Microbial modification of sedimentary surface structures

Abstract

In coastal salterns, physical forces cause the upfolding of surface layers. Gelsticky, microfibrous substrates produced by microbes interfere with these processes. Results are folds and buckles, which differ from abiogenic tepee structures. The modified tepees are termed petees. Basing upon the overthrusting mechanism involved, petees are classified into three types. Within the peritidal zone, petee environments range between subtidal and highest supratidal areas: alpha-petees may already develop in subtidal lagoons and reefs. Gypsum-encrusted beta- and gamma-petees rather indicate intertidal and lower supratidal exposure, and tepees finally the relatively highest topography where microbial mats are excluded. -from Authors