盆地中。全球陆地有超过40个泥火山发育区,海底有超过20个泥火山发育区,每个发育区有几座到200多座泥火山不等,陆地和浅海区共有2000多个泥火山。各地泥火山有不同的喷发周期,喷发物也各有不同的形态、成分、来源和年龄。尽管泥火山的成因机制尚颇有争议,但较快的沉积速率和活动大陆边缘横向构造挤压作用无疑是两个最为关键的因素。由于泥火山对大地构造属性、油气勘探、生物地球化学、地质灾害和全球气候变化等问题的研究有着重要的意义,已逐渐成为地球科学一个新的研究热点。     

准噶尔盆地南缘泥火山活动及其伴生油苗的地球化学特征和意义

文中对准噶尔盆地南缘乌苏四棵树和独山子泥火山的构造背景进行了分析,指出其形成主要是由于天山北缘中新生 代沉积层中地势高低造成的水压差和地层层间压力差,导致丰富的地下水沿着背斜顶端发育的断裂带上升,与通道周围的 泥质岩石相遇,泥浆形成并喷出地表而成为泥火山。论文还对四棵树和独山子泥火山的伴生油苗进行了全油色谱和生物标 记化合物研究,对比相关烃源岩地球化学特征及前人有关研究成果,指出油样有机质均处于成熟阶段,油源可能是侏罗系 与古近系烃源岩的混合产物。研究结果对探索该区泥火山的成因和油气成藏条件具有重要意义。     

Trace Elements in the Products of Mud Volcanoes in the Northwest Caucasus

Doklady Earth Sciences - Comparison of the distribution of trace elements in the products of mud volcanoes of the Northwest Caucasus, Dzhungar Basin, and Andaman Islands shows that these products...     

Patterns of the Distribution of Rare-Earth Elements in Waters of Mud Volcanoes

Doklady Earth Sciences - The original data on the distribution of rare-earth elements in waters of mud volcanoes of Sakhalin Island, Taman Peninsula, and Azerbaijan are presented. It has been shown...     

南海北部边缘盆地泥底辟及泥火山特征及其与油气运聚关系

泥底辟与泥火山成因机制相同,发育演化特征相似,但最终地质形态及存在形式有所差异.通过深入分析南海西北部莺歌海盆地泥底辟与东北部台西南盆地泥火山发育展布特点及伴生天然气地球化学特征,指出莺歌海盆地泥底辟主要分布于盆地中部的莺歌海深大凹陷,且沿盆地NW方向呈五行雁行式排列,泥底辟发育演化具有明显的低密、低速和异常高温超压的特点;而台西南盆地泥火山主要展布于南部凹陷陆坡深水区和台湾陆上台南-高雄地区,陆上泥火山多沿深大断裂带分布,地面形态特征类似火山形态,多具有喷口,海域泥火山的海底形态亦与其相似,但研究程度较低.泥底辟及泥火山伴生烃类天然气成因类型较多,但以成熟-高熟煤型烃类气为主;伴生的非烃气CO₂和N₂丰富,但以无机壳源型CO₂为主.泥底辟及泥火山的泥源层均为中新世及上新世海相坳陷沉积的巨厚泥页岩,本身即具生烃潜力,其成熟生烃及其与泥底辟/泥火山运聚通道和底辟伴生构造的良好配置,则构成了其独特的泥底辟/泥火山油气运聚成藏系统,进而控制了这种“泥底辟/泥火山型油气藏”的分布.      

Mud Volcanoes: Distribution Regularities and Genesis (Communication 2. Geological–Geochemical Peculiarities and Formation Model)

The work discusses relationships between mud volcanoes, tectonic faults, folds, and oil-and-gas deposits. The location of roots and centers of mud volcanic activity is analyzed. It proposes a new model of mud volcano formation, according to which these structures result from the development of elision systems of sedimentary basins.     

Mud volcanoes of Italy

The locations and information about the sizes of 61 mud volcanoes on the Italian mainland and Sicily, plus an area of mud diapirism in the Italian Adriatic Sea, are presented. Data about the emission products are also provided. The majority of these mud volcanoes are found where thick sedimentary sequences occur within a zone of tectonic compression associated with local plate tectonic activity: the movement of the Adriatic microplate between the converging African and Eurasian plates. The principal gas emitted by these mud volcanoes is methane, which probably originates from deep within the sediments. Other mud volcanoes, associated with igneous volcanism, produce mainly carbon dioxide. The mud diapirs in the Adriatic Sea are thought to form as a result of the mobilization of shallow gassy sediments. It has been shown that radon emissions from mud volcanoes are indicators of forthcoming earthquake events. Copyright © 2004 John Wiley & Sons, Ltd.     

