缅甸翡翠次生部位的元素成分演化特征

为研究缅甸翡翠次生部位的元素成分演化特征,采用主量元素测试、微量元素测试、电子探针及X射线粉晶衍射分析方法对缅甸翡翠的灰绿色次生色(翡翠界称之蓝雾)部位、黄蓝色次生色部位及黄(红)色次生色(翡翠界称之黄(红)雾)部位的元素及矿物成分进行了测试与分析。结果显示,与蓝色次色生部位相比较,黄色次生色部位中的Na、Al、Si元素的含量递增对应着X粉晶衍射中伊利石等的出现,黄色次生色部位的Fe、Mg等元素的含量递减对应着绿泥石的峰的消失。表明带有蓝雾的砾石被抬升到地表后,其中的大量的Fe被偏酸性的雨水淋滤带出,少量被氧化成Fe3+后沉淀形成黄、红雾。氧化条件加上湿热气候区偏酸性水的作用,能够使绿泥石和硬玉矿物逐渐地风化分解,形成高岭石和褐铁矿。     

珍珠岩成分分析标准物质研制

摘要：珍珠岩是十分重要的非金属矿,被广泛应用于建筑、水处理、农业等领域。目前,国内外尚未有珍珠岩成分分析标准物质,为满足针对珍珠岩的研究需要,本文研制了河南商城的珍珠岩成分分析标准物质(GBW07137)。对Ag、As、B、Ba、Be、Bi、Cd、Co、Cr、Cs、Cu、Ga、Hf、Hg、In、Li、Mo、Nb、Ni、Pb、Rb、Sb、Sc、Sn、Sr、Ta、Th、U、V、W、Zn、Zr、SiO2、Al2O3、TFe2O3、FeO、MgO、CaO、Na2O、K2O、MnO、TiO2、P2O5、LOI、TC、稀土元素等15项60种成分进行均匀性和稳定性检验,绝大部分成分的RSD小于3%,方差检验的F值均小于临界值F0.05(29, 60)=1.65,表明该标准物质均匀性良好。在稳定性考察期内,60种成分的含量没有统计学意义的明显差异,表明该标准物质稳定性良好。通过9家协作实验室采用重量法、容量法、电感耦合等离子体质谱/发射光谱法等比较有针对性的定值方法来确保珍珠岩定值成分的准确性。按照《标准物质定值的通用原则及统计学原理》进行数据的统计处理,采用格拉布斯法、狄克逊法进行离群值检验。经统计,珍珠岩标准物质原始数据共2500项,剔除68个离群值数据,剔除率为2.7%。经过对定值测试数据的统计处理,确定了本次研制的珍珠岩成分分析标准物质的标准值和不确定度。最终定值成分63种,涵盖了主量、微量及全部稀土元素,其中三种主量成分MgO、CaO和TFe2O3的含量低于1%,可以与现有的硅酸盐标准物质含量形成梯度。该珍珠岩标准物质在岩石地球化学研究及质量监控中能发挥作用, 也可为珍珠岩的科学利用和研究提供参考和借鉴。     

