5 years ago

3-D anatomy of an active fault-propagation fold: A multidisciplinary case study from Tsaishi, western Caucasus (Georgia)

Ongoing deformation processes combining fault propagation and folding are the cause of diffuse seismicity in many areas of the world. A detailed understanding of the structural evolution of tectonically active folds is crucial for the evaluation of seismic hazard. This paper proposes an integrated analysis of an active fold, consisting in the development of a 3D model by combination of geomorphological observations, field geological-structural data and seismic reflection sections. Our case study is the Tsaishi anticline, located at the southwestern tip of the Rioni Basin uplifted area, at the foothill of Greater Caucasus (Western Georgia). We recognized that the fold started to form since the beginning of the middle Miocene, although preliminary data suggest the possibility of initial local uplift in the Oligocene. Folding process continues up to nowadays giving rise to a south-vergent anticline, as shown by upwarped late Quaternary river deposits. The fold backlimb is affected by three main back-thrusts, whereas at the foot of the forelimb a main north-dipping thrust comes very close to the surface based on seismic sections. Here, field data show the presence of a 13-km-long fault scarp (or fold scarp). Along the scarp is located the epicenter of the strongest earthquake to date: the MS 6.0 Tsaishi earthquake that struck the area in 1614CE. Based on our results, we propose that the overall structure can be classified as an active fault-propagation fold. The recognition of its very recent growing associated with a major, underlying active fault, represents also a major contribution to the seismic hazard assessment of this populated area.

Publisher URL: www.sciencedirect.com/science

DOI: S0040195117303256

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.