【摘要】：將激光器(LA)和電感耦合等離子體質(zhì)譜儀(ICP-MS)聯(lián)用避免了溶液分析繁瑣、耗時的前處理操作,減少了樣品制備過程中可能帶來的污染,同時又具備分析成本低、測試速度快、分析數(shù)據(jù)精度高等優(yōu)勢。本文將LA與ICP-MS聯(lián)接使用,通過激光能量密度和剝蝕頻率組合來討論較低的元素分餾效應(yīng),同時匹配RF功率、采樣深度、載氣及He氣流速等主要工作參數(shù)以獲得較高的元素信號靈敏度和穩(wěn)定性,從而得到儀器最優(yōu)工作參數(shù)組合,建立了可靠的鋯石U-Pb定年方法。通過對鋯石標(biāo)樣91500、GJ-1及Ple2ovic互測結(jié)果表明,其206Pb/238U加權(quán)平均年齡分別為1063.9±6.0 Ma(2σ,n=20)、600.3±2.6 Ma(2σ,n=27)及337.6±1.7 Ma(2σ,n=20),測試結(jié)果準(zhǔn)確度和精度均在1%范圍內(nèi),與前人報道的誤差范圍一致。使用優(yōu)化后的儀器參數(shù)對來自鄂東南銅綠山礦區(qū)石英正長閃長玢巖巖體中的實(shí)際鋯石樣品進(jìn)行測試,獲得其206Pb/238U年齡與前人研究結(jié)果基本一致,表明本法能準(zhǔn)確地對鋯石進(jìn)行定年分析。
[Abstract]:The combination of laser (LA) and inductively coupled plasma mass spectrometer (ICP-MS) avoids the tedious solution analysis and time-consuming pretreatment operation, reduces the possible pollution in the sample preparation process, and at the same time has the advantages of low analysis cost and fast testing speed. Analysis of data accuracy and other advantages. In this paper, we use LA and ICP-MS to combine laser energy density and denudation frequency to discuss the low fractionation effect of elements, and match RF power and sampling depth. The main working parameters such as carrier gas and he gas flow velocity are used to obtain higher sensitivity and stability of element signal, thus the optimal working parameters combination is obtained, and a reliable zircon U-Pb dating method is established. The results of zircon standard 91500 GJ-1 and Ple2ovic show that the weighted mean age of 206Pb/238U is 1063.9 鹵6.0Ma (2 蟽 / nnf20), 600.3 鹵2.6Ma (2 蟽 / NJ ~ (27) and 337.6 鹵1.7Ma (2 蟽 / n ~ (20) respectively. The accuracy and accuracy of the test results are in the range of 1%, which is in agreement with the error range reported by others. The actual zircon samples from quartz syenite porphyrite in Tonglushan mining area in southeastern Hubei Province were tested by using the optimized instrument parameters. The 206Pb/238U age of the zircon samples obtained is basically consistent with the results of previous studies. The results show that this method can accurately analyze zircon.
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本文編號：2143366