内蒙古达里诺尔晚新生代火山群喷发特征研究

达里诺尔火山群有近百座晚新生代单成因火山,其地质地貌形态各异,喷发形式多样。这些火山既有爆破式喷发,如:夏威夷式喷发,斯通博利式喷发,强斯通博利式喷发和射汽岩浆喷发;也有溢流式喷发,如盾状火山;还有岩浆缓慢侵出,如大黑山。火山群内典型火山机构表明,不同的喷发方式穿插于火山喷发过程:早期火山活动多以侵出和溢流为主,逐渐转变为岩浆爆破式喷发(强斯通博利式,斯通博利式),晚期又过渡为溢流式喷发,喷发过程大体经历一个爆破强度弱-强-弱的转变。射汽岩浆型的火山则是以剧烈的射汽岩浆爆炸开始,后期逐渐转弱为岩浆爆破喷发和溢流喷发。火山喷发过程中火山产物出现牛顿流体,宾汉流体,层流,颗粒流,涌流,空降等不同类型的运动形式,自火口向远源运动,形成差异化的火山产物。岩浆的输送速率、上升速度,以及围岩的类型,可能是造成达里诺尔火山群多样化喷发的主要因素。     

Plate Tectonic Setting and Eruptive Characteristics of the K—rich Volcanic Belt in HeilingJiang Province,Northeast China

Various lines of geological,geophysical and geochemical evidence indicate that the K-rich volcanic belt in Northeast China as represented by the volcanic groups at Wudalianchi,Erkeshan and Kelo was developed,in terms of plate tectonics,in a rift valley system within the continental plate,The volcanic material includes effusive lavas and explosive pyroclastics whose characteristics and flowing/accumulation mechanisms were studied in detail,The distribution of pyroclastics shows that the eruption is of Strombolian type with increasing intensity towards the late stages.     

松辽盆地白垩系营城组古火山机构特征

在系统总结Hawaiian等7种喷发方式、互层状火山等3种火山机构的岩性岩相和垂向序列特征与识别标志基础上,通过剖面火山机构剖析及其与盆内埋藏火山机构对比,总结出营城组2类古火山机构特征。营城组玄武岩火山机构自下而上为枕状、渣状集块熔岩（占总厚度30%）,气孔杏仁和致密块状熔岩（70%）,喷溢相为主,火山口附近隐爆角砾岩发育,为夏威夷式喷发。火山机构厚度以200~500 m居多,顶面盾状,相对高差100~250 m,以坡角小于10°为特征,属于盾状火山。营城组流纹岩火山机构的纵向序列300~700 m,内部结构呈现上中下三段式：下部火山碎屑（熔）岩为主（30%）,爆发相为主,以基浪（base surge）沉积为标志,喷发方式主要表现为高粘度岩浆强烈气射作用的培雷式喷发;中部主要为气孔、石泡和流纹构造流纹岩（60%）,构成火山机构的主体,喷溢相为主,火山口附近常见侵出相珍珠岩穹隆,喷发类型接近于斯通博利式;上部主要为细粒（层）凝灰岩（火山灰湖相沉积,10%）,爆发相为主,以普林尼式喷发为主。流纹岩火山机构顶面呈丘状,相对高差200~300 m,以坡角多大于15°为特征,属于互层状火山。     

