Some Peculiarities of the Geological Structure of Strong Earthquake Source Zones of Armenia and Their Seismisity
Abstract
This article describes the geological structure of some of the source-zones of strong earthquakes which have often occurred on the territory of the Republic of Armenia. On the basis of the analysis of the reached results and their comparison with more than 30 earthquake zones of the Prehistorical, historical and recent periods, which have occurred in the adjacent regions. We have presented the geological structural model of the source zones of strong earthquakes of the Armenian Upland. Armenia Upland is located in the collision zone of the Arabian and Eurasian plates and encompasses a part of the territory of Southern Caucasus, Eastern Anatolia and North-West Iran. This area is characterized by high seismicity. Numerous sources of strong (M>6.0) Prehistorical and historical earthquakes are exerted. About 20 strong earthquakes occurred only in 20th century here. The present paper is dedicated to the geological-structural peculiarities of the sources zone is a part physical-geological model of strong earthquakes sources of Armenian Upland . The Armenian Upland has composite mosaic-bloc frame which has been formed beginning form the Pre- Cambrian period up to the Holocene included. The sources of strong earthquakes are dated for different geological-structural conditions. At the same time definite regularities of the geological structure and tectonic position are observed. Assemblage of these regularities will allow us to create the source zone geological "image." This can be used for seismic hazard assessment and earthquake prediction in this region. In the contemporary structure the juncture zones are represented by sub parallel long live, modern active faults included. Their intensely folded, scaly structure is clearly pronounced. An expansion of ophiolits, olistostrom, as well as a linear (according to a general structure) stretch of intrusive bodies is typical for this zones. Sources of the other earthquakes represent zones of deep faults. These zones are either buried (unseen) or pronounced on the day surface only by individual fault fragments of that zone. While studying the structure of some source zones of strong earthquakes we can notice that went active faults are situated in the place where tectonic mélange and olistostrome level of Mesozoic and Cenozoic age spread. In this work described young ruptures, probably seismogenic natures. Connection of modern geodynamics with geodynamic active structures of the geological past is considered.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2008
- Bibcode:
- 2008AGUFM.S21C1850A
- Keywords:
-
- 7215 Earthquake source observations (1240);
- 8010 Fractures and faults