Characteristics of phosphatization and its effects on the geochemical compositions of basalts from the Mid-Pacific Mountains
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摘要:
大洋玄武岩是研究地幔不均一性、岩浆起源与演化的重要对象。然而,由于其长期与周围的海水相互作用,极易发生蚀变和次生变化。磷酸盐化是大洋玄武岩最常见的次生变化之一,会影响到其全岩地球化学成分,且目前仍没有去除磷酸盐化的有效方法。因此,研究磷酸盐化特征以及评估其对玄武岩全岩地球化学成分的影响至关重要。本文以中太平洋海山群(九皋和紫檀海山)玄武岩为研究对象,通过能谱面扫描元素分布图、主量元素以及微量元素揭示玄武岩的磷酸盐化特征,评估磷酸盐化对其全岩主微量元素的影响。面扫描元素分布图显示,中太平洋海山群玄武岩的磷酸盐化作用主要发生在玄武岩气孔和裂隙周围,以交代早期的碳酸盐化基质,形成细小的磷酸盐矿物,呈浸染状分布在玄武岩基质中为特点,并且磷酸盐化会不同程度地改变玄武岩的主量元素和微量元素成分:比如磷酸盐化会使玄武岩的MgO、CaO、Na2O、MnO含量降低,K2O和Fe2O3T含量升高,同时也会对相容元素(如Cr、Co、Ni等)、大离子亲石元素(Rb、Ba、Cs等)和稀土元素造成不同程度的影响。值得注意的是,在磷酸盐化过程中,玄武岩的Al2O3、SiO2和高场强元素(Nb、Ta、Zr、Hf和Ti)几乎不受影响。
Abstract:Oceanic basalts are ideal samples in deciphering geodynamics, mantle heterogeneity, and magma origin and evolution. However, due to its long-term interaction with the surrounding seawater, it is easy to undergo alteration and secondary alteration. Phosphatization is one of the most common secondary alteration in oceanic basalts, which can affect the geochemical compositions of basalt and there is no effective method to eliminate it yet. Therefore, it is important to evaluate the effect of phosphatization on the geochemical compositions of basalt. The mapping of element distribution by energy spectrum surface scanning with energy dispersive spectrometer, and analyses of major and trace elements of the phosphatized basalts from the Mid-Pacific Mountains were conducted. The elemental mapping shows that the phosphatization occurred mainly around the vesicles and fissures of basalts. It metasomatized the early-formed carbonated matrix by which fine phosphate minerals were formed. Phosphatization would change the major elements and trace elements of basalt. For example, phosphatization could decrease the contents of MgO, CaO, Na2O and MnO, and increase the contents of K2O and Fe2O3T in the basalt. Meanwhile, it also affected the compatible elements (such as Cr, Co, Ni, etc.), large ion lithophile elements (Rb, Ba, Cs, etc.), and rare earth elements. It is noted that Al2O3, SiO2, and high field strength elements (Nb, Ta, Zr, Hf and Ti) of the basalts are nearly unaffected the the phosphatization.
