On the distinction of tectonic and nontectonic faulting in palaeoseismological research: a case study from the southern Marmara region of Turkey

ÖZAKSOY V.

INTERNATIONAL JOURNAL OF EARTH SCIENCES, cilt.107, sa.5, ss.1777-1788, 2018 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 107 Sayı: 5
  • Basım Tarihi: 2018
  • Doi Numarası: 10.1007/s00531-017-1571-9
  • Dergi Adı: INTERNATIONAL JOURNAL OF EARTH SCIENCES
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.1777-1788
  • Anahtar Kelimeler: Argilliturbation, Gilgai, Nontectonic thrust, Slickenside, Ulubat Fault, Vertisol, MEDITERRANEAN REGION, GILGAI, PLATE, AUSTRALIA, SOILS
  • Akdeniz Üniversitesi Adresli: Evet

Özet

This study reports on spectacular deformation structures, including arrays of striated thrusts, discovered by excavation work in Holocene deposits in vicinity of a major neotectonic strike-slip fault in one of the tectonically most active regions of Turkey. The deformation structures were initially considered an evidence of sub-recent tectonic activity, but their detailed multidisciplinary study surprisingly revealed that the deformation of the clay-rich soil and its strongly weathered Jurassic substrate was of nontectonic origin, caused by argilliturbation. This phenomenon of vertisol self-deformation is well-known to pedologists, but may easily be mistaken for tectonic deformation by geologists less familiar with pedogenic processes. The possibility of argilliturbation thus needs to be taken into consideration in palaeoseismological field research wherever the deformed substrate consists of clay-rich muddy deposits. The paper reviews a range of specific diagnostic features that can serve as field criteria for the recognition of nontectonic deformation structures induced by argilliturbation in mud-dominated geological settings.