Crustal and upper mantle velocity model along the DOBRE-4 profile from North Dobruja to the central region of the Ukrainian Shield: 1. seismic data


Дәйексөз келтіру

Толық мәтін

Ашық рұқсат Ашық рұқсат
Рұқсат жабық Рұқсат берілді
Рұқсат жабық Тек жазылушылар үшін

Аннотация

For studying the structure of the lithosphere in southern Ukraine, wide-angle seismic studies that recorded the reflected and refracted waves were carried out under the DOBRE-4 project. The field works were conducted in October 2009. Thirteen chemical shot points spaced 35–50 km apart from each other were implemented with a charge weight varying from 600 to 1000 kg. Overall 230 recording stations with an interval of 2.5 km between them were used. The high quality of the obtained data allowed us to model the velocity section along the profile for P- and S-waves. Seismic modeling was carried out by two methods. Initially, trial-and-error ray tracing using the arrival times of the main reflected and refracted P- and S-phases was conducted. Next, the amplitudes of the recorded phases were analyzed by the finite-difference full waveform method. The resulting velocity model demonstrates a fairly homogeneous structure from the middle to lower crust both in the vertical and horizontal directions. A drastically different situation is observed in the upper crust, where the Vp velocities decrease upwards along the section from 6.35 km/s at a depth of 15–20 km to 5.9–5.8 km/s on the surface of the crystalline basement; in the Neoproterozoic and Paleozoic deposits, it diminishes from 5.15 to 3.80 km/s, and in the Mesozoic layers, it decreases from 2.70 to 2.30 km/s. The subcrustal Vp gradually increases downwards from 6.50 to 6.7–6.8 km/s at the crustal base, which complicates the problem of separating the middle and lower crust. The Vp velocities above 6.80 km/s have not been revealed even in the lowermost part of the crust, in contrast to the similar profiles in the East European Platform. The Moho is clearly delineated by the velocity contrast of 1.3–1.7 km/s. The alternating pattern of the changes in the Moho depths corresponding to Moho undulations with a wavelength of about 150 km and the amplitude reaching 8 to 17 km is a peculiarity of the velocity model.

Авторлар туралы

V. Starostenko

Institute of Geophysics

Хат алмасуға жауапты Автор.
Email: vstar@igph.kiev.ua
Украина, Kiev

T. Janik

Institute of Geophysics

Email: vstar@igph.kiev.ua
Польша, Warsaw

O. Gintov

Institute of Geophysics

Email: vstar@igph.kiev.ua
Украина, Kiev

D. Lysynchuk

Institute of Geophysics

Email: vstar@igph.kiev.ua
Украина, Kiev

P. Środa

Institute of Geophysics

Email: vstar@igph.kiev.ua
Польша, Warsaw

W. Czuba

Institute of Geophysics

Email: vstar@igph.kiev.ua
Польша, Warsaw

E. Kolomiyets

Institute of Geophysics

Email: vstar@igph.kiev.ua
Украина, Kiev

P. Aleksandrowski

Polish Geological Institute—National Research Institute

Email: vstar@igph.kiev.ua
Польша, Wroclaw

V. Omelchenko

Institute of Geophysics

Email: vstar@igph.kiev.ua
Украина, Kiev

K. Komminaho

Institute of Seismology

Email: vstar@igph.kiev.ua
Финляндия, Helsinki

A. Guterch

Institute of Geophysics

Email: vstar@igph.kiev.ua
Польша, Warsaw

T. Tiira

Institute of Seismology

Email: vstar@igph.kiev.ua
Финляндия, Helsinki

D. Gryn

Institute of Geophysics

Email: vstar@igph.kiev.ua
Украина, Kiev

O. Legostaeva

Institute of Geophysics

Email: vstar@igph.kiev.ua
Украина, Kiev

G. Thybo

Department of Geography and Geology

Email: vstar@igph.kiev.ua
Дания, Copenhagen

A. Tolkunov

State Geophysical Enterprise Ukrgeofizika

Email: vstar@igph.kiev.ua
Украина, Kiev

Қосымша файлдар

Қосымша файлдар
Әрекет
1. JATS XML

© Pleiades Publishing, Ltd., 2017