2.5D seismic velocity modelling in the south-eastern Romanian Carpathians Orogen and its foreland

A Bocin, Randell Stephenson, A Tryggvason, I Panea, V Mocanu, F Hauser, L Matenco

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32 Citations (Scopus)

Abstract

The DACIA-PLAN (Danube and Carpathian Integrated Action on Processes in the Lithosphere and Neotectonics) deep seismic reflection survey was performed in August-September 2001, with the objective of obtaining new information on the deep structure of the external Carpathians nappe system and the architecture of the Tertiary/Quaternary basins developed within and adjacent to the Vrancea zone, including the rapidly subsiding Focsani Basin. The DACIA-PLAN profile is about 140 km long, having a roughly WNW-ESE direction, from near the southeast Transylvanian Basin, across the mountainous southeastern Carpathians and their foreland to near the Danube River. A high resolution 2.5D velocity model of the upper crust along the seismic profile has been determined from a tomographic inversion of the DACIA-PLAN first arrival data. The results show that the data fairly accurately resolve the transition from sediment to crystalline basement beneath the Focsani Basin, where industry seismic data are available for correlation, at depths up to about 10 kin. Beneath the external Carpathians nappes, apparent basement (material with velocities above 5.8 km/s) lies at depths as shallow as 3-4 km, which is less than previously surmised on the basis of geological observations. The first arrival travel-time data suggest that there is significant lateral structural heterogeneity on the apparent basement surface in this area, suggesting that the high velocity material may be involved in Carpathian thrusting. (c) 2005 Elsevier B.V. All rights reserved.

Original languageEnglish
Pages (from-to)273-291
Number of pages19
JournalTectonophysics
Volume410
Issue number1-4
DOIs
Publication statusPublished - 9 Dec 2005
Event4th Stephan Muller Topical Conference of the European Geosciences Union - Cheile Butii, Romania
Duration: 31 May 20035 Jun 2003

Keywords

  • Vrancea Zone
  • tomographic inversion
  • velocity model
  • travel-time tomography
  • Vrancea region
  • SE Carpathians
  • southeastern Carpathians
  • tectonic evolution
  • Moesian platform
  • slab
  • lithosphere
  • mantle
  • basin

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