Late Miocene Yellow River formation in Qingtongxia area, North China: Detrital zircon and heavy mineral analysis at Niushou Mountain, Ningxia

Abstract

The development and formation times of the Yellow River, the second largest drainage system in China, remain controversial. The Ganhegou Formation, a set of Upper Miocene–Pliocene fluvial facies sediments, developed around Niushou Mountain in the outermost edge of the arcuate structural belt in the northeastern margin of the Tibetan Plateau and has a sediment composition very similar to that of the Yellow River. In this article, the relationship between the deposition of the Ganhegou Formation and the Yellow River is confirmed through the analysis and comparison of sediment composition, detrital zircons, and heavy mineral characteristics of the Ganhegou Formation, a Yellow River terrace, and the modern Yellow River. The sediments of the Ganhegou Formation contain abundant well‐ground and sorted fluvial pebbles that are largely consistent with Yellow River sediments. The analysis of the composition of zircons and heavy minerals shows that the age peaks of all detrital zircons are primarily among 200–300 Ma, 400–500 Ma, and 1,700–2,000 Ma and that all the heavy minerals are generally characterized by the combination of ‘haematite + garnet + zircon + epidote + quartz and altered minerals’. Therefore, the Ganhegou Formation in the Niushou Mountain area of Ningxia is a likely sediment of the ancient Yellow River, which has existed at Qingtongxia since at least the Late Miocene.