Kaibab Limestone is a type of sedimentary rock found primarily in the Grand Canyon region of Arizona. It was formed during the late Permian period, around 270 million years ago, from the accumulation of marine sediments in a shallow sea. This limestone is characterized by its light color, often appearing white or cream, and contains fossils of ancient marine life. The Kaibab Limestone is significant for its role in the geology of the Grand Canyon, forming the uppermost layer of the canyon's rock formations. It serves as a crucial source of information for geologists studying the Earth's history and the evolution of life during the Permian period.