GBW10010a大米标准物质复(研)制及数据特征

随着我国对生态文明建设的重视,自然资源综合调查势在必行,对生物标准物质亦提出了新的需求。当前相关调研工作已经大面积开展,自然资源综合调查、农产品与食品安全评价都需要对生物样品元素组成进行准确测试,需要以生物标准物质作为生物成分测试量值比对和溯源的基础,因此对生物基体标准物质的需求量大幅增加。大米作为主要粮食之一,其食品安全日益受到重视,对大米中的化学成分进行准确的分析测试具有重要的现实意义,因而对大米标准物质的需求量尤为突出,但目前大米成分分析标准物质已供不应求。本文严格按照《标准物质定值的通用原则及统计学原理》（JJF 1343—2012）和《地质分析标准物质的研制》（JJF 1646—2017）等相关规范要求,开展了GBW10010a大米成分分析标准物质的复（研）制工作,包括样品采集、加工制备、均匀性检验、稳定性检验、多家实验室协作定值测试及不确定度评定等关键环节。结果表明：本次复（研）制的大米标准物质定值成分多样、量值准确可靠,符合国家一级标准物质的要求。GBW10010a共定值54项主微量元素,包括Ag、Al、As、B、Ba、Be、Bi、Ca、Cd、Ce、Co、Cr、Cs、Cu、Dy、Er、Eu、Fe、Gd、Ge、Hg、Ho、K、La、Li、Ho、Mg、Mn、Mo、N、Na、Nb、Nd、Ni、P、Pb、Pr、Rb、S、Sb、Sc、Se、Si、Sm、Sr、Tb、Th、Tl、Tm、U、V、Y、Yb、Zn,其中的39项元素给出了标准值及不确定度,包括Ag、Al、As、B、Ba、Ca、Cd、Ce、Co、Cs、Cu、Dy、Er、Fe、Hg、K、Li、Mg、Mn、Mo、N、Na、Nd、Ni、P、Pb、Pr、Rb、S、Sb、Se、Si、Sm、Sr、Tb、Tl、Y、Yb、Zn;15项元素提供参考值,包括Be、Bi、Cr、Eu、Gd、Ge、Ho、Ho、La、Nb、Sc、Th、Tm、U、V。与原有GBW10010大米标准物质相比较,GBW10010a中As、Cd、Co、Cr、Cu、Hg、Mn、Mo、Ni、Zn等重金属元素含量显著下降,其中Cd、Cu、Zn降幅较大,分别下降约39%、43%、38.7%,一定程度上反映了农田生态环境的改善。本批标准物质定值元素总数量增加了6项,新增定值元素Ag、Nb（Nb给出参考值）,并且各项元素不确定度范围整体上有所缩小,如Al、Cd、Cu、Fe、K、Mg、Mo、Na、P、Pb、Se、Zn等对生物易有影响的重要元素,表明了地质分析测试方法技术的进步及定值水平的提高。本批标准物质定值元素涵盖了具有生物效应的大部分主微量元素,适用于农业生态环境地球化学调查与评价、生物样品测试、农产品质量与食品安全评价样品测试时的分析仪器校正、分析方法评价和分析质量监控等多个领域。     

On the Interpretation of Orthonormal Coordinates for Compositional Data

The simplex with the Aitchison geometry is a natural sample space for compositional data, that is, observations carrying only relative information (especially proportions, percentages, etc., often occurring in the geosciences). For this reason, standard statistical methods that rely on Euclidean structure of the real space cannot be used directly for statistical analysis. At first, compositional data need to be expressed in coordinates of an orthonormal basis on the simplex (with respect to the Aitchison geometry). The mathematical interpretation of the orthonormal coordinates is derived from the procedure by which they are constructed (called sequential binary partition), and they act as balances between groups of compositional parts. The goal of this paper is to describe the covariance structure of coordinates and, consequently, to provide a complementary interpretation based on log-ratios of parts of the original composition. It must be noted that, in a composition, the ratios themselves contain all the relevant information. The possibilities as well as the limitations of this approach are demonstrated through illustrative examples.     

Singularity and Nonnormality in the Classification of Compositional Data

Geologists may want to classify compositional data and express the classification as a map. Regionalized classification is a tool that can be used for this purpose, but it incorporates discriminant analysis, which requires the computation and inversion of a covariance matrix. Covariance matrices of compositional data always will be singular (noninvertible) because of the unit-sum constraint. Fortunately, discriminant analyses can be calculated using a pseudo-inverse of the singular covariance matrix; this is done automatically by some statistical packages such as SAS. Granulometric data from the Darss Sill region of the Baltic Sea is used to explore how the pseudo-inversion procedure influences discriminant analysis results, comparing the algorithm used by SAS to the more conventional Moore–Penrose algorithm. Logratio transforms have been recommended to overcome problems associated with analysis of compositional data, including singularity. A regionalized classification of the Darss Sill data after logratio transformation is different only slightly from one based on raw granulometric data, suggesting that closure problems do not influence severely regionalized classification of compositional data.     

Compositional Data Analysis of Some Alkaline Glasses

The approach to the analysis of compositional data involving log-ratio transformation of the data has not been generally adopted by researchers wishing to analyse such data. In the context of exploratory methods of multivariate analysis, such as principal components analysis, where the hope is to identify (cluster) structure in the data, this may be because traditional methods can produce more interpretable results than the log-ratio approach. After illustrating this with an example, circumstances under which the log-ratio approach performs poorly when traditional approaches work well are identified. Log-ratio analysis can be dominated by variables having low absolute presence and high relative variation that do not contribute to, and can obscure, structure in the data. Traditional methods can detect certain kinds of structure in the data that correspond to structure on a ratio scale, after a suitable redefinition of the composition. Since traditional methods often detect such structure more directly than log-ratio analysis it can be concluded that claims that the traditional analysis is inappropriate or meaningless are exaggerated. This conclusion is based on empirical experience rather than theoretical concerns. The arguments are illustrated using compositional data for alkaline glasses, but have more general application.     

