Question: When did the river where Morelos Dam is located start to form the Grand Canyon?

full_context: Document 1: Morelos Dam: After a 1944 United States Mexico Treaty the Morelos Dam was built in 1950 across the Colorado River. It is located about below the junction of the California border and the Colorado River between the town of Los Algodones, Baja California, in northwestern Mexico and Yuma County, Arizona in the southwestern United States. The eastern half of the dam lies inside United States territory; but Mexico is responsible for all maintenance. The dam allows Mexico to divert its allotted water from the Colorado River to highly developed crop lands in the Mexicali, Mexico Valley. The Morelos Dam is the final dam on the Colorado River. It is run by the International Boundary and Water Commission (IBWC).
Document 2: Mars: The large canyon, Valles Marineris (Latin for ``Mariner Valleys '', also known as Agathadaemon in the old canal maps), has a length of 4,000 km (2,500 mi) and a depth of up to 7 km (4.3 mi). The length of Valles Marineris is equivalent to the length of Europe and extends across one - fifth the circumference of Mars. By comparison, the Grand Canyon on Earth is only 446 km (277 mi) long and nearly 2 km (1.2 mi) deep. Valles Marineris was formed due to the swelling of the Tharsis area, which caused the crust in the area of Valles Marineris to collapse. In 2012, it was proposed that Valles Marineris is not just a graben, but a plate boundary where 150 km (93 mi) of transverse motion has occurred, making Mars a planet with possibly a two - tectonic plate arrangement.
Document 3: San Diego: The city shares a 15-mile (24 km) border with Mexico that includes two border crossings. San Diego hosts the busiest international border crossing in the world, in the San Ysidro neighborhood at the San Ysidro Port of Entry. A second, primarily commercial border crossing operates in the Otay Mesa area; it is the largest commercial crossing on the California-Baja California border and handles the third-highest volume of trucks and dollar value of trade among all United States-Mexico land crossings.
Document 4: Amistad Dam Port of Entry: The Amistad Dam Port of Entry is a port of entry into the United States from Mexico. It was built when Amistad Dam was completed in 1969. The Dam was a bi-national effort to establish flood control on the Rio Grande and provide sources of water. Although US Department of Transportation statistics combine traffic counts with Del Rio Texas Port of Entry, approximately 65,000 vehicles crossed the dam into the US in 2005.
Document 5: Geology: All of these processes do not necessarily occur in a single environment, and do not necessarily occur in a single order. The Hawaiian Islands, for example, consist almost entirely of layered basaltic lava flows. The sedimentary sequences of the mid-continental United States and the Grand Canyon in the southwestern United States contain almost-undeformed stacks of sedimentary rocks that have remained in place since Cambrian time. Other areas are much more geologically complex. In the southwestern United States, sedimentary, volcanic, and intrusive rocks have been metamorphosed, faulted, foliated, and folded. Even older rocks, such as the Acasta gneiss of the Slave craton in northwestern Canada, the oldest known rock in the world have been metamorphosed to the point where their origin is undiscernable without laboratory analysis. In addition, these processes can occur in stages. In many places, the Grand Canyon in the southwestern United States being a very visible example, the lower rock units were metamorphosed and deformed, and then deformation ended and the upper, undeformed units were deposited. Although any amount of rock emplacement and rock deformation can occur, and they can occur any number of times, these concepts provide a guide to understanding the geological history of an area.
Document 6: Malpaso Dam: The Malpaso Dam, officially known as the Nezahualcóyotl Dam, is located in the Centro region of Chiapas, Mexico near the border with Tabasco and Veracruz. It was the first of several major dams built on the Grijalva River to generate hydroelectric energy and has the second largest reservoir in Mexico, after the Belisario Dominguez Dam. Construction of the dam occurred in the 1960s and flooded not only the riverbed but also hectares of rainforest and farmland, various towns and villages and archeological sites. These include the former town of Quechula, whose 16th century Dominican church will appear when water is at low levels, and the archeological site of San Isidro which contains one of only two known double Mesoamerican ball courts. Commissioning of the dam's 1,080 MW power station began in 1969 and ended in 1977. The reservoir and later construction of a federal highway has spurred ecotourism in the area.
