3.1. The pattern of decay of the model soft-bodied organismArtemia salina in different sediments.
In our burial experiments, we used five different model sediments with
various mineral and chemical compositions: chamosite, clinochlore,
kaolinite, montmorillonite, and artificial silica (Table 2, see
Materials and Methods). The experimental aqueous sediments with the
buried nauplii of A. salina (see Methods) quickly (within the
first week) changed their coloration (Figure 1). In the kaolinite,
clinochlore, and chamosite, prominent light-colored spots formed around
every carcass (Figure 1 C, F, I). In the silica, dead nauplii clustered
in a subsurface layer which remained light-colored on the otherwise
darkened background (Figure 1 K, L). In the montmorillonite, a bright
red layer formed by the 5th month and stayed well visible to the end of
the experiment (5 years, Figure 1 M). The patterns in the sediment
controls (prepared by the same protocol but without any buriedArtemia ) differed dramatically: their coloration remained
unchanged (Fig 1 A, D, G, J). This difference implies some active
chemical, organic-mineral processes within the sediments that contain
decaying soft-bodied organisms.