New Compositional and Structural Constraints on the Smithsonian Microanalytical Reference Materials: Amphiboles from Kakanui and Arenal

The amphiboles from Kakanui and Arenal are two natural minerals that have been used worldwide as microanalytical reference materials, but their compositions and crystal structures are still poorly constrained. In this paper, we report new data on H₂O and trace element mass fractions and single-crystal structural refinement of these two amphiboles. H₂O mass fractions of the Kakanui and Arenal amphiboles determined via Karl-Fischer titration are 0.92 ± 0.18 (2s) and 1.56 ± 0.22% m/m (2s), respectively; these values estimated based on crystal-structure refinement are 0.86 and 1.46% m/m, respectively. Trace element mass fractions measured via LA-ICP-MS in two laboratories are in good agreement, and spots from five fragments for both Kakanui and Arenal amphiboles are generally consistent within reproducibility precision (2s). Our measurements indicate a better homogeneity for the amphiboles from Kakanui than that from Arenal. According to the latest scheme for amphibole classification and nomenclature (Hawthorne et al. 2012), the sample from Arenal is a (partially dehydrogenated) pargasite, and that from Kakanui is a kaersutite. The significant amount of oxo-component and that ^CTi⁴⁺ content is strongly ordered at the M(1) site for both amphiboles indicate crystallisation under high fO₂ conditions.     

Identification of Anthropogenic Features Through Application of Principal Component Analysis to Hydrochemical Data from the Sines Coastal Aquifer, SW Portugal

The Sines coastal sedimentary basin, a tectonic trough with a NE-SW orientation filled with Mesozoic and Cenozoic deposits, has two hydrogeological systems: the Mio-Pliocene and the Jurassic. Both systems are supplying water to the entire region with highly populated and industrialized areas. The aquifers are recharged in the outcrop areas, although the Jurassic aquifer also receives some contribution from the overlying Miocene rocks. The main groundwater flow direction in the Jurassic aquifer is E to W towards the Atlantic Ocean. In order to understand the influence of anthropogenic activities on the water quality, a statistical principal components analysis (PCA) was performed on the physical–chemical data from groundwater samples in both aquifers. Four components were obtained in the Jurassic and three in the Miocene. The principal components analyses indicate water–rock interactions as the major mechanism responsible for the groundwater solutes (mainly calcium-bicarbonate type), from the calcareous and dolomitic units. Anthropogenic contamination was identified in the influence of the water compositions, corresponding to local polluting inputs. These were magnesium, sulfate, nitrate, iron and copper for PC 3 in the Jurassic and sodium, chloride, nitrate and manganese for PC 2 in the Miocene. These account for about 13% of the system total variance in the Jurassic aquifer and near 23% in the Miocene one.     

Magma Mixing and the Production of Compositional Variation within Granite Suites: Evidence from the Granites of Southeastern Australia

Granite suites are groups of plutons possessing characteristicfeatures that are a result of their derivation from source materialof a specific composition. Variation within suites has beenascribed to a variety of processes. Magma mixing or minglingis a popular hypothesis, generally proposed in terms of blendingbetween a crustal melt and mafic material from the mantle thatcaused that melting. When the compositions of pairs of suitesfrom the Bega Batholith of southeastern Australia are compared,any differences seen at either end of the range in compositionare also seen at the other limit, so that both the most maficand most felsic rocks show similar relative abundances of particularelements. Similar relationships are seen for other granitesin the region. These observations are not consistent with large-scalemagma mixing or mingling and, although those processes may operateon a small scale, they cannot have been responsible for themajor compositional variations. Likewise, assimilation of countryrocks had no significant role in producing variation in thegranites of southeastern Australia. The production of variationby differential separation of melt from residual solid sourcematerial, or restite, must be favoured for many of the granitesuites of this region. KEY WORDS: assimilation; enclaves; granite suites; magma mixing; restite     

利用爆炸震源资料获得三分量旋转地震动

三分量旋转地震动是目前地球物理研究重点之一.利用爆炸震源的平动地震仪观测资料,通过间接计算获得三分量旋转地震动.利用了3炮500 kg炸药的观测资料,3个爆炸点到观测台阵的距离分别是1.8、2.8和8.9 km,计算得到了台阵相对于这3个爆炸点的旋转地震动,其最大峰值旋转角速度分别是41.65、21.98和0.29 μrads/s,与国际同行的旋转地震动结果量级接近.地震动峰值随震中距的衰减是地震工程中关注的问题.提取出三分量的旋转角速度峰值,利用指数函数对三分量的峰值进行拟合,初步得到三分量的旋转地震动角速度峰值随震中距的衰减关系.衰减曲线的主要特征是,1~3 km旋转角速度能量迅速衰减,大于5 km以后衰减逐渐减慢,随着震中距增大曲线的变化越来越趋于平缓.      