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Keywords:
- basalts /
- phosphatization /
- geochemical compositions /
- seamount groups /
- Mid-Pacific Mountains
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地震绕射波是地下构造细节和异常的反映,地下构造的不连续点会产生绕射波,如裂缝、断层、溶洞和地层尖灭等。在原始地震勘探数据中,既存在绕射波也存在反射波,反射波是地质背景的综合反映,绕射波则是地质细节的小构造的反映。相对反射波而言,绕射波的能量往往很弱,甚至难以识别,导致绕射信息常常被高能量的反射信息所覆盖,而绕射波信息是提高地震勘探分辨率的重要信息载体。在地震资料处理解释中,正确识别断层、尖灭和小尺寸散射体等地质不连续性是一个重要问题,绕射波包含有关产生绕射波的介质结构和组成的有价值信息。然而,在标准地震资料处理中,绕射波常被视为噪声而被抑制[1-3]。把绕射波从原始地震勘探记录中分离出来进行单独成像,可以加强小型地震异常体的成像,从而提高复杂断块的地震成像精度。
在过去的几十年,许多地球物理学者对地震绕射波分离方法做了相关研究。1988年Kanasewich和Phadke[4]提出了一种适用于共偏移距道集的绕射波走时曲线直接拾取绕射波的方法来分离绕射波。1992年Claerbout[5]首次提出了平面波预测滤波器的概念,并在信噪分离方面得到了很好的应用。Fomel[6]进一步完善了平面波预测滤波器,并提出了平面预测滤波器的残差可以作为绕射波的近似。Nowak等[7]根据反射波和绕射波同相轴的几何差异,采用加权双曲Radon滤波器分离地震绕射波。Berkovitch等[8]利用绕射波多次聚焦叠加剖面将绕射波聚焦到绕射点位置,同时将反射波反聚焦到整个道集记录,从而分离绕射波。Koren和Ravve[9]提出了方位相关反射波属性,通过构建加权叠加滤波器将绕射波和反射波分离。Klokov等[10]根据角度域共成像点道集中反射波和绕射波的差异,首先压制去除反射顶点附近反射能量,然后利用混合Radon变换去除剩余反射波能量,进而分离出绕射波。Moser和Howard[11]提出基于深度域的反射聚焦,从叠前数据中过滤反射进而对绕射波分离成像的方法。Decker等[12]使用人工模拟数据和从皮森盆地获得的野外实际数据进行绕射波分离,评估解决绕射特征的多种方法,证明平面波预测滤波器方法能使图像保存更多绕射能量和较少的迁移伪影,但不足是无法消除斜率不连续的反射变量。上述绕射波分离算法主要是利用了绕射波和反射波在不同地震数据道集中的差异,通过数学变换或者信号预测的方法将绕射波识别和分离出来。在国内研究方面,赵娟娟等[13]利用F-K滤波方法分离成像绕射波,通过F-K域斜率滤波去除反射波从而分离出绕射波信息。马永生[14]从油藏中具有代表性的地质模型出发,分析VSP中绕射波的基本特点,理论上总结了绕射波运动学的部分认识规律。黄建平等[15]着重介绍了平面波预测滤波器及其在叠前域、叠后域分离并成像绕射波的方法原理,探讨了绕射波分离成像方法的应用前景和改进方向。朱生旺[16]提出一种局部倾角滤波和预测反演联合起来分离绕射波的方法。蒋波等[17]提出一种基于反射波层拉平的绕射波分离与成像方法用于碳酸盐岩缝洞储集体地质目标,提高对溶洞、裂缝等特殊异常体的刻画精度。李正伟等[18]根据倾角域共成像点道集中菲涅耳带变化特点,通过倾角-偏移距道集中精确切除菲涅耳带的方法来分离绕射波。本文在平面波分解绕射波分离[6]基础上,分析了绕射波与反射波信号特征的差异,深入研究了平面波预测的绕射波分离方法的影响因素,并探讨了噪声和平面波预测滤波器平滑参数对地震绕射波分离结果的影响,为在实际地震数据处理中应用平面波分解方法进行绕射波分离提供了理论指导。
1. 平面波预测绕射波分离
地震记录既含有反射波同相轴也含有绕射波同相轴,在点震源激发时,反射波和绕射波波形在炮记录中都是双曲线,不易于分离反射波和绕射波。在平面波震源激发时,来自反射界面的反射波是平面波,而来自绕射体的绕射波是双曲线。因此,在平面波震源条件下反射波和绕射波具有明显的几何差异,更有利于绕射波分离。在实际地震勘探中大都是点源激发,反射波和绕射波的同相轴不易区分,但我们根据爆炸反射面理论将共偏移距剖面近似为平面波震源获得的地震记录,这样绕射波和反射波有较好的几何差异,根据其几何差异进行绕射波分离。