Geochemical and Isotope Characteristics of Carbonates from Ejecta of Mud Volcanoes of the Kura Basin,Azerbaijan

Lithology and Mineral Resources - This paper is devoted to the vein and dispersed carbonates from ejecta of mud volcanoes of Azerbaijan. The vein calcites are morphologically diverse and related to...     

Thermobaric Depth Settings of Sedimentary Rock Basins and Their Fluid Dynamics: Communication 2. Superhigh Pressures and Mud Volcanoes

Lithology and Mineral Resources - The paper addresses regularities in the location of mud volcanoes and their spatial association with tectonic faults, anticlinal uplifts, and oil-and-gas fields....     

Mud volcano eruptions and earthquakes in the Northern Apennines and Sicily, Italy

The relations between earthquakes and the eruption of mud volcanoes have been investigated at the Pede–Apennine margin of the Northern Apennines and in Sicily. Some of these volcanoes experienced eruptions or increased activity in connection with historical seismic events, showing a good correlation with established thresholds of hydrological response (liquefaction) to earthquakes. However, the majority of eruptions have been documented to be independent of seismic activity, being mud volcanoes often not activated even when the earthquakes were of suitable magnitude and the epicentre at the proper distance for the triggering. This behaviour suggests that paroxysmal activity of mud volcanoes depends upon the reaching of a specific critical state dictated by internal fluid pressure, and implies that the strain caused by the passage of seismic waves can activate only mud volcanoes in near-critical conditions (i.e., close to the eruption). Seismogenic faults, such as the Pede–Apennine thrust, often structurally control the fluid reservoirs of mud volcanoes, which are frequently located at the core of thrust-related folds. Such an intimate link enables mud volcanoes to represent features potentially suitable for recording perturbations associated with the past and ongoing tectonic activity of the controlling fault system.     

Influence of Layered Structures of the Seabed on the Formation of Gas Hydrates in the Area Surrounding Deep-Sea Mud Volcanoes: A Mathematical Model

Doklady Earth Sciences - The evolutionary processes of gas hydrate accumulations associated with deep-sea mud volcanoes are discussed. A mathematical model and the results of numerical modeling of...     

东海与泥底辟构造有关的天然气水合物初探

根据所获得的高分辨率地震资料分析,发现冲绳海槽南部西侧槽坡附近以及海槽内部发育有一系列泥火山（底辟）构造,在地形上表现为泥火山地貌,在穿过泥火山的地震剖面上,表现出典型的泥底辟构造。对穿过泥底辟构造的DMS01-5地震剖面进一步的处理和解释发现,泥底辟构造顶部存在明显的似海底反射（BSR）,其与海底反射波组极性相反,在BSR之上存在振幅空白带,在速度谱上出现速度异常,指示存在与泥火山有关的天然气水合物。从世界广泛发现的与泥底辟构造有关的天然气水合物来看,天然气水合物既可以在泥底辟构造的丘状外围成藏,也可以在其外围的海底沉积物中产出。在泥底辟构造的丘状外围附近,天然气水合物的形成机制类似于传统的矿物低温热液的形成;在泥底辟构造外围海底沉积物中,其形成过程类似于传统的矿物交代形成机制。冲绳海槽泥底辟构造的发育与很高的沉积速率和槽坡的活动断层有关。在冰期期间,长江携带大量的陆源物质直接输送到大陆坡地区,沉积速率达300 m/Ma,产生异常高压,同时张性断层极为发育,为流体的迁移提供了良好的通道,在异常压力以及上覆地层压力作用下大量流体向上运移,从而发育大量的泥底辟构造。富含甲烷的流体易在其外围及外围海底沉积物中形成天然气水合物藏。     

Mud volcanoes of the Black Sea as a prospecting indicator of methane gas hydrates

Relationship between methane gas hydrates and mud volcanoes in the Black Sea is considered. It is suggested that they are mainly confined to compensation troughs near mud volcanoes.     

