Environmental Engineering Reference
In-Depth Information
Table 2.1
Deep lake sediments in the Mediterranean Basin
Age of bottom
sediments
Lake or basin
Location
References
3.5
×
10
6
years
Hula Basin
Israel
Horowitz, 1989
Tenaghi-Philippon
Northeast Greece
1.35
×
10
6
years
Mommersteeg
et al.,
1995
Tzedakis
et al.,
2006
Ioannina
Northwest Greece
500
×
10
3
years
Tzedakis et al, 2003
500
×
10
3
years
Kopais
Southeast Greece
Okuda
et al.,
2001
Tzedakis, 1999
250
×
10
3
years
Valle di
Castiglione
Central Italy
Follieri
et al.,
1988
Magri, 1989
×
10
3
years
Ohrid
Border of Albania
and Macedonia
(FYROM)
40
Wagner
et al.,
2009
Vogel
et al.,
2010
c. 500
×
10
3
years
Bouchet/Praclaux
Massif Central,
France
Reille
et al.,
1988
Reille and de Beaulieu,
1995
Cheddadi
et al.,
2005
Mediterranean mountains. They do, however, reflect trends in environmental change
in the terrestrial environment in more detail than marine sediments.
The longest record is from the Hula Basin, Israel, in which the bottom sediments
are 3.5
×
10
6
years old and in which the pollen assemblages reflect shifts between
forests during cold/glacial stages and steppe during warm/interglacial stages (see
above). There are three long cores from Greece: Tenaghi-Philippon - which pro-
vides the longest record extending back 1.35
10
6
years - Ioannina and Kopais.
Three further sites provide additional information on palaeoenvironments: Lac du
Bouchet/Praclaux in the Massif Central, France; Valle di Castiglione in central Italy;
and the more recently investigated Lake Ohrid on the border between Albania and
the Former Yugoslavian Republic of Macedonia. In many lakes there are tephra lay-
ers that facilitate
40
Ar/
39
Ar dating as well as inter-core correlation and correlation
with marine cores.
All have been investigated for their pollen content, from which vegetation history
can be reconstructed. The dominant pattern of vegetation history is that of alternat-
ing steppe and forest, as long, cold stages alternated with relatively short, warm
stages respectively. The steppe communities were characterized by
Artemisia and
Chenopodiacae as well as grasses but were not uniform; interstadials of sufficient
warmth and precipitation to support woodland punctuated the long cold stages but
were much shorter (typically between 2500 and 6500 years) than interglacials of be-
tween 10 000 and 15 000 years duration. There is considerable agreement between
cores in terms of the timing and direction of environmental change, and between the
cores and the oxygen-isotope stratigraphy of marine cores. This reflects the over-
all influence of climate within the region, not least climatic change as driven by
×