Eerie shapes athwart microbial layer
stacks - (5)
Microbial layer
stacks are not rare in the red Permian cherts from Doehlen Basin. They
may appear more or less plane, deformed, torn,
or broken,
which need not give rise to wonder. Wondrous and even disturbing are
the occasionally observed distinct red structures mimicking big or
small cracks but, after
closer inspection, turn
out no such. This becomes
obvious by making use of the above-mentioned layer stacks as
reference frames in the chert which would immediately reveal any
displacement caused by wide cracks before final silicification.
Fig.1 (right): Enigmatic shapes
resembling wide gel cracks without having caused any disturbance in the
orderly stack of microbial layers, thus looking like spooky objects.
Image width 3.5mm.
Fig.2 (below): Enigmatic thick red plate penetrating a microbial
layer stack.
Image width 5mm.
As a
surprising result, there is no indication of displacements related to
the enigmatic red structures. This is well seen with the egg-shaped
enclosure in Fig.1, where the "egg shell" is mainly composed of tiny
parts of the microbial layers stained red.
Hence, what
looks like cracks with red fill in Figs.1,2 is no such. It is a
crack-shaped space in the chert which never had been a crack but is
bounded as if by smooth crack faces. Since there seem to be no material
boundaries to the crack-shaped
red space, and the red fill of hematite must have formed from iron ions
which got there by diffusion, it is highly wondrous why the staining
process was strictly confined
to within definite bounds.
The phenomenon of spooky red formations in chert as described in Permian
Chert News 18, 27,
28, 36 has remained so enigmatic that no explanation is
proposed here. New finds with related shapes will be commented on.
(Fig.1 had been shown before in 28.)
Samples: old fragments of a Lower Permian
chert layer,
found among
glacial river deposits at Hänichen, H/375.1(1999),
and Wilmsdorf, W/8.1 (1991);
Döhlen basin, Freital near Dresden, Saxony.
H.-J.
Weiss 2022
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