O heterochroniczności linii Teisseyre'a-Tornquista

Abstract

ON HETEROCHRONEITY OF THE TEISSEYRE-TORNQUIST LINE Summary There is growing evidence for heterochroneous character of the Teisseyre-Tornquist Line. The section from Koszalin to the Black Sea may be treated as a part of the Caledonian Deformation Front (31-2, 18) and its origin explained as due to sinistral-strike movements. The movements resulted in cutting off a corner of the East-European Platform and its replacement by a part of Early Caledonian fold belt ( 4), developed on Dalslandian-Cadomian basement. This is why this section may be treated as formed of deep crustal fractures marking SW boundary of the East-European Platform. A right-lateral shearing from the Late Paleozoic (1, 4, 33) resulted in rejuvenation of the Koszalin-Black Sea section as well as origin of its Baltic-Scania extension, thus giving rise to the Teisseyre-Tornquist Line. In the Baltic-Scania section, we are no longer dealing with fractures delineating margin of the East-European Platform but rather those of the intraplatform type. However, the above explanation of the nature of the latter section makes it necessary to assume some deformations of the Caledonian Deformation Front, especially its bending in the Koszalin area, which would precede its formation. This seems to be the case and the deformations may be easily explained by the rotation of Baltica at the turn of the Silurian and Devonian. The right-lateral shearing, following the deformations, could result in some translocation of basement blocks along the whole TTL. Some data (2) suggest dextral translocation of basement blocks along the Romelese horst at about 30 km distance but it remains an open question whether this is due to Variscan movements, Alpine ones or net result of the former and Alpine rejuvenation. A rejuvenation of TTL in the future appears fairly probable.