云南腾冲大六冲火山机构的发现及意义

腾冲火山群位于我国云南省西部和缅甸交界处的腾冲县境内,是我国著名的第四纪火山群,既有黑空山、打鹰山、马鞍山等一系列晚第四纪新期火山,也有早更新世以来有过喷发活动的大六冲、余家大山、来凤山等老火山。其中,位于腾冲火山区中东部的大六冲山势高峻,其顶峰是本区内的最高峰。野外地质调查发现,大六冲山体由一系列巨厚层爆发相火山碎屑堆积物和少量溢流相熔岩类岩石构成,喷发物类型极其丰富。在大六冲最高峰以南约100m处,首次发现存在着一个直径超百米的火山通道,可能是区内早期火山喷发的主通道,火山颈、熔岩穹丘、岩墙、爆发相与溢出相堆积物构成了大六冲完整的火山机构,在其周边多处地方还发现了因山体岩石破碎后形成的垮塌和滑坡堆积物。大六冲火山机构及其滑塌物的发现,不仅可以解释腾冲火山区大范围分布的火山碎屑岩的来源,也为防治以后类似大规模喷发可能造成的次生地质灾害提供了理想的研究样本和未来灾害预警。     

滇西腾冲更新世粗面安山岩Ar-Ar年代学、地球化学特征及其构造意义

腾冲芒棒地区广泛发育新近纪以来的火山岩,本文首次对该区粗面安山岩进行的高精度40Ar/39Ar同位素定年,其坪年龄分别为2.1±0.1Ma和2.0±0.1Ma,代表其喷溢时代为早更新世。岩石地球化学特征研究显示,粗面安山岩属高钾钙碱性系列,富集大离子亲石元素、亏损高场强元素,具有弧火山岩与大陆板内火山岩的双重属性,推测其形成于后造山环境。综合研究表明,腾冲地块更新世火山岩的形成与印度-欧亚板块俯冲-碰撞造山隆升后的伸展垮塌、富集地幔部分熔融作用密切相关,而印支陆块向东南逃逸以及腾冲弧形走滑断裂带(龙川江断裂带、大盈江断裂带)的活化促使了该期火山岩的喷发与侵位。     

松辽盆地改造残留的古火山机构与现代火山机构的类比分析

现代火山机构形态有盾状、锥状和穹状,可按喷发样式进一步划分为7种类型。据此分类,在松辽盆地周缘剖面及其北部徐家围子断陷区可识别出4类火山机构：盾状火山机构,由喷溢相熔岩组成,可夹有薄层爆发相火山碎屑岩;层火山机构,由互层的熔岩与火山碎屑岩组成,喷溢相与爆发相交替的序列明显;火山碎屑锥,几乎全部由火山碎屑（熔）岩组成,爆发相为主;熔岩穹丘由高粘度的流纹质、英安质熔岩堵塞火山口后缓慢挤出形成,喷溢相和侵出相发育,兼有火山通道相。盆地内埋藏火山机构最小坡度为3°,最大坡度为25°,底部直径为2～14 km,分布面积为4～50 km²,火山岩厚度为100～600 m;总体上呈现出数目多、个体规模小、受区域大断裂控制、具裂隙式-多中心喷发、彼此相互叠置的特征。火山岩岩性和岩相是控制松辽盆地古火山机构类型及形态的主要因素。     

塔河油田火山岩的层位归属、火山岩岩石学与岩相学特征

火山岩顶、底地层中的微古化石组合研究表明:塔河油田火山岩的形成时代为二叠纪。岩石学、岩相学、地球物理测井与地震学综合研究结果显示,火山岩主要为英安岩和玄武岩。存在两次火山喷发旋回,形成下部玄武岩、上部英安岩或单一英安岩的垂向火山喷发序列。玄武岩呈带状分布于研究区西部和南部古地貌低洼区,以上平下凸的透镜状河谷充填式地震反射为特点;英安岩分布于北部及东北部地区,以下平上凸的丘形反射形态为特征。可划分出火山爆发相、火山溢流相和火山沉积相3个岩相带。火山爆发相位于火山喷发中心地带,研究区以火山熔岩溢流相为主,火山沉积相布范围局限,位于岩体边缘。火山活动具有喷发频率低、间隔时间短、以宁静的溢流式喷发为主间或伴随较强烈的爆发式喷发为特点。火山活动喷发中心可能是由西南逐渐向东北方向迁移的。     

Process-facies Types and Sequences of Devonian Volcanic Sedimentary Successions in Northern Xinjiang and Their Relation to Plate Tectonics

