Application of Activity and Wavelet Analysis on Well Logging Sedimentary Cycle Division

The method of sedimentary cycle division is studied based on comprehensive research and activity analysis of well logging, combined with wavelet analysis and characteristics of stratigraphic cycle. Based on the method above, this paper divided stratigraphic cycles and finely classified the tratifigraphic by taking H1518 in HSS oilfield as an example. The result shows that sedimentary cycle can be divided effectively based on key stratum study, activity and wavelet analysis of well log, and the research of sedimentary cycle characteristics. H1 formation can be divided into 1 sand group, 3 sand layers and 7 single layers.

Study and Simulated the Natural Radioactivity (NORM) U-238, Th-232 and K-40 of Igneous and Sedimentary Rocks of Al-Atawilah (Al-Baha) in Saudi Arabia

In this work, gamma-ray spectroscopy based on semiconductor hyper pure germanium (HPGe) detector was used to evaluate the activity concentrations of the natural radionuclides (U-238 (Ra-226), Th-232 and K-40) and the fallout nuclide (Cs-137) for thirty samples of igneous and sedimentary rocks of Al-Atawilah (Al-Baha). The mean values of the activity concentrations of U-238 (Ra-226), Th-232, K-40 and Cs-137 in the igneous samples are found as (11.0, 11.50, 1172.71, 1.47) Bq/Kg respectively. In the sedimentary rocks, the mean values of the activity concentrations of the natural radionuclides (U-238 (Ra-226), Th-232 and K-40) and the fallout nuclide (Cs-137) equal to (12.04, 13.18, 1131.36, 1.60) Bq/Kg respectively. The averages of radiological hazards (Raeq, Hex and Iγ) were calculated and found to be within the UNSCEAR permissible limit values (370 Bq/kg for Raeq, and 1 for Hex and Iγ), except for a slight increase of average value of Iγ in the igneous rock samples (1.36). The results indicate that the dose rate values depend on the kind of rocks (high in some igneous rock samples, and most of sedimentary rock samples have low dose rate). The activities of naturalnuclides were predicted and simulated in T time using a written MATLAB R2020a script based on the average activity concentrations and respective half-lives of U-238 and Th-232 series, and K-40, this is to evaluate the future effects of natural radionuclides on the population and estimate the human inputs in the future.

Recent sedimentary records in the East China Sea inner shelf and their response to environmental change and human activities

The East China Sea continental shelf is a unique area for the study of land-sea interactions and paleoenvironmental change because it receives a large amount of terrestrial material inputs. In recent decades, human activities and global climate change have greatly aff ected river discharges into the sea. However, changes in the deposition process caused by these factors in the East China Sea continental shelf are unclear. We collected eight short sediment cores from the East China Sea inner shelf(ECSIS) using a box core sampler in 2012 and 2015. The grainsize, 2 10 Pb, and 1 37 Cs of these cores were analyzed in order to reconstruct the deposition history since the 1950 s, and to reveal human activity and climate change influences on sediment deposition in the ECSIS. Results indicated that sediment grain size became finer after 1969, turned coarser after 1987, and then further coarser since 2003, corresponding well to the three steps of sediment load drop in the Changjiang(Yangtze) River, which are mainly caused by human activities(particularly the closure of the Three Gorges Dam). Simultaneously, the East Asian Monsoon influenced the deposition process in the ECSIS by changing the intensity of coastal currents. Mean grain size variations in the fine-grained population(divided by grain size vs. standard deviation method) coincided with that of the East Asian Winter Monsoon strength and reflected its weakness in 1987. Abrupt changes in sediment grain size over a short time scale in these sediment cores were generally caused by floods and typhoons. Spectral analyses of the sediment cores showed periodicities of 10–11 and 20–22 years, corresponding to the periodicity of solar activity(Schwabe cycle and Hale cycle). Mean grain size time series also displayed a 3–8 year periodicity corresponding to El Ni?o Southern Oscillation periodic change.

