Palaeomagnetism of the Upper Cretaceous Sânpetru Formation (Haţeg Basin, South Carpathians)

This paper reports on the palaeomagnetism of 10 localities from Upper Cretaceous sediments of the Sânpetru Formation exposed in the Haţeg Basin (South Carpathians, Romania). The Sânpetru Formation is one of the best exposed latest Cretaceous continental successions of Eastern Europe being famous for its unique assemblage of dinosaurs, mammals and other vertebrates. A total of 169 samples were collected from 66 strata through an 860-m-thick section. For most of the samples, the remanences were soft and/or noisy, forcing us to reject 63% of the collection. In the rest of the collection, both polarities are observed and inclination-only analysis indicates that pre-tilting remanence is preserved for many samples. These data, along with published palaeomagnetic results from the Haţeg Basin, pass a regional fold test. The palaeomagnetic study has provided an acceptable magnetostratigraphy which shows that the studied part of the Sânpetru Formation was deposited between the beginning of the Chron 32n.1n and the end of Chron 31n. These first palaeomagnetic results obtained from the Upper Cretaceous sedimentary rocks from the South Carpathians confirm the previous palaeomagnetic results obtained from magmatic rocks: the subtropical palaeolatitude during Late Cretaceous and the large clockwise rotation during the Tertiary.