平面波预测滤波器利用未知的局部倾角构造最优非稳态预测误差滤波器,根据相邻地震道的数据,在局部倾角平滑变化约束下,使预测误差最小化以此预测目标道数据。通过最优化方法不断迭代可获得局部倾角场,倾角场能够反映反射波场几何信息。
局部平面波的微分方程表示为[6]:
$$\frac{{\partial P}}{{\partial {{x}}}} + \sigma \frac{{\partial P}}{{\partial t}} = 0$$ (1) 其中,
$P\left( {t,x} \right)$ 是波场,$x$ 、$t$ 分别是炮检距和旅行时,$\sigma $ 是局部倾角,是$x$ 和$t$ 的函数,局部倾角是旅行时对炮检距的导数。Fomel给出了Z变换域平面波预测的形式[6]:
$${\hat P_{x + 1}}\left( {{Z_t}} \right) = {\hat P_x}\left( {{Z_t}} \right)\frac{{B\left( {{Z_t}} \right)}}{{B\left( {{\rm{1/}}{Z_t}} \right)}}$$ (2) 式中,
${{\hat P}_x}\left( {{Z_t}} \right)$ 是相应记录道的Z变换形式,$B\left( {{Z_t}} \right){\rm{/}}B\left( {{\rm{1/}}{Z_t}} \right)$ 等价于全通数字滤波器。用Taylor级数展开拟合得到${B\left( {{Z_t}} \right)}$ 五阶中心滤波器:$$ \begin{split} {B_5}\left( {{Z_t}} \right) =& \frac{{(1 - \sigma )(2 - \sigma )(3 - \sigma )(4 - \sigma )}}{{1\;680}}Z_t^{ - 2} + \\ &{\frac{{(4 - \sigma )(2 - \sigma )(3 - \sigma )(4 + \sigma )}}{{420}}Z_t^{ - 1} + }\\ &{\frac{{(4 - \sigma )(3 - \sigma )(3 + \sigma )(4 + \sigma )}}{{280}} + }\\ &{\frac{{(4 - \sigma )(2 + \sigma )(3 + \sigma )(4 + \sigma )}}{{420}}{Z_t} + }\\ &{\frac{{(1 + \sigma )(2 + \sigma )(3 + \sigma )(4 + \sigma )}}{{1\;680}}Z_t^2} \end{split} $$ (3) 利用平面波预测滤波器预测分离绕射波的过程中,关键一步是反射波同相轴局部倾角的估计。如果局部倾角已知的情况下,可以用
$C\left( \sigma \right)$ 表示地震数据与二维滤波器的褶积算子。因此,在最小平方意义下,可通过求解如下最小二乘目标函数估计局部倾角:$$C\left( \sigma \right)d \approx 0$$ (4) 其中,
$d$ 为已知的地震数据。优化问题(3)可以利用高斯—牛顿线性化迭代的方法求解:$$C'\left( {{\sigma _0}} \right)\Delta \sigma d + C\left( {{\sigma _0}} \right)d \approx 0$$ (5) 式中,
$\Delta \sigma $ 为倾角增量,${{\sigma _0}}$ 为初始倾角,$C\left( {{\sigma _0}} \right)$ 为对应初始倾角${{\sigma _0}}$ 估计的褶积算子。$C'\left( {{\sigma _0}} \right)$ 为$C\left( {{\sigma _0}} \right)$ 的导数值。为了保证倾角场稳定可靠,在反演求解过程中引入正则化约束项,控制倾角场沿着空间和时间两个方向平滑。由于平面预测是针对平面波形的预测,而绕射波难于满足其预测方程,因此一旦估计出了倾角场,将倾角参数代入预测方程(4),预测的残差就是绕射波的近似。图1给出了平面波预测绕射波分离算法的流程图。在平面波预测绕射波分离方法中,倾角场估计的正则化平滑参数是一个重要的参数,它控制着倾角的空间平滑性,从而约束着预测的范围。同时,实际地震勘探中噪声的存在也会影响倾角的估计和绕射波的分离,因此需要对噪声和正则化参数进行深入的分析讨论。
2. 噪音水平和光滑半径影响因素
