Crust and upper mantle structure along the DSS Baltic profile in SE Finland

• Published in: Geophysical journal international Vol. 101; no. 1; pp. 89 - 110
• Main Authors: Luosto, U., Tiira, T., Korhonen, H., Azbel, I., Burmin, V., Buyanov, A., Kosminskaya, I., Ionkis, V., Sharov, N.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-04-1990; Blackwell
• Subjects: Applied geophysics; deep seismic sounding; Earth sciences; Earth, ocean, space; Exact sciences and technology; Fennoscandian Shield; Internal geophysics; Ladoga-Bothnian Bay zone; lithospheric structure; Rapakivi intrusion; Crust; Traveltime; Transit time; Europe; Refraction; Velocity structure; Two dimensional model; P-waves; S-waves; Deep seismic sounding; Thickness; Seismogram; Upper mantle; Wave refraction; Earth crust; Mohorovicic discontinuity; Seismograms; Two-dimensional models; Finland; P wave; S wave; Stratification
• ISSN: 0956-540X; 1365-246X
• DOI: 10.1111/j.1365-246X.1990.tb00760.x

The 430 km long DSS Baltic profile in SE Finland runs through the Rapakivi intrusion, the Svecokarelian geosynclinal complex, including the Ladoga-Bothnian Bay zone, and the Archean basement complex. A brief description of field operations in 1982 is presented. Record sections of P- and S-waves were used for the interpretations. A starting model was constructed by inverse methods and improved by dynamic ray tracing modelling. Three blocks are indentified on the cross-section from SW to NE. These are the southern, associated with the Rapakivi Massif, depth to Moho (M) about 40 km; the central, Ladoga-Bothnian Bay zone, with M of approximately 55–60 km, and the northern, Archean crystalline basement, with M about 40–45 km. The average crustal velocity is 6.6–6.7 km s−1. The crustal structure along the Baltic profile is compared with the surrounding DSS profiles, Finnish Sveka and Soviet Kem-Tulos and Ladoga profiles. The eastern border of the Ladoga-Bothnian Bay zone was located and specific features of the crust and uppermost mantle along the profile area are discussed.