利用钻孔资料确定降雨入渗系数

在河北省地下水水资源评价的基础上,提出利用钻孔资料来具体确定降雨入渗系数的大小,从而为区域地下水资源评价的精确计算提供依据。     

Groups of Parts and Their Balances in Compositional Data Analysis

Amalgamation of parts of a composition has been extensively used as a technique of analysis to achieve reduced dimension, as was discussed during the CoDaWork'03 meeting (Girona, Spain, 2003). It was shown to be a non-linear operation in the simplex that does not preserve distances under perturbation. The discussion motivated the introduction in the present paper of concepts such as group of parts, balance between groups, and sequential binary partition, which are intended to provide tools of compositional data analysis for dimension reduction. Key concepts underlying this development are the established tools of subcomposition, coordinates in an orthogonal basis of the simplex, balancing element and, in general, the Aitchison geometry in the simplex. Main new results are: a method to analyze grouped parts of a compositional vector through the adequate coordinates in an ad hoc orthonormal basis; and the study of balances of groups of parts (inter-group analysis) as an orthogonal projection similar to that used in standard subcompositional analysis (intra-group analysis). A simulated example compares results when testing equal centers of two populations using amalgamated parts and balances; it shows that, in certain circumstances, results from both analysis can disagree.     

新疆阿尔泰可可托海3号伟晶岩脉岩浆-热液过程:来自电气石化学组成演化的证据

新疆阿尔泰可可托海3号脉不同结构带及其蚀变围岩中电气石化学组成电子探针(EMPA)分析结果显示,蚀变围岩、外接触带和内接触带中电气石为是富钙-铁的镁电气石,电气石化伟晶岩中电气石为富镁-铁的锂电气石,伟晶岩早期结构带(Ⅰ-Ⅳ带)中电气石为黑电气石-锂电气石系列,而伟晶岩晚期结构带(Ⅴ-Ⅶ带)中电气石为锂电气石。蚀变围岩、外接触带和内接触带中电气石以Y位中低Al,高Mg、Ca以及显著低的Al/(Al+Fe)、Fe/(Fe+Mg)比值为特征,主要存在R3++O2-=R2++OH-的置换;伟晶岩内部结构带(Ⅰ-Ⅶ带)中电气石以Y位上极低Mg、Ca,高Fe、Al、Li以及显著高的Al/(Al+Fe)、Fe/(Fe+Mg)比值为特征,主要存在+Al3+=Na++Fe(Mg)2+和Li++Al3+=Fe(Mn)2++Mg2+的置换。蚀变围岩、外接触带和内接触带中电气石化学组成特征指示存在围岩-流体、围岩-熔体相之间的相互作用。伟晶岩早期结构带(Ⅰ-Ⅳ带)中电气石无明显组成分带,为岩浆成因;晚期结构带(Ⅴ-Ⅶ带)中电气石显示振荡环带,形成于岩浆-热液过渡阶段体系。随着伟晶岩由外向里固结,温度逐渐降低,伟晶岩内部结构带中电气石显示Y位上Al、Li、Mn及Fe/(Fe+Mg)比值逐渐增大的演化趋势;内部结构带中电气石几乎不含Mg,指示3号伟晶岩脉岩浆-热液演化是在相对封闭体系中进行的。     

区域地球化学评价中变异系数校正参数的意义

通过对我国新疆西天山各地球化学区数据的归纳和研究,计算西天山12种常见成矿元素在各地球化学区的富集系数,提出校正系数公式,并将变异系数进行合理的校正与排序。与实际矿床和矿点结合,验证校正系数的正确性和适用性,预测元素成矿有利顺序和规律,总结出西天山富集系数与变异系数在成矿中的制约关系。该方法实现了不同成矿元素之间成矿条件的对比,拓宽了地球化学参数的适用性,提高了在勘探程度较低的地区地球化学评价方法的准确性,为地球化学评价提供科学依据。     

Weighting of Parts in Compositional Data Analysis: Advances and Applications

Mathematical Geosciences - It often occurs in practice that it is sensible to give different weights to the variables involved in a multivariate data analysis—and the same holds for...     

