While we are looking at the chert, the chert sometimes looks back at us
as if inviting us to look deeper. Inspecting a cut and polished face of
Rhynie chert compares to wandering about a secret garden with strange
everywhere and crawling creatures mostly in hiding.
400 million years ago there was not much diversity so that it is
not difficult to learn the names of all the Rhynie plants by heart. It
is more difficult to tell which section of a plant part seen in the
chert belongs to which plant.
This picture shows a section of the most common plant in the chert,
formerly known as Rhynia
major but arguably renamed Aglaophyton major.
The odd-shaped outline and double central strand indicate that it is an
inclined cut near a forking point of the shoot.
The seam of loosely clustered dark dots consists of cells invaded by
the fungus Glomites
rhyniensis, which lives in a close relation with the plant.
The chert preserves not only things but also information on the still
not fully understood process of its formation from mud and silica-rich
water. The lines running across the face in this picture are cracks.
they are essentially restricted to the plant section, they must be
shrinkage cracks due to the well-known contraction during the formation
of chalcedony from a gel-like precursor stage. They show that
silicification proceeded at differential rates inside and outside the