SOME SEISMIC SIGNATURES IN THE ROMANIAN CRUST

Some new seismic reflection data in the W of the Moesian platform, Foc sani depression and Transylvania depression show seismic patterns whic h reflect the local structure and evolution of the each area. These lo cal areas were affected by subsidence which over-printed the changes o n the old pattern. The old and more or less reflective lower crust was fractured and some rigid blocks have preserved the reflectivity up to the present. The Bailesti section illustrates a transparent or diffra ctive upper crust and a well-marked lower crust by an alternation of r eflective and non-reflective zones. The crystalline crust of the Ramni cu Sarat section has two patterns: one relatively reflective, near the bottom of the depression (the W side), whilst the other, on the E fla nk of depression, is transparent. The E flank seems to be more fractur ed due to some tensile fractures originating in the bending stress dur ing subsidence. The Targu Mures section has a specific crustal pattern . A near-transparent crystalline crust overlies a very large crust-man tle transition zone which is fragmented in alternated reflective and t ransparent blocks. (C) 1998 Elsevier Science B.V. All rights reserved.