Iron Speciation of Mud Breccia from the Dushanzi Mud Volcano in the Xinjiang Uygur Autonomous Region, NW China

Organic-inorganic interactions occurring in petroleum-related mud volcanoes can help predict the chemical processes that are responsible for methane emissions to the atmosphere. Seven samples of mud breccia directly ejected from one crater were collected in the Dushanzi mud volcano, along with one argillite sample of the original reddish host rocks distal from the crater, for comparison purposes. The mineral and chemical compositions as well as iron species of all samples were determined using XRD, XRF and M?ssbauer spectroscopy, respectively. The results indicate that a series of marked reactions occurred in the mud volcano systems, more specifically in the mud breccia when compared to the original rocks. Changes mainly included: (1) some conversion of clay minerals from smectite into chlorite and illite, and the precipitation of secondary carbonate minerals such as calcite and siderite; (2) silicon depletion and significant elemental enrichment of iron, manganese, magnesium, calcium and phosphorus; and (3) transformation of iron from ferric species in hematite and smectite into ferrous species in siderite, chlorite and illite. These geochemical reactions likely induced the color changes of the original reddish Neogene argillite to the gray or black mud breccia, as a result of reduction of elements and/or alteration of minerals associated with the oxidation of hydrocarbons. Our results also suggest that greenhouse gases emitted from the mud volcanoes are lowered through a series of methane oxidation reactions and carbon fixation (i.e., through carbonate precipitation).     

Mud volcanoes, olistostromes and Argille scagliose in the Mediterranean region

Tectonic and sedimentary mélanges, rocks with block-in-matrix fabric often referred to as 'chaotic', are widespread in the circum-Mediterranean collisional orogenic belts as well as in submerged Mediterranean Arcs. These rock types have been defined originally as 'Argille scagliose' (Bianconi, 1840) and 'olistostromes' (Flores, 1955, 1959) in the outcrops of the Apennine chain (Italy). Both terminology and concepts have undergone a rather complex evolution through time owing to the gradual recognition of similar chaotic bodies in all the circum-Mediterranean orogenic belts. Submarine mud volcanoes of the Mediterranean region, also composed by block-in-matrix, more commonly referred to as mud breccias, have a much younger history. These mud breccias were discovered in 1981 and, since then, a growing number of sea-going geophysical and geological expeditions have allowed the recognition of a major mud volcano belt in the Eastern Mediterranean and of a number of mud diapirs and mud volcano fields from the Black Sea to the Gulf of Cadiz. Structural, textural and genetic similarities between the mud breccias of the Mediterranean mud volcanoes and the olistostromes and Argille scagliose of the Apennines were noted from the very beginning, but the matter has not been the focus of any detailed study. In this paper, the use of the terms in the geological literature is analysed, the distribution of these rock units in the Mediterranean region explored and the assumed genetic processes are identified in order to formulate a common genetic model that can be applied to the evolution of the circum-Mediterranean sedimentary basins.     

Mud volcanic natural phenomena in the South Caspian Basin: geology,fluid dynamics and environmental impact

The South Caspian sedimentary basin is a unique area with thick Mesozoic-Cenozoic sediments (up to 30–32 km) characterized by an extremely high fluid generation potential. The large amount of active mud volcanoes and the volumes of their gas emissions prove the vast scale of fluid generation. Onshore and offshore mud volcanoes annually erupt more than 10⁹ cubic meters of gases consisting of CH₄ (79–98%), and a small admixture of C₂H₆, C₃H₈, C₄H₁₀, C₅H₁₂, CO₂, N, H₂S, Ar, He. Mud volcanism is closely connected to the processes occurring in the South Caspian depression, its seismicity, fluctuations of the Caspian Sea level, solar activity and hydrocarbon generation.The large accumulations of gas hydrates are confined to the bottom sediments of the Caspian Sea, mud volcanoes crater fields (interval 0–0.4 m, sea depth 480 m) and to the volcanoes body at the depth of 480–800 from the sea bottom. Resources of HC gases in hydrates saturated sediments up to a depth of 100 m and are estimated at 0.2×10¹⁵–8×10¹⁵ m³. The amount of HC gases concentrated in them is 10¹¹–10¹² m³.The Caspian Sea, being an inland closed basin is very sensitive to climatic and tectonic events expressed in sea level fluctuations. During regressive stages as a result of sea level fall and the reducing of hydrostatic pressure the decomposition of gas hydrates and the releasing of a great volume of HC gases consisting mainly of methane are observed.From the data of deep drilling, seismoacoustics, and deep seismic mud volcanic activity in the South Caspian Basin started in the Lower Miocene. Activity reached its highest intensity at the boundary between the Miocene and Pliocene and was associated with dramatic Caspian Sea level fall in the Lower Pliocene of up to 600 m, which led to the isolation of the PaleoCaspian from the Eastern ParaTethys. Catastrophic reduction of PaleoCaspian size combined with the increasing scale of mud volcanic activity caused the oversaturation and intoxication of water by methane and led to the mass extinction of mollusks, fishes and other groups of sea inhabitants. In the Upper Pliocene and Quaternary mud volcanism occurred under the conditions of a semi-closed sea periodically connected with the Pontian and Mediterranean Basins. Those stages of Caspian Sea history are characterized by the revival of the Caspian organic world.Monitoring of mud volcanoes onshore of the South Caspian demonstrated that any eruption is predicted by seismic activation in the region (South-Eastern Caucasus) and intensive fluid dynamics on the volcanoes.     