Sedimentary Characteristics and Response to Climate Change and Human Activities in Shilianghe Reservoir,Jiangsu Province

Reservoirs,as artificial lakes,suffer from silting inevitably since being constructed,the sediments from surrounding environment can provide a continuous record of environmental change.Shilianghe Reservoir,the largest artificial lake in Jiangsu Province,was constructed in 1959,and plays an important role in flood control,irrigation,water supply,and so on.Nevertheless,the silting situation of the reservoir is also quite serious.In this paper,the grain-size distribution of core from Shilianghe Reservoir and its response to environmental changes were studied.It is due to two driving factors:climate variability and human activities.Based on the analysis of the grain size distribution data,the sediments were mainly composed of clayey silt and silty clay with a clear tendency of upward fining.But a grain-size peak appeared at 86 cm,and the sand proportion was also very big,indicating that hydrodynamic force was stronger.There was a consistent trend of change between sediment record in Shilianghe Reservoir and historical precipitation in the basin.According to the dating mark of137 Cs,it can be determined primarily that the abnormal grain-size at 86 cm reflected possibly the rainstorm and flood event occurring in 1970.Human activities reduced the hydrodynamics of depositional environment.Hydraulic projects are direct human activities,and land use/cover changes are indirect human activities.It turned out that sediment yield and sediment load were more and more less,and sedimentation rate showed a decreasing trend.Furthermore,sediments tended to become smaller and had better sorting property.

Sedimentary elements,evolutions and controlling factors of the Miocene channel system:a case study of the deep-water Taranaki Basin in New Zealand

Deep-water channel systems are important petroleum reservoirs,and many have been discovered worldwide.Understanding deep-water channel sedimentary elements and evolution is helpful for deep-sea petroleum exploration and development.Based on high-resolution 3D seismic data,the Miocene channel system in the deep-water Taranaki Basin,New Zealand,was analyzed by using seismic interpretation techniques such as interlayer attribute extraction and strata slicing.The channel system was divided into five composite channels(CC-I to CC-V)according to four secondary level channel boundaries,and sedimentary elements such as channels,slump deposits,inner levees,mass transport deposits,and hemipelagic drape deposits were identified in the channel system.The morphological characteristics of several composite channels exhibited stark variances,and the overall morphology of the composite channels changed from relatively straight to highly sinuous to relatively straight.The evolution of the composite channels involved a gradual and repeated process of erosion and filling,and the composite channels could be divided into three evolutionary stages:initial erosion-filling,later erosion-filling(multistage),and channel abandonment.The middle Miocene channel system may have formed as a consequence of combined regional tectonic activity and global climatic change,and its intricate morphological alterations may have been influenced by the channel's ability to self-regulate and gravity flow properties.When studying the sedimentary evolution of a large-scale deep-water channel system in the Taranaki Basin during the Oligocene-Miocene,which transitioned from a passive margin to plate convergence,it can be understood how tectonic activity affected the channel and can also provide a theoretical reference for the evolution of the deepwater channels in areas with similar tectonic conversion environments around the world.

基于地球河流扇预测模型的火星地表水径流量预测

【目的】火星表面的水活动地质历史一直是科学界关心的热点,直接影响着火星探测的研究方向。【方法】根据火星和地球的可对比性,建立了融合345个地球现代河流扇沉积的数据集并形成了高精度扇体面积预测模型,从而识别火星上的河流扇沉积,预测火星河流扇发育期的地表水径流量。【结果】结果表示,在火星南部高地霍尔顿陨石坑附近识别出一个面积约84.35 km^(2)的典型河流扇沉积,并反向预测出该扇体形成需要的年平均地表水径流量为1.8828×10^(6)m^(3),推测出该区域径流量不是由单一降水构成,为雪山(冰川)融水和降水多种来源。【结论】该成果是河流扇研究在行星沉积学中的应用,为进一步深入研究火星和其他天体地表水活动提供了新的方法。

松辽盆地北部青山口组富烃页岩形成环境与成因

通过古地温、古地貌、沉积环境定量恢复及地质事件综合研究,分析青山口组富烃页岩形成环境及成因。结果表明,松辽盆地青山口组富烃页岩R_(o)介于0.75%~1.60%,游离烃含量高,介于(4~12)mg/g,形成于古地温梯度(50~70)℃/km的高温热盆背景;在拉伸大地动力学及热沉降背景下形成了正断层密集断裂带控制的页岩层系,两凹一凸的古地貌为页岩形成演化提供富集场所;湖相温湿气候及岩浆热液为藻类繁殖成为厚层富烃页岩发育奠定物质基础;缺氧的半深湖—深湖还原—强还原环境有利于有机质埋藏。综合分析表明,构造、湖相沉积与古地温耦合作用奠定了富烃页岩的构造背景和热动力条件,温湿气候、缺氧环境及火山热液带来的营养物质是富烃页岩形成的重要原因。

