EARLY DIAGENETIC STABILIZATION OF TRACE ELEMENTS IN REPTILE BONE REMAINS AS AN INDICATOR OF MAASTRICHTIAN-LATE PALEOCENE CLIMATIC CHANGES: EVIDENCE FROM THE NARAN BULAK LOCALITY, THE GOBI DESERT (SOUTH MONGOLIA)

Abstract

Maastrichtian dinosaur bone remains from the Naran Bulak locality (the Gobi Desert) with well-preserved bone textural features are enriched in some trace elements, primarily in REE. These features of vertebrate fossils were formed during diagenesis following rapid burial in mudflow sediments, and prior to postfossilization epigenetic changes. Trace elements are mainly concentrated in diagenetic apatite. Their contents in the bones correlate with that in their enclosing sediments for both maxima and minima. Fossil and sediment compositions were established under the influence of paleoclimate. They are correlated with long-term climatic changes with the aridity maximum at the K/T boundary. Climatic changes were recorded via the change of salinity of waters interacting with the buried vertebrate remains.