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V. Pernegre, V. Dupret. Biostratigraphic correlations within Wood Bay Formation
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The fauna of the BE locality is composed of Doryaspis sp. 1 and Doryaspis sp. 2 for
the pteraspidiforms and Arctolepis decipiens and Arctaspis maxima as representatives
of placoderms. In the C4 site we recognise the same pteraspidiforms as in the BE,
associated with Arctolepis decipiens and an osteostracans, Meteoraspis lanternaria.
The faunal list of the BD samples comprises Doryaspis sp. 1, Doryaspis sp. 2, Arctaspis
maxima and Arctolepis sp. Those three field localities belong to the Keltiefjellet basal
layers due to the occurrence of Arctolepis decipiens, Arctaspis maxima and Doryaspis
sp. 1. So, these localities follow stratigraphically the preceding Kapp Kjeldsen ones (H
1-
, BG, BC).
3
In conclusion, the new huge Doryaspis species can be used as a guide fossil for the
transitional beds of the Kapp Kjeldsen - Keltiefjellet boundary (Fig. 2).
The characteristic Keltiefjellet pteraspidiform fauna is identified in the samples from
the A 16
and BH localities (Fig. 1). The occurrence of Doryaspis nathorsti in all this
material suggests this interpretation. We establish the presence of Arctaspis sp. in both
localities and of Arctolepis decipiens in the BH site, thus confirming the Keltiefjellet
age. Two osteostracans have been identified in the material from the A 16
locality,
Meteoraspis oblongata and Meteoraspis sp. The presence of Doryaspis nathorsti
associated with Arctolepis decipiens is sufficient to characterise the Keltiefjellet faunal
division (Fig. 2).
Dicksonfjord and Austfjord area (Austfjorden and Dicksonfjorden
Members) and comparison with the Woodfjord localities and fauna
Other Spitsbergen material is available in the paleontological collections of the Muséum
National d’Histoire Naturelle, Paris. Part of it was collected in 1964 by J. P. Lehman at
Grønhorgdalen and another part was collected in the Dicksonfjord-Austfjord area during the
1969 French expedition (Fig. 1).
Friend (1961) defines in this region two stratigraphic units based on their lithologic
facies. The Austfjord Sandstone is composed of green-grey sandstones and
conglomerates with intraclasts (Friend 1961). It is presented as the basal unit. The
overlying unit named the Dicksonfjord Sandstone is similar lithologically to the upper
northern divisions (red siltstones and sandstones). These units were revised by Friend
et al. (1966) who renamed them as members. They considered the Austfjord Member as
a lateral equivalent of the Kapp Kjeldsen faunal division and the Dicksonfjord Member
as strictly similar to the Keltiefjellet and Stjørdalen divisions. This interpretation is only
based on lithological conclusions without any faunal considerations.
We know three localities from the Austfjord Member: B∆, B∆’, and BS (Fig. 1). We
find in our samples from B∆ and B∆’ the pteraspidiforms Doryaspis sp. nov. and
Gigantaspis laticephala, in association with the well preserved placoderms
Dicksonosteus arcticus, Heintzosteus brevis, and Lehmanosteus hyperboreus (Goujet
1984). The same Doryaspis species with Nectaspis areolata and Hildenaspis digitalis
is present in the BS samples. The fauna identified in this member (Fig. 2) is easily
correlateable with the equivalent one of the Sigurdfjellet - Kapp Kjeldsen divisions
(mainly the association Doryaspis – Gigantaspis with the occurrence of Heintzosteus
for Kapp Kjeldsen). This faunal correlation confirms the Friend et al. (1966) geological