Page 16 - TINA Dergi Sayi 10

TINA

Denizcilik Arkeolojisi Dergisi

Fig.2: The water exchange sys-
tem depicted in Fig.4.

This delicate system is controlled by the strait of the ring into the Marmara at times. Or it may become very
Dardanelles. When global sea levels fall below 45 me- low during cold episodes, when all the surface waters
ters of its present level, the entire system, from the Sea of Europe are blocked by ice or snow, exposing a large
of Marmara up to the Caspian, becomes disconnected coastal plain in its western section. When the connec-
from the oceans, each area developing on the modali- tion to the Marmara is interrupted, the Black Sea beco-
ties of their local environmental conditions (fig.3). As mes brackish or even fresh, cold but with full vertical
the passage of warm saline waters of the Aegean is in- oxygen circulation.
terrupted, the Marmara, with limited input of fresh wa- The first penetration of saline waters from the Darda-
ter, becomes a brackish lake, rather small in size with nelles must have taken place around the 9 millennium
th
poor vertical oxygen circulation. What happens as a BCE, probably mixing with the overflow of melted ice
consequence of the detachment from the ocean system water from the Black Sea, providing optimum conditi-
varies based on what is taking place in the catchment ons for fishing communities inhabiting estuaries along
areas of each unit. For example, the water table of the the coast (fig.4). Actually, due to the elevated rock near
Black Sea, the main marine body of the system, will the northern end of the Bosporus, transition of warm
vary considerably. It may become very high, due to ex- saline waters coming in from the Dardanelles to the
ceeding amounts of fresh water input from major rivers Black Sea was considerably delayed, possibly taking
such as the Danube, Dnieper, and Dniester, even pou- place around 5500 BCE.
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