Wyniki wyszukiwania - BazTech

1

Seismic structure of the lithosphere between the East European Craton and the Carpathians from the net of CELEBRATION 2000 profiles in SE Poland

Janik T., Grad M., Guterch A.

Geological Quarterly

|

2009

|

Vol. 53, No 1

141-158

EN

During the CELEBRATION 2000 experiment, the area of SE Poland was investigated by relatively dense system of deep seismic sounding profiles. Apart from five main profiles CEL01–CEL05, eight additional profiles were executed between the edge of the East European Craton and the Carphatians: CEL06, CEL11, CEL12, CEL13, CEL14, CEL21, CEL22 and CEL23. In this paper, we present results of modelling of refracted and reflected waves with use of a 2D ray tracing technique. All 13 profiles were jointly inter reted with verification of models at crossing points, and a quasi 3D model of the crust and upper mantle was developed. The obtained P-wave velocity models of the crust and uppermost mantle are very complex and show a differentiation of the seismic structure for tectonic units in SE Poland. The depth of the Moho discontinuity in the investigated area changes from about 30 to about 52 km. As a summary of all seismic models, the Moho depth map for SE Poland is presented, as well as a map of the extent of the most characteristic crustal elements in the area: a high velocity body in the upper crust, division into two- and three-layer consolidated crust, ranges of very deep layers with low velocities in the upper and middle crust, aproximate ranges of detected velocity anisotropy in the upper/middle crust, ranges of the high-velocity lower crust and high-velocity uppermost mantle. Both maps are com pared with the main struc tural el e ments from tec tonic map. This could form the base for a new geotectonic in ter pre ta tion of this com plex area.

2

Lithospheric structure of the TESZ in Poland based on modern seismic experiments

Guterch A., Grad M.

Geological Quarterly

|

2006

|

Vol. 50, No. 1

23-32

EN

This paper presents the results of seismic investigations on the structure of the lithosphere in the area of the Trans-European Suture Zone (TESZ) in Poland that is located between the southwestern margin of the East European Craton (EEC) to the north-east, the West and Central European Palaeozoic Platform (PP) to the south-west and the Carpathians to the south. Based on results of the modern POLONAISE’97 and CELEBRATION 2000 projects, as well as older profiles, models are presented for the configuration and extent of different crustal types. In the investigated area, the EEC has a relatively uniform crustal thickness of 40 to 50 km with its three-layered crystalline crust displaying P-wave velocities of 6.1–6.4, 6.5–6.8 and 6.9–7.2 km/s in the upper, middle and lower parts, respectively. The Variscan consolidated crust is covered by 1–2 km thick sediments and consists of two layers with velocities of 5.6–6.3 and 6.5–6.65 km/s. In the Carpathians, sediments reaching to depths of some 20 km and are characterized by velocities of <5.6–5.8 km/s, whilst the underlying two-layered crystalline crust displays velocities of 6.0–6.2 and 6.5–6.9 km/s. The crust of the TESZ can be divided into the Małopolska, Kuiavia and Pomerania blocks that are overlain by up to 9–12 km thick sediments having velocities <5.4 km/s. In the area of the TESZ, the upper part of the consolidated crust has to depths of 15–20 kmrelatively low velocities of <6.0 km/s and is commonly regarded as consisting of deformed and slightlymetamorphosed Early Palaeozoic sedimentary and volcanic series. In this area the middle and lower crust are characterized by velocities in the range of 6.3–6.6 km/s and 6.8–7.2 km/s, respectively, that are comparable to the EEC. Based on the dense network of seismic profiles the map of the depth toMoho is given for the area of Poland. Uppermost mantle reflectors occur about 10 to 15 km below the Moho whereas the deepest reflectors are recorded at depths of 90 km. Future investigations ought to aim at an integrated geological-geophysical program, including deep near-verical reflection-seismic profiling and ultimately the drilling of deep calibration boreholes.

3

Holy Cross Mts. area - crustal structure, geophysical data and general geology

Dadlez R.

Geological Quarterly

|

2001

|

Vol. 45, No 2

99-106

EN

At the start of international seismic experiment CELEBRATION 2000 an attempt at the compilation of the present geophysical and geological data in the Holy Cross Mountains and their surroundings has been made. Five geological units of the first order and four their dividing fault zones have been distinguished in the area studied: uplifted part of the Precambrian Craton (A), Lublin Unit (B), Radom-Łysogóry Unit (C), Kielce-Nida Unit (D), and Upper Silesian Massif (E). They are separated by fault zones: Kock Fault Zone (1) between A and B, Kazimierz Fault Zone (2) between B and C, Holy Cross Fault (3) between C and D, Cracow-Lubliniec Fold Zone (4) between D and E. The first and last units bordering the area are not discussed in this paper. Units B and C are built on the cratonic crust up to 54 km thick. Unit C is composed of poorly correlated mosaic of crustal blocks with crust 35-45 km thick. Fault zones 1 and 3 coincide with crustal fractures while zone 2 has not its counterpart in crustal structure.