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114-545: The Front Range runs north-south between Casper, Wyoming , and Pueblo, Colorado , and rises nearly 10,000 feet above the Great Plains. Longs Peak , Mount Blue Sky , and Pikes Peak are its most prominent peaks, visible from the Interstate 25 corridor. The area is a popular destination for mountain biking, hiking, climbing, and camping during the warmer months and for skiing and snowboarding during winter. Millions of years ago,

228-538: A Berriasian–Barremian warm-dry phase, an Aptian–Santonian warm-wet phase, and a Campanian–Maastrichtian cool-dry phase. As in the Cenozoic, the 400,000 year eccentricity cycle was the dominant orbital cycle governing carbon flux between different reservoirs and influencing global climate. The location of the Intertropical Convergence Zone (ITCZ) was roughly the same as in the present. The cooling trend of

342-542: A former army air base built during World War II. The runways are large, having been built for bombers. It replaced Wardwell Field north of Casper which later became the town of Bar Nunn, Wyoming . The airport is located west of the city just off of US Highway 20/26. In July 2004, the airport facilities were renovated. Passenger service at the airport is offered by United Express ( SkyWest Airlines and GoJet Airlines ), and Delta Connection (SkyWest Airlines). FedEx Express and FedEx Feeder provide cargo airline service to

456-557: A generating capacity of 16.5 MW. Energy Transportation Inc. is headquartered in Casper. This logistics firm transports overweight and outsized components used in the wind power industry. The Casper landfill is also a disposal site for windmill blades. Casper is home to Casper College , a community college that offers bachelor's degrees in sixteen areas of study from the University of Wyoming through their UW/CC Center. Public education in

570-509: A male householder with no wife present, and 37.5% were non-families. Of all households 30.3% were made up of individuals, and 10.1% had someone living alone who was 65 years of age or older. The average household size was 2.38 and the average family size was 2.95. The median age in the city was 36 years. 23.9% of residents were under the age of 18; 10.2% were between the ages of 18 and 24; 26.7% were from 25 to 44; 26.4% were from 45 to 64; and 12.9% were 65 years of age or older. The gender makeup of

684-535: 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

798-502: A railhead, survives to the present day. This rail presence also made Casper the starting off point for the "invaders" in the Johnson County War , since the chartered train carrying the men from Texas stopped at Casper. In more recent history, the city received a significant influx of visitors during the solar eclipse of August 21, 2017 , due to its position along the path of totality. Interstate 25 , which approaches Casper from

912-660: A straight shell, flourished in the seas along with reef-building rudist clams. Inoceramids were also particularly notable among Cretaceous bivalves, and they have been used to identify major biotic turnovers such as at the Turonian-Coniacian boundary. Predatory gastropods with drilling habits were widespread. Globotruncanid foraminifera and echinoderms such as sea urchins and starfish (sea stars) thrived. Ostracods were abundant in Cretaceous marine settings; ostracod species characterised by high male sexual investment had

1026-551: A ~0.6 °C increase in temperature. The latter warming interval, occurring at the very end of the Cretaceous, was triggered by the activity of the Deccan Traps. The LKEPCI lasted into the Late Palaeocene , when it gave way to another supergreenhouse interval. The production of large quantities of magma, variously attributed to mantle plumes or to extensional tectonics , further pushed sea levels up, so that large areas of

1140-578: Is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era , as well as the longest. At around 79   million years, it is the ninth and longest geological period of the entire Phanerozoic . The name is derived from the Latin creta , ' chalk ', which is abundant in the latter half of the period. It is usually abbreviated K , for its German translation Kreide . The Cretaceous

1254-603: Is found in England, northern France, the low countries , northern Germany , Denmark and in the subsurface of the southern part of the North Sea . Chalk is not easily consolidated and the Chalk Group still consists of loose sediments in many places. The group also has other limestones and arenites . Among the fossils it contains are sea urchins , belemnites , ammonites and sea reptiles such as Mosasaurus . In southern Europe,

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1368-526: Is land and 0.34 square miles (0.88 km ) is water. Casper, as with most of the rest of Wyoming, has a continental semi-arid climate ( Köppen climate classification : BSk ), with long, cold, but dry winters, hot but generally dry summers, mild springs, and short and crisp autumns. Normal daily maxima range from 35.2 °F (1.8 °C) in January to 89.0 °F (31.7 °C) in July. Snow can fall heavily during