Distribution and characters of the mud diapirs and mud volcanoes off southwest Taiwan

In order to identify the mud diapirs and mud volcanoes off SW Taiwan, we have examined ∼1500 km long MCS profiles and related marine geophysical data. Our results show ten quasi-linear mud diapirs, oriented NNE–SSW to N–S directions. Thirteen mud volcanoes are identified from the multibeam bathymetric data. These mud volcanoes generally occur on tops of the diapiric structures. Moreover, the active mud flow tracks out of mud volcanoes MV1, MV3 and MV6 are observed through the high backscatter intensity stripes on the sidescan sonar images. The heights of the cone-shaped mud volcanoes range from 65 m to 345 m, and the diameters at base from 680 m to 4100 m. These mud volcanoes have abrupt slopes between 5.3° and 13.6°, implying the mudflow is active and highly viscous. In contrast, the flat crests of mud volcanoes are due to relative lower-viscosity flows. The larger cone-shaped mud volcanoes located at deeper water depths could be related to a longer eruption history. The formation of mud diapirs and volcanoes in the study area are ascribed to the overpressure in sedimentary layers, compressional tectonic forces and gas-bearing fluids. Especially, the gas-bearing fluid plays an important role in enhancing the intrusion after the diapirism as a large amount of gas expulsions is observed. The morphology of the upper Kaoping Slope is mainly controlled by mud diapiric intrusions.     

东沙岛西南泥火山区的地震烃类检测

近年来通过多道地震、浅剖及海底采样调查在东沙岛西南海域发现了大量喷溢甲烷的泥火山,通过研究泥火山可能会发现含气层,具有重大的油气资源指示意义.一条多道地震剖面显示,在该海域一泥火山MV3附近存在一个具有极性反转的埋藏背斜构造,其振幅绝对值随偏移距增大而增大.为探究该背斜是否含有烃类气体,开展了速度分析、AVO反演和频率...     

Volcanoes and peat bogs

Peat bogs in the British Isles contain tephra from volcanic eruptions in Iceland; tephra in the Falkland Islands most likely derives from Andean volcanoes. Study of these far-travelled volcanic products is making a significant contribution to our understanding of past environmental changes.     

Newly discovered mud volcanoes in the Coastal Belt of Makran,Pakistan—tectonic implications

The Makran accretionary wedge has a much larger number of mud volcanoes then those reported earlier. Using high-resolution satellite images, over 70 active mud volcanoes were identified. These mud volcanoes occur within a well-defined zone; we call it the Makran zone of active mud volcanoes (MZAMV), which is parallel to the regional trend of the accretionary wedge. Mud volcanoes within the zone occur as clusters, which form linear belts parallel to the regional thrusts associated with anticlines. The MZAMV zone also includes the offshore mud volcanoes occurring in the shallow shelf area, including the recurrently emerging mud islands. Several occurrences of thick deposits of old mud volcanoes (Pleistocene or even older) are also present within this zone, which also display recognizable features that are characteristic of the fossil mud volcanoes. We propose that the MZAMV developed and evolved in response to the continued compression within the Makran accretionary wedge, which in turn, is a response of the subduction process. Mud diapirism has been an ongoing phenomena since Pleistocene or even earlier. The events of enhanced mud extrusion in mud volcanoes and/or emergence of island(s) have relevance with seismic phenomena and, therefore, may be closely monitored.