Stosunki paleohydrologiczne i geneza węgli brunatnych facji markoduriowej

Abstract

PALEOHYDROLOGICAL REGIME AND ORIGIN OF BROWN COALS OF SO-CALLED MARCODURIA FACIES Summary Mass occurrence of remains of plant Marcoduria inopinata W l d. (Weyland, 1957, 1959) of uncertain affinity was found in stratified Miocene brown coals. Ribbon remains of this plant form distinct horizons of remarkable thickness, so-called Marcoduria facies (Litke, 1966, Schneider, 1969). This plant is known from Nadrenia, Lower and Upper Lausitz, southern Bulgaria, and from Konin and Turów in Poland. Marcoduria was hitherto considered to be water plant of the order Helobiae. Recently, it was interpreted as rootstock of Phragmites (Juchniewicz, in press). The paper presents further evidence supporting the interpretation of that plant as a reed-community, Phragmites inopinata (W l d.) J u с h п. The coal rich in the remains of that reed is assumed to represent an equivalent of reed-peat. That interpretation implies that the stratified brown coal forming so-called Marcoduria-facies did not originate under limnetic conditions (open water basin), as it was widely assumed, but rather under telmatic conditions, i.e. in off-shore waters under conditions of high water-table oscillations and intermittent rheogenic and ombrogenic water regime. The interpretation matches well and confirms validity of the hypothesis of rushes origin of coals (Kulczyński, 1952) in the case of the stratified brown coals.