1482-509: Is now used worldwide. In many parts of the world, alternative local subdivisions are still in use. From youngest to oldest, the subdivisions of the Cretaceous period are: The lower boundary of the Cretaceous is currently undefined, and the Jurassic–Cretaceous boundary is currently the only system boundary to lack a defined Global Boundary Stratotype Section and Point (GSSP). Placing a GSSP for this boundary has been difficult because of

1596-484: Is the state's oldest radio station. For television, Casper is served by the following stations: KTWO-TV (channel 2) is affiliated with ABC , KCWY (channel 13) is affiliated with NBC (with The CW on DT2), KGWC-TV (channel 14) is affiliated with CBS , and KFNB (channel 20) is affiliated with Fox . Casper also has a member station of PBS , KPTW, on channel 8. Almost all of the city's FM stations and all of its TV stations broadcast from Casper Mountain south of

1710-492: The 2020 census . Casper is nicknamed "The Oil City" and has a long history of oil boomtown and cowboy culture, dating back to the development of the nearby Salt Creek Oil Field . Casper is located in east central Wyoming on the North Platte River . The city was established east of the former site of Fort Caspar , in an area that grew for European settlers during the mid-19th century mass migration of land seekers along

1824-474: The Denver and Salt Lake Railway , the former Rio Grande is used for freight by both Union Pacific and BNSF , and it is also used by Amtrak 's California Zephyr and Winter Park Express . Casper, Wyoming Casper is a city in and the county seat of Natrona County, Wyoming , United States. Casper is the second-most populous city in the state after Cheyenne , with the population at 59,038 as of

1938-680: The Mancos Shale of western North America. These shales are an important source rock for oil and gas , for example in the subsurface of the North Sea. In northwestern Europe, chalk deposits from the Upper Cretaceous are characteristic for the Chalk Group , which forms the white cliffs of Dover on the south coast of England and similar cliffs on the French Normandian coast. The group

2052-684: The North American Cordillera , as the Nevadan orogeny was followed by the Sevier and Laramide orogenies . Gondwana had begun to break up during the Jurassic Period, but its fragmentation accelerated during the Cretaceous and was largely complete by the end of the period. South America , Antarctica , and Australia rifted away from Africa (though India and Madagascar remained attached to each other until around 80 million years ago); thus,

2166-603: The Oregon , California , and Mormon trails, where several nearby ferries offered passage across the North Platte River in the early 1840s. In 1859, Louis Guinard built a bridge and trading post near the original ferry locations, allowing overland travel to continue through the area. The government also posted the military garrison to protect telegraph and mail service. It was under the command of Lieutenant Colonel William O. Collins . Native American attacks increased after

2280-560: The Sand Creek Massacre in Colorado in 1864, bringing more troops to the post, which was by now called Platte Bridge Station. In July 1865, Lt. Colonel William Collins' beloved son Lieutenant Caspar Collins was killed near the post by a group of Indian warriors, and three months later the garrison was renamed Fort Caspar in his son's honor. In 1867, the troops were ordered to abandon Fort Caspar in favor of Fort Fetterman , downstream on

2394-543: The Selli Event . Early Aptian tropical sea surface temperatures (SSTs) were 27–32 °C, based on TEX 86 measurements from the equatorial Pacific. During the Aptian, Milankovitch cycles governed the occurrence of anoxic events by modulating the intensity of the hydrological cycle and terrestrial runoff. The early Aptian was also notable for its millennial scale hyperarid events in the mid-latitudes of Asia. The BAWI itself

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2508-613: The Terrain Crétacé , using strata in the Paris Basin and named for the extensive beds of chalk ( calcium carbonate deposited by the shells of marine invertebrates , principally coccoliths ), found in the upper Cretaceous of Western Europe . The name Cretaceous was derived from the Latin creta , meaning chalk . The twofold division of the Cretaceous was implemented by Conybeare and Phillips in 1822. Alcide d'Orbigny in 1840 divided

2622-707: The Turonian Age, based on isotopic evidence. However, this has subsequently been suggested to be the result of inconsistent isotopic proxies, with evidence of polar rainforests during this time interval at 82° S. Rafting by ice of stones into marine environments occurred during much of the Cretaceous, but evidence of deposition directly from glaciers is limited to the Early Cretaceous of the Eromanga Basin in southern Australia . Flowering plants (angiosperms) make up around 90% of living plant species today. Prior to

