岩矿测试
巖礦測試
암광측시
ROCK AND MINERAL ANALYSIS
2014年
6期
813-821
,共9页
王志海%叶美芳%董会%赵慧博%王轶
王誌海%葉美芳%董會%趙慧博%王軼
왕지해%협미방%동회%조혜박%왕질
流体包裹体%低温拉曼光谱法%NaCl-H2 O%CaCl2 -H2 O%盐度
流體包裹體%低溫拉曼光譜法%NaCl-H2 O%CaCl2 -H2 O%鹽度
류체포과체%저온랍만광보법%NaCl-H2 O%CaCl2 -H2 O%염도
fluid inclusions%cryogenic Raman Spectroscopy%NaCl-H2 O%CaCl2-H2 O%salinity
氯盐溶液作为流体包裹体中最普遍和最重要的盐水化合物，是测定包裹体盐水溶液含盐度的主要溶质，但由于其强离子键化合物的分子特性在常温、常压下没有拉曼效应，拉曼光谱测试无法获取氯盐的有效特征信息，使得利用激光拉曼光谱研究流体包裹体分子组分及含盐度的方法存在严重缺陷。本文联合利用激光拉曼光谱探针和冷热台，原位采集了不同盐度的NaCl －H2 O和CaCl2－H2 O 标准盐水溶液在低温下（－185℃）形成的冰、NaCl水合物和CaCl2水合物的拉曼光谱，分析了不同盐度标准盐水溶液形成的水合物拉曼特征峰的变化规律，尝试建立流体包裹体盐度低温拉曼光谱测定方法。分析表明，NaCl水合物约3425 cm－1拉曼特征峰与冰约3120 cm－1拉曼特征峰峰面积比值和配制的NaCl－H2 O标准溶液盐度呈良好的正相关（r2＝0．9995），CaCl2水合物约3431 cm－1拉曼特征峰与冰约3120 cm－1拉曼特征峰峰面积比值也和配制的CaCl2－H2O标准溶液盐度呈较好的正相关（r2＝0．9458）。利用愈合人工水晶法合成的NaCl－H2 O和CaCl2－H2 O包裹体标样检验了用上述方法低温测定流体包裹体盐度的可靠性，结果表明该技术用于盐度大于0．5 mol／L的NaCl－H2 O体系流体包裹体时，数据精度好于20％；用于盐度大于0．5 mol／L的CaCl2－H2 O体系流体包裹体时，数据精度最高可达5％，完全可达到半定量－定量测定的要求。研究还发现，包裹体内压可能对低温拉曼光谱测定流体包裹体盐度影响不大，分析中获得的冰拉曼特征峰的拉曼位移（约3120 cm－1）与前人略有差异，可能与实验条件下获得的冰的多型不同有关。与国内外同行的研究结果比较，本研究更加注重该项实验技术的实际应用，通过对不同体系盐水溶液系列进行拉曼光谱实验分析，对实验条件和方法进行不断优化，在确定流体体系的同时实现了包裹体盐水溶液盐度半定量－定量测定，准确度优于传统方法，并且该方法具有很强的实用性。
氯鹽溶液作為流體包裹體中最普遍和最重要的鹽水化閤物，是測定包裹體鹽水溶液含鹽度的主要溶質，但由于其彊離子鍵化閤物的分子特性在常溫、常壓下沒有拉曼效應，拉曼光譜測試無法穫取氯鹽的有效特徵信息，使得利用激光拉曼光譜研究流體包裹體分子組分及含鹽度的方法存在嚴重缺陷。本文聯閤利用激光拉曼光譜探針和冷熱檯，原位採集瞭不同鹽度的NaCl －H2 O和CaCl2－H2 O 標準鹽水溶液在低溫下（－185℃）形成的冰、NaCl水閤物和CaCl2水閤物的拉曼光譜，分析瞭不同鹽度標準鹽水溶液形成的水閤物拉曼特徵峰的變化規律，嘗試建立流體包裹體鹽度低溫拉曼光譜測定方法。分析錶明，NaCl水閤物約3425 cm－1拉曼特徵峰與冰約3120 cm－1拉曼特徵峰峰麵積比值和配製的NaCl－H2 O標準溶液鹽度呈良好的正相關（r2＝0．9995），CaCl2水閤物約3431 cm－1拉曼特徵峰與冰約3120 cm－1拉曼特徵峰峰麵積比值也和配製的CaCl2－H2O標準溶液鹽度呈較好的正相關（r2＝0．9458）。利用愈閤人工水晶法閤成的NaCl－H2 O和CaCl2－H2 O包裹體標樣檢驗瞭用上述方法低溫測定流體包裹體鹽度的可靠性，結果錶明該技術用于鹽度大于0．5 mol／L的NaCl－H2 O體繫流體包裹體時，數據精度好于20％；用于鹽度大于0．5 mol／L的CaCl2－H2 O體繫流體包裹體時，數據精度最高可達5％，完全可達到半定量－定量測定的要求。研究還髮現，包裹體內壓可能對低溫拉曼光譜測定流體包裹體鹽度影響不大，分析中穫得的冰拉曼特徵峰的拉曼位移（約3120 cm－1）與前人略有差異，可能與實驗條件下穫得的冰的多型不同有關。與國內外同行的研究結果比較，本研究更加註重該項實驗技術的實際應用，通過對不同體繫鹽水溶液繫列進行拉曼光譜實驗分析，對實驗條件和方法進行不斷優化，在確定流體體繫的同時實現瞭包裹體鹽水溶液鹽度半定量－定量測定，準確度優于傳統方法，併且該方法具有很彊的實用性。
록염용액작위류체포과체중최보편화최중요적염수화합물，시측정포과체염수용액함염도적주요용질，단유우기강리자건화합물적분자특성재상온、상압하몰유랍만효응，랍만광보측시무법획취록염적유효특정신식，사득이용격광랍만광보연구류체포과체분자조분급함염도적방법존재엄중결함。본문연합이용격광랍만광보탐침화랭열태，원위채집료불동염도적NaCl －H2 O화CaCl2－H2 O 표준염수용액재저온하（－185℃）형성적빙、NaCl수합물화CaCl2수합물적랍만광보，분석료불동염도표준염수용액형성적수합물랍만특정봉적변화규률，상시건립류체포과체염도저온랍만광보측정방법。분석표명，NaCl수합물약3425 cm－1랍만특정봉여빙약3120 cm－1랍만특정봉봉면적비치화배제적NaCl－H2 O표준용액염도정량호적정상관（r2＝0．9995），CaCl2수합물약3431 cm－1랍만특정봉여빙약3120 cm－1랍만특정봉봉면적비치야화배제적CaCl2－H2O표준용액염도정교호적정상관（r2＝0．9458）。이용유합인공수정법합성적NaCl－H2 O화CaCl2－H2 O포과체표양검험료용상술방법저온측정류체포과체염도적가고성，결과표명해기술용우염도대우0．5 mol／L적NaCl－H2 O체계류체포과체시，수거정도호우20％；용우염도대우0．5 mol／L적CaCl2－H2 O체계류체포과체시，수거정도최고가체5％，완전가체도반정량－정량측정적요구。연구환발현，포과체내압가능대저온랍만광보측정류체포과체염도영향불대，분석중획득적빙랍만특정봉적랍만위이（약3120 cm－1）여전인략유차이，가능여실험조건하획득적빙적다형불동유관。여국내외동행적연구결과비교，본연구경가주중해항실험기술적실제응용，통과대불동체계염수용액계렬진행랍만광보실험분석，대실험조건화방법진행불단우화，재학정류체체계적동시실현료포과체염수용액염도반정량－정량측정，준학도우우전통방법，병차해방법구유흔강적실용성。
