Granulite facies metamorphism and crust melting in the Huai'an terrane at ̃1.95Ga, North China Craton: New constraints from geology, zircon U-Pb, Lu-Hf isotope and metamorphic conditions of granulites

摘要: Abstract Geological implications of ∼1.95 Ga and ∼1.85 Ga metamorphic ages for HP granulites in the Huai’an terrane are still controversial, which have affected crustal evolution models North China Craton. This study reports two geological sections distinct relationships a quartz-dioritic tonalitic dike cutting through mafic granulite facies meta-sedimentary rocks described. In these sections, magmatic dikes, preserve conformable foliation to indicate their similar deformation history. The U–Pb dating Lu–Hf isotopic analysis zircons from meta-igneous provide new constraints on timing mechanism thermal events associated with events. Both dikes were formed around overprinted by later event during ∼1.85 Ga. S-type granite, at section (GS) 1, revealed its formation age was 1959 ± 34 Ma (n = 3, MSWD = 1.5), 1840 ± 8 Ma (n = 10, MSWD = 1.2). Additionally, GS2 dominated 1972 ± 22 Ma (n = 6; MSWD = 0.03) few grains recording an 1856 ± 29 Ma (n = 3; MSWD = 0.17). situ analyses dike, reveal that derived partial melting ∼2.0–2.2 Ga meta-basic granite generated meta-sediments beyond 840 ± 50 °C. It suggested those taken into lower crust certain way conditions ca. 1.95 Ga ago. A clockwise P-T path acquired peak 880–890 °C 11–13 kbar. temperature results recorded granulite, high-pressure mineral assemblage matrix, suggest metamorphism approximately According above, this contribution concludes metamorphosed together under ago, followed high-temperature gave rise ∼1.95 Ga. Huangtuyao graphite mine experienced same history after pelitic interpreted be collisional products Paleoproterozoic cratonization NCC.