Microbially Induced Sedimentary Structures: A New Category
详细信息   在线全文   PDF全文下载
摘要

Cyanobacterial films and mats syndepositonally influence erosion, deposition, and deformation of sediments. The biomass levels surface morphologies, and microbial mats stabilize depositional surfaces and shelter the sediment against erosion or degassing. Growing microbial mats dredge grains from their substrate upwards, whereas cyanobacterial filaments that are oriented perpendicular to the mat surface reach into the supernatant water and baffle, trap, and bind suspended particles. These and similar biotic-physical interactions are reflected in syndepositional formation of microbially induced sedimentary structures. We distinguish structures on bedding planes (leveled bedding surfaces, wrinkle structures, microbial mat chips, erosional remnants and pockets, multidirectional ripple marks, and mat curls) and internal bedding structures (sponge pore fabrics, gas domes, fenestrae structures, sinoidal laminae, oriented grains, benthic ooids, biolaminites, mat-layer-bound grain sizes).

We propose to place this group of microbially mediated structures as a fifth category (bedding modified by microbial mats and biofilms) in Pettijohn and Potter's (1964) existing classification of primary sedimentary structures.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700