Jeszcze w sprawie wieku cieszynitów

Abstract

W artykule omówiono szczegółowo problematykę wieku intruzji cieszynitów w Karpatach ze szczególnym uwzględnieniem dyskusji z poglądami wyrażonymi ostatnio przez T. Wiesera (1971) i W. Nowaka·(1976). Wyrażono przekonanie, że procesy intruzywne odbywały się w trzech etapach: środkowym (związanym z fazą austryjską), pooligoceńskim (faza sawska) i sarmackim (faza attycka).

FURTHER COMMENTS ON THE AGE OF TESCBENITES

Recent publications on teschenites (I. Gucwa, W. Nowak and T. Wieser, 1971; W. Nowak, 1971; T. Wieser; 1971; W. Nowak, 1972; W. Nowak, T. Wieser, 1973 and ·W. Nowak, 1976) are reviewed in the paper. Three main periods of teschenite intrusions are distinguished with reference to history of the development of complex tectonics of the external Carpathians.

The oldest period of intrusions of teschenites was interpreted by the present author as early as 1938 (K. Konior, 1938) as related to the first phase of the formation of digited Cieszyn nappe during the Mid-Cretaceous Austrian movements. The main foldings from the Tatra Mts are also dated at the Middle Cretaceous.

Teschenites subsequently intruded Cretaceous-Paleocene deposits of the Subsilesian and Cieszyn nappes which were folded and thrusted over the forefield. This took place during the post-Oligocene (Aquitanian) Saavian phase. The oldest, Austrian phase resulted in intrusions of teschenites into the Cieszyn beds, and the Saavian phase - into both the Cieszyn and Subsilesian beds.

Marginal parts of the Subsilesian and Cieszyn nappes were affected by marine transgressions during the Miocene. In that time the "Carpathian land" exposed to destructive action of waves was the source of both pebbles and blocks of flysch rocks and debris of teschenites from intrusions in these rocks.

The last period of igneous intrusions was related to the overthrusting of flisch deposits on the Miocene, and shifting to their present position. These movements were accompanied by not numerous igneous intrusions into deposits of Paleozoic substratum and the Miocene. This took place in the phase of the Attic movements.

The relationship between teschenite intrusions and the main phases of development of tectonics of the external Carpathians has been supported up to the present solely by geological data. Hence, some doubts concerning the nature age and history of "teschenite phenomenon" may be arising until all types of teschenite rocks are correlated with the successive periods of intrusions on the basis of a thorough and accurate mineralogical-petrographic analysis of the core material. The present interpretation of this "phenomenon" aims at correlating and explaining some facts and views which seems to be conflicting from the geological standpoint.