The Golbasi basin, southeastern Turkey: A complex discontinuity in a major strike-slip fault zone

We show that the 33 km long Golbasi basin on the East Anatolian fault zone marks the triple junction between the African. Arabian, and Turkish plates. The main strand of the Turkish-Arabian plate boundary, the Goksu fault, enters this basin from the ENE before splaying to form faults which develop farther southwest into the Turkish-African and African-Arabian boundaries. The Golbasi-Turkoglu fault, the Turkish-African boundary, is shown to have slipped 16 km; the prevously unrecognised Kirkpinar fault, the African-Arabian boundary, has slipped 17 km. We propose that this fault geometry developed at c. 3 Ma following earlier slip, starting at c. 5 Ma, on other strike-slip faults nearby which marked the start of westward motion of the Turkish plate.