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

Different jadeites have different characteristics. In this paper, the La-ICP-MS test is used to compare and analyze the elemental characteristics of jadeite in Guatemala and the Qing dynasty. The test results show that the highest value of Guatemalan jadeite Ca can reach 2.5 apfu, while the highest value of Qing dynasty jadeite is 0.73 apfu. The highest value of Na is the same for both. The concentration distribution range and highest value of Guatemalan jadeite and Qing dynasty jadeite Mg/(Mg + Fe) are the same. Guatemalan jadeite and Qing dynasty jadeite have a very wide content of trace elements. Qing dynasty Ca/(Mg + Fe) distribution is wider. Concentrations of Guatemalan and Qing dynasty jadeite Sr/Ba, which is a marine sediment, are greater than 1. The Ba in the Qing dynasty jadeite sediments contains a large amount of clay, resulting in higher levels than the average amount in Guatemalan jadeite Ba. The standard distribution map is similar, showing a “horn” shape. The Sr distribution is uneven. Guatemalan jadeite is heavily enriched in rare earths. Eu shows positive and negative abnormalities. The total rare earth value is 8.15 ppm. Qing Dynasty jadeite shows light rare earth enrichment, and Eu is a positive anomaly. The total rare earth value is 7.07 ppm. The characteristics of the two elements are somewhat similar, but different, which does not rule out the possibility that Qing dynasty jadeite came from Guatemala.