Characterization of detrital zircon U-Pb age patterns of the sandy and Gobi desert and implication for Chinese loess source

Abstract:

Detrital zircon age distribution pattern provides a possibility to discriminate the potential sources of aeolian sand and loess in north China. 8 surface samples from the North Tibetan Plateau (NTP) plain and Gobi Altay Mountains (GAMs) plain and 21 modern sand samples from the Tengger desert and Mu Us sand field are collected to obtain detrital zircon age distribution patterns for the investigation of the potential provenance of aeolian sand and silt in north China. Combined with existing detrital zircon age data from potential source areas, zircon grains at different ages can be assigned different origins. Using the zircon age distribution pattern of all samples on the NTP plain as one end member, that on the GAMs plain as another, and those from the North China Craton (NCC) as a third, the mixing ratio of the three deposits could be calculated. Following this, deposits in the Tengger Desert, Mu Us sand field and CLP are divided into different groups by different sources. Tengger Desert sediments are mainly made of sediments from GAM plain, except for thoes on the southern edge, which are mainly influenced by sediments from the NTP plain. Sediments in the northeast Mu Us sand field are largely from NCC material and those in the southwest are mainly from the NTP plain. Moreover, we estimate that at least more than 60% of Quaternary loess materials on the CLP probably originate from the materials on the NTP plain. The CLP sediment involved in this study can be considered as broadly homogenous.