Projects

To meet new INQUA strategy on Project-based activity the following Project have been submitted for evaluation of INQUA Executive Committee:

Working Group: Working Group on Paleosols and Paleoclimatic Change in Eastern and Central Asia

Project title: Paleosols on the Western Loess Plateau and Northeastern Tibetan Plateau as witnesses of climatic changes and uplift of the Tibetan Plateau

Leaders: Fang Xiaomin (Lanzhou University), A. Bronger (Geographisches Institut der Universitat Kiel), S. Sedov (Moscow University), A. Makeev (Dokuchaev Soil Institute of Moscow), R. Langhor and G. Stoops (Univ. of Gent), and Yugo Ono (Hokkaido University).

Duration: Three years (present inter-congress period)

Main objectives: Recent high resolution loess-paleosol studies on the western Loess Plateau and northeastern Tibetan Plateau show that temporal and spatial variations of soil genesis not only response to Asian monsoonal changes driven in low frequency by Astronomical forcing, but also have been thought influenced in high frequency by short cold episodes (Heinrich and Dansgaard events) in the North Atlantic region through westerlies waves. Besides, they indicate further the Asian monsoonal circulation has experienced big changes trending an accelerative drying in Asian inland area with the uplift of the Tibetan Plateau (through hindering moisture input of the summer monsoon and intensifying Mongolian high for the winter monsoon) since the last interglacial. To prove exactly the existence of short cold episodes in loess paleosol records and to detect the impact of the uplift of the Tibetan Plateau on monsoonal climates form main objectives of this project. We, therefore, need to make a standard high resolution loess-paleosol climate record including the entire last glacial cycle and to reconstruct air circulation patterns and precipitation-temperature (P-T) matching regimes of the Asian monsoonal system in some key time intervals. However, high resolution loess-paleosol records are limited only in a few localities or in some time intervals of the last glacial cycle and have not been transformed into P-T data. We propose firstly to assess all the well-dated high resolution loess paleosol records in the proposed studied region above; secondarily to fill in gaps where some time intervals have been not analyzed for such high resolution records to cover the entire last glacial cycle; thirdly to add more additional supporting sections in some key localities sensitive to monsoonal changes for controlling spatial variation of the Asian monsoonal circulation; and finally to establish tentatively transformation functions between the development of modern soils and climates in West China.

Method/approach: Because in the studied region the climate varies from sub-humic to arid (monsoonal margin), loess-paleosol records (including modern soils) have temporal-spatial continuities, dust input is highest in the world, and pedogenic disturbance is weak, we have advantages 1) to build up transformation functions between modern soil genesis and climatic conditions through selecting soil profiles located at different climatic zones but having same or similar parent material (loess) and micro-landform (platform such as uplifted basin surface and valley terrace), 2) to capture high resolution paleosol climatic records, 3) to use spatial variations of the degree and type of paleosols to reconstruct monsoonal circulation patterns, and 4) to apply soil stratigraphy for age control. It has been demonstrated that the summer monsoon mainly causes soil formation and the winter monsoon is principally responsible for dust transportation. The reliability of data from soil magnetisms, micromorphology, clay minerals, and chemical compositions that have been thought as proxy indicators to describe the type and degree of soil genesis and grain size of soil parent material loess that is sensitive to changing strength of the winter monsoon will be carefully assessed on the basis of a search for the published evidence and our forthcoming studies above. Quantification and spatial contourization of these data by using soil-climate transformation functions and directly grain sizes will form a base to reconstruct spatial mean circulation patterns and temporal evolution of the monsoons. We will assess also dating methods that have been applied to control ages of the studied sections. Based on the obtained and assessed ages, we will tune loess-paleosol records to astronomical forcing variations to make comparable time series. Ages of the supporting sections can be determined by correlating their paleosol sequences and climatic curves with the astronomical- tuned ones. Since a plenty of work involved into this project, we should constrain our focus in reconstructing circulation pattern in key intervals of the last interglacial, mega-interstadial, last glacial maximum and Holocene that are keys for global paleoclimatic data base and numerical circulation modeling, and ask help from other countries where some researchers have or will be involved in this project. For example, soil-climate transformation functions will be carried out on the cooperation between University of Gent and Lanzhou University; extracting of high resolution paleosol climatic records (e.g., grain size) will lend support from colleagues in Hokkaido University who have worked for some time in the proposed area. In addition, the field and partial laboratory work of this project has been put on list for financial supporting in the China Ninth Five-Year Projects (1996-2000) by the Chinese Government. More funds will be seeked from countries where researchers will involve in.

