马里亚纳弧前Quaker蛇纹岩泥火山自生烟囱生长模式

佟宏鹏, 姚凯, 陈琳莹, 胡海明, 崔彩英, 陈多福

佟宏鹏, 姚凯, 陈琳莹, 胡海明, 崔彩英, 陈多福. 马里亚纳弧前Quaker蛇纹岩泥火山自生烟囱生长模式[J]. 海洋地质与第四纪地质, 2021, 41(6): 15-26. DOI: 10.16562/j.cnki.0256-1492.2021062501
引用本文: 佟宏鹏, 姚凯, 陈琳莹, 胡海明, 崔彩英, 陈多福. 马里亚纳弧前Quaker蛇纹岩泥火山自生烟囱生长模式[J]. 海洋地质与第四纪地质, 2021, 41(6): 15-26. DOI: 10.16562/j.cnki.0256-1492.2021062501
TONG Hongpeng, YAO Kai, CHEN Linying, HU Haiming, CUI Caiying, CHEN Duofu. Formation model of authigenic chimneys on the Quaker serpentinite mud volcano in the Mariana forearc[J]. Marine Geology & Quaternary Geology, 2021, 41(6): 15-26. DOI: 10.16562/j.cnki.0256-1492.2021062501
Citation: TONG Hongpeng, YAO Kai, CHEN Linying, HU Haiming, CUI Caiying, CHEN Duofu. Formation model of authigenic chimneys on the Quaker serpentinite mud volcano in the Mariana forearc[J]. Marine Geology & Quaternary Geology, 2021, 41(6): 15-26. DOI: 10.16562/j.cnki.0256-1492.2021062501

马里亚纳弧前Quaker蛇纹岩泥火山自生烟囱生长模式

基金项目: 国家自然科学基金项目“马里亚纳弧前蛇纹岩泥火山烟囱状自生沉积的成因及深源蛇纹石化流体渗漏活动记录”(41776080),“马里亚纳弧前海底蛇纹岩泥火山无机成因甲烷形成水合物的条件及潜力分析”(41776050)
详细信息
    作者简介:

    佟宏鹏(1985—),女,博士,副研究员,主要从事海底流体活动沉积记录研究,E-mail:hptong@shou.edu.cn

    通讯作者:

    陈琳莹(1988—),女,助理研究员,主要从事沉积物和孔隙水样品实验方法研究,E-mail:lychen@shou.edu.cn

  • 中图分类号: P736

Formation model of authigenic chimneys on the Quaker serpentinite mud volcano in the Mariana forearc

  • 摘要: 马里亚纳弧前蛇纹岩泥火山顶发育烟囱状自生沉积,由海底低温碱性流体渗漏形成,它对示踪蛇纹石化流体渗漏有重要意义,但烟囱生长模式仍未明确。本文选取马里亚纳弧前Quaker蛇纹岩泥火山烟囱状自生碳酸盐岩,进行岩石学、矿物学和元素地球化学研究,查明不同生长阶段烟囱元素组成、矿物类型及演化规律,提出烟囱生长模式。幼年烟囱具有高MgO(18.5%~37.5%)和低CaO含量(12.2%~32.1%),由方解石(52.0%~77.6%)及以水镁石为主的富镁碱性矿物组成;成熟烟囱MgO含量显著降低(1.5%~23.6%),CaO含量显著升高(18.6%~53.3%),除发育方解石(59.8%)和少量富镁矿物外,还发育文石(23.4%);死亡烟囱不含富镁矿物,文石含量最高(33.2%),显微镜和扫描电镜下均观察到文石交代富镁矿物。不同类型烟囱间元素和矿物组成差异以及岩石学特征,说明渗漏流体导致方解石和水镁石沉淀,而文石为交代产物,在烟囱成熟过程中亚稳定的水镁石最终被文石交代,文石及CaO和MgO含量可指示烟囱的成熟程度。同一烟囱横截面由内向外微区样品的MgO含量依次降低,CaO含量依次升高,说明烟囱内侧较新,外侧较老,烟囱由外向内生长。同一烟囱下部横截面MgO含量低于上部横截面,CaO含量则相反,说明下部先形成,指示烟囱自下而上生长。
    Abstract: Authigenic chimneys, found at the top of serpentinite mud volcanos in the Mariana forearc, are induced by the seepage of low temperature and alkaline fluids. They are critical significant to trace the eruption of serpentinization fluids. However, few is known with regards to the formation mechanism of these chimneys. In this paper, detailed investigations are carried out on the petrology, mineralogy, and major elemental geochemistry of the chimneys collected from the Quaker serpentinite mud volcano in the Mariana forearc region so as to explore the formation model of these authigenic chimneys. Base on the mineral and elemental compositions, as well as neomorphic processes, three types of chimneys are identified. It is found that infancy chimneys are high in MgO (18.5%~37.5%) and low in CaO contents (12.2%~32.1%), and mineralogically composed of calcite (52.0%~77.6%) and magnesium-rich alkaline minerals, such as brucite, hydromagnesite, and hydrotalcite, while the mature chimneys are characterized by reduced MgO contents (1.5%~23.6%) and enhanced CaO contents (18.6%~53.3%), and mineralogically composed of calcite (59.8%), magnesium-rich minerals and aragonite (23.4%). Dead chimneys have the highest aragonite content (33.2%), but do not contain any magnesium-rich minerals. In addition, microscopic observation results have revealed the precursory magnesium-rich alkaline minerals replaced by aragonite. The variations of elemental and mineral compositions among different types of chimneys, and their petrological characteristics suggest that the fluid seepage induced calcite and brucite precipitation, while aragonite represents a replaced phase of brucite. Brucite occurrences indicate newly formed fabrics, while aragonite reflects an old precursory mineral. Micro-drilled samples from the same chimney cross section show successively decrease of MgO content and increase of CaO content from inner to outer, suggesting that the outer texture is older than the inner. The top of a chimney displays higher MgO and lower CaO contents than the bottom, indicating that the top is relatively younger.
  • 天然气水合物主要赋存于大陆边缘和大陆永久冻土区[1-2],以层状、块状、分散状、胶结状、瘤状等形式赋存于地层中[3],可归结为两大类,即孔隙充填型和裂隙充填型。孔隙充填型水合物替代了孔隙中的流体,赋存于沉积物孔隙中[4];裂隙充填型水合物则以纯水合物形式与沉积物互相接触,一般存在于沉积物裂隙、地层裂隙、断层或泥火山等特殊地质体中。因此,由于赋存状态和岩石物理性质不同,针对孔隙充填型、裂隙充填型水合物往往采用不同的方法进行资源评估。然而,在野外勘探过程中,如何通过简便的方法识别水合物类型,尚无较为成熟的识别方法。

    已有钻探结果为认识孔隙充填型和裂隙充填型水合物打下了良好基础[5-6]。中国、美国、印度、韩国等钻探表明,中国南海神狐海域天然气水合物以孔隙充填为主[7],而美国墨西哥湾[8]、韩国Ulleung盆地[9]和印度K-G盆地[10-11]的细粒沉积物中均发现了裂隙充填型水合物。2006年,印度国家天然气水合物计划(NGHP01)在K-G盆地通过测井和钻探发现大量裂隙充填型水合物富集,测井和红外成像显示水合物多呈结核状、脉状、瘤状,充填于高角度(60°~120°)裂隙以及近水平层理中,其中充填水合物的裂隙层位厚度最大可达135 m,长度达数米以上[1, 5, 11]。孔隙充填型水合物和裂隙充填型水合物最主要的区别在于非微观尺度研究中,孔隙充填型水合物通常被看作是各向同性介质,而裂隙充填型水合物则是各向异性介质[12]。中国地质调查局广州海洋地质调查局2013年在中国南海北部海域开展的第二次水合物勘探GMGS2,在13个站位布设了21个钻井,并取得了保压岩心[13],其中5个站位发现了水合物,这一航次中同时发现了孔隙充填型和裂隙充填型水合物。

    由于孔隙充填型和裂隙充填型水合物的形成机理和地球物理响应都存在差异,因此,在无钻探井位的区域,准确识别两类水合物在沉积层中的分布形态,对于水合物资源评价、钻采安全以及环境等方面都至关重要[14]。目前为止,关于孔隙充填型和裂隙充填型水合物识别的文献相对较少。戴丹青等[15]利用中观衰减理论,用斑块饱和模型和双孔隙模型针对水合物在地层中的赋存状态,研究了地震频带内BSR界面反射系数的变化特征,并将研究结果应用到存在孔隙充填型水合物的南海神狐海域和存在裂隙充填型水合物的布莱克海台,模拟结果与实际情况吻合较好。王吉亮等[3]为识别印度东海岸NGHP01-10D井的水合物赋存状态,利用等效介质理论(EMT)和层状介质横向各向异性模型分别计算了水合物的饱和度,发现层状介质横向各向异性模型计算的结果与实际情况吻合较好,且存在的裂隙多为高角度裂隙。Lee等[16]利用各向同性模型和横向各向同性理论计算了韩国东海Ulleung 盆地UBGH2-3B井中水合物层的电阻率、纵波速度和水合物饱和度,研究结果表明井中局部范围水合物的赋存类型为裂隙充填型,气烟囱上半部分(5~14 mbsf)地层中主要赋存裂隙角度约7°的裂隙充填型水合物,下半部分(45~103 mbsf)中赋存高角度裂隙充填型水合物。Liu等[17]提出利用纵波速度和电阻率交汇图的斜率来识别两类水合物。Sriram等[18]对含孔隙充填型/裂隙充填型水合物地层的BSR进行了AVA(振幅随入射角的变化)模拟,通过模拟将两者的AVA类别进行归类,从而达到水合物在储层中赋存形态的识别。Liu等[19]通过岩石物理模拟分别计算了孔隙充填型和裂隙充填型水合物的密度和速度,提出用密度速度属性识别孔隙充填型及裂隙充填型水合物的方法。

