242 / 2019-06-29 21:30:41

Chemical indexes of the Paleoproterozoic sedimentary rocks from the Liaohe Group, North China Craton: Implications for paleoclimate and provenance

provenance,Liaohe Group,Paleoproterozoic,chemical index,paleoclimate

Paleoproterozoic supracrustal materials have been widely identified in North China Craton, such as Liaohe, Hutuo and Lüliang groups. The Liaohe Goup in the eastern part of the North China Craton is dominated by deformed and metamorphosed sedimentary and volcanic successions. Compared with that of the coeval volcanics, geochemistry of the sedimentary rocks of the Liaohe Group has rarely been studied in detailed, which can possibly provide information on the paleoclimate and provenance. Here we synthesize the whole-rock and detrital zircon geochemistry of sedimentary rocks from the Liaohe Group against a uniform process and propose their different ways of palaeoweathering of the lower and upper formation. That is to say, although the lower and upper formations within the Liaohe Group might be derived from the similar source composition in a tectonically active setting, the paleoclimate that they experienced was not exactly the same. The predominant derivations are the Paleoproterozoic granitoids and basalts of the Liaohe Group, with minor input of Archean continental crust. This study highlights the contributions of the Paleoproterozoic mafic sources that is always overlooked in the previous researches.