以地震勘探中被广泛采用的Sigsbee 2A模型为例对绕射波分离算法的影响因素进行分析。在绕射波分离的过程中,倾角场预测结果对绕射波分解效果影响较大,而噪声和平面波预测平滑参数均对倾角场的估计产生影响。图2-4中,在目标数据中增添了不同方差的均值为0的正态分布随机噪音,给出了不同噪声水平下的倾角场估计结果和绕射波分离结果。随着噪音水平的增大,原始数据共偏移距地震数据变得复杂,估计的倾角场准确性降低,尤其在低信噪比情况下倾角场估计的误差变大,但是高信噪情况下倾角场估计的结果较好,尽管在原始数据中可以观察到噪声,但估计的倾角几乎和没有噪声数据估计的倾角一致,其主要原因是正则化平滑技术约束了倾角场的平滑性,提高估计的稳定性和可靠性。在高信噪比情况下,尽管倾角场估计比较准确,但是绕射波的分离仍然受到了噪声影响,其原因为在平面波预测中我们只把可预测的平面波提取出来,而噪声也被留在了残差中,而残差正是绕射波的估计,因此在分离的绕射波中含有噪声。噪声水平越强,分离的绕射波效果越差,在低信噪比条件下,倾角场的估计也变差,绕射波分离结果几乎被淹没在噪声和假象下,无法得到较好的绕射波信息。由于噪声会降低倾角场估计的精度,同时噪声也会影响分离算法的效果,因此,在利用平面波预测法进行绕射波分离时,必须要先压制随机噪音,从而提高分离结果的精度。
倾角估计问题属于反问题范畴,存在多解性和不适定性,为了解决这一问题,需要采用正则化技术对估计的局部倾角场进行约束。在反问题正则化中光滑半径参数控制着正则化程度,下面讨论在倾角估计过程中,沿着水平方向平滑和沿垂直方向平滑半径大小对倾角预测和绕射波分离结果的影响。图5显示了不同平滑半径下倾角估计和绕射波分离的结果。随着水平或垂直方向光滑半径的不断增大,倾角估计值的范围越来越小,倾角估计的结果在水平或垂直方向上越来越平滑,随着光滑半径的进一步增大,理论上当光滑半径趋于无穷大时,倾角估计结果也会趋于与坐标轴平行。从对应的绕射波分离结果来看,随着光滑半径的增大,倾角估计值变小,绕射波分离结果显得越来越干净,信噪比明显提高。具体原因有两方面:一是大的光滑半径将部分噪音平滑掉了,减少了噪音对分离结果的干扰;二是大的光滑半径将小的绕射波忽略了,这样大尺度的绕射波就显得很干净。光滑半径太小会使倾角估计的范围大于理论值,使绕射波分离结果中出现许多全波场中没有的小尺度绕射波,使得绕射波分离结果信噪比降低,利用这些小尺度绕射波偏移成像后可能出现许多小尺度地质构造体假象,即造成偏移噪音和偏移假象[19]。
图 5 不同平滑半径对倾角估计及绕射分离结果的影响a-b是光滑半径为3的结果,c-d是光滑半径为10的结果,e-f是光滑半径为50的结果。Figure 5. Influence of different smoothing radius on dip angle estimation and diffraction separation results.a-b is the result of smooth radius of 3, c-d is the result of smooth radius of 10, e-f is the result of smooth radius of 50.因此,在应用平面波预测进行倾角估计和绕射波分离时应选择合适的光滑半径。光滑半径较小时,算法对小型地质体的绕射波识别更敏感。光滑半径较大时,小尺度绕射波没有很好地分离出来,不利于小尺度地质体的识别与成像。但较大的光滑半径对大型的绕射波聚焦顶点的识别非常清晰。在处理实际数据时,应根据具体的研究目的对平滑参数做适当的调整。例如,识别的目标是地下小尺度构造体、小型缝洞时,可以选择较小的光滑半径;若研究的目标是大型裂缝、断层、不整合面以及地层缺失时,应当选择较大的光滑半径。
3. 地震数据绕射波分离算例
为了说明平面波预测地震绕射波分离的效果,我们将其应用于一个模拟数据和两个实际数据绕射波分离中。图6a是一个模拟的共偏移距道集,可以清楚地看到绕射波和反射波互相干扰。图6b是预测出的倾角场,这里的光滑半径为5。图6c是经过分离后的结果,可以看出分离的绕射波中反射波同相轴几乎不存在,绕射波信息明显,该算例表明平面波预测滤波器可以很好地预测出反射波信息并对其进行压制。
然后,我们将其应用于实际海洋地震勘探的共偏移距叠前道集(图7a),可以发现该数据绕射波非常发育,从叠前共偏移距道集上可以清楚看到一些绕射波,尤其是对于3.5 s处复杂断块引起的绕射波非常清楚,我们首先估计其局部倾角场(图7b),光滑半径确定为5。在反射波发育的地方,倾角场比较平滑且数值较小,而在绕射波发育的地方倾角较大,从分离的绕射波结果(图7c)可以看出平面波预测方法可以很好地分离绕射波,这些被分离出的绕射波可以很好地进行断块构造的成像[20]及储层表征[21]。