The process-facies types of the Devonian volcanic sedimentary successions in northern Xinjiang include explosive facies, effusive facies, pyroclastic-calcareous-terrigenous tempestite facies, and coarse~-, medium~- and fine-grained pyroclastic turbidite facies, volcanic eruption tsunamite facies, syndepositional and soft-deformed seismite facies, sandy and silt-muddy contourite facies. This paper presents their characteristics and diagnostic indicators, and discusses the temporal and spatial structures of both the process-facies and the environment-facies of the Zhifang section, east Junggar, and the Mount Sarburti section, west Junggar, and their relation to plate tectonism. The author holds that the facies analysis dominated by process-facies is the facies analysis' nucleus in an orogenic belt and active continental margin.     

三塘湖盆地石炭系卡拉岗组火山岩岩相研究

三塘湖盆地石炭系卡拉岗组火山岩岩性揭示该区火山岩岩相主要包括火山爆发相、溢流相,火山沉积相不发育。为了明确不同岩相分布规律,本文系统利用测井、地质、地震等多种资料,建立测井岩性识别模板,以单井相作为约束,开展地震反演,明确火山岩岩相的平面分布规律。研究结果表明:该区火山喷发方式以裂隙式为主,火山口呈串珠状沿主断裂排列;溢流相平面呈层状分布,溢流相安山岩最为发育。研究结果可有效指导该区火山岩油藏的勘探评价工作,同时为火山岩岩相研究提供可借鉴的研究思路。     

内蒙中部辉腾锡勒第四纪火山群初步研究

辉腾锡勒火山群位于内蒙古中部卓资县、察哈尔右翼中旗和后旗交界处的高山草原区。处于中国东部大同-阿尔山-诺敏河第四纪火山喷发带南段。火山群坐落在太古宙变质岩系、二叠纪花岗岩和新近纪汉诺坝玄武岩之上。平面上呈低洼的菱形台地，四周为山地，总面积约260km²。因上覆在汉诺坝玄武岩台地之上，故以往将其误归为新近纪汉诺坝玄武岩。火山群内发育近百座火山，大多数火山形貌保存基本完整。火山产物主要为一套碱性橄榄玄武岩，次为不同成因的火山碎屑物（岩）。碱性玄武岩覆盖在晚更新世坡积物和黄土之上。火山活动的时代主体为晚更新世，可进一步分为早、中、晚三期。早期为裂隙-中心式喷发，火口已剥蚀殆尽；中期主要形成"地池式"和玛珥式火山，火山形貌较完整，火口呈特征的圆形或椭圆形，大部分积水成湖，当地习称"九十九眼泉"或"海子"。晚期以熔浆的溢流为主，形成结构完整的盾片状火山。火山活动经历了沿裂隙的喷溢到中心式弱爆发、溢流-射汽岩浆爆发-溢流再到溅落堆积的演化过程。辉腾锡勒火山群是在新近纪汉诺坝玄武岩台地上新解体确定的第四纪火山群，这为研究蒙古高原南部地壳深部结构及其活动性提供了又一天然窗口，对了解新构造活动、环境及灾害预警研究都具有重要的理论和实际意义。     