2736-513: The Wyoming Symphony Orchestra . During the summer months, Casper's City Band performs free concerts Thursday evenings at Washington Park, weather permitting. Wyoming National Bank , a mid-century modern tower, was designed by Charles Deaton and is featured in Casper's logo. Interstate Highways : US Routes : Wyoming State Highways : The city has scheduled air service at Casper–Natrona County International Airport ,

2850-475: The tuatara ) disappeared from North America and Europe after the Early Cretaceous , and were absent from North Africa and northern South America by the early Late Cretaceous . The cause of the decline of Rhynchocephalia remains unclear, but has often been suggested to be due to competition with advanced lizards and mammals. They appear to have remained diverse in high-latitude southern South America during

2964-964: The Albian regularly expanded northward in tandem with expansions of subtropical high pressure belts. The Cedar Mountain Formation's Soap Wash flora indicates a mean annual temperature of between 19 and 26 °C in Utah at the Albian-Cenomanian boundary. Tropical SSTs during the Cenomanian-Turonian Thermal Maximum were at least 30 °C, though one study estimated them as high as between 33 and 42 °C. An intermediate estimate of ~33-34 °C has also been given. Meanwhile, deep ocean temperatures were as much as 15 to 20 °C (27 to 36 °F) warmer than today's; one study estimated that deep ocean temperatures were between 12 and 20 °C during

3078-565: The Cenozoic Era   —   the ichthyosaurs , last remaining temnospondyls ( Koolasuchus ), and nonmammalian cynodonts ( Tritylodontidae )   —   were already extinct millions of years before the event occurred. Coccolithophorids and molluscs , including ammonites , rudists , freshwater snails , and mussels , as well as organisms whose food chain included these shell builders, became extinct or suffered heavy losses. For example, ammonites are thought to have been

3192-621: The Coniacian through the Maastrichtian. During the Cretaceous, the late- Paleozoic -to-early-Mesozoic supercontinent of Pangaea completed its tectonic breakup into the present-day continents , although their positions were substantially different at the time. As the Atlantic Ocean widened, the convergent-margin mountain building ( orogenies ) that had begun during the Jurassic continued in

3306-605: The Cretaceous is sharply defined, being placed at an iridium -rich layer found worldwide that is believed to be associated with the Chicxulub impact crater , with its boundaries circumscribing parts of the Yucatán Peninsula and extending into the Gulf of Mexico . This layer has been dated at 66.043 Mya. At the end of the Cretaceous, the impact of a large body with the Earth may have been

3420-555: The Cretaceous is usually a marine system consisting of competent limestone beds or incompetent marls . Because the Alpine mountain chains did not yet exist in the Cretaceous, these deposits formed on the southern edge of the European continental shelf , at the margin of the Tethys Ocean . During the Cretaceous, the present North American continent was isolated from the other continents. In

3534-527: The Cretaceous seas. Stagnation of deep sea currents in middle Cretaceous times caused anoxic conditions in the sea water leaving the deposited organic matter undecomposed. Half of the world's petroleum reserves were laid down at this time in the anoxic conditions of what would become the Persian Gulf and the Gulf of Mexico. In many places around the world, dark anoxic shales were formed during this interval, such as

Front Range - Misplaced Pages Continue

3648-763: The Dakota Hogback. The non-chalky shales of the 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. The Denver Formation contains fossils of dinosaurs like Tyrannosaurus rex and Triceratops . While

3762-565: The Fountain Formation. 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. Uplifted beds of Lyons Sandstone are found along

3876-770: The French Cretaceous into five étages (stages): the Neocomian , Aptian, Albian, Turonian, and Senonian, later adding the Urgonian between Neocomian and Aptian and the Cenomanian between the Albian and Turonian. The Cretaceous is divided into Early and Late Cretaceous epochs , or Lower and Upper Cretaceous series . In older literature, the Cretaceous is sometimes divided into three series: Neocomian (lower/early), Gallic (middle) and Senonian (upper/late). A subdivision into 12 stages , all originating from European stratigraphy,

3990-424: The Front Range are Interstate 70 , which crosses west of Denver, Colorado, and Interstate 80 , which crosses near Laramie, Wyoming. U.S. Route 34 travels through the mountains near Loveland, Colorado , although this route is typically closed from October to May. U.S. Route 24 travels through the southern Front Range west of Colorado Springs , eventually connecting with I-70 west of Vail, Colorado . Along with