新疆冰达坂含金剪切带内组分分异及对金矿化的影响

糜棱岩及花岗质原岩组分特征,结果表明花岗质岩石容矿的金矿床剪切变形过程中组分发生分异,动力分异与流体分异对金矿化所起作用及相对程度不同,研究区金成矿主要与流体分异作用有关。流体分异作用过程中,相对于高应变带,低应变带内强分异形成的高Fe环境及扩容空间为金矿化、沉淀提供更有利条件,且碱(Na)交代排出的s1为浅层次硅化蚀变糜棱岩型及石英脉型矿化提供物源基础,K、Ca、Mg形成绢云母化、碳酸盐化、绿泥石化等蚀变,从而为区内金矿化定位及共生蚀变提供了合理解释。结合已有研究成果,认为钠长石化带下部应发育钾长石化带.且作为矿根相存在,矿带东、西段深部均有较好金矿化前景。     

Characterization of Distributional Forms for Compositional Data and Associated Distributional Tests

A variety of approaches to the testing of distributional forms for compositional data has appeared in the literature, all based on logratio or Box–Cox transformation techniques and to a degree dependent on the divisor chosen in the formation of ratios for these transformations. This paper, recognizing the special algebraic–geometric structure of the standard simplex sample space for compositional problems, the use of the fundamental simplicial singular value decomposition, and an associated power-perturbation characterization of compositional variability, attempts to provide a definitive approach to such distributional testing problems. Our main consideration is the characterization and testing of additive logistic–normal form, but we also indicate possible applications to logistic skew normal forms once a full range of multivariate tests emerges. The testing strategy is illustrated with both simulated data and applications to some real geological compositional data sets.     

基于特征导向主成分分析遥感蚀变异常提取方法

为利用多光谱遥感数据提取蚀变异常信息, 在分析蚀变矿物的先进星载热发射和反射辐射仪(advanced spaceborne thermal emission and reflection radiometer, ASTER)和影像短波近红外(visible and near IR-short wave-length IR, VNIR-SWIR)谱带的特征光谱曲线的基础上, 对传统的主成分分析法进行了改进, 利用特征导向主成分分析法对辽宁兴城地区进行矿物蚀变信息提取, 成功的对该地区内的褐铁矿(Fe3+)、绿泥石(Mg-OH基团矿物)和高岭石(Al-OH基团矿物)进行了蚀变异常信息提取.通过实践验证和研究区地质资料表明, 特征导向主成分分析法能够有效地提取蚀变信息并识别研究区内主要矿物, 可以为该区的成矿预测工作提供一定的依据.      

乌龙茶和绿茶成分分析标准物质复研制

20世纪80年代至今,中国已研制了9种茶叶成分标准物质。中国地质调查局于2004年下达中国地质科学院地球物理地球化学勘查研究所研制的一套适用于覆盖区农业生态地球化学评价的生物地球化学系列标准物质,其中包括两种茶叶标准物质,定值组分60余项,包括植物营养元素、有毒、有害元素和重金属污染元素以及人们关心的一些微量营养元素等,满足了相关食品卫生安全及生物样品成分检验分析的需要,取得了显著的社会效益。随着农业生态地质调查工作全面部署和展开,对生物样品的分析测试任务加大,对相应地球化学标准物质的需求也随之增加。本文复制了GBW10016a和GBW10052a两种茶叶标准物质,候选物分别为福建武夷山乌龙茶和江西上饶市婺源绿茶。研制过程严格按照JJG 1006—1994、JJF 1343—2012和JJF1646—2017等相关规范要求,侯选物经粗碎、干燥、细碎、过筛、混匀等步骤制备而成,经统计学检验,样品均匀,稳定性良好,定值采用多家实验室合作定值的方式进行,优选国内技术实力较强、仪器设备先进、且有相关标准物质定值测试经验的11家实验室,采用电感耦合等离子体质谱/发射光谱法（ICP-MS/OES）、原子荧光光谱法（AFS）等准确可靠的方法共分析61项指标。GBW10016a最终给出认定值54项,参考值3项;GBW10052a定值57项,参考值3项。本次研制的茶叶标准物质定值成分多样、量值准确可靠,符合国家一级标准物质的要求。与原批次标准物质相比,GBW10016a定值指标增加了Ag和Sn,Ge和Tl由原批次的参考值升级为标准值;GBW10052a增加了Al、Ag、Cl、I、N、S、Sb、Sc、Si及Sn由原批次的参考值升级为标准值。本次复研制的标准物质,在同类型中占据重要地位,研制过程严格按照相关规范执行,测试方法经典可靠,定值结果准确度高,于2019年被审批为国家一级标准物质,能够有效支撑农业生态环境地球化学调查与评价、生物样品的分析及食品与农产品分析测试的需要。