Palaeotemperatures of the Palaeogene sea basins in the Lublin area on the basis of oxygen and carbon stable isotopes

Abstract

Oxygen and carnon stable isotopes entering into fossils’ composition are utilized to determine palaeotemperatures of sea basins. Using the isotopes one can also determine the character of sea basins, i.e., estimate whether they were open or inland seas. The paper presents the results of oxygen and carbon isotopic composition studies of some fossils species (foraminifers. molluscs and sea urchin spines). The samples of fossils have been collected in the Nasiłów. Bochotnica and Góra Piotrkowska sediments ofthe Palaeocene and in Siemień sediments of the Upper Eocene age. The results of isotopic studies confirm the minimum Palaeocene temperature (l6.8, 17,4 and 18,8ºC) and the optimum Eocene temperature (23,8°C) of the Tertiary basin of the central-east part of Poland. Because the Palaeocene fauna could be redeposited from Upper Cretaceous sediments, only palaeotemperatures of the Upper Eocene sea basin can be treated as authoritative results of the study of the Palaeocene sea area. The determination of isotopic proportion in the fossils indicates the open sea character of the Palaeocene basin.