Naslov
Terrestrial response to early Toarcian environmental perturbations from the Ordos Basin (North China).

Autori
Baranyi, V., Jin, X., Shi, Z., Kemp, D.B., Han, Z., Luo, G., He, F., Chen, L., Hu., J., Preto, N., Dal Corso, J.

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Abstract Book / - , 2022, 81-81

Skup
11th European Palaeobotany and Palynology Conference

Mjesto i datum
Stockholm, Švedska, 19.06.2022. - 22.06.2022

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Toarcian, vegetation change, palynology, China

Sažetak
Global climate change and carbon cycle perturbations during the Mesozoic have been shown to have a significant effect on the biosphere, including vegetation. During the early Toarcian Anoxic Event or Jenkyns Event (Early Jurassic), increased oceanic and continental carbon burial, global warming, increased storminess, enhanced hydrological cycle and runoff are all linked to the large-scale release of 12C-enriched carbon into the ocean- atmosphere system. Compared to the marine realm, the terrestrial record of the Jenkyns Event is relatively less known. We have investigated the vegetation response to this event conducting palynological analysis extended with Hg and Cu concentrations from the lacustrine Anya section in the Ordos Basin, North China. Palynostratigraphy constrained the studied Anya section with two negative carbon isotope excursions (CIE) to the late Pliensbachian-early Toarcian interval. The palynological assemblages show a significant turnover between the Pliensbachian, pre-CIE and the early Toarcian, characterized by the pronounced increase in Classopollis abundance. The rise of Cheirolepidiaceae pollen is paralleled by the decrease in fern spores and seed-fern-related pollen grains. The loss of these understory and low-mid canopy vegetation elements, exacerbated by increased wildfire activities from PAH and fossil charcoal data, contributed to enhanced runoff from the inundated land to the lacustrine basin. During the CIE interval, the increase of unbalanced and conjoined Classopollis tetrads and the increase of spore tetrads together with dwarfism in ferns spores indicate severe environmental stress. Mutagenesis in spores and pollen, such as the formation of unbalanced spore-pollen tetrads, have been related to heat stress, UV-B radiation, heavy metal toxicity or in the case of Classopollis grains, polyploidy. The latter, in many cases, represents evolutionary advantage for the parent plant which might explain the proliferation of Cheirolepidiaceae conifer pollen during the early Toarcian.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

POVEZANOST RADA