Evolution of the Archean and Paleoproterozoic lower crust beneath the Trans-North China Orogen and the Western Block of the North China Craton

摘要: Abstract We report U–Pb ages and Hf isotopes of zircons in granulites from two continental suture zones the North China Craton (NCC)—from granulite xenoliths entrained Cenozoic Hannuoba basalts within Trans-North Orogen (TNCO) that amalgamates Western Eastern Blocks, a mafic associated with ultrahigh-temperature (UHT) Inner Mongolia Suture Zone (IMSZ) welds Yinshan Ordos Blocks. The these rocks, together inherited Mesozoic subalkalic intrusives regions, show several distinct age populations provide constraints on evolution lower crust beneath NCC. Parts older TNCO yield discordant data project to about 2.5 2.7 Ga. These old TDM model 2.6–2.9 Ga suggesting existence Archean TNCO, which is coupled Neoarchean metamorphic basement greenstone belt. A major zircon population grew at 1.75–2.0 Ga, consistent timing Paleoproterozoic collision between various crustal blocks NCC, this event had significant effect crust. Block also younger 1.8 1.9 Ga. This intrusion magmatic protoliths UHT rocks khondalite belt IMSZ. 2.0–2.5 Ga NCC be dominantly Paleoproterozoic, decoupled region. Yet another banded xenoliths, garnet-bearing pyroxenite cumulate dark large spread Phanerozoic concordant ranging 470 Ma 40 Ma peaks 315 Ma, 220–230 Ma, 120 Ma 46 Ma. Late Paleozoic predominantly occur variable eHf(t) values − 24 + 18. Triassic–Cretaceous mainly highly values, − 48 + 16. Tertiary only restricted dominant range 0 suggest episodic underplating ancient lasting continuously throughout Phanerozoic, producing underplated magmas or providing heat source for recrystallization Our clearly demonstrate important events Neoarchean–Paleoproterozoic