新疆博格达山北缘二叠纪中—晚期构造运动的沉积响应

博格达山北缘是准噶尔盆地与天山造山带之间的关键部位,是研究盆山关系的重点区域。博格达山北缘二叠纪中、晚期的构造演化与沉积时空演变关系存在较大争议。本研究通过野外实地勘测、镜下岩石薄片鉴定、粒度分析实验和地震资料解析等方法,针对博格达山北缘东、西部两条剖面—大龙口剖面和井井子沟剖面开展研究,分析其沉积类型和演变过程,解析盆山构造变形和发育特征,探讨构造运动的沉积响应。研究结果表明:瓜德鲁普统乌拉泊组为湖成三角洲相,井井子沟组至红雁池组为湖泊相,乐平统泉子街组为冲积扇—河流相沉积,梧桐沟组和锅底坑组为滨浅湖—三角洲相沉积;研究区可分为两个主要构造层,下构造层以伸展断陷为主要结构,上构造层以前陆冲断为主要构造变形;多期构造活动控制瓜德鲁普统、乐平统沉积演化过程,在挤压构造背景下,瓜德鲁普统的湖泊相转变为乐平统冲积扇—河流相沉积,晚期构造活动趋于稳定,区域进入准平原化作用阶段。

Rh-MoS_(2)/泡沫镍电催化还原对氟苯酚

采用电沉积法制备了MoS_(2)/泡沫镍电极,在此基础上,通过原子掺杂的方式制备了Rh-MoS_(2)/泡沫镍复合电极,运用多种手段表征了电极的结构、形貌和电化学性能,比较了掺杂Rh前后MoS_(2)/泡沫镍电极对对氟苯酚(4-FP)的催化还原效果,探讨了4-FP的降解机理。表征结果显示:Rh的掺杂促进了2H相MoS_(2)转变为1T相MoS_(2),改善了MoS_(2)的催化性能;在0.05 mol/L的Na_(2)SO_(4)溶液中,当电流密度为10 mA/cm^(2)时,Rh-MoS_(2)/泡沫镍的过电位和Tafel斜率分别为190.3 mV和70 mV/dec,远低于MoS_(2)/泡沫镍。实验结果表明:在工作电位-1.3 V、初始pH 3.3、温度293 K的条件下,电解180 min后,Rh-MoS_(2)/泡沫镍复合电极对4-FP的去除率为96%;Rh-MoS_(2)/泡沫镍复合电极催化还原4-FP的主要活性物种为e-和活性氢(H*);经过5次循环实验,Rh-MoS_(2)/泡沫镍复合电极对4-FP的去除率由96%降低至88%,表现出良好的稳定性。

Formation,evolution,reconstruction of black shales and their influence on shale oil and gas resource

Black shales are important products of material cycling and energy exchange among the lithosphere,atmosphere,hydrosphere,and biosphere.They are widely distributed throughout geological history and provide essential energy and mineral resources for the development of human society.They also record the evolution process of the earth and improve the understanding of the earth.This review focuses on the diagenesis and formation mechanisms of black shales sedimentation,composition,evolution,and reconstruction,which have had a significant impact on the formation and enrichment of shale oil and gas.In terms of sedimentary environment,black shales can be classified into three types:Marine,terrestrial,and marine-terrestrial transitional facies.The formation processes include mechanisms such as eolian input,hypopycnal flow,gravity-driven and offshore bottom currents.From a geological perspective,the formation of black shales is often closely related to global or regional major geological events.The enrichment of organic matter is generally the result of the interaction and coupling of several factors such as primary productivity,water redox condition,and sedimentation rate.In terms of evolution,black shales have undergone diagenetic evolution of inorganic minerals,thermal evolution of organic matter and hydrocarbon generation,interactions between organic matter and inorganic minerals,and pore evolution.In terms of reconstruction,the effects of fold deformation,uplift and erosion,and fracturing have changed the stress state of black shale reservoirs,thereby having a significant impact on the pore structure.Fluid activity promotes the formation of veins,and have changed the material composition,stress structure,and reservoir properties of black shales.Regarding resource effects,the deposition of black shales is fundamental for shale oil and gas resources,the evolution of black shales promotes the shale oil and gas formation and storage,and the reconstruction of black shales would have caused the heterogeneous distribution of oil and gas in shales.Exploring the formation mechanisms and interactions of black shales at different scales is a key to in-depth research on shale formation and evolution,as well as the key to revealing the mechanism controlling shale oil and gas accumulation.The present records can reveal how these processes worked in geological history,and improve our understanding of the coupling mechanisms among regional geological events,black shales evolution,and shale oil and gas formation and enrichment.

