International Journal of Marine Science 2015, Vol.5, No.31, 1-6
2
an appropriate response for mentioned questions, it is
tried to reveal the hidden secrets of Urmia Lake. In
this regard, the few studies have been conducted by
researchers. For the first time, Bobek (1934),
identified sedimentary terraces around Urmia Lake in
45 and 55 meters elevations above from the lake level,
and after him Schreiber (1978) detected more old
sedimentary terraces on the heights overlooking the
lake, also the age of invertebrates mollusk shell
showed that the sedimentary materials belonged to
upper Pleistocene or 35000 years ago, so it can be
resulted that the lake with brackish to fresh water was
dominant in so larger areas at that time, in comparison
with current position (Keltz and Shahrabi 1986).The
studies conducted by Jamali on the pollens existed in
the most bottom 100-m long cores of sediments, in the
axis line of bridge, have illustrated that the oldest
sediments in the lake bed belongs to 200,000 years
ago or upper Pleistocene(Djamali 2008). He identified
the performance of glacial and interglacial periods
which were affected by biochemical and chemical
sedimentary regimes in wet and dry periods
respectively (Djamali 2008). Besides, the seismic
geophysical studies in the axis of Urmia lake
causeway have identified that the bedrock has been
formed from volcanic materials and is located under
colloidal – clastic and carbonate sediments (Tarh No
Andishan Company, 2003). Now by the help of results
obtained from previous studies and findings from field
studies, we will try to reconstruct the past fluctuations
of Urmia Lake.
1 The study area
The Urmia Lake with the area about 51,460 km
2
is
located between 28
°
29´and 35°40´northern latitudes
and 44° 13´and 47° 53´eastern longitudes. This
watershed contains 3.21% of the country total area
(Seivani, 1991). This plain is the small part of the Iran
central watersheds, which is limited in north by Aras
river watershed, in east by Sefidrood river watershed,
in south by GhezelOzan watershed, Sirvan and west
by Zab river basin at border and finally is limited to
Iraq and Turkey borders. The Urmia lake watershed is
surrounded by the northern parts of Zagros Mountains,
southern slopes of Sabalan Mountain and also
northern, western and southern slopes of Sahand
Mountain (Figure 1). The elevation of different parts
in watershed varies from 1271 m up to 3800 m, but
most of it is morphologically a plain with the height of
1380 m up to 2000 meters. The most elevated point is
Sabalan Mountain top with the height more than 3850
meters and the lowest is the lake coastal line about
1271 m. The Urmia super saturated salt lake with
tectonic structure is located in a closed
intercontinental basin. The length of lake 125 km and
its width is estimated about 15 to 50 km, and average
width is about 40 kilometers. The area of the lake
surface is various upon water level changes and
currently the average depth is about 1.5 meters.
Figure 1 physiographic schematic Figure of Urmia Lake basin
2 Materials and Methods
In order to identify the geographic and climatic
conditions and previous fluctuations of the lake, some
evidences and markers are required to illustrate the
development rate of coastal line, since the formation
up to now. The most important detectable evidences
and clues have been recorded in the sediments as
biological residuals. Actually regarding the uniformity
principle of stratigraphy which considers current
situation, as a key to solve past questions, it can be
possible to reconstruct and identify the old geographic
and climatic conditions of the lake by the use of
geological markers. In order to do this, it is required to
have access to the sediments of deposited lake bed and
