盐类矿物结晶水H和O同位素研究的科学意义与测定方法  

Scientific significance of study of hydrogen and oxygen isotopes in hydration water of salt minerals and determination methods

作　　者：谭红兵[1] 孔娜[1] 张文杰[1] 苏治国[1] 

机构地区：[1]河海大学地球科学与工程学院,江苏南京210098

出　　处：《河海大学学报（自然科学版）》2013年第4期307-314,共8页Journal of Hohai University(Natural Sciences)

基　　金：国家自然科学基金(41073034;41173049)

摘　　要：为建立精确测定盐类矿物结晶水H和O同位素组成方法,进一步丰富自然界矿物流体H和O同位素分馏机理,并为发展和推广盐类矿物结晶水H和O同位素地球化学应用研究打基础,在全面论述盐类矿物结晶水H和O同位素研究的科学意义及前人研究工作的基础上,以蒸发岩沉积序列中分布普遍、含结晶水量大的石膏(早期沉积阶段矿物)与光卤石(晚期沉积阶段矿物)为代表性矿物,通过实验室等温蒸发条件实验及天然矿物分析,建立了盐类矿物结晶水分离提取及测试的关键技术方法。实验结果表明,采用当前通用的基于MAT253质谱系统连续流进样,可以准确、快速地测定自然界盐类矿物结晶水H和O同位素组成。This study aims to develop a method for precisely determining hydrogen and oxygen isotopic compositions in hydration water of salt minerals,to understand the mechanisms of hydrogen and oxygen isotopic fractionations in mineral fluid,and to provide a basis for their geochemical applications.Based on an overview of previous study of hydrogen and oxygen isotopes in hydration water of salt minerals,two general salt minerals,gypsum（at the early sedimentary stage） and carnallite（at the late sedimentary stage）,were selected as typical minerals.Through laboratory experiments on isothermal evaporation conditions and natural mineral analysis,a new method for extraction of hydration water of salt minerals was established.Experimental results show that an online method can be used for rapid analysis of both stable oxygen and hydrogen isotopic ratios for salt mineral hydration water using a carbon-reducing furnace connected to a continuous-flow mass spectrometer system（MAT253） after extracting the gypsum hydration water offline.

关 键 词：盐类矿物 结晶水 H同位素 O同位素 同位素测定方法 

分 类 号：P597.2[天文地球—地球化学]