SHRIMP zircon dating and LA-ICPMS Hf analysis of early Precambrian rocks from drill holes into the basement beneath the Central Hebei Basin, North China Craton

Neoarchean reworking of Mesoarchean and Paleoarchean crust (3.4 ∼ 3.0 Ga) within the North China Craton: Constraints from zircon U-Pb geochronology and Lu-Hf isotopes from the basement of the Bohai Bay Basin

“…Available zircon U-Pb data for the early Precambrian rocks from drill holes into the basement beneath the BBB are summarized in Table 2. In this study, magmatic zircon U-Pb data gave crystallization ages of ~3.1 Ga and 2.60-2.45 Ga for the protolith magmas of TTGs, granites and supracrustal rocks, in good agreement with previous zircon U-Pb ages of ~3.1 Ga and 2.6-2.5 Ga, respectively, obtained for different lithologies from drill holes within different depressions in the basement of the BBB (Song et al, 2011;Wan et al, 2014b;Wang et al, 2019). As shown in Table 2, in general, TTG magmatism, including granodiorite, tonalite and trondhjemite rocks, occurred during 3.16-3.12 Ga and 2.60-2.45 Ga, respectively.…”

“…As shown in Table 2, in general, TTG magmatism, including granodiorite, tonalite and trondhjemite rocks, occurred during 3.16-3.12 Ga and 2.60-2.45 Ga, respectively. The diorite and granites were almost simultaneously emplaced at ~2.5 Ga. For the supracrustal rock (sample CH917-3), we obtained two magmatic ages of 2486±21 Ma and 3081±19 Ma, which are consistent with previous magmatic zircon U-Pb ages of ~3166 Ma and 2.35-2.54 Ga from the Jidong and Bozhong depressions (Wan et al, 2014b;Wang et al, 2019), respectively.…”

“…(3) The Eastern Block of the North China Craton may have been significantly influenced by a mantle plume ~2.5 Ga, and the area with the most intensive the mantle plume activity might have been located beneath the BBB and peripheral areas. Yang et al, 2008;Li et al, 2010;Wan et al, 2011;Wang et al, 2011b;Lv et al, 2012;Peng et al, 2012a;Wang et al, 2012;Liu et al, 2013;Meng et al, 2013;Wang et al, 2013;Wu et al, 2013;Wan et al, 2014b;Guo et al, 2015;Wu et al, 2016;Sun et al, 2020 Data source for Archean basement of around the Bohai Bay Basin: Wu et al, 2008;Yang et al, 2008;Li et al, 2010;Wan et al, 2011;Wang et al, 2011b;Lv et al, 2012;Peng et al, 2012a;Wang et al, 2012;Liu et al, 2013;Meng et al, 2013;Wang et al, 2013;Wu et al, 2013;Wan et al, 2014b;Guo et al, 2015;Wu et al, 2016;Sun et al, 2020 Fig.11 Age histogram of of magmatic zircons.…”

“…In recent years, a few boreholes have revealed the existence of Precambrian basement beneath the BBB (Meng et al, 2017;Wang et al, 2019). However, little information about the early Precambrian is known from the basement of the BBB (Wan et al, 2014b), because of the covering Paleozoic to Cenozoic strata (Li et al, 2005).…”

“…Recently, some samples from drill holes were dated by U-Pb zircon, and Precambrian ages of ~2.5 Ga and ~3.0 Ga were obtained (Song et al, 2011;Wan et al, 2014b;Meng et al, 2017;Wang et al, 2019), proving the existence of Precambrian rocks beneath the BBB. Although Archean tectono-thermal events have been identified beneath the BBB, the lack of studies on the origin of Neoarchean rocks has limited our understanding of the tectonic setting of the late Neoarchean in the EB.…”