中国古亚洲域沉积盆地火山岩油气藏储层特征比较及其差异分析

在中国古亚洲域沉积盆地火山岩储层母岩年代和岩性、储集空间类型以及火山岩岩相综合分析的基础上,探讨了火山岩油气藏的储层特征及其差异性。研究表明,中国古亚洲域火山岩储层的母岩发育年代西早东晚,西部的准噶尔、三塘湖和吐哈盆地发育晚古生代海相、海陆交互相的中基性安山岩、玄武岩及火山碎屑岩;东部的松辽、二连和海拉尔盆地发育中生代陆相中酸性流纹岩、安山岩。火山岩原生储集空间包括气孔、孔洞以及冷凝收缩裂缝等;次生储集空间包括各种溶蚀孔及构造裂缝、风化裂缝等。火山岩岩相可分喷出相、火山通道相、次火山相和火山沉积相。其中中基性岩类多以溢流相开始,相序类型为溢流相、爆发相/火山沉积相;中酸性岩类多以爆发相或火山通道相发端,主要相序为爆发相、溢流相/侵出相。溢流相一般发育原生气孔、构造缝;爆发相多为粒间孔,而侵出相以角砾间孔和原生裂缝为主。火山岩储层的差异受多因素影响,包括岩性岩相、喷发环境以及后期构造、成岩作用等。前者奠定火山岩储层形成与分布的基础和储集空间的发育程度;后者则改造储层的储渗性能。     

风化店中生界火山岩储层特征与油气成藏模式

基于钻井、录井、测井、薄片和化学分析等资料,对风化店地区中生界火山岩储层特征及油气成藏模式进行分析研究。结果表明：火山喷发活动具有多次间歇性喷发特征,喷发中心交替转移,发育3个喷溢中心;火山岩酸性程度稍高,碱性程度略低,可分为熔岩类、火山碎屑岩类、沉积火山碎屑岩类和火山碎屑沉积岩类4类;火山岩划分为火山爆发相、火山溢流相和火山沉积相3个岩相带,并围绕3个喷溢中心呈环带状分布;油气储集空间包括原生孔隙、次生孔隙和裂缝;深大断裂沟通生油岩与储集体,形成供油网络,使油气垂向运移并于良好储层富集成藏。     

内蒙东部晚第四纪火山活动与新构造

本文所指的晚第四纪包括晚更新世和全新世。内蒙东部晚第四纪火山活动强烈,北起大兴安岭北部的鄂伦春诺敏河火山群、经阿尔山-柴河、锡林浩特-阿巴嘎火山群,南抵察右后旗乌兰哈达火山群,断续延伸约1000km,分布着约390余座大小不一、形态各异的火山,构成了内蒙东部壮观的北北东向第四纪火山喷发带。火山类型包括玛珥式、夏威夷式、斯通博利式、亚布里尼式和冰岛式,以斯通博利式最为发育。爆破式火山作用包括射汽、射汽-岩浆爆发和岩浆爆发。火山岩类型主要为碱性玄武岩及其火山碎屑物(岩),火山岩具初期裂谷构造属性。火山活动主体受北北东向基底断裂控制,但就具体火山群而言,又多处于北东和北西向基底深断裂交会处。区内新构造与火山活动密切相关,深部岩浆的上侵,可能是控制本区新构造活动的主因。尤其是全新世火山的空间展布,显示了内蒙东部新构造的活动性。     

From sink to volcanic source: Unravelling missing terrestrial eruption records by characterization and high‐resolution chronology of lacustrine volcanic density flow deposits,Lake Inawashiro‐ko,Fukushima, Japan