    迄今为止,对水合物赋存形态识别的研究多以模拟手段为主来计算两种类型水合物储层的电阻率、纵波速度、地震衰减/反射系数及AVA/AVO属性。截至目前,未发现将模拟结果与实验实测数据进行对比分析的案例。本文针对孔隙充填型水合物选取了EMT(A、B模式)、BGTL和STPE模型,针对裂隙充填型水合物(本文仅以裂隙空间发育的纯水合物为研究对象)(图1a)选取了横向各向同性理论(TIT),模拟了两种类型水合物的密度和声波速度与水合物体积分数间的变化特征,并通过声学实验获取了孔隙充填型和裂隙充填型水合物的纵波速度特征。

    图  1  裂隙充填型水合物的类型[20]
    a. 裂隙空间发育的纯水合物,b. 黏土质沉积物夹杂含水合物的砂质沉积介质, c. 黏土沉积物中发育连续微裂隙中的水合物,d. 黏土沉积物中不连续微裂隙中的水合物。
    Figure  1.  Types of fracture-filling hydrates[20]
    a. Pure hydrate in fracture space, b. sandy sedimentary medium with hydrate in clay sediment,c. hydrate in continuous microfractures developed in clay sediments,d. hydrate in discontinuous microfractures in clay sediments.

    Liu等[18]、胡高伟[21]、王吉亮等[3]等关于孔隙充填型水合物岩石物理模拟的研究结果表明,等效介质理论(EMT)、BGTL理论和简化三相方程(STPE)的计算结果与实验测试波速的吻合程度相比其他岩石物理模型更具优势。因此,本文针对孔隙充填型水合物选取了EMT-A/B、BGTL和STPE岩石物理模型,计算了含孔隙充填型水合物的南海沉积物(孔隙度为0.4)的密度和纵波速度。表1为模拟计算所用的南海沉积物的弹性参数及含量表,模型计算公式见附录。

    表  1  南海泥质黏土的体积模量(K)、剪切模量(G)、密度(ρ)和含量(C[22]
    Table  1.  The bulk modulus (K), shear modulus (G), density (ρ) and content (C) of the silty clay in the South China Sea [22]
    沉积物组分K/GPaG/GPaρ/(g/cm3C/%
    方解石76.8322.7114
    石英36.6452.6528
    长石76262.7112
    云母62412.6826
    黏土20.96.852.5820
    水合物5.62.40.9
    2.501.03
    下载: 导出CSV 
    | 显示表格

    由于EMT-A和BGTL的密度计算公式相同,因此,两者模拟的密度曲线重合(图2),而EMT-B模式中,水合物形成后充当骨架的一部分,同时使得沉积物孔隙度减小,该模式计算密度时对沉积物孔隙度进行了修正,但最终计算结果与STPE相同。各模式计算的孔隙充填型水合物介质的密度尽管有差异,但最大差值仅为1.25%。

    图  2  EMT、BGTL、STPE模型计算的含孔隙充填型水合物的密度
    Figure  2.  The density of pore-filling hydrate calculated by EMT、BGTL and STPE models

    3类岩石物理模型计算的纵波速度均随水合物体积分数的增加而增大(图3),但不同模型的波速计算方式不同,波速初始起跳值也不同。当沉积物孔隙中未生成水合物(体积分数为0)时,EMT-A/B模式计算的沉积物纵波速度大于BGTL和STPE模型计算的波速,3类模型计算的纵波速度大小分两种情况:①当水合物体积分数小于17%时,波速大小为:EMT-B>EMT-A>STPE>BGTL;②水合物体积分数大于17%时,EMT-B>STPE>EMT-A>BGTL。EMT-B模式计算的波速值最大,BGTL的计算值最小,图3中横坐标体积分数40%对应水合物饱和度为100%。

    图  3  EMT、BGTL、STPE模型计算的含孔隙充填型水合物的纵波速度
    Figure  3.  The P-wave velocity of pore-filling hydrate calculated by EMT、BGTL and STPE models

    裂隙充填型水合物模型用横向各向同性理论(TIT)进行计算。模型由两个端元组成(图4),端元Ⅰ为裂隙,100%由纯水合物充填,端元Ⅱ为饱和水的南海沉积物(泥质黏土,孔隙度为0.4),其弹性参数及含量见表1。端元Ⅱ的体积模量和剪切模量基于Hill平均方程(B-5)和STPE模型计算。

    图  4  裂隙充填型水合物端元模型[23]
    Ⅰ为100%纯水合物充填的裂隙,Ⅱ为饱和水泥质黏土。
    Figure  4.  Fracture-filling hydrate end member model[23]
    Ⅰ: Fracture filled by pure hydrate; Ⅱ: Silty clay with saturated water.

    由横向各向同性理论计算的含裂隙充填型水合物的南海沉积介质的密度和纵波速度结果(图5)发现,随着水合物体积分数增大,沉积介质的总密度减小,且当模型中端元Ⅰ占比为100%时,裂隙中为纯水合物,此时介质密度最小,水合物的密度为0.93 g/cm3;纵波速度曲线最小值代表南海沉积物的模型理论速度(1.84 km/s),最大值代表纯水合物的速度(3.08 km/s),纵波速度随着水合物体积分数增大而增大。

    图  5  横向各向同性理论计算的含裂隙充填型水合物的密度和纵波速度
    Figure  5.  The density and P-wave velocity of fracture-filling hydrate calculated by layered media model

    孔隙充填型水合物声学特性模拟实验装置如图6。实验之前需要先对弯曲元超声测速探头的固有声波走时和时域反射技术(TDR)测定沉积物中含水量的误差进行标定。速度测试时需要减去超声探头的固有声波走时,标定结果为$y = 2.242x \times $$ {10^{ - 3}} - 0.01246$$y = 9.291x \times {10^{ - 4}} - 9.812 \times {10^{ - 3}}$,弯曲元换能器中纵波的固有传播时间为5.56 μs,横波固有传播时间为10.56 μs;TDR实测值与理论值间的误差范围为0.17%~6.75%,由于TDR测量的结果为一个场平均值,因此,TDR系统测试精度满足实验要求。

    图  6  天然气水合物声学模拟实验装置
    Figure  6.  Acoustic experimental apparatus for natural gas hydrate

    实验模拟过程为:将饱和度水南海沉积物装入高压反应釜,并加入SDS(十二烷基硫酸钠)溶液(加快水合物的生成),通入纯甲烷气体(纯度99.99%)使釜内压力达到目标压力(约7 MPa),并放置24 h使甲烷气溶解到SDS溶液中,随后开启制冷系统使反应釜内部温度到约1 ℃。随着水合物生成,由TDR系统测试水合物的饱和度,弯曲元声波系统测试波速。

    实验中,孔隙充填型水合物的密度由沉积物中矿物及生成的水合物的密度及其含量计算得来。纵波速度为实验测试结果(图7)。由于南海沉积物中短期很难生成高饱和度水合物,因此,反应釜中生成水合物的最大体积分数为9.6%(对应饱和度为24%)。基于实验波速数据发现,纵波速度随水合物体积分数呈正比趋势,当水合物体积分数为9.6%时,沉积介质纵波速度达到最大值2.06 km/s。

    图  7  南海沉积物中孔隙充填型水合物的纵波速度和密度
    Figure  7.  P-wave velocity and density of pore-filling hydrate in deposits of the South China Sea

    先利用实验装置(图8)进行裂隙充填型水合物实验合成,其过程为:利用雾化喷头将纯水雾化后喷洒到液氮中,合成所需量的冰粉,将冰粉与沉积物按照比例装入多孔塑胶管中,反应釜密封后通入甲烷气使釜内压力达到水合物合成所需目标压力,再将反应釜置于循环水域控温装置中进行降温(约1 ℃),直至水合物合成完毕。最后开釜取出样品,连同塑胶管一同置于岩心夹持器(图9)上,利用超声探头发射/接收声波,进行波速测试。

    图  8  裂隙充填型水合物合成实验装置
    Figure  8.  Experimental apparatus for fracture-filling hydrate synthesis
    图  9  岩心夹持测试波速装置
    Figure  9.  Rock holding device for testing wave velocity

