Geochronology and geochemistry of the Paleoproterozoic meta-basalts from the Jiao-Liao-Ji Belt, North China Craton: Implications for petrogenesis and tectonic setting

摘要: Abstract Geochronology, geochemical and isotopic studies were carried out on the Paleoproterozoic meta-basalts related rocks from Jiao-Liao-Ji Belt, North China Craton, to understand mantle source characteristics geodynamic setting. U-Pb dating using LA-ICPMS method zircons metamorphosed volcanic reveals that they formed at ca. 2204–2158 Ma 1895–1919 Ma, respectively. The are of calc-alkali affinity have arc-like compositions. They enriched in LREEs ((La/Yb) N  = 3.5–5.1) LILEs (Sr, Ba, Rb), depleted HFSEs (Nb, Ta, Zr, Hf, Ti), show variable high ɛ Nd ( t ) values (+2.4 +4.5). basaltic experienced significant fractional crystallization minor crustal contamination during magma evolution. Modeling suggests parent was derived 20% partial melting spinel-garnet lherzolites previously metasomatized by subduction zone fluids/melts Late Archean. Petrological, geochronological data suggest an active continental margin setting subsequently deformed amphibolite facies due arc-continental collision 1.9 Ga, rather than a rifting as thought most workers.