最后,我们对叠后的实际地震数据进行绕射波分离(图8a),由于叠加会破坏一些绕射波的信息,因此在叠后的剖面上绕射波能量较弱,但是叠后的剖面信噪比较高,对估计倾角场比较有利。图8b为估计的局部倾角场信息,由于叠加对绕射波的压制,同时因为该数据剖面上的绕射波分布散乱,为了得到正确的倾角,此处的横向光滑半径为50,纵向光滑半径为20,图8c显示了叠后地震数据绕射波分离后的结果,可以发现绕射波很好地被分离出来。模拟和实际数据表明平面波预测方法可以有效分离绕射波。
4. 结论
平面波预测滤波器在反射波同相轴光滑连续的条件下,可以有效地估计地震数据的局部倾角场,进而分离出绕射波,该方法对隐藏在强反射能量下的小型绕射波信息起到很好的分离效果,为后期绕射波单独成像提供绕射波信息。通过对噪声和平滑参数对地震绕射波分离结果的影响分析,发现噪声水平严重影响绕射波分离效果,噪音过大分离结果会不准确;平面波预测滤波器光滑半径偏小会引入噪音和假象,光滑半径偏大会导致绕射波分离不彻底,小断块地震绕射波响应难以分离。在绕射波分离算法中,振幅保真性也是一个重要问题,因此提高算法的抗噪性和保真性是今后研究的重要方向。
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图 6 九皋玄武岩气孔周围能谱面扫描元素含量分布图
a:单偏光图像,b、c:背散射图像,d-i:硅、铝、镁、铁、钙、磷元素能谱面扫描图。
Figure 6. EDS (energy dispersive spectrometer) images around the vesicles of the Jiugao basalts
a: Photograph of plane-polarized light; b-c: photograph of BSE; d-i: EDS (backscattered electrons) images of Si, Al, Mg, Fe, Ca, and P.
表 1 九皋和紫檀海山玄武岩主量元素地球化学数据
Table 1 Major elements of the Jiugao and Zitan basalts
% 海山 样品编号 SiO2 TiO2 Al2O3 Fe2O3T MnO MgO CaO Na2O K2O P2O5 LOI SUM 九皋
海山CWD16-1.1 49.80 2.29 17.75 12.77 0.07 2.91 3.16 1.31 1.95 0.57 7.43 100.01 CWD16-1.2 47.94 2.32 17.89 11.40 0.19 2.42 5.18 1.55 2.06 1.47 7.10 99.51 CWD16-1.3 48.16 2.31 17.36 12.65 0.09 3.18 4.49 1.59 2.25 0.51 6.80 99.38 CWD16-1.4 46.90 2.46 18.85 12.76 0.10 3.53 6.20 1.51 1.39 0.47 6.09 100.27 CWD16-1.5 48.78 2.34 17.79 13.30 0.09 3.04 3.90 1.23 1.87 0.60 7.29 100.23 CWD16-1.6 48.67 2.39 18.29 12.21 0.11 3.05 3.75 1.42 2.06 0.32 7.18 99.46 CWD16-2.1 47.56 2.43 18.15 13.61 0.07 2.34 3.14 1.08 1.88 0.71 8.39 99.36 CWD16-2.2 48.85 2.43 17.21 14.19 0.04 2.50 2.94 1.01 2.42 0.52 7.87 99.98 CWD16-2.4 48.29 2.46 18.58 11.49 0.19 3.35 6.26 1.63 1.29 0.38 5.94 99.84 CWD16-2.5 46.02 2.42 16.73 13.23 0.14 5.22 8.10 1.11 0.95 0.35 5.76 100.03 CWD16-2.6 45.92 2.62 18.90 13.51 0.09 2.08 4.93 1.47 1.47 1.00 7.33 99.30 CWD10-2② 47.81 1.34 15.13 12.57 0.10 7.58 7.98 1.88 0.82 0.08 4.58 99.87 CWD10-3 47.75 1.28 15.30 13.05 0.10 7.41 7.26 1.84 1.06 0.13 4.59 99.75 紫檀
