Lake Tatta

Did You Know?

• Three mines in the lake produce 63% of all salt consumed in Turkey.
• Prehistoric Lake Tatta was a vast freshwater lake, larger than its modern remnant, supporting Hittite and other Anatolian civilizations.

Geography

The lake sits in a tectonic depression on the central plateau, fed by two major streams, groundwater, and surface water, with no outlet. Brackish marshes form where channels and streams enter. Arable fields surround the lake except in the south and southwest, where an extensive seasonally flooded salt-steppe exists. During winter, precipitation and runoff dissolve part of the salt, raising salinity to 32-34%.

Geology

Subsidence in the Tuz Gölü Lower Basin occurred from the Upper Senonian to the Lower Middle Eocene, followed by a regression from the upper Eocene through the Oligocene. During that earlier period, the basin formed a single depression northward with the Haymana region. The Haymana Basin, rising after Middle Eocene Nummulitic limestone deposition, separated the Tuz Gölü Basin via a fault zone along the eastern edge of the Karacadağ uplift. Connection with the Çankırı basin occurred during the Pliocene and continued through the Middle Eocene-Oligocene, when the lake basin became a graben bounded by northwest and northeast fault zones.

After late Oligocene or Miocene deformation, local Neogene basins formed, receiving volcanics and terrestrial sediments including lake limestones. The basin was little affected by recent Alpine compressional movements in the Pliocene; Neogene tension movements continuing into the Pliocene caused volcanic activities into historical times. A continuous salt layer of different densities extends 1,000 meters deep, ensuring ongoing salt production. The basin contains a 10 km-thick stacking from the Upper Cretaceous to the present, with flysch-character units (shale, sandstone, pebble stone, limestone) in deep parts and terrestrial and shallow marine units at margins.

Conglomerate and sandstones deposited in high-energy shallow marine and terrestrial environments, while shale, limestone, gypsum, and anhydrites formed in calm periods. Basement rocks include Temirözü, Mollaresul formations, Ankara complex, and Kırşehir crystalline complex in the north and northeast, and low-grade metamorphics in the west and southwest.

History

In antiquity, Lake Tuz was known as Tatta, situated on the frontier between ancient Lycaonia and Galatia. Initially part of Phrygia, the region was later annexed into Lycaonia. Ancient sources described the lake as highly saline, with water so briny that any substance dipped in became encrusted with salt, and birds flying near the surface could be caught. Stephanus of Byzantium mentions a salt lake in Phrygia called Attaea, near which stood a town named Botieum, tentatively linked to modern Şereflikoçhisar or Eskil.

In prehistoric times, Lake Tatta was a vast freshwater lake, larger than its modern remnant, fed and drained by numerous rivers, sustaining a rich ecosystem. Dense vegetation covered the surrounding landscape, supporting early civilizations including the Hittites and other Anatolian peoples, who thrived along its shores. After the last ice age, between 11,000 and 5,000 years ago, rising global temperatures and shifting precipitation caused many rivers to dry up or change course.

The lake shrank, its freshwater supply diminished, and salinity increased, transforming the lush landscape into arid steppe. This desiccation impacted nearby civilizations, prompting migration, new water management techniques, or integration into emerging urban centers as part of the Holocene climatic optimum demographic shift.