Late Devonian benthic ostracods from western Junggar, NW China: Implications for palaeoenvironmental reconstruction

Junjun Song (1) , S. Crasquin (2) , Yiming Gong (1)

1 CUG - China University of Geosciences [Wuhan]
2 CR2P - Centre de Recherche en Paléontologie - Paris

This study focuses on palaeoecology and palaeobiogeography of Late Devonian ostracods based on more than 4500 carapaces collected from sections in the western Junggar, NW China. According to the ostracod faunas from the Hongguleleng Formation, three ecological assemblages for an open oceanic island arc are proposed, i.e., OA1 (Ostracod Assemblage-1), OA2 (Ostracod Assemblage-2) and OA3 (Ostracod Assemblage-3). They characterize foreshore, nearshore and offshore, respectively. Water energy should be the first environmental factor controlling the composition of the ostracod assemblages from the Lower Member of the Hongguleleng Formation, and salinity fluctuations could be also involved. Many cosmopolitan species were present in the diversified ostracod faunas of the Hongguleleng Formation, suggesting possible biogeographic relationships between the Kazakhstan Plate and South China, North America and Russian plates. The ostracods from Late Devonian of the Kazakhstan Plate might migrate to the South China Block and Laurentia-Baltica by ocean currents and sea-level changes, which also implies that neritic faunal exchanges were possible along the Palaeo-Tethys during the Late Devonian.

Mots clés: palaeoecology; palaeobiogeography; Late Devonian; western Junggar; palaeoecology

Domaines: Paléontologie

Junjun Song, S. Crasquin, Yiming Gong. Late Devonian benthic ostracods from western Junggar, NW China: Implications for palaeoenvironmental reconstruction. Geological Journal, 2019, 54 (1), pp.91-100. ⟨10.1002/gj.3156⟩. ⟨hal-02613928⟩