An Early-Middle Ordovician acritarch and prasinophyte assemblage from Houping, Chongqing city, South China: Biostratigraphical and palaeoenvironmental implications.
摘要
A moderately diverse acritarch and prasinophyte assemblage is described from the Dacao and Yingpan formations of the Houping section, Chengkou, Chongqing, southwestern China (Upper Yangtze platform). The palynomorph assemblage consists of 41 species attributed to 25 genera (39 species and 23 genera of acritarchs and two species and two genera of prasinophytes). It is dominated by Polygonium, Leiosphaeridia, Rhopaliophora, and Peteinosphaeridium. The first appearances of several taxa show a potential for stratigraphical correlation in the Floian (Early Ordovician). First appearance data (FADs) of Aureotesta, Petaloferidium, Striatotheca, the Veryhachium lairdii group and the V. trispinosum group indicate levels near the base of the Floian, whereas Ampullula, Arbusculidium filamentosum, Coryphidium bohemicum, Sacculidium and Tongzia first appear slightly higher. The acritarch assemblages from ten localities in South China are analysed using principal component and cluster analysis for ecological discussion. Four acritarch associations are distinguished from ten localities and related to different marine environments respectively. Abstract Copyright (2013) Elsevier, B.V.