Samples

TTG gneisses are the dominant geological rock type in the Archean basement blocks of the North China Craton. Supplementary Figure ¹ shows the general spatial and temporal distribution of Meso- to Neoarchean TTG gneisses, and detailed zircon age data and sampling locations are summarized in Supplementary Data ³. The magmatic crystallization ages of TTG gneisses are almost continuous from 3.0 to 2.5 Ga, with three peaks occurring at ~2.91, ~2.72, and ~2.53 Ga, with the youngest defining the maximum peak. The ~2.9 Ga TTG gneisses are sporadically distributed in Jiaodong, Anhui and Eastern Hebei terranes, whereas the ~2.7 Ga TTG gneisses concentrate more in the North Liaoning-South Jilin, Jiaodong, West Shandong, Dengfeng-Taihua, Zanhuang and Fuping terranes. The ~2.5 Ga data are distributed throughout the entire Eastern Block of the North China Craton. All the TTG gneisses, irrespective of age exhibit similar petrographic characteristics, making the different age groups difficult to distinguish in the field. A detailed outline of the geological background of each terrane is given in the Supplementary Information. After carefully screening, only 155 samples of TTGs meet all the requirements, and we create further data subsets by grouping individual analyses with similar ages and localities (Supplementary Data ⁴–⁵). Our selected crustal-derived TTGs display low loss on ignition values of less than 2.0 wt%, and lack of significant Ce anomalies (δCe = Ce_N/sqrt(La_N × Pr_N) with values of 0.79–1.31, indicating that the rocks have not been subjected to any major alteration (Supplementary Data ⁴)⁵⁶. Therefore, the chemical composition of the crustal-derived TTGs is considered to be close to that of the TTG magmas.