4104-488: The Front Range. 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

4218-673: The Front range and form the gateway to the Garden of the Gods . 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 while

4332-645: The Jurassic, the North Atlantic already opened, leaving a proto-ocean between Europe and North America. From north to south across the continent, the Western Interior Seaway started forming. This inland sea separated the elevated areas of Laramidia in the west and Appalachia in the east. Three dinosaur clades found in Laramidia (troodontids, therizinosaurids and oviraptorosaurs) are absent from Appalachia from

4446-563: The LKEPCI. During this period of relatively cool temperatures, the ITCZ became narrower, while the strength of both summer and winter monsoons in East Asia was directly correlated to atmospheric CO 2 concentrations. Laramidia likewise had a seasonal, monsoonal climate. The Maastrichtian was a time of chaotic, highly variable climate. Two upticks in global temperatures are known to have occurred during

4560-521: The Late Cretaceous, where lizards remained rare, with their remains outnumbering terrestrial lizards 200:1. Choristoderes , a group of freshwater aquatic reptiles that first appeared during the preceding Jurassic, underwent a major evolutionary radiation in Asia during the Early Cretaceous, which represents the high point of choristoderan diversity, including long necked forms such as Hyphalosaurus and

4674-534: The Late Cretaceous-Early Palaeogene Cool Interval (LKEPCI). Tropical SSTs declined from around 35 °C in the early Campanian to around 28 °C in the Maastrichtian. Deep ocean temperatures declined to 9 to 12 °C, though the shallow temperature gradient between tropical and polar seas remained. Regional conditions in the Western Interior Seaway changed little between the MKH and

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4788-610: The MKH. Mean annual temperatures at the poles during the MKH exceeded 14 °C. Such hot temperatures during the MKH resulted in a very gentle temperature gradient from the equator to the poles; the latitudinal temperature gradient during the Cenomanian-Turonian Thermal Maximum was 0.54 °C per ° latitude for the Southern Hemisphere and 0.49 °C per ° latitude for the Northern Hemisphere, in contrast to present day values of 1.07 and 0.69 °C per ° latitude for

4902-516: The MKH. The poles were so warm that ectothermic reptiles were able to inhabit them. Beginning in the Santonian, near the end of the MKH, the global climate began to cool, with this cooling trend continuing across the Campanian. This period of cooling, driven by falling levels of atmospheric carbon dioxide, caused the end of the MKH and the transition into a cooler climatic interval, known formally as

5016-404: The Maastrichtian, bucking the trend of overall cooler temperatures during the LKEPCI. Between 70 and 69 Ma and 66–65 Ma, isotopic ratios indicate elevated atmospheric CO 2 pressures with levels of 1000–1400 ppmV and mean annual temperatures in west Texas between 21 and 23 °C (70 and 73 °F). Atmospheric CO 2 and temperature relations indicate a doubling of pCO 2 was accompanied by

5130-675: The North Platte along the Bozeman Trail . However, the town itself was settled twenty years later in 1887, and incorporated a year later by developers as an anticipated stopping point during the expansion of the Wyoming Central Railway . A site a few miles east was planned as the original site, where homesteader Joshua Stroud lived prior to the actual construction of the train station for the Chicago and North Western Railway . The site

5244-419: The South Atlantic and Indian Oceans were newly formed. Such active rifting lifted great undersea mountain chains along the welts, raising eustatic sea levels worldwide. To the north of Africa the Tethys Sea continued to narrow. During most of the Late Cretaceous, North America would be divided in two by the Western Interior Seaway , a large interior sea, separating Laramidia to the west and Appalachia to

5358-514: The Southern and Northern hemispheres, respectively. This meant weaker global winds, which drive the ocean currents, and resulted in less upwelling and more stagnant oceans than today. This is evidenced by widespread black shale deposition and frequent anoxic events . Tropical SSTs during the late Albian most likely averaged around 30 °C. Despite this high SST, seawater was not hypersaline at this time, as this would have required significantly higher temperatures still. On land, arid zones in

5472-403: The Tethys to the Arctic Ocean and enabling biotic exchange between the two oceans. At the peak of the Cretaceous transgression , one-third of Earth's present land area was submerged. The Cretaceous is justly famous for its chalk ; indeed, more chalk formed in the Cretaceous than in any other period in the Phanerozoic . Mid-ocean ridge activity—or rather, the circulation of seawater through