火山断陷型湖盆细粒沉积岩有机质富集模式——以松辽盆地梨树断陷下白垩统沙河子组二段下亚段为例

以松辽盆地梨树断陷下白垩统沙河子组二段下亚段(简称沙二下亚段)沉积特征为例,采用有机岩石学、主微量元素及生物标志化合物分析等方法,探讨火山断陷型湖盆细粒沉积岩有机质富集条件及富集模式。研究结果表明,沉积古环境的变化控制沙二下亚段不同岩相类型的垂向分布,并将其划分为上、下两部分,下部主要发育块状长英质泥岩夹含生屑长英质泥岩,上部主要发育纹层状长英质页岩和纹层状细粒混积页岩;下部有机质干酪根类型以Ⅱ2—Ⅲ型为主、上部以Ⅰ—Ⅱ1型为主,且总体呈现出上部有机碳含量较下部增高的特征。分析认为,火山断陷型湖盆有机质富集的主要条件为:①持续增强的裂陷作用是导致古水深加大的直接因素,基准面上升使深水沉积范围随之扩大,泥页岩发育规模相应增大;②相对强烈的水下火山喷发与裂陷作用具有同时性,火山活动可为湖盆提供大量营养物质,有利于藻类的勃发,并导致Ⅰ—Ⅱ1型干酪根生产力较高;③相对干旱的古气候导致河流淡水及陆源物质(包括陆源高等植物Ⅲ型干酪根)输入减少,形成高盐度、缺氧分层的水体,咸水湖盆有利于有机质保存。在此基础上,建立的火山断陷型湖盆细粒沉积岩有机质富集模式,对深化松辽盆地沙河子组乃至中国东北地区同期火山断陷型湖盆细粒沉积岩有机质富集机制的地质认识,具有一定的参考借鉴意义。

强人类活动下伶仃洋河口湾沉积地貌格局演化规律

基于伶仃洋河口湾1965—2016年不同年代水深数据,结合不同年代沉积物数据,分析了伶仃洋沉积地貌格局的演化规律,讨论了人类活动对伶仃洋沉积地貌格局的影响作用。结果表明:(1)过去40年,伶仃洋地形边界主要受围垦影响而大幅度变窄,河口湾滩槽格局整体受到挤压并向东偏移;在航道开挖、浚深以及河口采砂等人类活动的叠加影响下,水域面积减小、水体容积增加,地貌形态向窄深化发展;(2)从不同年代表层沉积物空间分布来看,1975年和2003—2004年沉积物由北往南呈粗-细-粗的分布规律,粒度参数整体呈条带状分布。2016年沉积物在南北方向上的分布规律不显著,细颗粒沉积物主要沿西滩、东滩分布,粗颗粒的陆源沉积物主要以斑块状分布于中滩、东槽的采砂坑以及外伶仃洋的深槽末段;粒度参数的空间分布由条带状转变为斑块状,整体沉积环境由单一向复杂转变。(3)新格局下河口湾存在3个沉积中心,即中滩北部的内伶仃洋沉积中心,外伶仃洋西侧、淇澳岛以南的西滩沉积中心以及伶仃航道末段的外伶仃洋沉积中心;它们与各区域的冲淤格局相对应。由此可见,过去40年,人类活动显著地影响了珠江伶仃洋河口湾的沉积地貌格局,本研究有助于揭示伶仃洋河口湾地貌演变趋势,对珠江河口综合治理、水资源高效利用管理与开发具有重要的实践意义。

Sedimentary facies characteristics and organic matter enrichment mechanism of lower Cambrian Niutitang Formation in South China