Eruption records in the terrestrial stratigraphy are often incomplete due to erosion after tephra deposition, limited exposure and lack of precise dating owing to discontinuity of strata. A lake system and sequence adjacent to active volcanoes can record various volcanic events such as explosive eruptions and subaqueous density flows being extensions of eruption triggered and secondary triggered lahars. A lacustrine environment can constrain precise ages of such events because of constant and continuous background sedimentation. A total of 71 subaqueous density flow deposits in a 28 m long core from Lake Inawashiro‐ko reveals missing terrestrial volcanic activity at Adatara and Bandai volcanoes during the past 50 kyr. Sedimentary facies, colour, grain size, petrography, clay mineralogy, micro X‐ray fluorescence analysis and chemistry of included glass shards characterize the flow event deposits and clarify their origin: (i) clay‐rich grey hyperpycnites, extended from subaerial cohesive lahars at Adatara volcano, with sulphide/sulphate minerals and high sulphur content which point to a source from hydrothermally altered material ejected by phreatic eruptions; and (ii) clay‐rich brown density flow deposits, induced by magmatic hydrothermal eruptions and associated edifice collapse at Bandai volcano, with the common presence of fresh juvenile glass shards and low‐grade hydrothermally altered minerals; whereas (iii) non‐volcanic turbidites are limited to the oldest large slope failure and the 2011 Tohoku‐oki earthquake events. The high‐resolution chronology of volcanic activity during the last 50 kyr expressed by lacustrine event deposits shows that phreatic eruption frequency at Adatara has roughly tripled and explosive eruptions at Bandai have increased by ca 50%. These results challenge hikers, ski‐fields and downstream communities to re‐evaluate the increased volcanic risks from more frequent eruptions and far‐reaching lahars, and demonstrate the utility of lahar and lacustrine volcanic density flow deposits to unravel missing terrestrial eruption records, otherwise the recurrence rate may be underestimated at many volcanoes.     

Time and space dependency in impact damage evaluation of a sub-Plinian eruption at Mount Vesuvius

The volcanic eruptions have produced death and devastation along the ages; the victims caused by the documented events are about 260,000. Today, people subjected to volcanic risk are 500 million. They live predominantly in large conurbations, such as Tokyo, Mexico City, Seattle and Naples, which are located in the proximity of volcanoes with a high probability to erupt. Further, cause of concern is the elevated growth rates of the urban populations in the developing countries, seeing that many cities are located just above the tectonic belts where are predominantly situated the World’s most explosive volcanoes. Therefore, the volcanic risk mitigation of these areas requires a careful territorial planning together with an adequate knowledge of the behaviour of constructions under the eruption effects. The problem is very complex considering that a several number of actions (such as lavas, earthquakes, ash fall, pyroclastic flows, ballistics, landslides, tsunami and lahars) with a peculiar time–space distribution are produced by an eruptive event. Moreover, for the impact evaluation of a volcanic eruption, the time–space effect acquires a great importance, differently by the case of single catastrophic event (such as tectonic earthquakes, debris flows, etc.), since the sequence of the several exceptional actions which occur during an eruptive event, that modify the resistance characteristics of the struck constructions, in consequence, the impact damage evaluation requires analyses, step by step, of the eruptive process, the damage accumulated on the buildings and the distribution of the damage on the territory. All these aspects are examined in this paper which furnishes a useful compendium relating to the impact damage assessment produced on buildings by an explosive volcanic eruption, through the time–space variability analysis. This document organically summarizes the results of about 15 years of researches conducted by the PLINIVS Study Centre (Study Centre for the Hydrogeological, Volcanic and Seismic Engineering) with reference to the volcanic risk assessment, in the framework of the scientific literature on the topic. The paper analyses the probabilistic approaches used these days to treat Hazard, Vulnerability and Exposure in risk and impact evaluation of volcanic eruptions. Reliability of the model available is discussed; open problems and future improvement of the research in progress are highlighted. In conclusion, recommendations to follow for impact estimation studies in volcanology are reported.     

松辽盆地含CO_2火山岩气藏的形成和分布

松辽盆地特有的深部构造背景和裂谷演化特征,造成盆地内含CO_2火山岩气藏的形成和富集。松辽裂谷盆地中新生代火山岩浆活动发育,总体上具有多期喷发、分布广泛和储集条件良好的特点。火山活动以中心式喷发为主,主要发育中基性-酸性火山岩,发育流纹岩、凝灰岩等多种岩石类型,爆发相和溢流相2种火山岩相。中生代火山岩在盆地内分布广泛,营域组构成深层有利储层,新生代火山岩在盆地外围出露较多,而在盆内出露较少。盆地高含量的二氧化碳为无机幔源成因,由青山口期和新生代幔源岩浆脱气形成。含CO_2火山岩气藏的形成主要受深部构造背景、深大断裂和中新生代火山岩控制。已发现含CO_2火山岩气藏主要分布于古中央隆起带及其两侧断陷的营城组火山岩中,具有点状、带状分布,局部富集的特点。根据主控因素分析,预测了5个CO_2富集区带。     

