THE ORGANIC-MATTER OF THE POTOSI BASIN (C ORDILLERA ORIENTAL, BOLIVIA) DURING THE UPPER CRETACEOUS LOWER TERTIARY - STRATIGRAPHIC AND PALEOGEOGRAPHIC DATA

Palynological and Rock-Eval pyrolysis studies of the Chaunaca and El M olino Fm (Santonian to Thanetian, Cordillera Oriental, Bolivia) indica te that some facies have economic significance as potential oil source rocks. The occurrence of Pediastrum and Azolla testify a lacustrine e nvironment. In the Upper Molino, the environmental interpretation of a n almost monospecific association of dinocysts is discussed. The prese nce of Apectodinium quinquelafum indicates that the age of the upper p art of the Upper El Molino Fm is likely to be Upper Thanetian.