Provenance of Cretaceous Dasheng Group Malanggou Formation in the mid-part of the Yishu fault zone, Shandong Province, China

Abstract

The Yishu fault zone has an important impact on sedimentary formation, magmatism, and mineralization in Shandong Province of eastern China. Determining the sedimentary source, tectonic setting, and age of the Cretaceous Dasheng Group Malanggou Formation is of great significance for clarifying the relationship between the tectonic evolution and mineralization of the Yishu fault zone. In order to decipher the source characteristics and associated sedimentary setting, elemental geochemistry and detrital zircon U–Pb geochronology of sandstones in the Malanggou Formation within the mid-part of the Yishu fault zone are studied. The results show that the provenance of the Malanggou Formation in the Dasheng Group was dominated by felsic volcanic rocks, and its sedimentation was in an arid and oxidized climate environment. The provenance of the Malanggou Formation was in a continental island arc setting. The major element concentrations and CIA value indicate that the Malanggou Formation has suffered weak chemical weathering. The abrasion of quartz and the trace element concentrations indicate that the Malanggou Formation is a set of proximal deposit. Detrital zircon age of the sandstone in Malanggou Formation can be divided into two age groups: 117–141 and 1852–2499 Ma. According to the age data of 117–141 Ma, the western Shandong uplift should be the main provenance of the Malanggou Formation, while according to the age data of 1852–2499 Ma, the Yishui Group in the Gongdanshan uplift had a certain contribution to the provenance of the Malanggou Formation.