Lead isotope analysis of melt inclusions by LA-MC-ICP-MS

Abstract

Pb isotope compositions of melt inclusions provide unique information about the composition of primary magmas and their source. In this study, we have developed a method for measuring Pb isotopes in small olivine-hosted melt inclusions (>40 mm) from young and old volcanoes by LA-MC-ICP-MS. We used a new interface cone assemblage consisting of a Jet sample cone and X skimmer cone. A small flow of N 2 gas was added to the carrier gas and passed through the assemblage to enhance the signal intensity. In addition the energy and repetition rate of the laser conditions were reduced and the signal integration time was shortened in order to lengthen the laser ablation time and to collect enough data. Mass bias and instrument drift were corrected using a standard-sample-standard bracketing method. The analysis routine employed eight ion counters to receive 238 basalts, but also from old samples that require correction for U-Th decay.

Strontium isotope measurement of basaltic glasses by laser ablation multiple collector inductively coupled plasma mass spectrometry based on a linear relationship between analytical bias and Rb/Sr ratios

“…This mass spectrometer is equipped with eight variable position Faraday cups and one fixed central Faraday cup, and nine ion counters, which can measure isotopic ratios with a relative mass dispersion up to 17%. An X skimmer cone, instead of an H skimmer cone, is used in the interface to improve the instrumental sensitivity . During Sr isotope measurement, seven Faraday cups were used to collect the signals on m/z 82, 83, 84, 85, 86, 87 and 88 in static mode.…”

“…An X skimmer cone, instead of an H skimmer cone, is used in the interface to improve the instrumental sensitivity. 20,21 During Sr isotope measurement, seven Faraday cups were used to collect the signals on m/z 82, 83, 84, 85, 86, 87 and 88 in static mode. The signals of 83 Kr and 85 Rb were used to monitor the interferences of 84 Kr, 86 Kr and 87 Rb on 84 Sr, 86 Sr and 87 Sr.…”

When Did the Paleotethys Ailaoshan Ocean Close: New Insights From Detrital Zircon U‐Pb age and Hf Isotopes

“…Both U‐Pb dating and Hf isotope analyses were conducted using a Neptune plus multicollector inductively coupled plasma mass spectrometer (MC‐ICP‐MS) with a RESOlution M‐50193‐nm laser ablation system at the State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (GIGCAS). Detailed equipment configuration was given in Xia et al () and L. Zhang, Ren, et al (). Detailed metadata for the LA‐ICP‐MS U‐Pb dating were given in Table S2, following the recommendations outlined by Horstwood et al ().…”

Chemical and Pb isotope composition of olivine-hosted melt inclusions from the Hannuoba basalts, North China Craton: Implications for petrogenesis and mantle source

“…The international reference materials NKT-1G and BHVO-2G were selected as the intensities of their 208 Pb peaks resemble those of the melt inclusions. These standards were measured in turn to evaluate the accuracy of the instrument prior to analysis (Zhang et al, 2014). Before and after every five analyses, an internal glass standard (BHVO-2G) was measured to detect instrumental drift.…”