Stratygrafia paleocenu z otworu Iława na podstawie badań mikropaleontologicznych

Abstract

STRATIGRAPHY OF PALAEOCENE FROM BORE HOLE IŁAWA ACCORDING TO MICROPALAEONTOLOGICAL INVESTIGATIONSSummary The Dano-Palaeocene deposits have been investigated by the present author within the Mazury-Suwałki elevation already in 1960 (E. Gawor-Biedowa, E. Witwicka 1960). These deposits, encountered by drillings in the area considered, are characterized by a poor assemblage of foraminifers. Frequently, this assemblage does not allow their age, i. e. Danian or Palaeocene, to be determined. The bore hole Iława is the first one within the Mazury-Suwałki elevation, where a rich assemblage of Palaeocene foraminifers has been encountered. Both, the number of species and the number of individuals within these species are here considerably high. A well preservation state of the foraminfers - a rareness in the region here discussed - allowed the author to illustrate almost all the species encountered (Tabs. I-V). Vertical ranges of the microfauna ascertained in bore hole Iława are presented in Fig. 1. The lack of the representatives of agglutinated foraminifers, and almost a complete lack of the genera and species of the family Nodosariidae are the characteristic feature of the Palaeocene foraminifers assemblage from the bore hole Iława. The family mentioned above is, within the remaining areas of Poland, very well developed in the Palaeocene. In the other parts of the Polish Lowland area the Palaeocene miocrofauna bears a Tertiary seal left by the representatives of the family Polymorphinidae, which in the Palaeocene deposits pierced by bore hole Iława is represented by one species only. The family Anomalinidae has most species in the Palaeocene deposits of the bore hole considered. It is a pity that due to a partial coring of the deposits in the bore hole Iława the thickness of the Palaeocene strata has not been determined. This is also why we do not know, if any Danian deposits are present in the area in study. The occurrence of the Cretaceous foraminifers in the deposits covering the Palaeocene ones represents an unexplained problem here. In the intervals from 226,00 to 130,00 m and from 77,00 to 57,00 m of these deposits Cretaceous foraminifers have been found, accompanied by charred plant remains, coprolites, pyritized skeletal elements of sponges, and ball-shaped iron sulphides. At a depth of 197,00-199,00 m the form Uvigerina botiesi Kaaschieter occurs, described from the Middle Eocene of Belgium.