Anticipated results: Transformation functions between soil development and climatic conditions (mainly mean annual precipitation and temperature) should be tentatively built up with certain confidences. The several orbital-tuned parallel high resolution loess-paleosol climatic records will provide evidence for proving Heinrich and Dansgaard events likely influence Central Asia and West China. P-T regimes and mean circulation patterns illustrated by spatial-contourized loess grain sizes and transformed pedogenic degree data of the Asian monsoon in some key time intervals will be reconstructed, likely namely, a strongest summer monsoon circulation pattern far stretching into Asian inland and the Tibetan Plateau will prevail in the last interglacial maximum in comparison with the present one; a strongest winter monsoon circulation will cover the entire studied region in the last glacial maximum. The evolution of P-T regimes and circulation patterns of the Asian monsoon may demonstrate an accelerative drying trend in the Asian inland and Tibetan Plateau, which suggest the Tibetan Plateau may experience a large magnitude of fast uplift since the last interglacial. Also may we have a preliminary understanding of P-T regimes of the Asian monsoon in some short cold episodes which is very helpful for further study and recognizing mechanisms of the Asian monsoon changes.

Workshops/meetings: Annual workshops or symposia are scheduled to make primary exchange and summary in data and ideas, some in conjunction with other national and international organizations or meetings and conferences. The first is planned on August 16-27, 1996 in Harbin, northeastern China, co-held by this project team and Sub-Commission of Soils and Geology (SCSG) of China Soil Science Society (this Sub-Commission has joined Commission on Paleopedology of INQUA/ISSS as a working group). The second is planned in August, 1997 in Tokyo/Sapporo in conjunction with Japan PEP-II and Working Group on Asian Glaciers and Environment, Commission on Glaciers, INQUA, as well as in September 24-26, 1997 in Rauischholzhausen near Marburg/Germany with International Working Meeting of ISSS-Commission V and INQUA-Commission on Paleopedology that will be attended by most of the project team. The third is planned on July 25-August 15 in Lanzhou/China in conjunction with the Qinghai-Xizang (Tibetan) Plateau Association of China and (SCSG). Between workshops, most communication and information will be exchanged by e-mail system. The final data and conclusions will be presented in a special symposium to be organized for the next INQUA Congress.

Publications: A series of papers will result from this project and will be mainly submitted to famous international magazines such as Palaeo-3, Quaternary Research, Quaternary Science Review, Quaternary International, Geoderma, Journal of Soil Science, etc.

Links to other INQUA or non-INQUA projects: The Project will be linked with Tibetan Project of the State Key Science Projects of China in 1995-2000 and PEP-II Project of PAGES.

Plans for including students and young scientists: Graduate students will be enlisted in each of the countries involved in this project to assist in searching for data, collecting and analyzing samples in field and laboratory, and modeling on computers. They also will be concluded into data analysis and as co-authors for paper writing, as appropriate. Funds for student travel and field work and meetings connected with this project would be reserved in the Project budget with partial adds from other projects and organizations in link with this project.

Further Development of Project Based Acti\vity

The INQUA Executive Committee met recently in Germany. The following decisions were made:

1. New project proposals can be submitted for the two years: August 1997- August 1999. The deadline will be around Christmas 1996. The revised proposal forms as well as some new guidelines for generating INQUA projects can be sent upon request in the nearest future.

2. If financial support can be raised from non-INQUA sources, it is up to the leaders of the commissions/committees to decide whether or not additional projects (i.e. projects which are not supported by INQUA money) should be regarded as commission/committee projects and listed under the commission's activities.

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