Velocity blocks and anisotropy in the crust of the central Fennoscandian Shield

Julkaisun otsikon käännös: Seismiset nopeuslohkot ja anisotropia Fennoskandian kilven keskiosan kuoressa

Tutkimustuotos: Artikkeli kirjassa/raportissa/konferenssijulkaisussaKirjan luku tai artikkeliTieteellinen

Kuvaus

The central Fennoscandian Shield has a complex structure. After several tectonic events, forming up island arcs, progressive thrusting and extensional phases, the crust is composed of varying size blocks and slanting belts. These blocks and belts are visualized by seismic tomography method. The tomography data comprises of P-wave and S-wave arrival data from controlled source and seismic tomography experiments, and from chemical explosions. The inverted seismic velocities vary locally in the whole crust expressing several distinct anomalies. The boundary zone between the Archean and the Proterozoic terranes of the Shield appears as an upper crustal low velocity zone. Lower velocities (Vp/Vs<1.70) are associated with schist belts, and higher velocities (Vp/Vs >1.76) with rapakivi batholiths and with the Central Finland Granitoid Complex suggesting hidden mafic blocks in the lower crust.
In the isotropic tomographic velocity models of the crust, anisotropic component is embedded in the residual component. Horizontal azimuthal dependency of residual component images the horizontal component of tectonic transport. An azimuthal anisotropy in tomographic model is verified when fast P-wave velocity direction is matched with slow one in the orthogonal direction. The resulting anisotropy directions coincide with transport directions drawn from structural observations.

Alkuperäiskielienglanti
OtsikkoLITHOSPHERE 2010 : SIXTH SYMPOSIUM ON THE STRUCTURE, COMPOSITION AND EVOLUTION OF THE LITHOSPHERE IN FINLAND
ToimittajatPekka Heikkinen, Katriina Arhe, Toivo Korja, Raimo Lahtinen, Lauri J. Pesonen, Tapani Rämö
Sivumäärä2
Vuosikerta2010
Julkaisupäivä27 lokakuuta 2010
Sivut17-18
ISBN (painettu)978-952-10-5055-8
ISBN (elektroninen)978-952-10-5056-5
TilaJulkaistu - 27 lokakuuta 2010
OKM-julkaisutyyppiB2 Kirjan tai muun kokoomateoksen osa

Julkaisusarja

NimiReport S-55
KustantajaInstitute of Seismology, University of Helsinki
NumeroS-55
Vuosikerta2010
ISSN (painettu)0357-3060

Tieteenalat

  • 1171 Geotieteet
  • lithosphere, crust, velocity tomography, anisotropy, Fennoscandia

Lainaa tätä

Hyvönen, T., Tiira, T., Korja, A., & Komminaho, K. (2010). Velocity blocks and anisotropy in the crust of the central Fennoscandian Shield. teoksessa P. Heikkinen, K. Arhe, T. Korja, R. Lahtinen, L. J. Pesonen, & T. Rämö (Toimittajat), LITHOSPHERE 2010: SIXTH SYMPOSIUM ON THE STRUCTURE, COMPOSITION AND EVOLUTION OF THE LITHOSPHERE IN FINLAND (Vuosikerta 2010, Sivut 17-18). (Report S-55; Vuosikerta 2010, Nro S-55).
Hyvönen, Tellervo ; Tiira, Timo ; Korja, Annakaisa ; Komminaho, Kari. / Velocity blocks and anisotropy in the crust of the central Fennoscandian Shield. LITHOSPHERE 2010: SIXTH SYMPOSIUM ON THE STRUCTURE, COMPOSITION AND EVOLUTION OF THE LITHOSPHERE IN FINLAND. Toimittaja / Pekka Heikkinen ; Katriina Arhe ; Toivo Korja ; Raimo Lahtinen ; Lauri J. Pesonen ; Tapani Rämö. Vuosikerta 2010 2010. Sivut 17-18 (Report S-55; S-55).
@inbook{4949b1f8e59d42aea81b5d5125e34fdd,
title = "Velocity blocks and anisotropy in the crust of the central Fennoscandian Shield",
abstract = "The central Fennoscandian Shield has a complex structure. After several tectonic events, forming up island arcs, progressive thrusting and extensional phases, the crust is composed of varying size blocks and slanting belts. These blocks and belts are visualized by seismic tomography method. The tomography data comprises of P-wave and S-wave arrival data from controlled source and seismic tomography experiments, and from chemical explosions. The inverted seismic velocities vary locally in the whole crust expressing several distinct anomalies. The boundary zone between the Archean and the Proterozoic terranes of the Shield appears as an upper crustal low velocity zone. Lower velocities (Vp/Vs<1.70) are associated with schist belts, and higher velocities (Vp/Vs >1.76) with rapakivi batholiths and with the Central Finland Granitoid Complex suggesting hidden mafic blocks in the lower crust. In the isotropic tomographic velocity models of the crust, anisotropic component is embedded in the residual component. Horizontal azimuthal dependency of residual component images the horizontal component of tectonic transport. An azimuthal anisotropy in tomographic model is verified when fast P-wave velocity direction is matched with slow one in the orthogonal direction. The resulting anisotropy directions coincide with transport directions drawn from structural observations.",
keywords = "1171 Geosciences, lithosphere, crust, velocity tomography, anisotropy, Fennoscandia",
author = "Tellervo Hyv{\"o}nen and Timo Tiira and Annakaisa Korja and Kari Komminaho",
year = "2010",
month = "10",
day = "27",
language = "English",
isbn = "978-952-10-5055-8",
volume = "2010",
series = "Report S-55",
publisher = "Institute of Seismology, University of Helsinki",
number = "S-55",
pages = "17--18",
editor = "Pekka Heikkinen and Katriina Arhe and Toivo Korja and Raimo Lahtinen and Pesonen, {Lauri J.} and Tapani R{\"a}m{\"o}",
booktitle = "LITHOSPHERE 2010",