    不加入水合物催化溶液时,南海沉积物中短期很难生成孔隙充填型水合物,且长时间内合成的水合物饱和度也很低[21]。该次裂隙充填型水合物合成实验中未向沉积物中加入SDS溶液,一个实验周期(约7天)内沉积物孔隙中几乎不会有水合物生成,实验介质可视为纯裂隙充填型水合物。

    含裂隙充填型水合物(裂隙为水平裂隙)的南海沉积介质的密度与纵波速度结果中(图10),密度计算公式为$\rho = {\eta _1}{\rho _{\rm{h}}} + {\eta _2}\left[ {{\rho _{\rm{s}}}(1 - \phi ) + {\rho _{\rm{w}}}\phi } \right]$,其中,${{\rm{\eta }}_{\rm{1}}}$${{\rm{\eta }}_{\rm{2}}}$分别为裂隙和沉积物的体积分数,${\rho _{\rm{h}}}$为纯水合物的密度,计算取值为0.93 g/cm3${\rho _{\rm{s}}}$为南海泥质黏土沉积物的骨架密度(2.66 g/cm3),${\rm{\phi }}$为沉积物孔隙度,${\rho _{\rm{w}}}$为水的密度(1 g/cm3);纵波速度为实验超声测试结果。当水合物体积分数为0时,整个沉积介质的密度即为沉积物的骨架密度(2.66 g/cm3),随着水合物体积分数增大,整个沉积介质(水合物+沉积物)的密度呈减小趋势,而当水合物体积分数为100%时,介质的密度即为纯水合物的密度值(0.93 g/cm3)。水合物体积分数为0和100%分别对应100%南海沉积物和100%纯水合物的波速,当水合物体积分数增大时,纵波速度也随之增大。

    图  10  含裂隙充填型水合物的南海沉积介质的密度与纵波速度
    Figure  10.  Density and P-wave velocity of sediment medium of South China Sea with fracture-filling hydrate

    两种类型水合物的岩石物理模拟和实验纵波速度结果中(图11),波速均随水合物体积分数增大而增大。实验中生成的孔隙充填型水合物的最大体积分数为9.6%(对应饱和度为24%)。孔隙充填型水合物的纵波速度在体积分数小于4%(对应饱和度为10%)时低于岩石物理模拟的波速,推断造成该现象的主要原因是当南海沉积物孔隙空间生成的水合物饱和度较低时,水合物呈悬浮状分散于沉积物孔隙内,导致声波信号发生衰减,且这种悬浮状态对沉积物骨架支撑几乎不起作用,故当水合物体积分数(饱和度)较低时,实验模拟的波速低于岩石物理模拟值。而当体积分数大于4%时,实验波速趋向于BGTL模型计算的理论波速。横向各向同性理论(TIT)计算的裂隙充填型(水平裂隙)水合物理论波速在水合物体积分数较大时(>40%)与实验测试的纵波速度吻合较好,但当水合物体积分数较小时,两者间的最大差为0.27 km/s,整体吻合较好。

    图  11  岩石物理模拟和实验测试的纵波速度
    Figure  11.  The P- wave velocity of petrophysical simulation and experimental test

    通过将密度与速度参数结合,计算了两种类型水合物的阻抗(ρVp)(图12)和$\rho {\sqrt V _{\rm{p}}}$属性(图13)。由于裂隙填充型水合物的实验阻抗斜率非严格负值,因此,基于阻抗无法进行两种类型水合物的判别。岩石物理模拟和实验测试的$\rho {\sqrt V _{\rm{p}}}$属性中,孔隙充填型水合物和裂隙充填型水合物曲线的斜率符号相反:孔隙充填型水合物的$\rho {\sqrt V _{\rm{p}}}$属性曲线斜率为正,而裂隙充填型水合物为负。孔隙充填型和裂隙充填型水合物的这一特征为两种类型水合物的判别提供了有效手段。

    图  12  岩石物理模拟和实验测试的孔隙充填型和裂隙充填型水合物的阻抗
    Figure  12.  The impedance of pore-filling and fracture-filling hydrates obtained by petrophysical simulation and experimental test
    图  13  岩石物理模拟和实验测试的孔隙充填型和裂隙充填型水合物的$\rho {\sqrt V _{\rm{p}}}$属性
    Figure  13.  The $\rho {\sqrt V _{\rm{p}}}$properties of pore-filling and fracture-filling hydrates obtained by petrophysical simulation and experimental test

    中国第二次天然气水合物钻探航次(GMGS2)在中国南海珠江口盆地东部第16井中同时发现了孔隙充填和裂隙充填型水合物,利用该井的密度和测井资料对$\rho {\sqrt V _{\rm{p}}}$属性识别水合物类型的方法进行验证。该16井中孔隙充填和裂隙充填型水合物平均饱和度分别为42%和50%,其中孔隙充填和裂隙充填型水合物分别位于井深(泥线以下:BML)189~198和10~20 m[18, 24]

    该井上部10~20 m验证结果(图14)表明该范围水合物类型以裂隙充填型水合物为主,夹杂部分孔隙充填型水合物。井深10~11.6、14~18.5 m深度含水合物层与背景层的$\rho {\sqrt V _{\rm{p}}}$属性差值小于零,指示该范围内存在裂隙充填型水合物,12~13.6、18.5~20 m深度$\rho {\sqrt V _{\rm{p}}}$属性差值大于零,代表赋存的水合物类型为孔隙充填型。井底部189~198 m赋存的水合物类型以孔隙充填型为主(图15),在194~196 m深度夹杂少量裂隙充填型水合物。从验证结果来看,基本与野外观测结果一致。

    图  14  GMGS2-16井上部含裂隙充填型水合物储层$\rho {\sqrt V _{\rm{p}}}$属性差值结果
    Figure  14.  Result of $\rho {\sqrt V _{\rm{p}}}$ attribute difference of fracture-filling hydrate reservoir in the upper part range of MGMS2-16 Well
    图  15  GMGS2-16井下部含孔隙充填型水合物储层$\rho {\sqrt V _{\rm{p}}}$属性差值结果
    Figure  15.  Result of $\rho {\sqrt V _{\rm{p}}}$ attribute difference of pore-filling hydrate reservoir in the lower part of GMGS2-16 Well

    密度和纵波速度间的差异提供了识别孔隙充填型水合物和裂隙充填型水合物在沉积物中赋存形态的基础。通过结合岩石物理模型和实验模拟,获得了南海沉积物中孔隙充填型和裂隙充填型水合物的密度和纵波速度参数,测试了两种类型水合物的阻抗和$\rho {\sqrt V _{\rm{p}}}$属性。研究结果表明基于$\rho {\sqrt V _{\rm{p}}}$属性可以有效识别孔隙型充填和裂隙充填型水合物:对于含孔隙充填型水合物的南海沉积物,岩石物理模型的$\rho {\sqrt V _{\rm{p}}}$属性与实验测试的$\rho {\sqrt V _{\rm{p}}}$属性曲线都是正斜率;对于含裂隙充填型水合物的南海沉积物,岩石物理模型和实验测试的$\rho {\sqrt V _{\rm{p}}}$属性都为负斜率。对于含孔隙充填型水合物的南海沉积介质,当水合物体积分数大于4%时,岩石物理模型计算的$\rho {\sqrt V _{\rm{p}}}$属性与实验数据吻合较好,尤其是STPE模型与实验结果吻合最佳,因此,STPE模型在计算南海沉积物中水合物的饱和度时相比其他模型更具优势。对于裂隙充填型水合物,当水合物体积分数较低(<40%)时,横向各向同性理论计算的$\rho {\sqrt V _{\rm{p}}}$属性和实验测试结果存在明显差异。因此,当水合物体积分数低于40%时,计算水合物的$\rho {\sqrt V _{\rm{p}}}$属性过程中需要对模型进行适当修正。

    最后利用$\rho {\sqrt V _{\rm{p}}}$属性对GMGS2航次16井赋存的孔隙充填和裂隙充填型水合物进行了验证表明结果与实际钻探结果一致,因此,利用$\rho {\sqrt V _{\rm{p}}}$属性识别孔隙充填和裂隙充填型水合物具有理论和实际可行性。

    Helgerud等[25-26]对水合物微观分布形态进行了研究,认为水合物与沉积物颗粒间的共生关系主要是充填于沉积物孔隙中,或胶结了沉积物骨架,与骨架呈支撑形态(图A-1)。对于模式A,水合物的生成替代了沉积物孔隙中的流体并占据了流体空间,因而该模式中,水合物也被认为是孔隙流体的一部分;模式B中,水合物被当作沉积物骨架的一部分,孔隙空间中只有流体,该模式对沉积物骨架的密度、体积模量和剪切模量产生了影响[21];模式C中,孔隙度的降低等同于模式B,另一方面,岩石骨架的体积模量和剪切模量发生了改变。南海沉积物中孔隙充填型水合物模拟选用A(水合物充当流体部分)和B(水合物充当骨架部分)模式进行计算。

