Geology Reference
In-Depth Information
Fig. 5.6
Permineralized embedded relicts and ghost traces of fungal
remains in the Neoproterozoic section of Mouila, Gabon depicting
typical fungal structures that colonized the substrates. Pictures are
from samples MOU26 (Fig.
5.6a, c
, d, mou26-15, 26-23, 26-9/2007/
ap), MOU 19 (Fig.
5.6b
, 19-2/2007/ap) and MOU22 (Fig.
5.6e, f
, 22-
23, 22-24/2007/ap) (
a
) Per-mineralized (now dolomitic) sporangi(a)um
(sp) appear attached to their sporangiophores (sph). In the
lower-left
appear two superposed sporangia. The
dashed lines
contour the visible
morphology of these forms. (
b
) A visible per-mineralized single spo-
rangium (sp) attached to its sporangiophore (sph). The inset figure
shows the entire contour of this reproduction structure and its complete
embedding in the rock matrix. (
c
) Various sporangia and
sporangiophores showing blackish color probably related to organic
content. In the lower part of the figure is a typical sporangial and
sporangiophore shape of fungi. Dichotomy is also visible. (
d
) Here,
together with Fig.
5.6a-c
, the pits
shapes can be at least partly related
to fungal remains, especially the sporangia from where the oval and
circular shapes of pits are seemingly inherited. The detailed scrutiny of
these figures reveals the rich colonization of these deposits by fungi.
(
e
) Normal SEM image showing similar fungal remains compared to
secondary backscattered image. (
f
) where the traces of the fungal
remains are deeply imprinted in the substrates
'
5.4.1 Honeycomb Dissolution Pattern
sections (4
0.5 cm) and rock slabs from Carbonifer-
ous dolomites of the Terwagne Formation (Vis´an, Bocahut
quarry at Avesnes-sur-Helpe, northern France, in Mamet and
Pr
´
at
2005
) were used as substrates for fungal interaction.
All samples were examined at the end of the experimental
work by FE-SEM, SEM and EDX.
2
The Neoproterozoic thin sections show secondary porosity
that is developed after dolomite crystal dissolution. Rhom-
bic and quadratic pore spaces are still discernable in many
instances (Fig.
5.8a
) and are typically arranged in a
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