Editing Front Range (section)

==Geology==
[[Image:Ppgog.JPG|thumb|left|[[Pikes Peak]] and [[Garden of the Gods]].]]
[[Image:Fountain Valley Trail (5974714678).jpg|thumb|right|Uplifted [[Lyons Sandstone]] slabs along the eastern edge of the Front Range]]

===Pikes Peak Granite===
About 1 billion years ago, a mass of magma rose to the surface through a much older mantle, cooling to form what is now known as the [[Precambrian]] [[Pikes Peak Granite]]. Over the next 500 million years, the granite eroded with no sedimentation forming over this first uplift, resulting in a local expression of the [[Great Unconformity]]. At about 500–300 million years ago, the region began to sink and sediments began to deposit in the newly formed accommodation space. Eroded granite produced sand particles that began to form strata, layers of sediment, in the sinking basin. Sedimentation would continue to take place until about 300 million years ago.<ref name="ancientdenvers" /><ref name= WilliamsChronic2014>{{cite book|title=Roadside Geology of Colorado|last1=Williams|first1=Felicie|last2=Chronic|first2=Halka|author-link2=Halka Chronic|orig-year=1980|edition=3rd|isbn=978-0878426096|year=2014|pages=9–11, 46–49}}</ref>

===Fountain formation===
Around 300 million years ago, the sinking suddenly reversed, and the sediment-covered granite began to [[Orogeny|uplift]], giving rise to the [[Ancestral Rocky Mountains]]. Over the next 150 million years, during the uplift the mountains continued to erode and cover their flanks 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 complete removal. The sediment from these mountains lies in the very red [[Fountain Formation]] today. [[Red Rocks Amphitheatre]] outside of Denver, Colorado, is set within the Fountain Formation.<ref name="ancientdenvers" />

===Lyons Sandstone===
At 280 million years ago, 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.<ref name="ancientdenvers" /> Uplifted beds of Lyons Sandstone are found along the Front range and form the gateway to the [[Garden of the Gods]].<ref name= WilliamsChronic2014/>

===Lykins Formation===
30 million years later, the sediment deposition was still taking place with the introduction of the [[Lykins Shale]]. This formation can be best attributed to its wavy layers of muddy [[limestone]] and signs of [[stromatolites]] that thrived in a [[tidal flat]] in present-day Colorado. 250 million years ago, the [[Ancestral Rockies]] were eroding away<ref name= WilliamsChronic2014/> 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 became extinct and a great deal on land as well.<ref name="ancientdenvers" />

===Morrison Formation===
After 100 million years of deposition, a new environment brought rise to a new formation, the sandstone [[Morrison Formation]]. The Morrison Formation contains some of the best fossils of the Late [[Jurassic]]. It is especially known for its sauropod tracks and sauropod bones, among other dinosaur fossils. As identified by the fossil record, the environment was filled with various types of vegetation such as [[fern]]s and ''[[Zamites]]''.<ref name="ancientdenvers" /> While this time period boasts many types of plants, grass had not yet evolved.<ref name="ancientdenvers" />

===Dakota Sandstone===
The [[Dakota Formation|Dakota Sandstone]], which was deposited around 100 million years ago at the opening of the [[Cretaceous]] [[Western Interior Seaway]] from the Arctic to the Tropics, shows evidence of ferns and dinosaur tracks. Sheets of ripple marks can be seen on some of the strata, confirming advancing and retreating near-shore environments.<ref name="ancientdenvers" /> These Dakota Group sandstone beds are resistant to erosion and have uplifted to form the [[Dakota Hogback]], a ridge between the mountains and the plains.<ref name= WilliamsChronic2014/>

