Editing Sangre de Cristo Range (section)

==Geology==
The Colorado Sangre de Cristos are [[Horst (geology)|fault-block]] mountains similar to the [[Teton Range]] in Wyoming and the [[Wasatch Range]] in Utah. Major fault lines run along the east and west sides of the range, and cut right through the mountains in some places.<ref name=":1">{{Cite web |date=2018-09-16 |title=The Sangre de Cristo Mountains |url=https://spanishpeakscountry.com/the-sangre-de-cristo-mountains/ |access-date=2022-05-03 |website=Spanish Peaks County - Explore Southern Colorado's rich history, natural wonders, and artistic inspiration |language=en-US}}</ref> Like all fault-block mountain ranges, the Sangre de Cristos lack [[foothills]] which means the highest peaks rise abruptly from the valleys to the east and west, rising {{cvt|7000|ft|||}} in only a few miles in some places. The mountains were pushed up around 5 million years ago, basically as one large mass of rock. The Sangre de Cristo range is still being uplifted today as faults in the area remain active. Due to uplift (elevation increase) and erosion, rock layers are missing, causing gaps in the range, called "unconformities."<ref name=":0">{{Cite web |title=USGS Circular 1349: The Geologic Story of Colorado's Sangre de Cristo Range |url=https://pubs.usgs.gov/circ/1349/ |access-date=2022-05-03 |website=pubs.usgs.gov}}</ref>

[[File:Dunes great sand 2.jpg|upright=1.75|thumb|left|The Sangre de Cristo Range rising above the [[Great Sand Dunes National Park]]]]

On the west side is the [[San Luis Valley]], a portion of the [[Rio Grande Rift]]. On the southeast side is the [[Raton Basin]], a quiet but still active [[volcanic field]]. On the northeast side are the [[Wet Mountains]] and the [[Front Range]], areas of [[Precambrian]] [[igneous rock|igneous]] and [[metamorphic rock|metamorphic]] rocks formed during the [[Colorado orogeny]] some 1.7 billion years ago and then uplifted more recently during the [[Laramide orogeny]].

The [[Blanca Peak|Blanca Massif]] is also Precambrian rock, while most of the rest of the Sangres is composed of younger [[Permian]]-[[Pennsylvanian (geology)|Pennsylvanian]] (about 250-million-year-old) rock, a mix of [[sedimentary rock|sedimentary]] [[conglomerate (geology)|conglomerates]], silty mudstones and [[shale]]s, sandstones, limestone beds <ref name="Tanner 144–161">{{Cite journal |last1=Tanner |first1=Lawrence H. |last2=Lucas |first2=Spencer G. |date=2017-04-01 |title=Paleosols of the upper Paleozoic Sangre de Cristo Formation, north-central New Mexico: Record of early Permian palaeoclimate in tropical Pangaea |journal=Journal of Palaeogeography |language=en |volume=6 |issue=2 |pages=144–161 |doi=10.1016/j.jop.2017.02.001 |issn=2095-3836|doi-access=free |bibcode=2017JPalG...6..144T }}</ref> and igneous [[intrusion]]s. These sedimentary rocks originated as [[sediment]] [[erosion|eroded]] from the [[Ancestral Rocky Mountains]]. Crestone Conglomerate are a feature on many of the peaks, including Crestone Needle.<ref>{{Cite web |title=Sangre de Cristo Mountains : Climbing, Hiking & Mountaineering : SummitPost |url=https://www.summitpost.org/sangre-de-cristo-mountains/171124 |access-date=2022-05-03 |website=www.summitpost.org}}</ref> The conglomerate settled near the uplift and contains boulders as large as 6 feet in diameter.<ref name=":0" />