Zhang, J. ; Hornung, Jens ; Lenz, O. K. ; Hinderer, Matthias ; Wang, P. (2013)
Sedimentology and treatment of huge microfossil datasets to reconstruct the palaeoenvironment and palaeoclimate in interrestrial settings: A Mesozoic case study (Junggar and Tarim Basins, NW-China).
Joint Conference Paläontologische Gesellschaft, Palaeontological Society of China 2013. Göttingen (23.-27.09.2013)
Konferenzveröffentlichung, Bibliographie

Kurzbeschreibung (Abstract)

Adjacent to the Tian Shan in NW China the Junggar and Tarim basins provide a continuous continental record of climatic and tectonic parameters during the entire Mesozoic. This makes them a natural laboratory to study how geodynamic processes interplay with surface topography and climate on a local, regional, and global scale. Of overall scientific interest is the role and intensity of the Early Mesozoic mega monsoon system at the easternmost end of Pangea and its evolution with repeated collisional events and increasing continental vs. global humidification and rearrangement of atmospheric circulation patterns. In this study Upper Triassic and lower Jurassic sections in north Tarim and south Junggar basin were investigated in terms of depositional processes and their palaeoenvironmental interpretation. To reconstruct palaeoenvironmental parameters on a regional scale a huge literature-dataset of about 64 papers was evaluated by picking the documented fossil and lithofacies distribution. Therefore a specially designed MS Access database was used, which automatically can crosslink all data. This part of the study focusses on quantitative sporomorph data to identify palaeoenvironmental changes, because palynomorphs are the most abundant microfossil group in this area. Hence, until now, nobody has tried to establish a palaeo-community model based on such a huge database in that region. Therefore, 337 genera of pollen and spores in 283 samples were used covering both basins. A program was compiled to create a cluster analysis, which show very pronounced quantitative sporomorph distribution patterns. The resulting clusters reveal sporomorph assemblages that correlate well with known sporomorph ecogroups from NW-Europe (Abbink et al. 2004), but also show new or missing members compared to the European ecogroups. In conclusion, specific and unique assemblages could be established which are special for that region and contribute to a better understanding of palaeoecological conditions. Based on the interpretation of these new sporomorph assemblages and their spatial distribution, new palaeoenvironmental maps could be automatically generated in a GIS system. This offers the unique possibility to study the sensitivity of compositional variations of the ecogroup-assemblages, to eliminate misinterpretations of palaeoenvironment and palaeoclimate of single species and to map lithofacies and sporomorph shifts in time and space. As an outcome this dataset will reveal completely new insights into the relationship of climate and tectonic processes in central Asia.

Frage zum Eintrag

Redaktionelle Details anzeigen