The purpose of this study was to examine the sedimentary facies characteristics of lower Cambrian Niutitang Formation(∈1n)in South China,to reveal the mechanism of organic matter enrichment,and to guide exploration of shale gas.Macro investigation and experimental analyses were used to assess the lithology in detail,total organic matter mass fraction w(TOC),mineral composition,and trace element characteristics of∈1n.The influencing factors of organic matter enrichment were discussed extensively,and a sedimentary facies mode was suggested.In the early stage of∈1n,the locations of Well E’yangye 1,Well Ciye 1,Well Changye 1,and Well Anye 1 respectively develop,platform inner sag,outer shelf,Jiangnan slope belt,and South China detention basin.In the late stage of∈1n,the sedimentary facies evolve with decreasing sea level.The study area presents a complete three-step basin in the Early Cambrian.In the early stage of∈1n,the first step is the Yangtze carbonate platform,the second step is the outer shelf and slope,and the third step is the deep-water basin.From the Yangtze carbonate platform to the deep-water basin,w(TOC)and the mass fraction of quartz gradually increase,the mass fraction of carbonate mineral decreases,and the mass fraction of clay mineral is higher in the second step.The sea level fluctuation results in a higher w(TOC)vertically in the lower∈1n shale,and the paleogeographic(provenance)conditions lead to better horizontal development of organic matter in the outer shelf,slope and detention basin.Trace elements are abundant in the lower∈1n,and w(TOC)is correlated positively with many trace elements.In the outer shelf,slope,and adjacent areas,hydrothermal activity and upwelling current bring nutrient-rich material and promote organic matter enrichment under a strong reducing condition.Deep-shelf,slope and deep-water basin are the best facies for the formation and preservation of organic matter,especially deep-water basin facies.It remains necessary to strengthen the exploration of shale gas in the deep-water basin of∈1n in central Hunan,China.

DETERMINATION OF SEDIMENTARY RATE IN ESTUARY AND COAST BY ^(228)Th TECHNIQUE

Analysis of 232 Th, 230 Th , and 228 Th in sediments showed that there was an excess of 228 Th over that supported by the parents 232 Th or 228 Ra in sediments in many regions. This excess 228 Th with a half life of 1.91 years can be used for dating purpose over a time period of the order of a decade, so average sedimentary rates in the Yalujiang River Estuary, and in the Huanghe River Estuary and its adjacent Laizhou Bay can be obtained from decreases in the excess 228 Th activity as a function of depth in sediment.

Centurial Evolution of an Offshore Mud Deposition Area in the Changjiang (Yangtze) Estuary and Its Links to Environmental and Anthropogenic Activities

Large amounts of sediments originating from the Changjiang(Yangtze)River are deposited in the subaqueous delta and in the adjacent muddy area off the mouth and on the inner shelf of the East China Sea.The terrestrial sediments deposited in these areas not only contain information about the composition and environment of the source area,but they also record changes in anthropogenic activities.A sediment piston core(CJ0702)was extracted from the Changjiang subaqueous depocenter(31.00°N,122.67°E)in a water depth of 22.0 m.The core was subsampled at 1–2 cm intervals and analyzed for grain size,clay mineralogy,and major element geochemistry.Results indicate a relatively high sediment accumulation rate of approximately 3.11 cm yr−1.These parameters exhibited only minor cyclical fluctuations in the core,which resulted from many factors.During the past 120 years,the Changjiang River-derived sediment is the primary source of sediment in the offshore mud area without evidence for the Yellow River-derived sediment increasing.After the trunk stream shifted from the North Branch to South Branch,the variations of proxies are controlled by the periodic fluctuation possibly linked to El Niño-Southern Oscillation(ENSO)and the Pacific Decadal Oscillation(PDO).In addition,anthropogenic heavy metal concentrations can be divided into three stages,which coincide well with economic development and environmental protection policies.

Apply X-Ray Fluorescence and γ-Ray Spectroscopy to Analyze Igneous and Sedimentary Environmental Samples of Al-Atawilah (Al-Baha), Saudi Arabia

Igneous and sedimentary rocks contain an amount of natural radioactivity (NORM). U-238, Th-232 and their decay products, and K-40 are important sources of gamma-radiation. Knowledge of the radionuclide content of rocks is necessary to estimate the exposure of the population to the radiation. Many types of rocks are used in building and industries, thus the radiation detection is important, it provides a baseline map of levels of the radioactivity in the study region. The purpose of this study is to evaluate the activity concentrations of the natural radionuclides (U-238 (Ra-226), Th-232 and K-40) and the fallout nuclide (Cs-137) (if found) in thirty samples of igneous and sedimentary rocks of Al-Atawilah (Al-Baha). The samples were collected and prepared during 2018/2019, and analyzed with a good experimental instrument (High energy resolution γ-ray spectroscopy with HPGe detector), also these rock samples were analyzed with X-ray fluorescence to subdivided these rocks based on the major oxides proportions contained of each sample. The mean activity concentrations of naturally radionuclides were found in the igneous rock samples varied depending on the type of the igneous rock. For sedimentary rock samples, the activity concentrations were found high for quartz sandstone sample, which may be due to its high proportion of SiO2 and K2O. The estimated mean values of absorbed dose rate are within the permissible limit value. The findings indicate high dose level values in granite (rhyolite) and most of diorite (andesite) igneous rock samples while gabbro (basalt) igneous rock samples (except for one sample) record low levels of dose rate. All sedimentary rock samples have low dose rate (except for the quartz sand-stone sample).