      A-1  水合物在沉积物中的3种赋存形态
      A-1.  Three types of hydrate occurrence in sediment

    (1)模式A

    沉积介质的纵波速度及密度计算公式如下:

    $$\tag{A-1}\begin{array}{l} {V_{\rm{p}}} = \sqrt {\frac{{{K_{{\rm{sat}}}} + \displaystyle\frac{4}{3}{G_{{\rm{sat}}}}}}{{{\rho _{\rm{b}}}}}} \\ {\rho _{\rm{b}}} = (1 - \phi ){\rho _{\rm{s}}} + \phi {\rho _{\rm{f}}} \end{array}$$

    式中,KsatGsat分别是等效介质的体积模量和剪切模量;${\rho _{\rm{s}}}$${\rho _{\rm{f}}}$分别为岩石固相和流体相的体积密度。ϕc为临界孔隙度,一般取0.36~0.40 [27]。当沉积物中充填体积模量为Kf的流体时,可以根据Gassmann方程,通过如下公式得到沉积物的体积模量Ksat和剪切模量Gsat

    $$\tag{A-2}{K_{\rm{sat}}} = {K_{\rm{ma}}}\frac{{\phi {K_{\rm{dry}}} - (1 + \phi ){K_{\rm f}}{K_{\rm{dry}}}/{K_{\rm{ma}}} + {K_{\rm f}}}}{{(1 - \phi ){K_{\rm f}} + \phi {K_{\rm{ma}}} - {K_{\rm f}}{K_{\rm{dry}}}/{K_{\rm{ma}}}}}$$
    $$\tag{A-3}{G_{{\rm{sat}}}} = {G_{{\rm{dry}}}}$$

    式中,Kma为岩石固相的体积模量,KdryGdry分别为干岩石的体积模量和剪切模量,Kf为流体的体积模量。模式A中,孔隙中有水合物生成,因此,Kf计算公式为:

    $$\tag{A-4}{K_{\rm f}} = {\left[\frac{{1 - {S_{\rm h}}}}{{{K_{\rm w}}}} + \frac{{{S_{\rm h}}}}{{{K_{\rm h}}}}\right]^{ - 1}}$$

    式中,ShKh分别代表水合物占孔隙的体积分数和水合物的体积模量,Kw为水的体积模量。

    式(A-2)中,KdryGdry的计算公式为:

    $$\tag{A-5}{K_{\rm{dry}}} \!= \left\{ {\begin{array}{*{20}{c}} {{{\left[\frac{{\phi /{\phi _{\rm c}}}}{{{K_{\rm{HM}}} + \displaystyle\frac{4}{3}{G_{\rm{HM}}}}} + \frac{{1 - \phi /{\phi _{\rm c}}}}{{{K_{\rm{ma}}} + \displaystyle\frac{4}{3}{G_{\rm{HM}}}}}\right]}^{ - 1}} \!-\! \displaystyle\frac{4}{3}{G_{\rm{HM}}},\phi < {\phi _{\rm c}}} \\ {{{\left[\frac{{(1 - \phi )/(1 - {\phi _{\rm c}})}}{{{K_{\rm{HM}}} + \displaystyle\frac{4}{3}{G_{\rm{HM}}}}} + \frac{{(\phi - {\phi _{\rm c}})/(1 - {\phi _{\rm c}})}}{{\displaystyle\frac{4}{3}{G_{\rm{HM}}}}}\right]}^{ - 1}} \!-\! \displaystyle\frac{4}{3}{G_{\rm{HM}}},\phi \geqslant {\phi _{\rm c}}} \end{array}} \right.$$
    $$\tag{A-6}{G_{\rm{dry}}} \!= \left\{ {\begin{array}{*{20}{l}} {{{\left[\displaystyle\frac{{\phi /{\phi _{\rm c}}}}{{{G_{\rm{HM}}} + Z}} \!+\! \frac{{1 - \phi /{\phi _{\rm c}}}}{{G + Z}}\right]}^{ - 1}} - Z,\phi < {\phi _{\rm c}}} \\ {{{\left[\displaystyle\frac{{(1 \!-\! \phi )/(1 - {\phi _{\rm c}})}}{{{G_{\rm{HM}}} + Z}} \!+\! \frac{{(\phi \!-\! {\phi _{\rm c}})/(1 \!-\! {\phi _{\rm c}})}}{Z}\right]}^{ - 1}} \!- \!Z,\phi \geqslant {\phi _{\rm c}}} \end{array}} \right.$$
    $$\tag{A-7}Z = \frac{{{G_{\rm{HM}}}}}{6}\left(\frac{{9{K_{\rm{HM}}} + 8{G_{\rm{HM}}}}}{{{K_{\rm{HM}}} + 2{G_{\rm{HM}}}}}\right).$$

    其中,

    $$\tag{A-8}\begin{split} {K_{\rm{HM}}} =& {\left[\displaystyle\frac{{{n^2}{{(1 - {\phi _{\rm c}})}^2}{G_{\rm{ma}}}^2}}{{18{\pi ^2}{{(1 - \nu )}^2}}}P\right]^{\frac{1}{3}}}\\ {G_{\rm{HM}}} =&\displaystyle\frac{{5 - 4\nu }}{{5(2 - \nu )}}{\left[\frac{{3{n^2}{{(1 - {\phi _{\rm c}})}^2}{G_{\rm{ma}}}^2}}{{2{\pi ^2}{{(1 - \nu )}^2}}}P\right]^{\frac{1}{3}}} \end{split} $$

    式(A-8)中,P为有效压力;KmaGma分别是岩石骨架的体积模量、剪切模量,由公式(A-13)计算;ν是岩石骨架的泊松比,且$\nu = 0.5({K_{\rm{ma}}} - \displaystyle\frac{2}{3}{G_{\rm{ma}}})/({K_{\rm{ma}}} +$$ {G_{\rm{ma}}}/3) $n为临界孔隙度时单位体积内颗粒平均接触的数目,一般取8~9.5[28-29]

    (2)模式B

    模式B中水合物被认为是岩石骨架的一部分,产生了两个效应:一个是使孔隙度减小,另一个是改变了骨架的体积模量和剪切模量。因此,在模式A的基础上,需对沉积物孔隙度进行修正,即ϕr=ϕ(1-Sh)。同时,应将水合物作为矿物组分代入公式(A-9)来计算岩石的KmaGma。此外,沉积物孔隙中只有水,孔隙流体密度和体积模量等直接用水的替代。

    BGTL理论(Biot-Gassmann Theory modified by Lee的简称)建立在经典的BGT理论(Biot-Gassmann Theory)上,在预测速度时不仅考虑了分压的影响,而且还考虑了岩石的孔隙度、固结度等因素的影响,其公式为:

    $$\tag{A-9}{V_{\rm{p}}} = \sqrt {\frac{{k + 4\mu /3}}{\rho }} ,{V_{\rm s}} = \sqrt {\frac{\mu }{\rho }} $$

    式中,$k$$\mu $分别为沉积介质的体积模量和剪切模量。

    $$\tag{A-10}k = {k_{\rm{ma}}}(1 - \beta ) + {\beta ^2}M,\frac{1}{M} = \frac{{\beta - \phi }}{{{k_{\rm{ma}}}}} + \frac{\phi }{{{k_{\rm{fl}}}}}$$

    式中,${k_{\rm{ma}}}$为岩石骨架的体积模量,${k_{\rm{fl}}}$为孔隙中流体的体积模量;$\beta $是Biot系数,表征了流体体积变化与岩石体积变化的比值,与沉积介质的孔隙度有关;M为一模量,表征了沉积介质体积不变的情况下,将一定量的水压入沉积介质所需要的静水压力增量[30]。BGTL理论假设沉积介质速度比率与沉积物基质速度比率之间存在如下关系:

    $$\tag{A-11}{V_s} = {V_{\rm{p}}}G\alpha {(1 - \phi )^n}$$

    式中,$\alpha $为基质部分的Vs/VpG是与沉积物中黏土含量有关的常数,n取决于分压大小及岩石的固结程度。

    由公式(B-2)和(B-3)得出沉积介质的剪切模量为:

    $$\tag{A-12}\mu = \frac{{{\mu _{\rm{ma}}}{G^2}{{(1 - \phi )}^{2n}}k}}{{{k_{\rm{ma}}} + 4{\mu _{\rm{ma}}}[1 - {G^2}{{(1 - \phi )}^{2n}}]/3}}$$

    式中,${\mu _{\rm{ma}}}$为岩石骨架的剪切模量。${k_{\rm{ma}}}$${\mu _{\rm{ma}}}$由Hill平均方程计算[31]:

    $$\tag{A-13}\begin{array}{l}{k_{\rm{ma}}} = \displaystyle\frac{1}{2}\left[\sum\limits_{i = 1}^m {{f_i}} {k_i} + {\left(\sum\limits_{i = 1}^m {{f_i}/{k_i}} \right)^{ - 1}}\right],\\ {\mu _{\rm{ma}}} = \displaystyle\frac{1}{2}\left[\sum\limits_{i = 1}^m {{f_i}{\mu _i} + {{\left(\sum\limits_{i = 1}^m {{f_i}/{\mu _i}} \right)}^{ - 1}}} \right] \end{array}$$