5586-532: The airport. Public transit in the Casper area had been provided by the Casper Area Transportation Coalition but is now offered by the city of Casper as Casper Area Transit . They offer fixed route service called Casper Area LINK and an on-request service called ASSIST from Monday to Saturday. Scheduled bus service once offered by Power River Bus Lines is now offered by ExpressArrow (formerly Black Hills Stages). Cretaceous The Cretaceous ( IPA : / k r ɪ ˈ t eɪ ʃ ə s / krih- TAY -shəss )

5700-425: The ancestors of modern-day birds also diversified. They inhabited every continent, and were even found in cold polar latitudes. Pterosaurs were common in the early and middle Cretaceous, but as the Cretaceous proceeded they declined for poorly understood reasons (once thought to be due to competition with early birds , but now it is understood avian adaptive radiation is not consistent with pterosaur decline ). By

5814-400: The area as Greenhorn of the Benton Group and the Niobrara Formation . Within these beds are found abundant marine fossils ( ammonites and skeletons of fish and such marine reptiles as mosasaurs , plesiosaurs , and extinct species of sea turtles ) along with rare dinosaur and bird remains. Today, the Fort Hays Limestone member forms flatirons or secondary hogbacks on the east slope of

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5928-423: 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 ferns and Zamites . While this time period boasts many types of plants, grass had not yet evolved. The Dakota Sandstone , which was deposited around 100 million years ago at

6042-445: The city of Casper is provided by Natrona County School District #1 , the sole school district for the county. The district operates sixteen elementary schools, five middle schools, and three high schools in Casper. The high schools are Kelly Walsh , Natrona County , and Roosevelt High Schools. A program called CAPS is being added to Natrona County School District, which will provide more space and classrooms for juniors and seniors at

6156-401: The city was $ 36,567, and the median income for a family was $ 46,267. Males had a median income of $ 34,905 versus $ 21,810 for females. The per capita income for the city was $ 19,409. About 8.5% of families and 11.4% of the population were below the poverty line , including 15.4% of those under age 18 and 7.3% of those age 65 or over. Casper is a regional center of banking and commerce. After

6270-524: The city was 49.7% male and 50.3% female. As of the census of 2000, there were 49,644 people, 20,343 households, and 13,141 families residing in the city. The population density was 2,073.2 people per square mile (800.5 people/km ). There were 21,872 housing units at an average density of 913.4 per square mile (352.7/km ). The racial makeup of the city was 94.03% White, 0.86% Black, 1.00% Native American, 0.49% Asian, 0.02% Pacific Islander , 2.04% from other races , and 1.56% from two or more races. 5.35% of

6384-454: The city. Sports teams based in Casper include: Casper is home to a number of museums and historical sites: Casper has three locations offering theater : the Gertrude Krampert Theatre at Casper College, Stage III Community Theatre, and the Casper Events Center where an annual series of touring Broadway shows, Broadway in Casper , can be seen. Casper is home to the Troopers , a drum and bugle corps in Drum Corps International , and

6498-408: The continental crust were covered with shallow seas. The Tethys Sea connecting the tropical oceans east to west also helped to warm the global climate. Warm-adapted plant fossils are known from localities as far north as Alaska and Greenland , while dinosaur fossils have been found within 15 degrees of the Cretaceous south pole . It was suggested that there was Antarctic marine glaciation in

6612-458: The discovery of crude oil in the region during the 1890s, Casper became the regional petroleum industry center. Oil has figured prominently in its history from nearly the outset. Oil was first discovered in the famous Salt Creek Oil Field in 1889, approximately 40 miles (64 km) north of Casper; the first refinery in Casper was built in 1895. The city has featured a refinery ever since, although various refineries have been built and closed over

6726-544: The early and mid-Cretaceous (becoming extinct during the late Cretaceous Cenomanian-Turonian anoxic event ), plesiosaurs throughout the entire period, and mosasaurs appearing in the Late Cretaceous. Sea turtles in the form of Cheloniidae and Panchelonioidea lived during the period and survived the extinction event. Panchelonioidea is today represented by a single species; the leatherback sea turtle . The Hesperornithiformes were flightless, marine diving birds that swam like grebes . Baculites , an ammonite genus with

6840-407: 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. 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