松辽盆地营城组火山岩相量化表征与应用

盆地火山岩及其储层的地震解释需要量化的岩相模型提供地质约束。三维揭露的盆缘剖面是实现岩相量化表征的最佳区。在松辽盆地东南隆起营城组建组剖面区开展了爆发相、喷溢相和侵出相的三维量化研究。爆发相出现在火山旋回早期,延伸千米量级、厚度百米量级,外形呈楔形尖灭状,坡度上陡下缓、呈平均15°左右的上凹形轮廓;始于热基浪亚相、向上为热基浪与空落亚相互层,终于热碎屑流亚相。喷溢相多出现在火山旋回中后期,覆于爆发相之上,延伸千米量级、厚度百米量级,外形呈凸透镜向外尖灭状,坡度上缓下陡、呈平均20°左右的上凸形轮廓;自下而上依次为下部、中部和上部亚相。侵出相出现在火山旋回后期,可见对其它相带呈切割-披覆关系的内、中、外三个亚相,侧向延伸和垂向厚度多为百米量级、通常最大不超过1km,呈顶缓缘陡的蘑菇状。用火山岩相模型约束井旁地震解释、建立岩相-地震相响应关系,可为无井区的火山岩地震识别提供模板。火山机构的后期改造只改变相序的完整性、不改变原始喷发相带间的相邻与相依性,不影响用岩相模式预测相变关系。非同源喷出物之间的叠置会干扰盆地火山岩相的解译,且使岩相模型的约束作用失效。     

深圳大鹏半岛火山和香港火山活动特征对比研究北大核心CSCD

深圳大鹏半岛和香港地区古火山活动带,分布于广东省东部火山活动亚带莲花山火山喷发带上,属于浙闽粤港火山活动带,也是环太平洋火山活动带的一部分。为研究两地火山岩的成因机制、构造演化过程以及两地火山活动的异同点,本文采用实地考察、同位素测年等方法,从火山地层、构造和火山活动性等方面,对大鹏半岛与香港火山活动特征异同点进行对比研究。研究发现两地火山具有相似的沉积环境、相同区域地质构造背景,经历了相似的地质演化过程,火山活动时期也基本相同。二者的不同之处是地貌特征和地质景观不同,各具特色。香港的火山机构存在超级破火山口,六边形柱状节理普遍发育。大鹏半岛火山以火山穹丘为特征,典型火山地质现象是球粒、石泡、流纹、火山碎屑较为发育。根据同位素测年分析,大鹏半岛火山岩同位素年龄值为137~161 Ma,为侏罗纪晚期至白垩纪早期的产物。     

Stratigraphic constraints for explosive activity in the past 100 ka at Etna Volcano, Italy

The pyroclastic deposits of Etna have been correlated over the whole volcanic edifice for the first time, allowing the construction of a continuous record of tephra-producing events, which extends from approximately 100 ka to the Present. In this interval, five main periods of explosive activity have been identified: (a) ~100-ka strombolian to subplinian activity; (b) 80- to 100-ka plinian benmoreitic activity; (c) 16- to 80-ka strombolian to subplinian from basaltic to mugearitic activity; (d) 15.5- to 15-ka plinian benmoreitic activity accompanying the caldera-forming eruptions of the Ellittico Volcano; and (e) the most recent 13-ka basaltic explosive activity of strombolian and subplinian type of the present edifice that also includes the 122-B.C. plinian eruption. This study results in a semi-quantitative and in some cases quantitative definition of the intensity and chronology of the explosive activity at Etna. Moreover, this work gives a new significance to the volcanic hazards of Etna, a volcano generally considered to be the site of gentle effusive eruptions.