    式中,m为岩石固相部分中矿物的种数,${f_i}$为第i种矿物占固相部分的体积分数;${k_i}$${\mu _i}$分别为第i种矿物的体积模量和剪切模量。

    利用Lee[32]的简化三相方程(STPE)可以计算各向同性的气体水合物填充沉积物孔隙空间的速度。Lee推导出低频下气体水合物填充沉积物孔隙空间的体积模量和剪切模量,用于测井和地震数据:

    $$\tag{A-14}k = {K_{\rm{ma}}}\left( {1 - {{\rm{\beta }}_{\rm{p}}}} \right){\rm{ + }}{{\rm{\beta }}_{\rm{p}}}^{\rm{2}}{K_{{\rm{av}}}},{\rm{\mu }} = {{\rm{\mu }}_{\rm{ma}}}\left( {{\rm{1 - }}{{\rm{\beta }}_{\rm{s}}}} \right)$$
    $$\tag{A-15}\frac{1}{{{K_{\rm{av}}}}}{\rm{ = }}\frac{{{{\rm{\beta }}_{\rm{p}}}{\rm{ - }}{\rm{\phi }}}}{{{K_{\rm{ma}}}}} + \frac{{{{\rm{\phi }}_{\rm w}}}}{{{k_{\rm w}}}} + \frac{{{{\rm{\phi }}_{\rm h}}}}{{{K_{\rm h}}}},{{\rm{\beta }}_{\rm p}} = \frac{{{{\rm{\phi }}_{\rm{as}}}\left( {1 + {\rm{\alpha }}} \right)}}{{1 + {\rm{\alpha }}{{\rm{\phi }}_{\rm{as}}}}},{{\rm{\beta }}_{\rm s}} = \frac{{{{\rm{\phi }}_{\rm {as}}}\left( {1 + {\rm{\gamma \alpha }}} \right)}}{{1 + {\rm{\gamma \alpha }}{{\rm{\phi }}_{\rm {as}}}}}$$
    $$\tag{A-16}{{\rm{\phi }}_{{\rm{as}}}} = {{\rm{\phi }}_{\rm w}} + {\rm{\varepsilon }}{{\rm{\phi }}_{\rm h}},{{\rm{\phi }}_{\rm w}} = (1 - {S_{\rm h}}){\rm{\phi }},{\rm{\phi }}h = {S_{\rm h}}{\rm{\phi }}$$

    式中,α为固结参数,γ是与剪切模量相关参数,可由公式γ=(1+2α)/(1+α)得到,KmaKwKh是骨架、水和水合物的体积模量,μma是骨架的剪切模量,ϕ为孔隙度。参数ε是水合物形成使沉积物骨架发生硬化的降低量,Lee推荐使用ε=0.12为建模数值。气体水合物填充沉积物孔隙空间的纵横波速度可由下式得:

    $$\tag{A-17}{V_{\rm{p}}} = \sqrt {\frac{{k + 4\mu /3}}{\rho }} ,{V_{\rm{s}}} = \sqrt {\frac{\mu }{\rho }} $$
    $$\tag{A-18}{\rho _{\rm{b}}} = {\rho _{\rm{s}}}\left( {1 - {\rm{\phi }}} \right) + {\rho _{\rm{w}}}{\rm{\phi }}\left( {1 - {S_{\rm{h}}}} \right){\rm{ + }}{\rho _{\rm{h}}}{\rm{\phi }}{S_{\rm{h}}}$$

    式中,$\rho $是水合物填充沉积物孔隙空间的体积密度,固结参数α取决于沉积物的有效压力和固结程度。Mindlin[33]表明体积模量和剪切模量取决于有效压力的1/3次方。基于Mindlin的这一理论,深度或有效压力相关的α可由下式得:

    $$\tag{A-19}{{\rm{\alpha }}_{\rm{i}}} = {{\rm{\alpha }}_0}{({P_0}/{P_i})^n} \approx {{\rm{\alpha }}_0}{({d_0}/{d_i})^n}$$

    式中,α0是有效压力P0或深度d0处的固结参数,αi是有效压力Pi或深度di处的固结参数。

    层状介质的两端元模型(图7)表示为:

    $$\tag{B-1}\left\langle G \right\rangle = {\eta _1}{G_1} + {\eta _2}{G_2},{\left\langle {\frac{1}{G}} \right\rangle ^{ - 1}} = {\left( {\frac{{{\eta _1}}}{{{G_1}}} + \frac{{{\eta _2}}}{{{G_2}}}} \right)^{ - 1}}$$

    式中,${G_1}$${G_{\rm{2}}}$分别代表模型中组分1和组分2的任意弹性参数或参数组合,${\eta _1}$${\eta _{\rm{2}}}$分别代表组分1和组分2的体积分数。模型相速度可以根据White由拉梅常数[34]求得:

    $$\tag{B-2}{V_p} = {\left( {\frac{{A{{\sin }^2}\varphi + C{{\cos }^2}\varphi + L + Q}}{{2\rho }}} \right)^{1/2}}$$
    $$\tag{B-3}{V_s}^H = {\left( {\frac{{N{{\sin }^2}\varphi + L{{\cos }^2}\varphi }}{\rho }} \right)^{1/2}}$$

    其中:

    $$\tag{B-4}A = \left\langle {\frac{{4\mu (\lambda + \mu )}}{{(\lambda + 2\mu )}}} \right\rangle + {\left\langle {\frac{1}{{(\lambda + 2\mu )}}} \right\rangle ^{ - 1}}{\left\langle {\frac{\lambda }{{(\lambda + 2\mu )}}} \right\rangle ^2}$$
    $$\tag{B-5}C = {\left\langle {\frac{1}{{(\lambda + 2\mu )}}} \right\rangle ^{ - 1}}$$
    $$\tag{B-6}F = {\left\langle {\frac{1}{{(\lambda + 2\mu )}}} \right\rangle ^{ - 1}}\left\langle {\frac{\lambda }{{(\lambda + 2\mu )}}} \right\rangle $$
    $$\tag{B-7}L = {\left\langle {\frac{1}{\mu }} \right\rangle ^{ - 1}}$$
    $$\tag{B-8}N = \left\langle \mu \right\rangle $$
    $$\tag{B-9}\rho = \left\langle \rho \right\rangle $$
    $$\tag{B-10}Q \!=\! \sqrt {{{[(A \!-\! L){{\sin }^2}\varphi \!-\! (C \!-\! L){{\cos }^2}\varphi ]}^2} \!+\! 4{{(F \!+\! L)}^2}{{\sin }^2}\varphi {{\cos }^2}\varphi } $$

    其中,VpVsH分别代表纵波速度和水平极化横波速度,参数$ \varphi $代表入射波传播方向相对于裂隙对称轴的夹角。

    根据Thomson[35],群速度与相速度间的关系可表述为:

    $$\tag{B-11}{V_{\rm{p}}}\left( {\rm{\varphi }} \right){\rm{ = }}G{V_{\rm{p}}}\left( {{{\rm{\varphi }}_{\rm{g}}}} \right),{V_{\rm{s}}}^H\left( {\rm{\varphi }} \right) = G{V_{\rm{s}}}^H\left( {{{\rm{\varphi }}_{\rm{g}}}} \right)$$

    式中:GVp和GVsH分别代表VpVsH的群速度,$ {\varphi }_{g} $是射线方向和裂隙同相轴间的夹角,可由下式求得:

    纵波:

    $$\tag{B-12}\tan {{\rm{\varphi }}_{\rm{g}}} = {\rm{tan}}{\rm{\varphi }}[1 + 2\delta + {\rm{4}}(\varepsilon - \delta ){\rm{si}}{{\rm{n}}^2}{\rm{\varphi }}]$$

    SH波:

    $$\tag{B-13}\tan {{\rm{\varphi }}_{\rm g}} = \tan {\rm{\varphi }}(1 + 2\gamma )$$

    其中:${\rm{\gamma }} = \displaystyle\frac{{N - L}}{{2L}},{\rm{\delta }} = \frac{{{{(F + L)}^2} - {{(C - L)}^2}}}{{2C(C - L)}},{\rm{\varepsilon }} = \frac{{A - C}}{{2C}}$,γ,$ \mathrm{\delta } $$ \mathrm{\varepsilon } $是表征横向各向同性介质属性的参数。

  • 图  1   马里亚纳弧前蛇纹岩泥火山分布图及泥火山顶海底照片

    a. 蛇纹岩泥火山分布图,b和c. Quaker蛇纹岩泥火山顶烟囱建造海底照片。图b来自作者与P. Fryer 私人通讯,图c引用自文献 [41]。

    Figure  1.   Distribution map of serpentinite mud volcanoes and photos of the sea bottom at top of the serpentinite mud volcano in the Mariana forearc

    a. distribution map of serpentinite mud volcanoes,b and c are photos of the sea bottom at top of the Quaker seamount showing chimneys. b from private communication with P. Fryer,c after reference [41].

