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Highlights: [•] Lower succession of the Soutpansberg Group commenced deposition at around 1830Ma. [•] Limpopo Belt Central Zone is the source for zircons in Soutpansberg rocks. [•] The identified 3937±4Ma zircon age is one of the oldest zircon ages in Africa. [ABSTRACT FROM AUTHOR]

The Quanji (全吉) Massif is located in the Northwest China, which is interpreted as a micro-continent that is composed of metamorphic basement and stable cover strata. There are some controversies of genetic relationship between the Quanji Massif and the major cratons in China. In this study, we obtained in situ zircon U-Pb and Hf isotopic compositions of the Yingfeng (鹰峰) rapakivi granites from the northwest Quanji Massif by application of LA-MC-ICP-MS technique. Twenty U-Pb age measurements points are concordant or near concordant, and their weighted mean Pb/Pb age is 1 793.9±6.4 Ma (MSWD= 1.09), yields an upper intercept age of 1 800±17 Ma (MSWD=0.41); 19 Hf isotope measurements yield a two-stage Hf model ages ( T) of 2.63 to 2.81 Ga, with a weighted average age of about 2.70±0.02 Ga and ɛHf( t) values variate between -8.91 to -5.35. This indicates that magma source of the Yingfeng rapakivi granites were produced from partial melting of late stage of Neoarchean juvenile crust, and suggests a significant crustal growth event occurred in the Quanji Massif at that time. The Quanji Massif might be an ancient continental segment detached from the Tarim Craton based on the crustal growth history and other geological records. The Tarim Craton (including the Quanji Massif) and the North China Craton had a similar or homological early crustal evolution around ∼2.7 Ga, which implies that Tarim Craton might be one of the component parts of North China Craton. [ABSTRACT FROM AUTHOR]

A method for quasi-simultaneous determination of U-Pb ages and Hf isotope compositions on a single zircon spot is developed, by use of a multiple-collector ICPMS coupled with an excimer laser-ablation system. The ICPMS used in this study is equipped with variable zoom lens to change the dispersion of the analyzer and bring ion beams into the collector coincidentally. This feature allows rapid switching between U-Pb and Hf collector configuration, which is used to quasi-simultaneously determine the zircon U-Pb and Hf isotope compositions. The analytical results on three reference zircon standards, 91500, CZ3 and Plesovice and one nature zircon sample, agree with literature/known values, thereby demonstrating feasibility of the method. [ABSTRACT FROM AUTHOR]