The Central Anatolian segment of the Alpine-Himalayan orogen contains "interior" basins, the largest of which is the Tuzgölü (Salt Lake) basin (>20,000 km2). It is bounded on the east by the Tuzgölü (Salt Lake) fault zone and on the west by the Yeniceoba and Cihanbeyli fault zones. Structural, stratigraphic, and sedimentologic evidence suggests that the Tuzgölü basin started as a fault-controlled basin during late Maastrichtian tectonism when the present-day northwest-trending faults that bound the basin were initiated. These faults may have been formed as normal faults suggesting extension or strike-slip faults with a normal component of movement indicating a large transtension at the time of their initiation. The late Maastrichtian faults were reactivated as strike-slip faults in response to late Eocene compression in the region that produced the Central Anatolian thrust belt to the north and the late Eocene south-dipping thrust faults of the Ulukisla basin to the south. This reactivation is suggested by structurally repeated and missing Paleocene-Eocene deposits in some of the basin's wildcat wells. The late Eocene regression in the Tuzgölü basin was caused by the combined effects of Eocene shortening and a large environmental change. Late Eocene evaporites suggest that the basin was dry before the start of the Neotectonic period, while during the Neotectonic itself the Tuzgölü fault zone was reactivated again, predominantly as a normal fault with a right-lateral strike-slip component. This is evidenced by (1) a major unconformity between the post-Eocene Koçhisar Formation of the Tuzgölü basin and the underlying Eocene rock units; (2) a well-developed rollover anticline observed on seismic reflection profiles; and (3) a right-step along the Tuzgölü fault zone seen in the field.

The timing of exhumation of metamorphic rocks and granitoids of the Niğde metamorphic dome, at the southern tip of the Central Anatolian Crystalline Complex, is a matter of debate. According to some authors, the metamorphic rocks are overlain nonconformably by a sedimentary sequence of late Maastrichtian to Late Palaeocene age. In contrast, other authors recently argued that the Niğde dome represents an extensional core complex of Oligocene–Early Miocene age, finally unroofed during late Miocene times. On the one hand, the results of our study contradict the latter interpretation. A sedimentary sequence of earliest Eocene to early Middle Eocene age nonconformably overlies the high-grade rocks of the Niğde dome on its southeastern flank. Pebbles from the metamorphic rocks are ubiquitous in the conglomerates of this sequence. As a result, the Niğde metamorphic rocks must have reached the surface before Eocene times, or at the very beginning of the Eocene at the latest. The Üçkapılı granite, whose crystallization age has been inferred to be Early Miocene, has intruded the metamorphic complex during exhumation. The granite is also found as pebbles within the conglomerates of the Eocene sedimentary sequence and, thus, is actually older than the Eocene. Apatite fission track dates of 12–11 Ma across the Niğde dome do not indicate that the metamorphic rocks were still on their way to the surface at that time; instead, they must reflect a later event, which is most probably heating during late Neogene magmatism. Lastly, there is no ductile-then-brittle extensional detachment in the two areas where it has been invoked, that is, on the western and southern flanks of the dome. An extensional detachment nevertheless exists at the top of the Niğde dome, best documented in its northern part, where the detachment fault superposes a superficial unit made up of massive ophiolitic rocks onto the high-grade metamorphic sequence. Field evidence indicates that this detachment developed before Eocene times. On the other hand, our observations do not confirm the nonconformity of the sedimentary sequence dated as late Maastrichtian–Late Palaeocene onto the Niğde high-grade rocks. Field relations show either a tectonic contact between the two, or the direct nonconformity of the Eocene sediments onto the metamorphic rocks. The lack of coarse clasts originating from the Niğde high-grade rocks within the Maastrichtian–Palaeocene sequence further suggests that the metamorphic dome did not reach the surface before Late Palaeocene times. These results compare well with available data from the north-western part of the Central Anatolian Crystalline Complex, suggesting that exhumation has been broadly synchronous on the scale of the massif, as a result of an episode of high magnitude extension that affected the region in Campanian to Palaeocene times.

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