    图  2   Quaker海山烟囱样品手标本

    a. 锥形幼年烟囱底部,外壁浅黄色,烟囱内部呈白色疏松多孔结构,最内侧由白色片状矿物组成,发育中空残余流体通道;b. 手指状幼年烟囱,表皮呈象牙白色,烟囱内部组构与a类似;c. 螺旋手指状成熟烟囱,表皮浅灰色,风化特征明显,烟囱内部由白色疏松组构及最内侧白色片状矿物组成,发育中空残余流体通道;d. 成熟烟囱,烟囱表皮及内部主体与c类似,但中心发育白色片状组构;e. 不规则形态死亡烟囱,表皮棕黑色,风化特征显著,主体由白色致密组构组成,局部发育针状文石可能为残余流体通道充填物。

    Figure  2.   Chimney samples from the Quaker seamount

    a. an infancy chimney showing light yellow crust, loose and poriferous rim, white flaky core and remnant cavity of fluid channel, b. a finger shaped infancy chimney with bright white crust, but similar inner textures like the sample of a, c. a finger shaped mature chimney showing weathered light gray crust, loose and poriferous rim, white flaky core and remnant cavity of fluid channel, d. a mature chimney with crust and rim texture like the sample of c, but a filled channel, e. a dead chimney with anormal shape showing serious weathered brown crust, with most dense part and trace acicular aragonite. All the scale bars are 3 cm.

    图  3   Quaker海山自生烟囱样品体视镜照片

    a. 烟囱通道内壁片状富镁碱性矿物,b. 烟囱内壁及外壁之间发育的疏松多孔组构,c. 充填烟囱残余流体通道的针状文石。

    Figure  3.   Stereoscope photos of chimneys from Quaker seamount

    a. magnesium-rich alkaline mineral from inner rim of an infancy chimney, b. the loose and poriferous texture between crust and inner rim, c. acicular aragonite filling in a channel.

    图  4   Quaker蛇纹岩泥火山海底自生烟囱扫描电镜照片

    a和b幼年烟囱内壁发育的棱柱状方解石和细叶片状水镁石,棱柱状方解石呈双晶或多晶穿插结构;c. 细叶片状水镁石/水菱镁矿集合体呈不规则放射状;d. 粗叶片状或刀刃状水菱镁矿;e. 细叶片状水镁石附近发育六方板状镁铝碳酸根型水滑石类矿物;f. 放射状文石集合体交代水菱镁矿。白色十字表示能谱测量点。

    Figure  4.   SEM images of authigenic chimneys from Quaker serpentinite mud volcano

    a & b prismatic calcite with and thin foliated brucite in an inner rim of an infancy chimney, c. aggregations of thin foliated brucite/hydromagnesite showing irregular radial texture. Top right corner is a zoomed-in image, d. thick foliated or blade hydromagnesite, e. hexagonal hydrotalcite occurring near brucite, f. acicular aragonite replacing precursory hydromagnesite. The white cross represent measurement point of EDS.

    图  5   Quaker海山烟囱样品显微结构照片

    a和b 成熟烟囱靠近内壁的部分,孔隙度高,由方解石及呈波状消光的富镁碱性矿物组成,少量文石为交代富镁矿物产物(a单偏光;b正交偏光);c和d成熟烟囱中间部分,孔隙度中等,主要由方解石和文石组成,方解石呈自形-半自形,文石呈放射状交代先驱富镁矿物(c单偏光;d正交偏光);e. 成熟烟囱外壁,低孔隙度,大部分孔隙被充填,几乎全部由方解石和文石组成,方解石重结晶呈半自形-他形(单偏光);f. 充填死亡烟囱残余流体通道的针状文石(正交偏光)。

    Figure  5.   Microstructures of chimneys from Quaker seamount

    a & b a part near inner rim of a mature chimney with high porosity composed of calcite and magnesium-rich alkaline mineral with wavy extinction. Trace magnesium-rich alkaline mineral were replaced by aragonite(a plane-polarized light; b polarized light), c & d a part between inner rim and outer rim with medium porosity mainly composed of euhedral-subhedral calcite and radial aragonite. Aragonite replaced the precursory magnesium-rich mineral(c plane-polarized light; d polarized light), e. the crust of a mature chimney with low porosity mainly composed of calcite and aragonite. Calcite suffered recrystallization is subhedral-anhedral(plane-polarized light), f. acicular aragonite filling in a channel of a dead chimney(polarized light).

    图  6   Quaker海山自生烟囱CaO和MgO元素含量特征图

    a. CaO和MgO元素含量相关图,b. 烟囱横截面由中心向外的 CaO含量变化图,c. 烟囱横截面由中心向外的 MgO含量变化图。b和c中点位表示微区取样位置,1,2,3,4依次向外。

    Figure  6.   The major elemental compositions of chimneys from Quaker seamount

    a. CaO vs. MgO plot, b. the CaO contents of micro-drilled samples of chimney cross sections from inner to outer, c. the MgO contents of micro-drilled samples of chimney cross sections from inner to outer. The Arabic numerals represent sampling point in the cross sections. 1, 2, 3, 4 outward successively.

    表  1   Quaker海山烟囱样品XRD数据

    Table  1   XRD data of chimneys from Quaker seamount

    %
    样品编号样品描述方解石文石水菱镁矿水镁石水滑石类石盐
    Q1a幼年烟囱52.0017.318.312.30
    Q1b幼年烟囱77.6018.53.900
    Q3成熟全岩59.823.40016.80
    Q4死亡烟囱63.933.20002.8
    下载: 导出CSV

    表  2   Quaker海山烟囱状自生沉积主量元素分析结果

    Table  2   The major elemental compositions of the chimneys from Quaker seamount

    %  
    样品编号样品描述CaOMgONa2OAl2O3P2O5K2OFe2O3-T
    Q101幼年烟囱截面12.237.52.00.120.020.050.0007
    Q102幼年烟囱截面21.729.01.60.050.030.030.0015
    Q103幼年烟囱截面32.118.51.40.020.040.020.0135
    Q201成熟烟囱顶截面18.623.62.94.010.140.100.0029
    Q202成熟烟囱顶截面34.215.01.30.210.030.030.0267
    Q203成熟烟囱顶截面36.513.01.30.030.030.030.0174
    Q204成熟烟囱底截面28.414.82.82.790.090.090.0020
    Q205成熟烟囱底截面51.92.01.20.290.040.010.0029
    Q206成熟烟囱底截面53.31.71.20.040.050.010.0028
    Q207成熟烟囱底截面52.71.51.30.010.050.010.0019
      注:Fe2O3-T代表全岩铁含量。
    下载: 导出CSV
  • [1]

    Evans B W, Hattori K, Baronnet A. Serpentinite: what, why, where? [J]. Elements, 2013, 9(2): 99-106. doi: 10.2113/gselements.9.2.99

    [2]

    Schrenk M O, Brazelton W J, Lang S Q. Serpentinization, carbon, and deep life [J]. Reviews in Mineralogy and Geochemistry, 2013, 75(1): 575-606. doi: 10.2138/rmg.2013.75.18

    [3] 黄瑞芳, 孙卫东, 丁兴, 等. 蛇纹石化过程中铁活动性的高温高压实验研究[J]. 岩石学报, 2015, 31(3):883-890

    HUANG Ruifang, SUN Weidong, DING Xing, et al. Experimental investigation of iron mobility during serpentinization [J]. Acta Petrologica Sinica, 2015, 31(3): 883-890.

    [4] 王先彬, 欧阳自远, 卓胜广, 等. 蛇纹石化作用、非生物成因有机化合物与深部生命[J]. 中国科学: 地球科学, 2014, 57(5):878-887 doi: 10.1007/s11430-014-4821-8

    WANG Xianbin, OUYANG Ziyuan, ZHUO Shengguang, et al. Serpentinization, Abiogenic Organic Compounds, and Deep life [J]. Science China Earth Sciences, 2014, 57(5): 878-887. doi: 10.1007/s11430-014-4821-8

    [5] 焦鑫, 柳益群, 周鼎武, 等. "白烟型"热液喷流岩研究进展[J]. 地球科学进展, 2013, 28(2):221-232 doi: 10.11867/j.issn.1001-8166.2013.02.0221

    JIAO Xin, LIU Yiqun, ZHOU Dingwu, et al. Progress of research on “White Smoke Type” exhalative hydrothermal rocks [J]. Advances in Earth Science, 2013, 28(2): 221-232. doi: 10.11867/j.issn.1001-8166.2013.02.0221

    [6] 王先彬, 郭占谦, 妥进才, 等. 中国松辽盆地商业天然气的非生物成因烷烃气体[J]. 中国科学 D辑: 地球科学, 2009, 52(2):213-226 doi: 10.1007/s11430-009-0015-1

    WANG Xianbin, GUO Zhanqian, TUO Jincai, et al. Abiogenic hydrocarboris in commercial gases ftom the Songliao Basin, China [J]. Science China Ser D: Earth Science, 2009, 52(2): 213-226. doi: 10.1007/s11430-009-0015-1

    [7]

    Fryer P. Serpentinite mud volcanism: observations, processes, and implications [J]. Annual Review of Marine Science, 2012, 4: 345-373. doi: 10.1146/annurev-marine-120710-100922

    [8]

    Kelley D S, Karson J A, Früh-Green G L, et al. A serpentinite-hosted ecosystem: the lost city hydrothermal field [J]. Science, 2005, 307(5714): 1428-1434. doi: 10.1126/science.1102556

    [9]

    Russell M J, Hall A J, Martin W. Serpentinization as a source of energy at the origin of life [J]. Geobiology, 2010, 8(5): 355-371. doi: 10.1111/j.1472-4669.2010.00249.x

    [10]

    Fryer P, Wheat C G, Williams T, et al. Expedition 366 summary[M]//Fryer P, Wheat C G, Williams T, et al. Proceedings of the International Ocean Discovery Program. College Station, TX: International Ocean Discovery Program, 2018, 366: 1-23.

