Horqin and Otindag sandy lands
The Horqin and Otindag sandy lands lie north of the North China Craton within the 'Northern accretionary complexes and post-Palaeozoic intracontinental fold belts' shown in the tectonic map below. These belts are made up of pieces of old oceanic crust (ophiolite) and other small pieces of continental crust which have collided along this margin (Zhang et al. 1984). There are also pieces of very old Precambrian crust and magmatic arcs. This is part of what is called the Central Asian Orogenic Belt.
Fig 1. Stevens et al. 2013 tectonic map of China showing the main crustal units.
Both sandy lands are underlain by rocks of Mesozoic to Cenozoic in age which comprise of eroded continental material and igneous intrusions. The location of the sandy lands and the geology of the area are shown in Fig. 2. The sandy lands are made up of stabilized sand dunes.
Fig 1. Stevens et al. 2010 tectonic map of China with close up of the Horqin and Otindag sandy lands with accompanying geology map. The stars show where the samples from this area were collected for Stevens et al. 2010.
Previous work on the provenance of these areas suggest that the sandy lands were derived from rocks of the Phanerozoic Yanshan Fold Belt, Central Asia Orogenic Belt and the North China Craton, based on heavy mineral assemblages (Xie & Ding 2007). Stevens et al. (2010) undertook zircon U-Pb dating on samples from these areas (stars in Fig. 2), which agreed with the heavy mineral data in that there is evidence of grains from the Yanshan Fold Belt. This data is shown in Figs. 3 and 4.
Fig. 3 and Fig. 4 - zircon U-Pb probability plot for samples from the Horqin and Otindag Sandy Lands.
Zhang, Zh.M., Liou, J.G., Coleman, R.G. 1984. An outline of the plate tectonics of China. Geological Society of America Bulletin, 95, 295-312.
Stevens, T., Palk, C., Carter, A., Lu, H. & Clift, P.D. 2010. Assessing the provenance of loess and desert sediments in northern China using U-Pb dating and morphology of detrital zircons. Geological Society of America Bulletin.
Stevens, T., Carter, A., Watson, T.P., Vermeesch, P., Ando, S., Bird, A.F., Lu, H., Garzanti, E., Cottam, M. & Sevastjanova, I. 2013. Genetic linkage between the yellow River, the Mu Us desert and the Chinese Loess Plateau. Quaternary Science Reviews.