Document 7: Palo Verde Dam: The Palo Verde Dam (officially called the Palo Verde Diversion Dam) is a diversion dam on the Colorado River in La Paz County, Arizona, and Riverside County, California, in the southwestern United States, approximately northeast of Blythe. The dam is earthen and rockfill, built solely to divert water into irrigation canals serving the Palo Verde Irrigation District. It measures long at its crest, which is at an elevation of , and stands high above the riverbed, containing approximately of material. Construction of the dam, which began in 1956 and ended in 1958, was authorized by the U.S. Bureau of Reclamation. The dam was constructed to raise the water level of the river because the upstream Hoover and Davis Dams blocked sediment, causing significant degradation of the riverbed that hampered water diversion.
Document 8: Grand Canyon: Nearly two billion years of Earth's geological history have been exposed as the Colorado River and its tributaries cut their channels through layer after layer of rock while the Colorado Plateau was uplifted. While some aspects about the history of incision of the canyon are debated by geologists, several recent studies support the hypothesis that the Colorado River established its course through the area about 5 to 6 million years ago. Since that time, the Colorado River has driven the down - cutting of the tributaries and retreat of the cliffs, simultaneously deepening and widening the canyon.
Document 9: Grand Canyon: The Grand Canyon is a river valley in the Colorado Plateau that exposes uplifted Proterozoic and Paleozoic strata, and is also one of the six distinct physiographic sections of the Colorado Plateau province. It is not the deepest canyon in the world (Kali Gandaki Gorge in Nepal is much deeper). However, the Grand Canyon is known for its visually overwhelming size and its intricate and colorful landscape. Geologically, it is significant because of the thick sequence of ancient rocks that are well preserved and exposed in the walls of the canyon. These rock layers record much of the early geologic history of the North American continent.
Document 10: Colorado River Compact: The Colorado River Compact is a 1922 agreement among seven U.S. states in the basin of the Colorado River in the American Southwest governing the allocation of the water rights to the river's water among the parties of the interstate compact. The agreement was signed at a meeting at Bishop's Lodge, near Santa Fe, New Mexico, by representatives of the seven states the Colorado river and its tributaries pass through on the way to Mexico.
Document 11: Grand Canyon: The Grand Canyon (Hopi: Ongtupqa; Yavapai: Wi: kaʼi: la, Navajo: Tsékooh Hatsoh, Spanish: Gran Cañón) is a steep - sided canyon carved by the Colorado River in Arizona, United States. The Grand Canyon is 277 miles (446 km) long, up to 18 miles (29 km) wide and attains a depth of over a mile (6,093 feet or 1,857 meters).
Document 12: Candor Chasma: Candor Chasma is one of the largest canyons in the Valles Marineris canyon system on Mars. The feature is geographically divided into two halves: East and West Candor Chasmas, respectively. It is unclear how the canyon originally formed; one theory is that it was expanded and deepened by tectonic processes similar to a graben, while another suggests that it was formed by subsurface water erosion similar to a karst. MRO discovered sulfates, hydrated sulfates, and iron oxides in Candor Chasma.
Document 13: Outflow channels: Outflow channels are extremely long, wide swathes of scoured ground on Mars, commonly containing the streamlined remnants of pre-existing topography and other linear erosive features indicating sculpting by fluids moving downslope. Channels extend many hundreds of kilometers in length and are typically greater than one kilometer in width; the largest valley (Kasei Vallis) is around long, greater than wide and exceeds in depth cut into the surrounding plains. These features tend to appear fully sized at fractures in the Martian surface, either from chaos terrains or from canyon systems or other tectonically controlled, deep graben, though there are exceptions. Besides their exceptional size, the channels are also characterized by low sinuosities and high width:depth ratios compared both to other Martian valley features and to terrestrial river channels. Crater counts indicate that most of the channels were cut since the early Hesperian, though the age of the features is variable between different regions of Mars. Some outflow channels in the Amazonis and Elysium Planitiae regions have yielded ages of only tens of million years, extremely young by the standards of Martian topographic features.
Document 14: Geological history of Earth: The geological history of Earth follows the major events in Earth's past based on the geologic time scale, a system of chronological measurement based on the study of the planet's rock layers (stratigraphy). Earth formed about 4.54 billion years ago by accretion from the solar nebula, a disk - shaped mass of dust and gas left over from the formation of the Sun, which also created the rest of the Solar System.
Document 15: Percha Diversion Dam: The Percha Diversion Dam is a structure built in 1918 on the Rio Grande in New Mexico, United States. It diverts water from the Rio Grande into the Rincon Valley Main Canal, an irrigation canal.
ground_truth: about 5 to 6 million years ago
sub_queries: Morelos Dam >> located on terrain feature Answer: Colorado River
when did Colorado River start to form the grand canyon Answer: about 5 to 6 million years ago