An automated algorithm for dating annually laminated sediments using X-ray radiographic images, with applications to Lake Van (Turkey), Lake Nautajarvi (Finland) and Byfjorden (Sweden)


Damci E., Cagatay M. N.

QUATERNARY INTERNATIONAL, cilt.401, ss.174-183, 2016 (SCI İndekslerine Giren Dergi) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 401
  • Basım Tarihi: 2016
  • Doi Numarası: 10.1016/j.quaint.2015.05.007
  • Dergi Adı: QUATERNARY INTERNATIONAL
  • Sayfa Sayıları: ss.174-183

Özet

Annually laminated (varved) sediments in marine and lake basins are important archives for paleoenvironmental and paleoclimatic reconstructions, especially with their property to provide a continuous chronology. In this study we introduce a new approach for counting laminae using both digital and analogue X-ray radiographic images. The requirement for the method is that the resolution of the image is higher than the minimum lamina thickness, so that the measurement interval should be at least one third of the minimum lamina thickness. In our method, 8-bit or 16-bit grey scale radiographic images are scaled to grey-scale values between 0 and 1, and every maximum and minimum peaks corresponding to seasonal lamination are defined along the sediment core. The algorithm counts laminae rather than varves, thus allowing control on estimation of more reliable age models. Detected peaks are summed cumulatively along the core length, using a step determined by the annual lamina number of the varve.