YINCHUAN, CHINA—China.org.cn reports that rare flooding in the Ningxia Hui Autonomous Region of northwest China has damaged some of the thousands of prehistoric carvings on the cliffs of Helan Mountain. The images are thought to have been created by nomads who lived in the area between 3,000 and 10,000 years ago. Some of the images were damaged by mud and silt, and about a dozen images that had been carved on individual rocks were carried away by the flood waters. Other pictures were lost when layers of mountain rock peeled off or cracked in the heavy rains. Hu Zhiping, deputy director of the Helan Mountain Cliff Painting Administration, said that the extent of the damage is still being assessed. To read more about archaelogy in China, go to "Tomb from a Lost Tribe."