海山CWD12-1① 51.03 1.30 15.20 14.19 0.02 2.88 4.88 1.86 3.57 0.41 4.79 100.13 CWD12-2 51.08 1.62 17.85 11.65 0.06 2.42 6.58 2.63 2.01 0.09 3.41 99.39 CWD12-3② 50.46 1.57 17.17 12.75 0.07 2.51 6.89 2.53 2.12 0.09 3.29 99.44 表 2 九皋和紫檀玄武岩微量元素地球化学数据
Table 2 Trace elements of the Jiugao and Zitan basalts
海山 样品编号 Sc V Cr Co Ni Ga Rb Sr Y Zr Nb Cs Ba La Ce Pr Nd Sm Eu 九皋海山 CWD16-1.1 24.9 103 319 10 104 18.4 50.8 627 64.1 286 63.6 2.31 567 55.1 58.9 9.93 40.3 7.54 2.31 CWD16-1.2 21.5 118 321 25.9 180 18.5 45.3 763 109 288 65.8 1.6 1070 117 64.9 13.4 54 9.21 2.78 CWD16-1.3 26.7 135 359 20.3 135 18.1 47.9 782 66.3 305 64.3 1.56 688 65.4 61.9 11.7 47.6 8.76 2.67 CWD16-1.4 28.1 212 350 24.1 113 17.9 34.9 735 44 320 69.1 1.39 601 47.1 64.2 9.7 39.1 7.55 2.4 CWD16-1.5 24.4 111 330 14.7 102 18.1 48.5 638 59.4 299 66.1 2.04 517 55.3 63.2 10.5 42.3 7.95 2.45 CWD16-1.6 25.4 156 335 22.6 124 18.5 43.2 704 43.4 314 68.5 1.43 579 46.1 60.2 9.38 38 7.25 2.26 CWD16-2.1 24.8 91 263 8.1 82.9 17.4 55 553 83.9 299 65.7 2.55 428 75.6 53.5 11.5 46.9 8.13 2.44 CWD16-2.2 24.9 120 326 5.67 57.6 14.4 56.9 499 107 329 67.7 2.37 427 97.3 52.6 17.9 74.6 13.7 3.92 CWD16-2.4 26.6 159 356 24.9 146 17.4 31.1 758 52.1 314 66.3 1.31 627 52.7 65.6 10.2 41.3 7.79 2.48 CWD16-2.5 27.6 243 258 32.2 121 18.4 21.5 619 46.3 291 63.3 0.86 411 42.4 61.3 8.86 36 7.04 2.24 CWD16-2.6 23.5 175 372 16.1 80.1 16.1 37.7 769 81.3 332 71.4 1.35 657 73.6 68.3 13.2 53.6 9.75 2.93 紫檀海山 CWD10-2② 30.5 220 418 44.1 337 17.3 30.2 141 18.7 74.2 7.52 2.62 41.9 6.15 9.38 1.72 8.32 2.22 0.842 CWD10-3 29.3 187 495 44.5 297 17.3 37.9 142 22.8 71.4 7.13 3.27 43.5 8.89 9.61 1.94 9.21 2.38 0.87 CWD12-1① 22.7 67 256 10.6 83.2 16.7 95.4 228 61.1 93 12.6 4.13 134 43.8 12.5 6.51 28.6 5.41 1.59 CWD12-2 30.1 162 186 29.5 136 20.2 56 224 16.3 97.7 13.6 2.89 105 7.25 11.7 1.68 7.74 1.91 0.79 CWD12-3② 31 171 185 24.2 99 20 61.2 221 18.4 97 13.4 3.02 99.8 8 12.8 1.99 9.22 2.28 0.875 海山 样品编号 Gd Tb Dy Ho Er Tm Yb Lu Hf Ta Pb Th U δEu δCe δY (La/Sm)N ∑REE 九
