The tracks of several major reptile groups continue almost up to the layer of rock marking the end of the Triassic geologic period 202 million years ago, then vanish in younger layers from the Jurassic period.
Over the years, windblown sand enveloped the workshop, preserving its tools in hardened sediments just below younger layers when life flourished at Blombos Cave and, most likely, it was often painted red.
The depositional facies within the model demonstrates that marine facies progressively move toward the younger layers, therefore suggesting transgression within the facies model.
But like all fashions, that one didn't last long: In the two upper, younger layers, "the shells are knotted together two by two, with their shiny side up" (see photos).
The younger layers show human footprints in profusion but the megafauna is gone to my mind, at least, mute but deeply eloquent testimony of the impact that humans had on the fauna they encountered when they arrived in South America.
However, the pronounced presence of earthworms in the younger layers stimulated microbial activity and as such increased carbon mineralization probably due to the fact that the microorganisms may have been less resource-limited as a result of earthworm activity, as indicated by the ratio of monounsaturated to saturated PLFAs.
In the younger layers of sand, a greater diversity of taxa were found, including the dominant Quercus, Fagus (beech), Alnus (alder), Betula (birch), Corylus (hazel), Fraxinus (ash), Salix (willow), Populus-Salix (poplar-willow-type), Acer (maple), Pinus (pine), Maloideae (apple subfamily), Tilia (lime), as well as some Ericaceae.
Species that cover shorter periods of time occur mainly in the higher, younger layers.
It is about this time that the estuarine waters Harlem and Hudson met, providing the site's youngest layer, the salt meadow.
