In-situ U Pb geochronology of vesuvianite in skarn deposits

In situ Sr–Nd isotope analysis of vesuvianite by LA-MC-ICP-MS: methodology and application

“…2d) exhibits enrichment in LREEs and a small positive Eu anomaly, like the FR vesuvianite. 14 In situ Sr isotope measurements yielded large variations during two analytical sessions, with 87 Sr/ 86 Sr ratios of 0.70945 ± 0.00032 (2s; n = 16) to 0.71018 ± 0.00040 (2s; n = 15) and an average of 0.70980 ± 0.00082 (2s; n = 31) (Table 3 and Fig. 3f).…”

“…M1439 vesuvianite also has a negative Eu anomaly, which is similar to that of DSL vesuvianite from the Dashunlong Sn deposit in the Nanling Range, southern China. 14 These three samples (including M659) have low Sr content (∼20 mg g −1 ; Table S1 †), which are not suitable for in situ Sr isotope analysis.…”

“…To assess the reliability of our methods, an in-house vesuvianite Fig. 5 Plots of (a) Rb-Sr and (b) Sm-Nd for the vesuvianite samples, including data from Halama et al, 6 Fukuyama et al, 7 Guo et al, 8 Caucia et al, 9 Xing et al, 13 Zhang et al, 14 Ma et al, 21 Su et al, 74 Xu et al, 75 and He et al The M6635 vesuvianite has a homogeneous Sr isotopic composition and was used to externally calibrate the other data during this study. Aer the corrections, the 87 Sr/ 86 Sr ratios calculated from the LA data are consistent with those obtained from the solution analyses (Fig.…”

“…10 The high isomorphic capacity and stability of vesuvianite favours the incorporation of variable amounts of U (several tens or hundreds of mg g −1 ), making it a potential mineral for U-Pb dating. [11][12][13][14] As a Ca-rich mineral, vesuvianite has moderate or high Sr (several tens to thousands of mg g −1 ) and low Rb (<1 mg g −1 ) contents, 6,7,9 which mean the measured 87 Sr/ 86 Sr ratio represents the initial Sr isotopic composition of the uid or melt from which the vesuvianite crystallised. 15,16 Furthermore, vesuvianite can be enriched in light rare earth elements (LREEs).…”

“…67 Four subgroups can be identified: (a) high REE contents with high (La/Lu) N values; (b) no obvious Eu anomalies; (c) negative Eu anomalies; and (d) positive Eu anomalies. The fields for the FR13, DSL, and FR vesuvianite samples are from Xing et al13 and Zhang et al14…”