Prehistory of Colorado provides an overview of the activities that occurred prior to Colorado's recorded history. Colorado experienced cataclysmic geological events over billions of years, which shaped the land and resulted in diverse ecosystems. The ecosystems included several ice ages, tropical oceans, and a massive volcanic eruption. Then, ancient layers of earth rose to become the Rocky Mountains.
Before humans, the dinosaur, mammoth, mastodon, camelops, and giant bison foraged for food in a verdant land. During the Ice Age summer, humans walked into the present Colorado area as they followed and hunted large animals.
The ancient hunters, the Paleo-Indians, evolved into modern Native American nations. The first people in Colorado were nomads, following and hunting large mammals using the Clovis point. As Megafauna became extinct, people adapted by hunting smaller animals, gathering wild plants, and cultivating food, such as maize. As the natives became more sedentary, there were significant technological and social advances, including basket, pottery, and tool making, and creation of permanent structures and communities. Trading with other indigenous people expanded the number and type of material items used for material goods, such as sea shells, stones for jewelry and tools, pottery and food.
Origins
Geological formations
The following is a summary of geological formations in Colorado:
Precambrian igneous and metamorphic rocks
Precambrian metamorphic rock that forms the core of the North American continent during the Precambrian eon 4.5–1 billion years ago. There is also Precambrian sedimentary argillite, dating back to 1.7 billion years ago. During the Paleozoic, western North America lay underneath a shallow sea, which deposited many kilometers of limestone and dolomite.
Pikes Peak granite
The Paleozoic era and during the Precambrian eon, about 300 million to one billion years ago, Pikes Peak Granite was formed from mass amounts of molten rock that would amalgamate, flow and combine, to form the continents. In Colorado it is known as the Precambrian Pikes Peak Granite. Over the next 500 million years, sedimentation (sediment deposition) occurred after the granite was produced. At about 500 to 300 million years ago, the region began to sink and lime and mud sediments deposited in the newly formed space. Eroded granite produced sand particles that formed strata, layers of sediment, in the sinking basin. At about 300 million years ago the land lifted, creating the ancestral Rocky Mountains.
Fountain Formation
Fountain Formation was formed during the Pennsylvanian period of the Paleozoic era, 290-296 million years ago. Over the next 150 million years, during uplift the mountains would continue to erode and cover themselves in their own sediment. Wind, gravity, rainwater, snow, and ice-melt supplied rivers that ultimately carved through the granite mountains and eventually led to their end. Fountain Formation is Pennsylvanian bedrock unit consisting primarily of conglomerate, sandstone, or arkose, in Colorado and Wyoming, along the east side of the Front Range of the Rocky Mountains, and along the west edge of the Denver Basin. The characteristic predominant red color and the composition of the Fountain reflect that of the granites and gneisses from which it was eroded. Related sites are: Flatirons, Garden of the Gods, Red Rocks Park, Roxborough State Park
Lyons Formation
Lyons Sandstone was formed during the Permian period of the Paleozoic era, 250-280 million years ago. At the beginning of the period, sea levels were low and present-day Colorado was part of the super-continent Pangaea. Sand deserts covered most of the area spreading as dunes seen in the rock record, known today as the Lyons Sandstone. These dunes appear to be cross-bedded and show various fossil footprints and leaf imprints in many of the strata making up the section. Related sites include: Garden of the Gods, Roxborough State Park, and the Lyons and neighboring Hall Ranch Open Space areas.
Lykins Formation
Lykins Formation was formed during the Jurassic and Triassic periods 150-250 million years ago. The sediment deposition of wavy layers of muddy limestone and signs of stromatolites that thrived in a smelly tidal flat at present-day Colorado. The Ancestral Rockies were burying themselves while the shoreline was present during the break-up of Pangaea. This formation began right after Earth's largest extinction 251 million years ago at the Permian-Triassic Boundary. Ninety percent of the planet's marine life was destroyed and a great deal on land as well. Related sites: Garden of the Gods, Red Rocks Park, Roxborough State Park