Detrital-zircon U–Pb geochronology of Jurassic sandstones in North China Craton (Daqingshan area, China): new constraints on provenance and tectonic implications

Abstract

The Daqingshan area in China located in the center part of the Khondalite belt, north of the Ordos Block and south of the Yinshan Block. The Daqingshan basin is the best-preserved Mesozoic basin that is oriented nearly east-west. Previous studies suggest that the provenance of Jurassic sediment is mainly the Khondalite belt and no material from Yinshan Block. We present detailed data on the detrital-zircon geochronology of the Jurassic sandstones from the Daqingshan area. The detrital-zircon U–Pb age data of the Wudanggou and Changhangou Formations show two peaks at ~2450 Ma and 1970–1930 Ma, with a few of Archean ages. The detrital-zircon age data of the Daqingshan Formation show three distinctive age populations of 2560–2460 Ma, 1950–1750 Ma, and 320–265 Ma. Comparison with the age of the surrounding magmatic rocks suggests that the main source area is the Wulashan–Daqingshan Complex, with the Yinshan Block being a lesser source. However, more Archean and Paleozoic detrital zircon occurs in the Daqingshan Formation, probably as a result of the rise of the western part of the basin and eastward movement of the center of the basin, thereby increasing provenance from the Yinshan Block. The Yanshan movement caused massive amounts of Yinshan material to move southward during the Middle-Late Jurassic. However, the barrier of the Yinshan Mountains caused Yinshan material to be deposited mainly in the eastern part of the basin.