    [11]

    Schwarzenbach E M. RESEARCH FOCUS: Serpentinization and the formation of fluid pathways [J]. Geology, 2016, 44(2): 175-176. doi: 10.1130/focus022016.1

    [12]

    Fryer P, Ambos E L, Hussong D M. Origin and emplacement of Mariana forearc seamounts [J]. Geology, 1985, 13(11): 774-777. doi: 10.1130/0091-7613(1985)13<774:OAEOMF>2.0.CO;2

    [13]

    Haggerty J A. Petrology and geochemistry of neocene sedimentary rocks from Mariana forearc seamounts: Implications for emplacement of the seamounts[C]//Keating B H, Fryer P, Batiza R, et al. Seamounts, Islands, and Atolls. Washington, DC: American Geophysical Union, 1987: 175-185.

    [14]

    Frery E, Fryer P, Kurz W, et al. Episodicity of structural flow in an active subduction system, new insights from mud volcano's carbonate veins – Scientific Ocean drilling expedition IODP 366 [J]. Marine Geology, 2021, 434: 106431. doi: 10.1016/j.margeo.2021.106431

    [15]

    Grimmer J C, Greiling R O. Serpentinites and low-K island arc meta-volcanic rocks in the Lower Köli Nappe of the central Scandinavian Caledonides: Late Cambrian–early Ordovician serpentinite mud volcanoes in a forearc basin? [J]. Tectonophysics, 2012, 541-543: 19-30. doi: 10.1016/j.tecto.2012.03.014

    [16]

    Lockwood J P. Sedimentary and gravity-slide emplacement of serpentinite [J]. GSA Bulletin, 1971, 82(4): 919-936. doi: 10.1130/0016-7606(1971)82[919:SAGEOS]2.0.CO;2

    [17]

    Pons M L, Quitté G, Fujii T, et al. Early Archean serpentine mud volcanoes at Isua, Greenland, as a niche for early life [J]. Proceedings of the National Academy of Sciences of the United States of America, 2011, 108(43): 17639-17643. doi: 10.1073/pnas.1108061108

    [18]

    Spaggiari C V, Gray D R, Foster D A. Formation and emplacement of the Dolodrook serpentinite body, Lachlan Orogen, Victoria [J]. Australian Journal of Earth Sciences, 2003, 50(5): 709-723. doi: 10.1111/j.1440-0952.2003.01021.x

    [19]

    Yoshida K, Iba Y, Taki S, et al. Deposition of serpentine-bearing conglomerate and its implications for Early Cretaceous tectonics in northern Japan [J]. Sedimentary Geology, 2010, 232(1-2): 1-14. doi: 10.1016/j.sedgeo.2010.09.002

    [20] 李鸿莉, 冯俊熙, 佟宏鹏, 等. 台湾利吉蛇纹岩角砾碎屑岩地球化学特征及其指示意义[J]. 地球化学, 2020, 49(1):50-61

    LI Hongli, FENG Junxi, TONG Hongpeng, et al. Geochemical characteristics and their indicative significance of serpentine breccia clasolites in Lichi, Taiwan, China [J]. Geochimica, 2020, 49(1): 50-61.

    [21]

    Albers E, Kahl W A, Beyer L, et al. Variant across-forearc compositions of slab-fluids recorded by serpentinites: Implications on the mobilization of FMEs from an active subduction zone (Mariana forearc) [J]. Lithos, 2020, 364-365: 105525. doi: 10.1016/j.lithos.2020.105525

    [22]

    Scambelluri M, Cannaò E, Gilio M. The water and fluid-mobile element cycles during serpentinite subduction. A review [J]. European Journal of Mineralogy, 2019, 31(3): 405-428. doi: 10.1127/ejm/2019/0031-2842

    [23]

    Alt J C, Shanks Ⅲ W C. Stable isotope compositions of serpentinite seamounts in the Mariana forearc: Serpentinization processes, fluid sources and sulfur metasomatism [J]. Earth and Planetary Science Letters, 2006, 242(3-4): 272-285. doi: 10.1016/j.jpgl.2005.11.063

    [24]

    Benton L D, Ryan J G, Tera F. Boron isotope systematics of slab fluids as inferred from a serpentine seamount, Mariana forearc [J]. Earth and Planetary Science Letters, 2001, 187(3-4): 273-282. doi: 10.1016/S0012-821X(01)00286-2

    [25]

    Benton L D, Ryan J G, Savov I P. Lithium abundance and isotope systematics of forearc serpentinites, Conical Seamount, Mariana forearc: Insights into the mechanics of slab-mantle exchange during subduction [J]. Geochemistry, Geophysics, Geosystems, 2004, 5(8): Q08J12.

    [26]

    Mottl M J. Pore waters from serpentinite seamounts in the mariana and izu-bonin forearcs, leg 125: evidence for volatiles from the subducting slab[M]//Fryer P, Pearce J A, Stokking L B, et al. Proceedings of the Ocean Drilling Program Scientific Results. College Station, TX: Ocean Drilling Program, 1992: 373-385.

    [27]

    Mottl M J, Komor S C, Fryer P, et al. Deep-slab fluids fuel extremophilic Archaea on a Mariana forearc serpentinite mud volcano: Ocean drilling program leg 195 [J]. Geochemistry, Geophysics, Geosystems, 2003, 4(11): 9009.

    [28]

    Mottl M J, Wheat C G, Fryer P, et al. Chemistry of springs across the Mariana forearc shows progressive devolatilization of the subducting plate [J]. Geochimica et Cosmochimica Acta, 2004, 68(23): 4915-4933. doi: 10.1016/j.gca.2004.05.037

    [29]

    Wheat C G, Fryer P, Takai K, et al. SPOTLIGHT•South chamorro seamount [J]. Oceanography, 2010, 23(1): 174-175. doi: 10.5670/oceanog.2010.81

    [30]

    Wheat C G, Seewald J S, Takai K. Fluid transport and reaction processes within a serpentinite mud volcano: South Chamorro Seamount [J]. Geochimica et Cosmochimica Acta, 2020, 269: 413-428. doi: 10.1016/j.gca.2019.10.037

    [31] 冯俊熙, 罗敏, 胡钰, 等. 海底蛇纹岩化伴生的碳酸盐岩研究进展[J]. 矿物岩石地球化学通报, 2016, 35(4):789-799 doi: 10.3969/j.issn.1007-2802.2016.04.019

    FENG Junxi, LUO Ming, HU Yu, et al. Progress of the research on authigenic carbonates associated with oceanic serpentinization [J]. Bulletin of Mineralogy, Petrology and Geochemistry, 2016, 35(4): 789-799. doi: 10.3969/j.issn.1007-2802.2016.04.019

    [32]

    Fryer P, Saboda K L, Johnson L E, et al. Conical seamount: SeaMARC II, Alvin submersible, and seismic reflection studies[M]//Fryer P, Pearce J A, Stokking L B, et al. Proceedings of the Ocean Drilling Program Initial Reports. College Station, TX: Ocean Drilling Program, 1990: 69-80.

    [33]

    Haggerty J A, Chaudhuri S. Strontium isotopic composition of the interstitial waters from Leg 125: Mariana and bonin forearcs[M]//Fryer P, Pearce J A, Stokking L B, et al. Proceedings of the Ocean Drilling Program, Scientific Results. College Station, TX: Ocean Drilling Program, 1992: 397-400.

    [34]

    Hulme S M, Wheat C G, Fryer P, et al. Pore water chemistry of the Mariana serpentinite mud volcanoes: A window to the seismogenic zone [J]. Geochemistry, Geophysics, Geosystems, 2010, 11(1): Q01X09.