}

Hyvönen, T, Tiira, T, Korja, A & Komminaho, K 2010, Velocity blocks and anisotropy in the crust of the central Fennoscandian Shield. julkaisussa P Heikkinen, K Arhe, T Korja, R Lahtinen, LJ Pesonen & T Rämö (toim), LITHOSPHERE 2010: SIXTH SYMPOSIUM ON THE STRUCTURE, COMPOSITION AND EVOLUTION OF THE LITHOSPHERE IN FINLAND. Vuosikerta 2010, Report S-55, Nro S-55, Vuosikerta 2010, Sivut 17-18.

Velocity blocks and anisotropy in the crust of the central Fennoscandian Shield. / Hyvönen, Tellervo; Tiira, Timo; Korja, Annakaisa; Komminaho, Kari.

LITHOSPHERE 2010: SIXTH SYMPOSIUM ON THE STRUCTURE, COMPOSITION AND EVOLUTION OF THE LITHOSPHERE IN FINLAND. toim. / Pekka Heikkinen; Katriina Arhe; Toivo Korja; Raimo Lahtinen; Lauri J. Pesonen; Tapani Rämö. Vuosikerta 2010 2010. s. 17-18 (Report S-55; Vuosikerta 2010, Nro S-55).

Tutkimustuotos: Artikkeli kirjassa/raportissa/konferenssijulkaisussaKirjan luku tai artikkeliTieteellinen

TY - CHAP

T1 - Velocity blocks and anisotropy in the crust of the central Fennoscandian Shield

AU - Hyvönen, Tellervo

AU - Tiira, Timo

AU - Korja, Annakaisa

AU - Komminaho, Kari

PY - 2010/10/27

Y1 - 2010/10/27

N2 - The central Fennoscandian Shield has a complex structure. After several tectonic events, forming up island arcs, progressive thrusting and extensional phases, the crust is composed of varying size blocks and slanting belts. These blocks and belts are visualized by seismic tomography method. The tomography data comprises of P-wave and S-wave arrival data from controlled source and seismic tomography experiments, and from chemical explosions. The inverted seismic velocities vary locally in the whole crust expressing several distinct anomalies. The boundary zone between the Archean and the Proterozoic terranes of the Shield appears as an upper crustal low velocity zone. Lower velocities (Vp/Vs<1.70) are associated with schist belts, and higher velocities (Vp/Vs >1.76) with rapakivi batholiths and with the Central Finland Granitoid Complex suggesting hidden mafic blocks in the lower crust. In the isotropic tomographic velocity models of the crust, anisotropic component is embedded in the residual component. Horizontal azimuthal dependency of residual component images the horizontal component of tectonic transport. An azimuthal anisotropy in tomographic model is verified when fast P-wave velocity direction is matched with slow one in the orthogonal direction. The resulting anisotropy directions coincide with transport directions drawn from structural observations.

AB - The central Fennoscandian Shield has a complex structure. After several tectonic events, forming up island arcs, progressive thrusting and extensional phases, the crust is composed of varying size blocks and slanting belts. These blocks and belts are visualized by seismic tomography method. The tomography data comprises of P-wave and S-wave arrival data from controlled source and seismic tomography experiments, and from chemical explosions. The inverted seismic velocities vary locally in the whole crust expressing several distinct anomalies. The boundary zone between the Archean and the Proterozoic terranes of the Shield appears as an upper crustal low velocity zone. Lower velocities (Vp/Vs<1.70) are associated with schist belts, and higher velocities (Vp/Vs >1.76) with rapakivi batholiths and with the Central Finland Granitoid Complex suggesting hidden mafic blocks in the lower crust. In the isotropic tomographic velocity models of the crust, anisotropic component is embedded in the residual component. Horizontal azimuthal dependency of residual component images the horizontal component of tectonic transport. An azimuthal anisotropy in tomographic model is verified when fast P-wave velocity direction is matched with slow one in the orthogonal direction. The resulting anisotropy directions coincide with transport directions drawn from structural observations.

KW - 1171 Geosciences

KW - lithosphere, crust, velocity tomography, anisotropy, Fennoscandia

M3 - Chapter

SN - 978-952-10-5055-8

VL - 2010

T3 - Report S-55

SP - 17

EP - 18

BT - LITHOSPHERE 2010

A2 - Heikkinen, Pekka

A2 - Arhe, Katriina

A2 - Korja, Toivo

A2 - Lahtinen, Raimo

A2 - Pesonen, Lauri J.

A2 - Rämö, Tapani

ER -

Hyvönen T, Tiira T, Korja A, Komminaho K. Velocity blocks and anisotropy in the crust of the central Fennoscandian Shield. julkaisussa Heikkinen P, Arhe K, Korja T, Lahtinen R, Pesonen LJ, Rämö T, toimittajat, LITHOSPHERE 2010: SIXTH SYMPOSIUM ON THE STRUCTURE, COMPOSITION AND EVOLUTION OF THE LITHOSPHERE IN FINLAND. Vuosikerta 2010. 2010. s. 17-18. (Report S-55; S-55).