Chlorides are the most common and important solutes in liquid phase of natural fluid inclusions,but they are difficult to be studied by Laser Raman Microscopy (LRM)at room temperature,due to their strong ionic bonds, which are not Raman active under experimental conditions.This problem seriously hinders the utilizing of LRM in a fluid inclusion study,neither for their specific components in both vapor and liquid phases,nor for their salinity.In combination with LRM and hot and cold operation boards,Raman spectra of ice,sodium chloride hydrate and calcium chloride hydrate, which were formed by frozen NaCl-H2 O and CaCl2-H2 O solutions with different concentrations at low temperature (-1 85℃)were acquired.According to systematic analysis and comparison of Raman spectra of sodium and calcium chloride hydrates with different concentrations,an attempt was made to establish a method for salinity determination by cryogenic LRM.Results show that the area ratios of Raman bands at about 3425 cm-1 of sodium chloride hydrates to that at about 31 20 cm-1 of ice were in good correlation with prepared concentrations of NaCl-H2O solutions (r2 =0.9995).Similarly,the area ratios of Raman bands at about 3431 cm-1 of calcium chloride hydrates to that at about 31 20 cm-1 of ice were also in good correlation with prepared concentrations of CaCl2-H2 O solutions(r2 =0.9458).Reliability of this method was examined by synthetic NaCl-H2 O and CaCl2-H2 O inclusions,which were prepared by healing microfracture of quartz crystals under high pressure and temperature conditions when the crystals were dipped in solution of specific concentration.Inspection results show that when this method is applied to >0.5 mol/L NaCl-H2 O fluid inclusions,the accuracy is better than 20%. Meanwhile,when applied to >0.5 mol/L CaCl2-H2 O fluid inclusions,the best accuracy might reach to 5%.The results meet semi-quantitative to quantitative analysis requirements for fluid inclusions.The interior pressure of fluid inclusions might be less important in salinity determination of fluid inclusions by cryogenic Raman Spectroscopy.The Raman bands of ice were somewhat different to those acquired by most other researchers (at about 31 20 cm-1 in this study),which is most likely due to different polymorphs formed under the experimental conditions.This method allows knowledge of the main fluid system to be attained as well as semi-quantitative to quantitative determination for the salinity of fluid inclusions with improved accuracy over traditional techniques.
