一种体色呈蓝色的铍扩散处理蓝宝石

针对近期市场上出现的一种体色呈蓝色或淡蓝色的Be扩散处理蓝宝石,采用EPMA,LA-ICP-MS、激光拉曼光谱仪、UV-NIS分光光度计等分析测试仪器,对50粒Be扩散处理蓝宝石样品的化学成分、拉曼光谱、UV-NIS吸收光谱特征进行了研究。测试与研究结果表明,这种Be扩散处理蓝宝石样品中,Be的质量分数最低为5.28×10-6%,最高为17.51×10-6%,平均为8.74×10-6%;其内普遍含有形态各异的斜锆石熔融或假象包裹体;由于Fe3 离子d-d电子跃迁,导致形成了样品的吸收光谱a带(377,386,451 nm)。在高温条件下,由Be扩散诱生的色心可能是导致蓝色蓝宝石呈色的主要缘由。     

LA-ICP-MS微区分析及其在金矿床研究中的应用

随着分析技术的飞速发展,从而使地质学研究逐渐由定性描述向数据定量评价转化。但多数地质分析测试技术对某些含量很低或比较特殊的样品分析时仍存在不足或不能满足研究目的;然而,激光剥蚀电感耦合等离子体质谱(LA-ICP-MS)微区分析技术可以实时、快速、高灵敏度、高分辨率及多元素同时测定,并可提供同位素比值信息而使上述问题得以解决。近年来,LAICP-MS分析技术在金矿中的应用,对准确厘定金矿床的成矿时代,探讨成矿物质来源、了解矿床的成矿机制及正确认识矿床的成因等方面具有重要意义。     

Using laser ablation inductively coupled plasma mass spectroscopy (LA-ICP-MS) to determine the provenance of the cobalt pigment of Qinghua porcelain from Jingdezhen in Yuan Dynasty of China (1271–1368AD)

The provenance of cobalt mineral of the blue decoration in Yuan Qinghua porcelain would reveal the technological and cultural interaction between ancient China and the Islamic world. However, the limitation of conventional methods in the determining trace elements of the blue decoration hampered the deep research on provenance of the cobalt mineral. In the paper, we employed the good advantage of Laser-ablation-inductively-coupled-plasma-mass-spectroscopy (LA-ICP-MS) to determine the major element and trace elements of blue decoration of the different type of Qinghua successfully. The blue decoration of all different types of samples shared the same characteristics of higher FeO and lower Mn, which suggested the potter adopted the non-native cobalt material of China to paint the Yuan Qinghua in Jingdezheng, and the difference on the outside appearance of blue decoration of different samples were supposed to be related to the tenor of ore, the different treatment process of cobalt material and the firing process in the kiln. In addition, the significant differences on the element concentrations of Cu, Ni, Pb, Zr and Sb in the blue decoration between Yuan Qinghua and the Islamic blue and white wares of 13–14th century provided a new evidence to discuss the provenance of the cobalt of Yuan Qinghua porcelain.     

昌都—芒康盆地西北缘始新世煌斑岩岩石成因及其对构造环境的指示——岩石地球化学和锆石U-Pb年代学约束

煌斑岩是反映深部构造-岩浆作用和源区地球化学性质的良好地质体。本文对昌都—芒康盆地西北缘出露的煌斑岩脉进行系统研究,煌斑岩中锆石U-Pb同位素年龄通过LA-ICP-MS测定,得到其²⁰⁶Pb/²³⁸U加权平均年龄分别为(36.05±0.29)Ma、(35.89±0.32)Ma、(37.67±0.16)Ma,该年龄值基本代表岩体的岩浆结晶时代,据此将研究区煌斑岩脉体形成时代归属为始新世。地球化学分析表明,煌斑岩属于钙碱性弱钾质—钾质系列,具有大离子亲石元素和轻稀土元素富集,高场强元素和稀土元素亏损的成分特征。综合分析表明煌斑岩具有俯冲带幔源岩石的成分特征,属于“俯冲-隆升”模式下新生代构造岩浆演化碰撞晚期构造环境的岛弧岩浆岩。在始新世(35～37 Ma)澜沧江构造带与金沙江结合带之间的走滑深大断裂构造带发生的大规模水平错移,导致局部区域发生俯冲,上涌的软流圈亏损地幔加热了地壳物质,导致其部分熔融,形成煌斑岩。     

祁连—秦岭造山带交接部位25亿年碎屑锆石的发现及其地质意义

对来自祁连与秦岭造山带交接部位秦安地区葫芦河流域的“葫芦河群”浅变质砂岩中大量碎屑锆石的LA-ICP-MSU-Pb测年结果发现,其中含有年龄为2302～2578Ma的锆石颗粒。这些锆石年龄均十分谐和,且阴极发光图象上显示具有典型岩浆型振荡环带结构和岩浆成因锆石的w(Th)/w(U)为0.11～1.42,表明这些锆石为新太古代末期构造岩浆作用的产物。这些锆石是该区域迄今发现的最古老的锆石,表明祁连与秦岭造山带交接部位可能存在比陇山岩群和秦岭岩群更古老的陆壳。     

Tree-ring elemental concentrations in oak do not necessarily passively record changes in bioavailability

Elemental concentrations in tree-rings from red and white oak trees at six sites across Southern Ontario, Canada, were assessed to determine whether they passively record changes in geochemical cycling in the presence of environmental stress. Periods of stress were defined as sustained periods with elevated delta(13)C values in tree-rings relative to atmospheric CO(2) during the same period. In some trees, nutrient concentrations (Ca, Mg, Mn) were erratic during historic periods of stress while chemically similar non-nutrients (Ba, Sr) and the anthropogenic pollutant Pb were not. Tree-ring concentrations of Ca and Sr were related to bedrock type and leachable concentrations in the soil. In contrast, tree-ring concentrations of Mg were not related to bedrock type, although Mg concentration in the soil leachate was. Tree-ring Mn, Ba and Pb concentrations were not related to bedrock type or soil concentrations, but were inversely related to soil pH. Erratic behavior of nutrient elements during historic periods of stress suggests that some nutrient concentrations in the environment were not always passively recorded by tree-rings.     

湘南宝山铜铅锌多金属矿床闪锌矿元素地球化学特征及其对成矿的制约

位于钦杭成矿带和南岭成矿带叠合部位的湘南地区是我国重要的W、Sn、Cu、Pb、Zn、Ag多金属矿集区,宝山Cu、Pb、Zn、Ag多金属矿床是湘南地区代表性的矿床.相比中部矽卡岩型矿体,西部和北部脉状矿体研究程度较低.本文拟通过电子探针(EPMA)和激光剥蚀电感耦合等离子体质谱(LA-ICP-MS)原位微区分析技术,对比...