title: Video-logging for examining biogenic structures in deep heterogeneous subsurface sediments.
abstract: Video-logging through a transparent tube is described as an alternative method for examining in situ the distribution of biogenic structures within the deep layers of heterogeneous sediments in which undisturbed cores are hard to be obtained. The method comprises four successive phases: the installation of transparent tubes into the sediment, the lowering of a video-camera for scanning sediments through the tube walls, the numerical treatment of images for correcting deformations and obtaining panoramic views of discrete sediment layers, and the mapping of biogenic structures. The method was used successfully to determine the density and depth distribution of galleries made by the oligochaetae Tubifex tubifex (Müller, 1874) within the infiltration bed of a stormwater basin.
authors.affiliation: Laboratoire d'écologie des hydrosystèmes fluviaux (UMR CNRS 5023), bât. Forel, université Lyon-1, 43, bd du 11-Novembre-1918, 69622 Villeurbanne, France. datry@univ-lyon1.fr
authors.forename: Thibault
authors.initials: T
authors.lastname: Datry
authors.forename: Florian
authors.initials: F
authors.lastname: Malard
authors.forename: Richard
authors.initials: R
authors.lastname: Niederreiter
authors.forename: Janine
authors.initials: J
authors.lastname: Gibert
mesh_terms: D017753:Ecosystem; D019015:Geologic Sediments / Q000032:analysis; D008954:Models, Biological; D014741:Video Recording