Those in the right foreground are heavily weathered limestone boulders. These deposits lie directly upon deeply eroded and weathered bedrock. This rock can be weathered and eroded, then redeposited and lithified into a sedimentary rock. An extremely old system, the hills have been extensively weathered and eroded over the years. Removing graffiti from weathered limestone is difficult because it is a porous and permeable material. Apparently the remaining forelimbs were weathered or eroded away. The area contains thousands of weathered limestone pillars. Inselbergs are common in eroded and weathered shields. Quartz sand that is recently weathered from granite or gneiss quartz crystals will be angular. In weathered and eroded shields inselbergs are common sights. The lime rocks have been weathered into characteristic karstic rock formations known as rauks. The valley's vivid red color comes from iron oxide exposed in the weathered siltstone. The Peterbilt 351 was weathered slightly darker, with more of a rust effect. Residual materials are mineral materials that have weathered in place from primary bedrock. Finger millet can grow on various soils, including highly weathered tropical lateritic soils.