Preface The expedition ARK XIX/3 with the German icebreaking RV ...

The most frequent rock type is sandstone (44 %; Fig. C5-2d), of which fine sandstone
(26 %) is more frequent then the middle sandstone (15 %) and the coarse sandstone
(3 %). Together with siltstones (19 %, Fig. C5-2a) and quartzites (11 %; Figs C5-2c,
C5-2f) siliciclastic sediments and meta-sediments build up 74 % of the ice-rafted
material. They probably originate from Svålbard for the major part.
Some clasts give more detailed information about their source areas (Fig. C5-2c). Red
fine- to middle-grained sandstones (0.9 % of the clasts; Fig. C5-2e) occur in Devonian
redbeds on northern Spitsbergen and Eastern Greenland. Weakly consolidated black
organic-rich siltstones (1.6 %) occur in Tertiary sediments on West Spitsbergen near
Longyearbyen and Ny Ålesund, where they have been mined for brown coals. Black
shales (6.9 %) occur in Jurassic deposits on Spitsbergen. In three clasts imprints of
Lias ammonites were discovered. Granites and granodiorites (2.5 %; Fig. C5-2f) are
frequent in the Scandinavian shield. Gabbros (0.3 %) occur on Franz Josef Land and
in Norway. Basalts (0.6 %) originate from Tertiary or Quaternary volcanism in Eastern
Greenland (e.g. Geikie Plateau), on Jan Mayen Island and on the Iceland-Faeroe-
Shetland Ridge. A single 5 mm large, angular, white, non-floating pumice fragment in
PS64/417 GKG (HG-V, 0 - 20 cm depth) has certainly been erupted from an Iceland
volcano and was transported with sea ice to the core location. Volcanic clasts are
more frequent in the westernmost locations (HG-IV, HG-V; see Fig. C5-1). Chalk (2.4
%; Fig. C5-2b) and flint (0.9 %, Fig. C5-2e) are present in almost all locations (Fig. C5-
1). These are indications for Cretaceous source rocks in the southern North Sea area.
The origin of one serpentinite clast (PS64/437, HG-III, 10 - 20 cm) is uncertain, it
might originate from submarine outcrops of meta-basalts on the Vesteris Ridge east of
the Molloy Hole.
Rocks for which an origin on Spitsbergen is certain (Tertiary, Jurassic and Devonian
sediments) comprise 2.5 % of the sediments, but many of the siliciclastic sediments
will originate from Svålbard as well. Medium- to high-grade metamorphic rocks and
plutonites from southern source areas (Eastern Greenland around Scoresby Sund,
Iceland, Norway) or from a small metamorphic belt along the western coast of
Spitsbergen make up 7.2 % of the IRD.
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