Examination of the Role of Boron in the Petrogenesis of Natural Granite Systems

硼在天然花岗岩系统岩石成因中的作用研究

• 批准号: 8816043
• 负责人: Peter Nabelek
• 金额: $ 6万
• 依托单位: University of Missouri-Columbia
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-01-01 至 1991-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8816043&HistoricalAwards=false
• 关键词: Examination; Role; Boron; Petrogenesis; Natural

This proposal is for a petrologic and geochemical study of the role of boron in the differentiation of granite magmas. Recent experiments (Chorlton and Martin, 1978; Pichaant, 19981, 1987; Maning, 1981) have demonstrated that the addition of boron and fluorine causes the minimum in the Q-Ab-Or system to move toward albite, that the solidus temperature is lowered and that the solubility of water in the melt is decreased (Bernard et al., 1985). In addition, the fluid/melt partition coefficient for boron of about 3 (Pichavant, 1981), suggests that much boron can be mobilized by a fluid coexisting with a granitic melt. The aim of the proposed study is to apply the available experimental results toward understanding the differentiation of boron-rich magmas, using the Harney Peak Granite, South Dakota, as an example. Using the combination of major and minor element, including boron, stable isotope, microprobe, fluid inclusion and Sm-Nd isotope analysis we will be able to describe the role of boron in large and small-scale chemical and mineralogic fractionations in granites. These include a wide range in Na/K ratios commonly observed in boron-rich granites, the generation of pegmatitic melts, and tourmalinization.

该建议是为了进行岩石学和地球化学研究 硼在花岗岩岩浆分异中的作用。 最近的实验（Chorlton和Martin，1978; Pichaant，19981， 1987; Maning，1981）已经证明， 氟使Q-Ab-Or系统中的最小值移动 向钠长石，固相线温度降低， 水在熔体中的溶解度降低（Bernard等人， 1985年）。 此外，流体/熔体分配系数为 硼含量约为3（Pichavant，1981），这表明， 被与花岗岩熔体共存的流体动员。 拟议研究的目的是应用现有的 实验结果有助于理解 富含硼的岩浆，利用南达科他州的哈尼峰花岗岩， 作为一个例子。 使用主元素和次元素的组合，包括 硼，稳定同位素，微探针，流体包裹体，Sm-Nd 同位素分析，我们将能够描述硼的作用， 大规模和小规模的化学和矿物分馏， 花岗岩 其中包括广泛的Na/K比， 在富硼花岗岩中观察到，伟晶岩的生成 熔融物和电气石化。