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V. Pernegre, V. Dupret. Biostratigraphic correlations within Wood Bay Formation
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The boundary between the Austfjord Member and Dicksonfjord Member is defined
as in the Woodfjord localities. We identify in the BR 1-3
samples the huge Doryaspis
sp.1 in association with Meteoraspis lanternaria (osteostracan) and Arctaspis maxima
(placoderm). The occurrence of Arctaspis maxima suggests this locality should be placed
in the Dicksonfjord Member. The presence of the huge Doryaspis sp.1 in this area is
interpreted as for the northern localities and indicates the extreme base of the considered
member (Fig. 2). According to a faunistic point of view, the Austfjord – Dicksonfjord
Member boundary corresponds to the Kapp Kjeldsen – Keltiefjellet one, due to the
occurrence of Doryaspis sp.1 in both cases (Fig. 3).
The Dicksonfjord Member is found at the C 17-19
, BY and BT sites (Fig. 1). Doryaspis
nathorsti and Doryaspis lyktensis are found in all the localities. They are associated
with Diademaspis poplinae (osteostracan) in the C18 site, with Arctaspis maxima in
C 19
, and with Nectaspis peltata and Arctolepis decipiens (placoderms) in the BY locality.
A great part of the fauna contained in the samples appears as strictly similar to what
is found in the northern Keltiefjellet faunal division. This confirms the Friend et al.
(1966) geological conclusions. We conclude that the Dicksonfjord Member is equivalent
to the Keltiefjellet division. This interpretation is well supported by the occurrence of
Doryaspis nathorsti and Arctolepis decipiens in both divisions (Fig. 3).
Conclusion
Fig.3. Comparison of the fauna present in the Woodfjord and Austfjord-Dicksonfjord areas.
Implied correlation between biostratigraphic and lithologic scales.
The new data on the Wood Bay fauna allows us to propose the first biostratigraphic
correlations between the two existing stratigraphic scales. On one hand, palaeontologists
divide the Wood Bay Formation into four faunal divisions. On the other hand, geologists
divide it into two members.
We have identified the pteraspidiform and placoderm content of the collected localities from
the 1969 French mission. Each of them is located geographically (Woodfjord or Austfjord-
Dicksonfjord region) and stratigraphically (faunal division or member).