The Colorful Mountain in Peru; Rainbow Mountain

One of the most impressive features within Peru is a beautiful mountain which contains almost all of the colors of the rainbow. This unique geologic formation was only recently discovered, as rising temperatures caused the glaciers overlying it to retreat. Known as Rainbow Mountain, this ancient mass of rock contains colorful near vertical layers of several unique rock types. It rises to a height of 5200 meters, or 17,060 feet above sea level. This video will discuss how this beautiful geologic feature formed, and mention what caused each of its numerous colors. Rainbow Mountain is located in the southeast portion of Peru, where it is only 80 kilometers or 50 miles east southeast of the city of Cusco. The formation of this geologic wonder began 600 million years ago off the west coast of what would later become South America. At the time, the beginnings of this rock formation was below sea level. Over the span of many millions of years, a thick layer of pulverized fine rock particles had collected on the seafloor. These particles were each less than 1 500th of a millimeter in size, thus defining them as clay. As numerous layers of clay began to pile on top of each other, the bottom layer of this material began to become compacted due to the force of gravity. Over time, this compaction changed a layer of clay into a rock type called mudstone. As this section of the seafloor became shallower and shallower, the sizes of particles deposited in the area began to increase in size. Larger particles of sand began settling in the area, eventually becoming compacted and forming sandstone. After several million years of uplift, this rock formation was just below sea level. The last rock sequence to form consisted of numerous small rocks rounded by river and wave action interspersed with finer particles called a conglomerate. The reason why this entire rock sequence was being forced upwards relates to a tectonic plate collision which was occurring in the vicinity. Just to the west, the Nazca tectonic plate was being subducted underneath the South American plate. As the collision continued over many millions of years, a thick layer of sedimentary rock which was located between these two plates became increasingly compressed. As these rocks became squeezed into a tighter and tighter space, they were forced upwards by thousands of meters. During this process, these layers of rock became tilted to the side, much like a multi-layered cake being placed on an angle. By the time the uplift had finished, a section of the Andes mountain range had been constructed. Over time, erosion from wind, water, and glaciers carved away at the rock formation, leaving behind a beautiful sequence of rocks. Today, Rainbow Mountain contains seven different colors, each of which represent a different rock type and source of fine particulates. The red layers form from clay, which is rich in iron. The pink layers form from slightly less iron rich clay, which is combined with minor amounts of mudstone and sand. The green layers form from finely grained clay, which is rich in a green mineral called chloride. The purple layers form from the staining of clay by interaction with high amounts of silicate and iron mineralization. The brown layers represent sequences of conglomerate which are rich in magnesium. The white layers represent a calcium carbonate rich mudstone called marl. Finally, the yellow coloration represents sandstone, which contains abundant sulfur rich minerals. Altogether, these numerous beautiful layers provide for a spectacular tourist destination in remote Peru. If you wish to visit this geologic wonder, a two hour drive from the city of Cusco and a 5 kilometer hike is required. Since Rainbow Mountain is located at a high elevation, the best time to visit it is between August and October when rainstorms and cloud cover are least likely to obscure the view. As a final note, watch out for altitude sickness during any future visit. I hope that you enjoyed this video. If you would like to request a specific topic, please leave a comment below. Additionally, if you wish to support this channel, consider becoming a patron on patreon.