Global Change Abstracts The Swiss Contribution - SCNAT

166 Global Change Abstracts – The Swiss Contribution | Past Global Changes
presence of sweet chestnut (Castanea sativa Mill.)
in southern Switzerland. Sweet chestnut trees
play a key role in Mediterranean woodlands, and
for longer than two millennia have been used as a
food source. Based on palynological evidence it is
commonly believed that in southern Switzerland
C. sativa was first introduced 2000 years ago by
the Romans, who cultivated it for wood and fruit
production. Our results indicate that this tree
species was present on the southern slopes of the
Alps similar to 1500 years earlier than previously
assumed, and therefore was likely introduced independently
from cultivation by the Romans.
Nuclear Instruments Methods in Physics Research
Section B Beam Interactions with Materials and
Atoms, 2007, V259, N1, JUN, pp 398-402.
08.1-334
Cosmogenic Be-10-ages from the Store Koldewey
island, NE Greenland
Hakansson L, Graf A, Strasky S, Ivy Ochs S, Kubik P
W, Hjort C, Schlüchter C
Switzerland, Sweden, USA
Paleontology , Cryology / Glaciology , Geology
Earlier work in northeast Greenland has suggested
a limited advance of the Greenland Ice Sheet
during the Last Glacial Maximum (LGM). However,
this concept has recently been challenged by marine
geological studies, indicating grounded ice on
the continental shelf at this time. New Be-10-ages
from the Store Koldewey island, northeast Greenland,
suggest that unscoured mountain plateaus
at the outer coast were covered at least partly by
cold-based ice during the LGM. It is, however, still
inconclusive whether this ice was dynamically
connected to the Greenland Ice Sheet or not. Regardless
of the LGM ice sheet extent, the Be-10 results
from Store Koldewey add to a growing body
of evidence suggesting considerable antiquity of
crystalline unscoured terrain near present and
Pleistocene ice sheet margins.
Geografiska Annaler Series A Physical Geography,
2007, V89A, N3, pp 195-202.
08.1-335
Evidence for recurrent changes in Lower Triassic
oceanic circulation of the Tethys: The delta
C-13 record from marine sections in Iran
Horacek M, Richoz S, Brandner R, Krystyn L,
Spoetl C
Switzerland, Austria
Paleontology , Geochemistry & Geophysics , Oceanography
, Geology
Stable carbon isotope curves derived from Lower
Triassic carbonate rocks from three Iranian sections
are established to investigate changes in the
carbon cycle during the Early Triassic in this area.
The sections are located in the south-center (Abadeh),
north (Amol), and northwest (Zal) of Iran.
All three curves show a similar pattern starting
out with high delta C-13 values in the uppermost
Permian decreasing across the Permian-Triassic
boundary, an increase toward more positive values
during the Griesbachian that slowly increase
further up during the Dienerian, followed by a
positive excursion to values as high as +8%o near
the Dienerian/Smithian boundary. During the
Smithian values return to below O%o, whereas
second positive excursion to values higher than +
3%o is recorded at the Smithian /Spathian boundary,
again followed by a drop in delta C-13 into
the Spathian and a final excursion to positive
values at the Spathian /Anisian boundary. The
results from these Iranian sections are consistent
with previous studies from Italy and China, thus
strongly suggesting that the recorded delta C-13
variability represents at least Tethys-wide geochemical
signals. Moreover, the new curves reveal
evidence of hich-amplitude, frequent oscillations
pointing toward rapid and profound changes in
the global carbon cycle during the Lower Triassic.
Stratification of the ocean interrupted by episodic
overturning transporting deep water to the ocean
surface is a viable mechanism to account for the
recorded isotope variations. Provided that the delta
C-13 curve is representative of the global Lower
Triassic ocean. it has high potential for accurately
dating sedimentary successions via chemostratigraphy.
Palaeogeography Palaeoclimatology Palaeoecology,
2007, V252, N1-2, AUG 20, pp 355-369.
08.1-336
1. Flaje-Kiefern (Krusne Hory Mountains): Late
Glacial and Holocene vegetation development
Jankovska V, Kunes P, van der Knaap W O
Czech Republic, Switzerland
Paleontology , Forestry , Plant Sciences
Grana, 2007, V46, N3, pp 214-216.
08.1-337
Microgram level radiocarbon (C-14) determination
on carbonaceous particles in ice
Jenk T M, Szidat S, Schwikowski M, Gäggeler H W,
Wacker L, Synal H A, Saurer M
Switzerland
Cryology / Glaciology , Geochemistry & Geophysics
Paleontology , Instruments & Instrumentation
In climate research the interest on carbonaceous
particles has increased over the last years because
of their influence on the radiation balance of the
earth. Nevertheless, there is a paucity of available