钡同位素在表生环境中的应用研究

Application of Barium Isotopes in Supergene Environment

钡属于难熔的流体活动性元素,高度富集于地壳当中,因此钡同位素可广泛应用于示踪俯冲过程中壳幔物质循环相关的地质过程。早期受分析技术的局限性,钡同位素在地球化学领域的发展相比于其他金属或非金属稳定同位素体系而言相对滞后。近十几年来,随着多接收电感耦合等离子体的广泛应用以及化学分析纯化流程的改进,使得钡同位素的测试精度显著提高,因此钡同位素作为一个强大的地球化学工具在表生地球化学、天体化学、生物地球化学、地球深部动力学等领域绽放出新的活力。来自实验以及理论计算的证据证实低温条件下矿物与溶液之间具有明显的钡同位素分馏现象,而且天然样品的钡同位素组成也存在明显的差异,生物以及非生物过程都会造成钡同位素的分馏,这为钡同位素作为指示剂在高低温过程中揭示不同地质现象与过程提供了新的契机。前人对于钡同位素在测试分析技术、天体化学以及高温过程方面的应用已经进行了较为详细的介绍,低温过程主要介绍了钡同位素在海洋中的应用,涵盖范围还不够全面。钡同位素在表生环境的研究还处于初级阶段,但目前已取得一些显著的成果,因此本文主要对钡同位素在表生环境中的应用进行了论述,并对钡同位素在目前研究中存在的问题进行了探讨与总结。

Barium is a refractory fluid active element,highly enriched in the crust,so barium isotopes can be widely used to trace the geological processes related to crust mantle material circulation during subduction.Due to the limitations of analytical techniques in the early stage,the development of barium isotopes in the geochemical field was relatively backw ard compared with other metal or non-metallic stable isotope systems.In recent ten years,with the extensive application of multi receiver inductively coupled plasma and the improvement of chemical analysis and purification process,the measurement accuracy of barium isotopes has been significantly improved.Therefore,barium isotopes,as a powerful geochemical tool,have shown new vitality in supergene geochemistry,astrochemistry,biogeochemistry,deep earth dynamics and other fields.Evidence from experiments and theoretical calculations confirms that there is an obvious barium isotope fractionation phenomenon between minerals and solutions under low temperature conditions,and there is also an obvious difference in the barium isotope composition of natural samples.Both biological and abiotic processes can cause barium isotope fractionation,which provides a new opportunity for barium isotopes as indicators to reveal different geological phenomena and processes during high and low temperature processes.The application of barium isotopes in measurement and analysis technology,astrochemistry and high temperature process has been introduced in detail by predecessors.The low temperature process mainly introduces the application of barium isotopes in the ocean,which is not comprehensive enough.The research of barium isotopes in supergene environment is still in the primary stage,but some remarkable achievements have been made at present.Therefore,this paper mainly discusses the application of barium isotopes in supergene environment,and discusses and summarizes the problems existing in the current research of barium isotopes.