Fig. 3

Thin-section photographs of the Lumazhai mound substrate and some polished slabs. a Thin-section photograph of the Lumazhai mound substrate with peloids (P), microbial mat debris (MM), and foraminifera (F); b Thin-section photograph of the Lumazhai mound substrate: most of the skeletal grains have micritic envelopes; c Polished slabs of phylloid algae boundstone: clotted micrite (CM), mosaic cement (MC), phylloid algae (Ph), radiaxial fibrous cement (RFC); d Details of the red box in (c); e Polished slabs of Ivanovia from the Zhongxinzhai mound: micritized bioclastic packstone (MBP), clotted micrite (CM); f Details of the red box in (e)