In the Chuar Group sequences of stromatolitic and cryptalgal carbonates can be found. Ooliths and pisoliths along with microfossils of various algal types are also present. Sedimentary structures such as ripple-marks and mudcracks indicate shallow-water sedimentation with intermittent desiccation. Limestones with stromatolites suggest subtidal to intertidal shalow waters. Pisolite horizons near the top of the Chuar sgain suggest subtidal shallow waters. The presence of megaplankton (CHUARIA) and abundant microplankton, stromatolites, and filamentous algae are indications of at least partial marine influences.

Fig.10 - Chuaria circularis-a mega-acritarch from the Walcott Member. Each carbonized disc is about 2mm in diameter.

Fig. 11 - Stromatolite bioherm from the Awatubi Member, Kwagunt Canyon