Pozzolan Quarry in Guatemala. (image) Martin-Luther-Universität Halle-Wittenberg Share Print E-Mail Caption This is a picture of a pozzolan quarry in Guatemala. There, large quantities of volcanic ash are added to cements in order to reduce CO2 emissions. Credit Herbert Pöllmann / MLU Usage Restrictions use with credit 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.