Natural Clinopyroxene Reference Materials for in situ Sr Isotopic Analysis via LA-MC-ICP-MS

Abstract

Clinopyroxene is a major host mineral for lithophile elements in the mantle lithosphere, and therefore, its origin is vital for constraints on mantle evolution and melt generation. In situ Sr isotopic measurement of clinopyroxene has been available since the recent development of laser ablation multicollector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) in the 2000s. Therefore, there is an increasing demand for natural clinopyroxene reference materials for Sr isotope microanalysis. In this contribution, we present six natural clinopyroxene reference materials from South Africa (JJG1424) and China (YY09-47, YY09-04, YY09-24, YY12-01, and YY12-02) for Sr isotope microanalysis. The Sr content of these clinopyroxenes ranges from 50 to 340 μg g−1, which covers most natural clinopyroxene compositions. Homogeneity of these potential reference materials were investigated and evaluated in detail over a 2-year period using 193-nm nanosecond and 257-nm femtosecond laser systems coupled to either a Neptune or Neptune Plus MC-ICP-MS. Additionally, the major and trace element of these clinopyroxenes were examined by electron probe microanalyzer (EPMA) as well as solution and laser ICP-MS. The in situ87Sr/86Sr values obtained for the six natural clinopyroxene reference materials agree well with data obtained using the thermal ionization mass spectrometer (TIMS) method. The Sr isotopic stability and homogeneity of these clinopyroxenes make them potential reference materials for in situ Sr microanalysis to correct instrumental fractionation or as quality control materials for analytical sessions. The new Sr isotope data provided here might be beneficial for microbeam analysis in the geochemical community.

A natural plagioclase reference material for microbeam Sr isotopic analysis

“…10,16 The ubiquitous occurrence of Sr-rich minerals concomitant with low Rb content due to the geochemical resemblance of Sr with major element Ca makes minerals such as plagioclase, apatite, and clinopyroxene particularly suitable for in situ Sr isotopic analysis. 14,15,[17][18][19][20] Successful cases indicate that plagioclase is one of the most important index minerals, which grows over a large range of magma compositions, from basaltic to rhyolitic, characterized by low Rb/Sr and high Sr contents, and is widely used in in situ Sr isotopic compositions to reveal magma evolution. 16,[21][22][23][24] Moreover, detrital plagioclase is also a useful mineral in sedimentary research and its Sr isotope ratios can reect various grain-size and weathering effects in addition to tracing sediment provenance.…”

“…18; JJG1424, YY09-47, YY09-04, YY09-24, YY12-01, YY12-02, ref. 20; HNB, ref. 34) and K-feldspar (Tuyk, ref.…”

In Situ Rb-Sr Dating Of Lunar Meteorites Using Laser Ablation MC-ICP-MS

“…The mass fractions of Sr and Rb and the 87 Sr/ 86 Sr ratios in the reference glasses are compiled from the literature. 13,[21][22][23][24][25][26][27][28] Two differentiated lunar meteorites (NWA 10597 and NWA 6950) were analyzed for Rb-Sr isotopes. NWA 10597 is a low-Ti mare basaltic lunar meteorite and consists mostly of mm-sized pyroxene and plagioclase, with minor olivine, spinel, ilmenite, phosphates, silica, and trace Zr-rich minerals, such as baddeleyite, zirconolite and tranquillityite.…”

Data Quality in Geochemical Elemental and Isotopic Analysis

“…For example, clinopyroxene mineral is a major host for lithophile elements and can provide critical information on the mantle evolution and melt generation, and in situ 87 Sr/ 86 Sr isotopic analysis is valuable for such studies. Zhao et al [47] attempted to develop six natural clinopyroxene reference materials from South Africa (JJG1424) and China (YY09-47, YY09-04, YY09-24, YY12-01, and YY12-02) for Sr isotope microanalysis. The homogeneity of these potential reference materials was investigated and evaluated in detail over a 2-year period using 193 nm nanosecond and 257 nm femtosecond laser systems coupled with MC-ICP-MS and verified by the TIMS method.…”