Age and Geochemistry of Zircon Megacrysts from Alluvial Deposits in the Huadian Area, Northeastern China

Megacrystic zircons have recently been found in alluvial deposits the Huadian area of northeastern China. However, studies rarely conducted on these zircons. In this article, we present systematic situ trace element, U-Pb age and Hf isotope data regarding zircons, with aim investigating their source characteristics provenance. The studied a diameter 0.7–1.2 cm, are dominantly irregular shape rounded termination, color ranging from near-colorless to reddish brown maroon. show oscillatory zoning CL images, Th/U value 0.18–1.27, which is consistent typical features magmatic positive εHf(t) (4.8–9.2) further indicates presence precipitation mantle-derived melt, limited contamination crustal components. obtained weighted mean 206Pb/238U for 17.9 ± 0.12 Ma, slightly older than eruptional ages associated alkali basalts (from 17.6 1.09 Ma 17.8 0.69 Ma), implying short residence time mantle before entrainment. incorporate wide range elements, including ΣREE (117–2790 ppm), (4902–11856 ppm) Y (145–3645 contents, generating mixed-source protolith assignments. As suggested by moderate variations seen isotopes, propose that melts complex nature, likely result chemical heterogeneity upper mantle.