    [35]

    Klein F, Humphris S E, Bach W. Brucite formation and dissolution in oceanic serpentinite [J]. Geochemical Perspectives Letters, 2020, 16: 1-5. doi: 10.7185/geochemlet.2035

    [36]

    Tran T H, Kato K, Wada H, et al. Processes involved in calcite and aragonite precipitation during carbonate chimney formation on Conical Seamount, Mariana Forearc: Evidence from geochemistry and carbon, oxygen, and strontium isotopes [J]. Journal of Geochemical Exploration, 2014, 137: 55-64. doi: 10.1016/j.gexplo.2013.11.013

    [37]

    Stern R J, Smoot N C. A bathymetric overview of the Mariana forearc [J]. Island Arc, 1998, 7(3): 525-540. doi: 10.1111/j.1440-1738.1998.00208.x

    [38]

    Haggerty J A. Evidence from fluid seeps atop serpentine seamounts in the Mariana forearc: Clues for emplacement of the seamounts and their relationship to forearc tectonics [J]. Marine Geology, 1991, 102(1-4): 293-309. doi: 10.1016/0025-3227(91)90013-T

    [39]

    Fryer P, Mottl M J. Lithology, mineralogy, and origin of serpentine muds recovered from conical and torishima forearc seamounts[M]//Fryer P, Pearce J A, Stokking L B, et al. Proceedings of the Ocean Drilling Program, Scientific Results. College Station, TX: Ocean Drilling Program, 1992: 343-362.

    [40]

    Oakley A J, Taylor B, Fryer P, et al. Emplacement, growth, and gravitational deformation of serpentinite seamounts on the Mariana forearc [J]. Geophysical Journal International, 2007, 170(2): 615-634. doi: 10.1111/j.1365-246X.2007.03451.x

    [41]

    Fryer P, Gharib J, Ross K, et al. Variability in serpentinite mudflow mechanisms and sources: ODP drilling results on Mariana forearc seamounts [J]. Geochemistry, Geophysics, Geosystems, 2006, 7(8): Q08014.

    [42]

    Taylor J C. Computer programs for standardless quantitative analysis of minerals using the full powder diffraction profile [J]. Powder Diffraction, 1991, 6(1): 2-9. doi: 10.1017/S0885715600016778

    [43]

    Ludwig K A, Kelley D S, Butterfield D A, et al. Formation and evolution of carbonate chimneys at the Lost City Hydrothermal Field [J]. Geochimica et Cosmochimica Acta, 2006, 70(14): 3625-3645. doi: 10.1016/j.gca.2006.04.016

    [44]

    Ohara Y, Reagan M K, Fujikura K, et al. A serpentinite-hosted ecosystem in the Southern Mariana Forearc [J]. Proceedings of the National Academy of Sciences of the United States of America, 2012, 109(8): 2831-2835. doi: 10.1073/pnas.1112005109

    [45]

    Okumura T, Ohara Y, Stern R J, et al. Brucite chimney formation and carbonate alteration at the Shinkai Seep Field, a serpentinite-hosted vent system in the southern Mariana forearc [J]. Geochemistry, Geophysics, Geosystems, 2016, 17(9): 3775-3796. doi: 10.1002/2016GC006449

    [46]

    Kelley D S, Karson J A, Blackman D K, et al. An off-axis hydrothermal vent field near the Mid-Atlantic Ridge at 30° N [J]. Nature, 2001, 412(6843): 145-149. doi: 10.1038/35084000

    [47] 王秀璋, 徐学炎. 我国发现的水菱镁矿特征及其成因的探讨[J]. 地质科学, 1965, 4:374-382

    WANG Xiuchang, XU Xueyan. On the mineralogical properties and origin of hydromagneiste from China [J]. Scientia Geologica Sinica, 1965, 4: 374-382.

    [48]

    Gharib J J. Clastic metabasites and authigenic minerals within serpentinite protrusions from the Mariana forearc: Implications for sub-forearc subduction processes[D]. Doctor Dissertation of University of Hawaii, 2006.

    [49]

    Curtis A C, Wheat C G, Fryer P, et al. Mariana forearc serpentinite mud volcanoes harbor novel communities of extremophilic Archaea [J]. Geomicrobiology Journal, 2013, 30(5): 430-441. doi: 10.1080/01490451.2012.705226

    [50]

    Yamanaka T, Mizota C, Satake H, et al. Stable isotope evidence for a putative endosymbiont-based lithotrophic Bathymodiolus sp. mussel community atop a serpentine seamount [J]. Geomicrobiology Journal, 2003, 20(3): 185-197. doi: 10.1080/01490450303876

    [51]

    Peckmann J, Thiel V. Carbon cycling at ancient methane-seeps [J]. Chemical Geology, 2004, 205(3-4): 443-467. doi: 10.1016/j.chemgeo.2003.12.025

    [52]

    Eickenbusch P, Takai K, Sissman O, et al. Origin of short-chain organic acids in serpentinite mud volcanoes of the mariana convergent margin [J]. Frontiers in Microbiology, 2019, 10: 1729. doi: 10.3389/fmicb.2019.01729

    [53]

    Giampouras M, Garrido C J, Bach W, et al. On the controls of mineral assemblages and textures in alkaline springs, Samail Ophiolite, Oman [J]. Chemical Geology, 2020, 533: 119435. doi: 10.1016/j.chemgeo.2019.119435

    [54]

    Königsberger E, Königsberger L C, Gamsjäger H. Low-temperature thermodynamic model for the system Na2CO3-MgCO3-CaCO3-H2O [J]. Geochimica et Cosmochimica Acta, 1999, 63(19-20): 3105-3119. doi: 10.1016/S0016-7037(99)00238-0

    [55]

    Purgstaller B, Dietzel M, Baldermann A, et al. Control of temperature and aqueous Mg2+/Ca2+ ratio on the (trans-) formation of ikaite [J]. Geochimica et Cosmochimica Acta, 2017, 217: 128-143. doi: 10.1016/j.gca.2017.08.016

    [56]

    Bayon G, Henderson G M, Bohn M. U-Th stratigraphy of a cold seep carbonate crust [J]. Chemical Geology, 2009, 260(1-2): 47-56. doi: 10.1016/j.chemgeo.2008.11.020

    [57]

    Feng D, Chen D F, Peckmann J, et al. Authigenic carbonates from methane seeps of the northern Congo fan: Microbial formation mechanism [J]. Marine and Petroleum Geology, 2010, 27(4): 748-756. doi: 10.1016/j.marpetgeo.2009.08.006

    [58]

    Ludwig K A, Shen C C, Kelley D S, et al. U–Th systematics and 230Th ages of carbonate chimneys at the Lost City Hydrothermal Field [J]. Geochimica et Cosmochimica Acta, 2011, 75(7): 1869-1888. doi: 10.1016/j.gca.2011.01.008

    [59]

    Palandri J L, Reed M H. Geochemical models of metasomatism in ultramafic systems: serpentinization, rodingitization, and sea floor carbonate chimney precipitation [J]. Geochimica et Cosmochimica Acta, 2004, 68(5): 1115-1133. doi: 10.1016/j.gca.2003.08.006

    [60]

    Teichert B M A, Eisenhauer A, Bohrmann G, et al. U/Th systematics and ages of authigenic carbonates from Hydrate Ridge, Cascadia Margin: recorders of fluid flow variations [J]. Geochimica et Cosmochimica Acta, 2003, 67(20): 3845-3857. doi: 10.1016/S0016-7037(03)00128-5

    [61] 刘长华, 曾志刚, 殷学博. 现代海底热液硫化物烟囱体的生长模式研究现状[J]. 海洋科学, 2006, 30(5):71-73 doi: 10.3969/j.issn.1000-3096.2006.05.014

    LIU Changhua, ZENG Zhigang, YIN Xuebo. Current research on chimneys growth model of modern sea-floor hydrothermal sulfide [J]. Marine Science, 2006, 30(5): 71-73. doi: 10.3969/j.issn.1000-3096.2006.05.014

  • 期刊类型引用(4)

    1. 王云龙,邢兰昌,魏伟,韩维峰,朱作飞,苏丕波. 基于多场耦合数值模型的含水合物多孔介质声学特性:骨架颗粒排列和形状的影响. 新能源进展. 2025(01): 7-16 . 百度学术
    2. 徐卫平,丁拼搏,张峰,狄帮让,蔡志光,梅璐璐. 天然气水合物岩石物理实验研究进展. 石油物探. 2023(06): 1016-1029 . 百度学术
    3. Yong-chao Zhang,Le-le Liu,Gao-wei Hu,Qing-tao Bu,Cheng-feng Li,Zheng-cai Zhang,Jian-ye Sun,Chang-ling Liu. Formation mechanism, experimental method, and property characterization of grain-displacing methane hydrates in marine sediment: A review. China Geology. 2022(02): 345-354 . 必应学术
    4. 赵金环,刘昌岭,邹长春,陈强,孟庆国,刘洋,卜庆涛. 基于ERT技术的含水合物沉积物可视化探测模拟实验. 海洋地质与第四纪地质. 2021(06): 206-212 . 本站查看

    其他类型引用(0)

图(6)  /  表(2)
计量
  • 文章访问数:  2132
  • HTML全文浏览量:  542
  • PDF下载量:  71
  • 被引次数: 4
出版历程
  • 收稿日期:  2021-06-24
  • 修回日期:  2021-07-01
  • 网络出版日期:  2021-09-26
  • 刊出日期:  2021-12-27

目录

/

返回文章
返回