Sandstone of the Precordillera (image) GFZ GeoForschungsZentrum Potsdam, Helmholtz Centre Share Print E-Mail Caption In the dry climate of the Andes rock is eroded at very slow rates. The stratification of the sandstone makes tectonic processes visible. Credit Photo: P. Val/University of Syracuse Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.