===Benton Group / Niobrara Formation===
Over the next 35 million years, the Cretaceous seaway repeatedly widened as far as Utah and Wisconsin and narrowed to near closure.<ref>{{cite journal |author= R.J. Weimer |year= 1984 |journal= AAPG Memoir |title= Relation of unconformities, tectonics, and sea-level changes, Cretaceous of Western Interior, United States |editor= J.S. Schlee |publisher= [[American Association of Petroleum Geologists]] |issue= Memoir 36, Interregional unconformities and hydrocarbon accumulation |page= 407 |url=https://terra.rice.edu/department/faculty/morganj/ESCI536/Readings/Weimer_CretaceousSeaway.pdf |access-date= March 21, 2021 }}</ref> With no mountains present at the time, the Colorado area was in the line of the deepest channel of the seaway; but being on the [[Transcontinental Arch]], the Front Range areas was relatively shallow and was near the last land to submerge as the seaway opened. Shale and chalk were deposited over the area as [[Greenhorn Limestone|Greenhorn]] of the [[Benton Shale|Benton Group]] and the [[Niobrara Formation]]. Within these beds are found abundant marine fossils ([[ammonite]]s and skeletons of fish and such marine reptiles as [[mosasaur]]s, [[plesiosaur]]s, and extinct species of [[sea turtle]]s) along with rare dinosaur and bird remains. Today, the [[Fort Hays Limestone Member|Fort Hays Limestone]] member forms [[Flatiron (geomorphology)|flatirons]] or secondary hogbacks on the east slope of the Dakota Hogback.<ref name=Noblett2011a>{{Cite book|last= Noblett |first=J.B. |title=A Guide to the Geological History of the Pikes Peak Region, Colorado Springs (2nd ed.) |publisher=Colorado College |year=2011|location=Colorado Springs, Colorado |pages=43}} ('''Benton Group''' is in current use in this location.)</ref>

===Pierre Shale===
The non-chalky shales of the [[Pierre Shale|Pierre Formation]] formed in the final cycle of the seaway. At about 68 million years ago, the Front Range began to rise again due to the Laramide Orogeny in the western half of the state, draining from being at the bottom of a sea to land again, giving yield to another fossiliferous rock layer, the Denver Formation.<ref name="ancientdenvers" />

===Denver Formation===
[[Image:Mmtn.JPG|thumb|right|Front Range near [[Estes Park, Colorado]] ([[Mummy Mountain (Colorado)|Mummy Mountain]])]]
The [[Denver Formation]] contains fossils of dinosaurs like ''[[Tyrannosaurus|Tyrannosaurus rex]]'' and [[Triceratops]]. While the forests of vegetation, dinosaurs, and other organisms thrived, their reign would come to an end at the [[Cretaceous–Paleogene boundary]] (which was formerly known as the K-T boundary). In an instant, millions of species were obliterated by a meteor impact in Mexico's [[Yucatán Peninsula]]. While this extinction led to the demise of the dinosaurs and other organisms, some life did prevail to repopulate the earth as it recovered from this tremendous disaster. The uplifted mountains continued to constantly erode and, by 40 million years ago, the region was once again buried in material eroded from the central mountains.<ref name="ancientdenvers" />

===Castle Rock Conglomerate===
Suddenly, 37 million years ago, a great volcanic eruption took place in the [[Collegiate Range]] and covered the landscape in hot ash that instantly torched and consumed everything across the landscape. An entire lush environment was capped in a matter of minutes with 20 feet of extremely resistant rock, [[rhyolite]]. However, as seen before, life rebounds, and after a few million years mass floods cut through the rhyolite and eroded much of it as plants and animals began to recolonize the landscape. The mass flooding and erosion of the volcanic rock formed the [[Castle Rock (Colorado)|Castle Rock Conglomerate]] that can be found in the Front Range.<ref name="ancientdenvers" />

===Quaternary deposits===
Eventually, at about 10 million years ago, the Front Range began to rise up again and the resistant granite in the heart of the mountains thrust upwards and stood tall, while the weaker sediments deposited above it eroded away. As the Front Range rose, streams and recent (16,000 years ago) glaciations during the [[Quaternary]] age literally unburied the range by cutting through the weaker sediment and giving rise to the granitic peaks present today.<ref name="ancientdenvers" /> This was the last step in forming the present-day geologic sequence and history of today's Front Range.<ref name="ancientdenvers" />
{{wide image|Mountains_from_westlands.jpg|1000px|The Front Range as viewed from [[Greenwood Village, Colorado|Greenwood Village]] south of Denver, [[Mount Blue Sky]] is on the far right, in the clouds.}}