Mine Shaft at Dakhleh Oasis (IMAGE) Washington University in St. Louis Caption A vertical shaft gives access to one of the Dakhleh mines. Small steps were cut into the shaft to make it easier to descend to the horizontal galleries that followed veins of the cobalt-bearing mineral alum. Credit Colin A. Hope/ Paul Kucera/ Monash University Usage Restrictions None License Licensed content 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.