title: Hf-Nd isotopic variability in mineral dust from Chinese and Mongolian deserts: implications for sources and dispersal.
abstract: Mineral dust provenances are closely related to the orogenic processes which may have distinct Hf-Nd isotopic signatures. Here we report the clay-sized (<2 μm) Hf-Nd isotope data from Asian dust sources to better constrain the source and transport dynamics of dust deposition in the North Pacific. Our results show that there is a more positive radiogenic Hf isotopic composition with clay-sized fractions than the corresponding bulk sample and a decoupling of the Hf-Nd couplets in the clay formation during the weathering process. The clay-sized Hf-Nd isotopic compositions of the desert samples from the Sino-Korean-Tarim Craton (SKTC) are different from those of the Gobi and deserts from the Central Asian Orogeny Belt (CAOB) due to varying tectonic and weathering controls. The Hf-Nd isotopic compositions of dust in the North Pacific central province (NPC) match closely with those from the Taklimakan, Badain Jaran and adjacent Tengger deserts, implying that the NPC dust was mainly transported from these potential sources by the westerly jet. Our study indicates that dusts from the CAOB Gobi deserts either didn't arrive in NPC or were quantitatively insignificant, but they were likely transported to the North Pacific margin province (NPM) by East Asian winter monsoon.
authors: 1] Key Laboratory of Surficial Geochemistry, Ministry of Education; School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China [2] Ningxia Geophysical and Geochemical Exploration Institute, Yinchuan 710001, China.
authors: Wancang
authors: W
authors: Zhao
authors: SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710075, China.
authors: Youbin
authors: Y
authors: Sun
authors: Department of Earth Sciences, Dartmouth College, Hanover, New Hampshire, USA.
authors: William
authors: W
authors: Balsam
authors: School of Geographic and Oceanographic Sciences, Institute for Climate and Global Change Research, Nanjing University, Nanjing 210023, China.
authors: Huayu
authors: H
authors: Lu
authors: Key Laboratory of Surficial Geochemistry, Ministry of Education; School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China.
authors: Lianwen
authors: L
authors: Liu
authors: Key Laboratory of Surficial Geochemistry, Ministry of Education; School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China.
authors: Jun
authors: J
authors: Chen
authors: Key Laboratory of Surficial Geochemistry, Ministry of Education; School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China.
authors: Junfeng
authors: J
authors: Ji