Geoscience Reference
In-Depth Information
Fig. 1. (a) Location of East Greenland Main Devonian
Basin and (b) field sections investigated in East
Greenland (Ø is island). Compiled from the
GMT database.
using palaeoclimate cycles to the new sections from
Nathorst Bjerg and Stensi¨ Bjerg. All the sections
(totalling over 1000 m) were directly logged on
a 10 cm scale (Fig. 2) with particular attention
paid to rock colour and sediment cycles. All GPS
co-ordinates are from UTM zone 27X with altitudes
determined by both an altimeter calibrated to sea
level and by GPS in 2006.
The Celsius Bjerg Group
Elsa Dal Formation
The Elsa Dal Formation, the oldest in the Celsius
Bjerg Group, is a c. 160 m thick interval of yellow
cross-bedded amalgamated sandstones (Figs 2 &
3). As shown by Olsen & Larsen (1993) it represents
the deposits of a sandy alluvial braid-plain system.
In the uppermost part of the formation there are
thin intercalations of black mudstone that contain
the only known palynomorphs (late Famennian GF
zone, Marshall et al. 1999) found in the lower part
of the Celsius Bjerg Group. These mudstones
occur in Agda Dal between Nathorst Bjerg and
Gunnbjørn Bjerg (in a section with the base of the
Elsa Dal Formation at 0434020 8143084) and in
Paralleldal (0426915 8158861, 856 m altimeter),
that is, are regional in extent. They represent an
Fig. 2. Detailed measured section of the Celsius
Bjerg Group from Stensi¨ Bjerg, Wimans Bjerg and
Nathorst Bjerg on Gauss Halvø. The cyclicity is
determined from the sediment colours. The red and
purple colours are shown by the pattern of black
blocks on the depth scale. The Britta Dal part of the log is
from Nathorst Bjerg so the position of Acanthostega can
only be approximate.