皋
海
山CWD16-1.1 8.48 1.25 7.56 1.67 4.78 0.71 4.42 0.716 5.92 3.68 10.9 4.98 1.15 0.88 0.61 1.38 4.6 203.67 CWD16-1.2 11.2 1.56 9.52 2.16 6.15 0.88 5.32 0.863 5.89 3.83 16.6 4.95 1.04 0.84 0.39 1.84 7.99 298.94 CWD16-1.3 9.73 1.41 8.28 1.76 4.88 0.714 4.4 0.696 6.2 3.89 13.7 5.21 1.04 0.88 0.54 1.33 4.7 229.9 CWD16-1.4 7.75 1.17 6.88 1.43 4.01 0.602 3.81 0.6 6.52 4.09 12.1 5.47 0.94 0.96 0.72 1.07 3.92 196.3 CWD16-1.5 8.7 1.29 7.65 1.66 4.75 0.71 4.45 0.727 6.12 3.82 20 5.06 0.96 0.9 0.63 1.27 4.38 211.64 CWD16-1.6 7.49 1.11 6.42 1.33 3.67 0.535 3.33 0.522 6.43 4.03 17.7 5.4 0.84 0.94 0.7 1.13 4 187.6 CWD16-2.1 9.82 1.39 8.39 1.93 5.45 0.791 4.84 0.792 6.24 3.85 15.2 4.87 1.12 0.83 0.44 1.59 5.85 231.47 CWD16-2.2 15.9 2.26 13.4 2.88 7.95 1.14 6.84 1.08 6.45 3.91 19.5 5.53 1.19 0.81 0.3 1.32 4.47 311.47 CWD16-2.4 8.22 1.21 7.07 1.49 4.11 0.599 3.72 0.592 6.47 4.07 14.7 5.2 0.67 0.95 0.68 1.23 4.26 207.08 CWD16-2.5 7.38 1.12 6.54 1.39 3.87 0.576 3.63 0.58 6.12 3.7 7.7 4.67 0.57 0.95 0.76 1.17 3.79 182.93 CWD16-2.6 10.9 1.59 9.58 2.1 5.93 0.87 5.35 0.849 6.83 4.37 13.7 5.56 1.35 0.87 0.53 1.38 4.75 258.55 紫
檀
海
山CWD10-2② 2.85 0.48 2.96 0.631 1.77 0.261 1.61 0.246 1.9 0.475 1.03 0.358 0.16 1.02 0.69 1.05 1.74 39.44 CWD10-3 3.1 0.514 3.2 0.699 1.94 0.285 1.78 0.274 1.83 0.452 0.943 0.374 0.18 0.98 0.56 1.16 2.35 44.69 CWD12-1① 7.02 0.982 5.94 1.33 3.68 0.517 3.04 0.479 2.01 0.752 9.07 0.67 0.42 0.79 0.18 1.66 5.09 121.4 CWD12-2 2.32 0.391 2.4 0.526 1.49 0.223 1.4 0.216 2.39 0.815 1.61 0.59 0.39 1.15 0.81 1.11 2.39 40.04 CWD12-3② 2.79 0.469 2.89 0.61 1.7 0.25 1.54 0.237 2.36 0.776 1.38 0.618 0.3 1.06 0.77 1.06 2.21 45.65 注:微量元素单位为10-6;δEu= EuN/(SmN × GdN)0.5,δCe= CeN/(LaN × PrN)0.5,δY=YN/(DyN × HoN)0.5。 -
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