top of page
Formation age, sediment provenance and wetting-drying pattern of the Mu Us desert
This science program is a collaboration between China, Denmark and Sweden. It attempts to answer questions when the Mu Us desert formed, the sedimentary sources and processes, as well as the timing of wetting periods in the late Quaternary. The Mu Us desert is located in the northern China, bordering the Yellow River on the west, the Kubuqi desert on the north, and the Chinese Loess Plateau on the east and south. Therefore, the evolutionary past of the Mu Us must be accompanied by a series of changes in its surroundings.
In this project, we employ the drilling technique to obtain core sediments from the Mu Us desert. Two long cores will penetrate the boundary between the desert and lower Cretaceous sandstone, and we also set several sites to obtain shorter cores.
To understand the history of Mu Us desert recorded in these sediments we need to know exactly when the sand was deposited. Scientists from the Technical University of Denmark, University of Aarhus, and Lanzhou University will utilize approaches of optical stimulated luminescence, cosmogenic nuclide, and magnetostratigraphy to constrain the ages for the sediments. Together with climate scientists from Uppsala University we will determine the exact timing of wetting of the Mu Us desert in the late Quaternary and its relationship with forcings of insolation and high latitude ice sheets. Furthermore, we will reveal the formation age of the Mu Us desert and constrain sedimentary sources and processes that cause sandy desert expansion.
Paleogeographic patterns and tectonic-geomorphologic processes of Tibetan Plateau after the India-Eurasia Collision
The Tibetan Plateau, also known as the “Roof of the World” and the “Asian Water Tower”, is an important birthplace of Asian water systems. The uplift of the Tibetan Plateau caused by India- Eurasia plate collision exerted a profound impact on global environmental change in the Cenozoic. For instance, the growth of the Tibetan Plateau reorganized the Asian climate from one dominated by global planetary wind systems to a regional monsoon climate pattern. This process was accompanied by ecosystem evolutions, river system reorganizations and geomorphic changes on and around the plateau.
The main goal of this project is to recover the paleogeographic patterns and geomorphological processes of the plateau, and to understand the paleogeographic background of Qiangtang, Hoh Xil, Altyn Tagh and Qilian Mountains. This project is expected to provide a comprehensive understanding of the uplift process and environmental resources of the Tibetan Plateau and to guide the construction of Tibetan Plateau National Park Cluster.
This is a multi-institutional project, scientists from Lanzhou University, Yunnan University and China Geological Survey and other research institutions are involved.
Pliocene precipitation variability and environmental impact across mid-latitude Asia
The Pliocene (5.3-2.6 Ma) is the last long interval featuring both high temperatures and high concentrations of atmospheric CO2. These conditions resemble current high CO2 and global warming trend, thus studying climatic and environmental changes during the Pliocene can help assess how climate will respond to progressively increased greenhouse gas concentrations. A major challenge in climate reconstruction is to retrieve sediment sequences with adequate resolution to reflect past climate conditions, this is because the deposited sediments can be easily removed by later depositional processes (e.g., erosion by fluvial and wind dynamics). Marine and lacustrine sediments usually have high continuity and fine sedimentation resolution.
Therefore, this project utilizes marine and lacustrine archives to reconstruct the precipitation and temperature records for the Pliocene. Through the integration of terrestrial and marine paleoclimatic records in the southwestern, central and southeastern Asia, we aim to understand how high latitude (ice sheets) and tropical (insolation and ITCZ) forcings have affected mid-latitude precipitation across the Asia during the Pliocene.
History of Cenozoic aridification and major paleoclimatic events in the Qaidam Basin
The history of the formation and evolution of the mid-latitude arid and semi-arid zones, which are the most widely distributed in the northern hemisphere, is an important scientific issue of paleoenvironmental evolution. Clarifying the causes and histories of inland Asian aridification helps evaluate the future aridification trending. The Qaidam Basin, located on the northern Tibetan Plateau, is a major dust source area in the downwind region. However, the onset and evolution of aridification of the Qaidam Basin are unclear due to the lack of long-term high-resolution paleoclimate records. We attempt to address these issues in this project.
In this project, we
1. combine paleomagnetic dating, fossil assemblage dating, and zircon U/Pb absolute dating to establish robust age models for the investigated sequences.
2. analyze sedimentary facies (collaborate with scientists from the University of Houston) and paleoclimatic indicators (clay mineral assemblages, evaporate salt types, sporulation, chemical index of alteration, carbon and hydrogen isotopes of leaf wax long-chain alkanes, TEX86). We expect the results to reveal the history of Cenozoic aridification and major climatic events in the basin, and to explore the driving mechanisms in comparison with a series of paleorecords such as ice volume records, CO2 records and tectonic events.
3. analyze the spatial variation of hydrogen isotopes of long-chain alkanes during the Pliocene-Early Quaternary to reveal the history of water vapor sources in the basin.
Effects of Pliocene-Pleistocene climatic changes on evolution of the Limpopo and the Zambezi River, Southern Africa
Evaluating the role of tectonics and climate changes in fluvial incision is a fundamental question in Earth Sciences. However, unraveling the complex interplay between the two is challenging. Southern African rivers such as Limpopo and the Zambezi River provide an excellent opportunity to explore the effects of late Cenozoic climatic changes on fluvial erosion and river evolution because tectonic activities in this area were limited during the Pliocene-Pleistocene.
The cores drilled by IODP around the Southern African continent hold great potential to capture the major river evolutionary events since the Pliocene. In this project, we aim to establish the accumulation rates and provenance variations for these core sediments. Furthermore, we perform provenance and geomorphological studies in the drainage areas of the Limpopo and the Zambezi River. Finally, we compare the records with established Pliocene-Pleistocene paleoclimate records to explore the role of climate changes on fluvial erosions and drainage area adjustments.
This is an international scientific program jointly conducted by Lanzhou University, Cold and Arid Regions Environmental and Engineering Research Institute in China, and the University of South Africa.
bottom of page