莫西庄地区三工河组断层活动差异性控制的转换沉积作用特征

针对莫西庄地区三工河组二段油水分布规律复杂、砂体沉积特征及沉积控制因素认识不清的问题,基于测井、岩心、物性和地震资料,结合断层活动性,对该区沉积特征进行分析,确定沉积控制因素,建立不同时期沉积模式,明确砂岩储层空间位置。研究表明:莫西庄地区发育辫状河三角洲前缘沉积体系,根据沉积特征划分为颗粒支撑砾岩相、砂砾岩相、含砾砂岩相、块状砂岩相、交错层理砂岩相、平行层理砂岩相、水平层理砂岩相、泥岩相等8种岩相和辫状水道、分流间湾、河道砂坝、河口坝、远砂坝、滨浅湖6种沉积微相;在三工河组二段下亚段沉积时期北断层活动强烈,使研究区形成坡折地貌,导致研究区南北地区出现水动力转换沉积特征;在湖平面上升和水动力减弱的背景下,上亚段沉积时期南断层活动加剧,与北断层形成的地堑构造控制了研究区东南部砂体沉积方向的转换,有利砂体的沉积方向转为了近东西向。该研究对判断莫西庄地区砂体储层的空间分布具有指导意义。

沉积岩中总有机碳测定的自动预处理方法

总有机碳(TOC)是衡量烃源岩有机质丰度的首要指标,实现其高效准确测定具有重要的现实意义。在TOC整体测试流程中,用稀盐酸去除无机碳的样品预处理过程目前主要采用手动法进行,存在周期长、氯化物残留等问题,成为制约整体测试效率的首要因素。学者们研究了溶样时间、溶样温度、离心洗样等对TOC测定值的影响,但尚未形成系统的预处理方法,预处理效率也未得到实质性改善。本文利用自主研制的有机碳自动预处理仪建立了两种自动预处理方法;根据国家标准《沉积岩中总有机碳的测定》(GB/T 19145—2022)规定的预处理流程,采用多种岩性、不同TOC水平的国家标准物质和质量控制样品对这两种预处理方法进行了方法验证;并进一步分析了自动预处理方法的优势。结果表明,两种自动预处理的方法回收率总体为96.23%~102.12%,相对标准偏差为0.37%~3.23%,满足标准规定的数据准确性、重复性和再现性要求,数据质量较手动法得到进一步提升;自动预处理法的预处理时长大幅缩短至4~6h/批,提高了测试效率;氯离子活度对洗样次数的变化更为敏感,且可监测并有效降低样品中氯化物的残留量,建议作为洗样终点的定量监测指标。建立的两种自动预处理方法可替代手动法进行TOC测试的样品预处理,在保障数据质量和测试效率的前提下又可解放人力,使总有机碳的测试能力得以显著提升。

火山活动对沉积古环境及有机质富集的影响

火山活动在古生态环境及生物演化过程中扮演重要角色。本研究以扬子地区奥陶纪/志留纪的火山活动记录为主要研究对象,结合准噶尔盆地、鄂尔多斯盆地、三塘湖盆地地质历史时期的火山活动记录及世界各地的现代火山活动,解析了火山活动对沉积古环境及有机质富集的影响机制。地质历史时期形成的凝灰岩、沉凝灰岩、斑脱岩及含凝灰质沉积岩是火山活动的物质表现,本研究通过对其从宏观到微观的岩石学、矿物学、地球化学特征进行分析,建立起一套多角度识别火山活动的剖面岩心—微观结构—全岩矿物—地球化学综合判断法。火山活动释放的营养元素导致海洋生物勃发、初级生产力上升,利于有机质积累,而有毒物质则危害生物生存,降低初级生产力。火山活动释放营养元素与有毒物质的相对含量可能影响海洋初级生产力的最终结果。低强度火山活动促进生物繁衍,剧烈的火山活动不断加大生态环境的修复压力,最终造成不可逆的破坏。火山活动加剧水体缺氧,提高有机质保存效率。火山气体形成硫酸气溶胶增加行星反照率,造成地表温度下降。