Quantitative estimation of the contribution of dustsources to Chinese loess using detrital zircon U-Pbage patterns

• The origin and provenance of the loess deposits of the Chinese Loess Plateau (CLP) are stilldebated. In order to pinpoint the dust sources, surface samples from the piedmont of the NortheasternTibetan Plateau, the Gobi Altai Mountains, and modern eolian dunes from the Tengger desert and Mu Ussand field were analyzed by using the detrital zircon dating technique. In order to quantitatively discriminatethe content of different potential sources, zircon grains of different ages were grouped according to theirtectonic origin. Zircon grains aged from 1300 to 550 Ma were assigned to the Northeastern Tibetan Plateau,and grains aged from 550 to 0 Ma to the Northeastern Tibetan Plateau or the Gobi Altai Mountains, or to acombination of the two. Zircon ages of around 2.8 Ga to 1.3 Ga may be a mixture of sources from theNortheastern Tibetan Plateau, Gobi Altai Mountains, or North China Craton. Sediments from the Tenggerdesert and Mu Us sand field consist of a mixture of the three sources and exhibit a high degree of spatialvariability in terms of their source. In the northern part of the two deserts, 43–83% of the sediments arederived from the Gobi Altai Mountains, while in the south, material from the Northeastern Tibetan Plateaucomprises 51–98% of the sediments. Loess deposits from the CLP also comprise a mixture of the threedifferent sources, with material from the Northeastern Tibetan Plateau making the dominant contribution(65–100%), with material from the North China Craton and the Gobi Altai Mountains comprising 0–35% and0–40% of the loess deposits, respectively. The contributions from the three sources to the loess deposits onCLP vary spatially. Application of the novel statistical method of provenance group analysis demonstratesthat the loess deposits comprise a mixture of material from a broad region of northern China and that theNortheastern Tibetan Plateau material makes the dominant contribution.

Subject headings

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Multidisciplinär geovetenskap (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Geosciences, Multidisciplinary (hsv//eng)

Keyword

desert and sand fields

detrital zircon U-Pb age

Northeastern Tibetan Plateau

Gobi Altai Mountains

Publication and Content Type

ref (subject category)

art (subject category)