THE GEOLOGICAL RECORD IN NONMARINE ENVIRONMENTS AROUND THE K T BOUNDARY (TREMP FORMATION, SPAIN)/

In the Ager basin and Benabarre area (southern Pyrenees, Spain), the C retaceous-Tertiary (K/T) boundary is recorded in a succession of non-m arine to coastal deposits (Lower Tremp Formation). Abundant diverse di nosaur tracks have been found at two localities on top of an estuarine sandstone body. A few meters above, grey marls at two localities cont ain Palaeocene mammals and fish. Both levels are correlated with the l atest part of chron C29R. These data have led to the location of the K /T boundary within a 3 m thick stratigraphic interval with no major br eaks in the sedimentation. A rapid fall in delta(13)C content is recor ded shortly after the WT boundary. The delta(13)C curve does nor suppo rt the hypothesis of a gradual shift due to volcanic activity. Both fo ssil vertebrates and isotope data are compatible with an abrupt change in the continental ecosystems close to the K/T boundary.