We work with a number or terrestrial archives including Neogene deposits in the Chinese Loess Plateau and NW Iran, and Eocene-Oligocene sequences in Inner Mongolia.
A long-term focus of our group has been on the East Asian Cenozoic palaeoenvironments and palaeoclimates, including the evolution of Asian monsoon system, emergence and expansion of grasslands, faunal distributions and depositional settings, as well as stratigraphical aspects of East Asia as a whole. We approach our research objectives by using a variety of modern sedimentological, palaeontological, geochemical and geophysical methods. The most recent field research activities have focused on the Eocene-Oligocene sequence in Ulantatal and Miocene deposits in Damiao, Inner Mongolia, and on the Neogene strata exposed in Lantian, Shaanxi Province.
Keywords: East Asian Monsoon, Palaeoenvironments, Asian aridification, C4 vegetation, Fossil mammals, Tibetan Plateau, Eocene-Oligocene transition, Neogene
Main Collaborators: Mikael Fortelius, Liu Liping, Benjamin H. Passey, Johanna Salminen, Zhang Zhaoqun
Key publications:
(Kaakinen et al 2015)
Doi: 10.1016/j.jseaes.2014.12.014
(Kaakinen et al 2013)
(Zhang et al 2013)
Doi: 10.7312/columbia/9780231150125.003.0006
(Suarez et al 2011)
(Passey et al 2009)
One of the main focuses of our group is to understand the age, provenance and transport process of wind-blown mineral dust deposits, especially the loess and red clay formations of northern China. This region has been accumulating dust for the past ~40 million years, creating one of the best terrestrial archives of climatic evolution for the late Cenozoic Era, the Chinese Loess Plateau. Fundamental in reconstructing the past wind patterns and aridification history is a detailed knowledge of the provenance of these deposits. We use an integrated methodology for sediment fingerprinting, such as the single-grain analyses of zircon U-Pb ages and rutile trace elements as well as detailed investigations of grain size and grain shape by using Dynamic Image Analysis (DIA) and Endmember modelling of size-shape distributions (EMM-SSD). These novel and established methods allow us to examine the transportation processes and source areas of the sediments, to constrain the past wind systems responsible for dust transport, to provide quantifications of the sediment fluxes, and to better understand the complex interactions between climate, plate tectonics and mineral dust. Our research on past aeolian deposits also extends to various other locations around the world.
Keywords: Red Clay, Loess, Atmospheric Dust, Palaeoclimate, Winter Monsoon, Chinese Loess Plateau
Main collaborators: Christiaan J. Beets, Hugh O’Brien, Maarten A. Prins, Thomas Stevens, Frode Stordal, Hui Tang
Key publications:
While our research has traditionally focused on past dust deposits, in recent years we have also begun investigating the properties of present-day mineral dust. As a key component of the Earth system, mineral dust affects the climate in many ways, both directly and indirectly. Many of these effects are determined by dust properties such as grain size, shape, colour, and mineralogy. Our group applies a range of techniques, from Dynamic Image Analysis to geochemistry combined with statistical methods, to examine both bulk dust and single-grain properties. Our current research primarily targets mineral dust sampled in the Arctic region and East Asia.
Key words: Mineral dust, Climate impacts, Dust properties, Grain size, Grain shape, Mineralogy, Arctic, East Asia
Main Collaborators: Outi Meinander, Johanna Salminen, Bin Wang, Hui Tang, Sergio Andò, Frode Stordal, Ove Haugvaldstad
Key publications:
The Maragheh Region in East Azarbaijan, northwestern Iran is a classical Pikermian fossil mammal locality and its geographical position is crucial to understanding the origin of open environments. These fossil sites in NW Iran are among the most renowned late Miocene in Eurasia; the recent fossil finds include also hominoid remains. Our work in Maragheh aims in understanding the origin of the open environments and their biota that developed in the course of the Miocene, the interactions between mammalian faunas and regional climatic change, in reconstructing late Miocene hominoid-bearing palaeoenvironments.
Keywords: Hominoid, Primate, Fossil mammals, Palaeoenvironments, Late Miocene, Iran
Main collaborators: Majid Mirzaie Ataabadi, Raymond Bernor, Mikael Fortelius, Tetsuya Sakai, Johanna Salminen
Key publications:
(Mirzaie Ataabadi et al 2016)
(Salminen et al 2016)
Doi: 10.1007/s12549-016-0239-y