Outcrop distribution and formation of carbonate rhizoliths in Badain Jaran Desert, NW China

Qingfeng Sun , Arnaud Huguet (1) , Kazem Zamanian

1 METIS - Milieux Environnementaux, Transferts et Interactions dans les hydrosystèmes et les Sols

9 Carbonate rhizoliths and related features are environmental and ecological 10 indicators of not only palaeosols, but also modern soils. They designate subaerial 11 vadose and pedogenic diagenesis environments. Rhizoliths are commonly used as a 12 tool for paleoenvironmental reconstructions, but uncertainty remains regarding their 13 formation mechanisms. Field characteristics of the dune rhizoliths in the Badain Jaran 14 Desert, NW China were analyzed to investigate formation mechanisms and interpret 15 paleoenvironmental significance. Systematic field sampling and intensive 16 examination showed that the tube-like rhizoliths without morphological structures of 17 plant roots have been placed at the dune soil surface following erosion and weathering 18 but the underground rhizoliths are still connected to the dead Artemisia roots. 19 Rhizoliths occurred only along the windward, long gentle slopes of mega-dunes. Their 20 distribution patterns of both types in connection with plant distribution and landscapes 21 have been studied. Their petrological and mineralogical characters were performed in 22 detail using microscopic and spectroscopic techniques (cathodoluminescence, 23 scanning electronic microscopy and energy dispersive X-ray spectroscopy) in 24 laboratory. Altogether, field and laboratory analyses showed that rhizolith cement is 25 calcium carbonate and despite the high porosity of soil and high aridness of climate, 26

Domaines: Sciences de l'environnement; Planète et Univers [physics]

Qingfeng Sun, Arnaud Huguet, Kazem Zamanian. Outcrop distribution and formation of carbonate rhizoliths in Badain Jaran Desert, NW China. CATENA, 2021, 197, pp.104975. ⟨10.1016/j.catena.2020.104975⟩. ⟨hal-03004076⟩