what are the names of some of the groups?
Unkar Group is one of them
Geology of the Grand Canyon area
he oldest section of the supergroup is the Unkar Group. It accumulated in a variety of fluvial, deltaic, tidal, nearshore marine, and offshore marine environments. The first formation to be laid down in the Unkar Group was the Bass Formation. Fluvial gravels initially accumulated in shallow river valleys. They later lithified into a basal conglomerate that is known as the Hotauta
what is the second layer of the grand canyon made of It is made up of nearly 40 major sedimentary rock layers how many layers are there? 40 layers how did this form? By deposition  in warm, shallow seas and near ancient, long-gone sea shores in western North America. do the layers have any names? One of them is the Vishnu Basement Rocks where is this canyon located? Arizona, United States. how big is it? thermochronometry showws that it  reached a depth near to the modern depth by 20 Ma was it extended? The Kaibab Uplift, Monument Upwarp, the Uinta Mountains, San Rafael Swell, and the Rocky Mountains were uplifted, at least in part, by the Laramide orogeny. is there any river near to it? Yes the Colorado River what is its origin? Beginning with small bands of nomadic hunter-gatherers, Native Americans have inhabited the Colorado River basin for at least 8,000 years. Between 2,000 and 1,000 years ago, the watershed was home to large agricultural civilizations—considered some of the most sophisticated indigenous North American cultures—which eventually declined due to a combination of severe drought and poor land use practices. what kind of impact has humans had on the canyon? Several species of predators such as mountain lions, eagles, and wolves were eradicated is there a museum located there? Yavapai Geology Museum when was it built? In 1928 who is it named after? UNANSWERABLE does it have any special exhibit? It contains three-dimensional models, photographs, and exhibits which allow park visitors to see and understand the complicated geologic story of the area. which park is located here? Grand Canyon National Park why is the canyon referred to as a supergroup? Because it is composed of nine varied geologic formations that were laid down from 1.2 billion and 740 million years ago in this sea
wiki:13001556
Geology of the Grand Canyon area [SEP] Grand Canyon Supergroup
The oldest section of the supergroup is the Unkar Group. It accumulated in a variety of fluvial, deltaic, tidal, nearshore marine, and offshore marine environments. The first formation to be laid down in the Unkar Group was the Bass Formation. Fluvial gravels initially accumulated in shallow river valleys. They later lithified into a basal conglomerate that is known as the Hotauta Member of the Bass Formation. The Bass Formation was deposited in a shallow sea near the coast as a mix of limestone, sandstone, and shale. Diagenesis later altered the bulk of the limestone into dolomite. It is thick and grayish in color.