6954-437: The east, then receded late in the period, leaving thick marine deposits sandwiched between coal beds. Bivalve palaeobiogeography also indicates that Africa was split in half by a shallow sea during the Coniacian and Santonian, connecting the Tethys with the South Atlantic by way of the central Sahara and Central Africa, which were then underwater. Yet another shallow seaway ran between what is now Norway and Greenland, connecting

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7068-535: The end of the AACS, which ended around 111 Ma with the Paquier/Urbino Thermal Maximum, giving way to the Mid-Cretaceous Hothouse (MKH), which lasted from the early Albian until the early Campanian. Faster rates of seafloor spreading and entry of carbon dioxide into the atmosphere are believed to have initiated this period of extreme warmth, along with high flood basalt activity. The MKH was punctuated by multiple thermal maxima of extreme warmth. The Leenhardt Thermal Event (LTE) occurred around 110 Ma, followed shortly by

7182-448: The end of the Cretaceous. The high sea level and warm climate of the Cretaceous meant large areas of the continents were covered by warm, shallow seas, providing habitat for many marine organisms. The Cretaceous was named for the extensive chalk deposits of this age in Europe, but in many parts of the world, the deposits from the Cretaceous are of marine limestone , a rock type that is formed under warm, shallow marine conditions. Due to

7296-411: The end of the period only three highly specialized families remained; Pteranodontidae , Nyctosauridae , and Azhdarchidae . The Liaoning lagerstätte ( Yixian Formation ) in China is an important site, full of preserved remains of numerous types of small dinosaurs, birds and mammals, that provides a glimpse of life in the Early Cretaceous. The coelurosaur dinosaurs found there represent types of

7410-407: The enlarged ridges—enriched the oceans in calcium ; this made the oceans more saturated, as well as increased the bioavailability of the element for calcareous nanoplankton . These widespread carbonates and other sedimentary deposits make the Cretaceous rock record especially fine. Famous formations from North America include the rich marine fossils of Kansas 's Smoky Hill Chalk Member and

7524-528: The extinction fed on insects , larvae , worms , and snails, which in turn fed on dead plant and animal matter. Scientists theorise that these organisms survived the collapse of plant-based food chains because they fed on detritus . In stream communities , few groups of animals became extinct. Stream communities rely less on food from living plants and more on detritus that washes in from land. This particular ecological niche buffered them from extinction. Similar, but more complex patterns have been found in

7638-505: The first records of the gharial-like Neochoristodera , which appear to have evolved in the regional absence of aquatic neosuchian crocodyliformes. During the Late Cretaceous the neochoristodere Champsosaurus was widely distributed across western North America. Due to the extreme climatic warmth in the Arctic, choristoderans were able to colonise it too during the Late Cretaceous. In the seas, rays , modern sharks and teleosts became common. Marine reptiles included ichthyosaurs in

7752-404: 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

7866-427: The genus Berriasella , but its use as a stratigraphic indicator has been questioned, as its first appearance does not correlate with that of C. alpina . The boundary is officially considered by the International Commission on Stratigraphy to be approximately 145 million years ago, but other estimates have been proposed based on U-Pb geochronology, ranging as young as 140 million years ago. The upper boundary of

7980-448: The granitic peaks present today. This was the last step in forming the present-day geologic sequence and history of today's Front Range. The Front Range includes the highest peaks along the eastern edge of the Rockies. The highest mountain peak in the Front Range is Grays Peak . Other notable mountains include Torreys Peak , Mount Blue Sky , Longs Peak , Pikes Peak , and Mount Bierstadt . The main interstate highways that run through

8094-570: The group Maniraptora , which includes modern birds and their closest non-avian relatives, such as dromaeosaurs , oviraptorosaurs , therizinosaurs , troodontids along with other avialans . Fossils of these dinosaurs from the Liaoning lagerstätte are notable for the presence of hair-like feathers . Insects diversified during the Cretaceous, and the oldest known ants , termites and some lepidopterans , akin to butterflies and moths , appeared. Aphids , grasshoppers and gall wasps appeared. Rhynchocephalians (which today only includes

8208-412: The high sea level, there was extensive space for such sedimentation . Because of the relatively young age and great thickness of the system, Cretaceous rocks are evident in many areas worldwide. Chalk is a rock type characteristic for (but not restricted to) the Cretaceous. It consists of coccoliths , microscopically small calcite skeletons of coccolithophores , a type of algae that prospered in

8322-546: The highest rates of extinction and turnover. Thylacocephala , a class of crustaceans, went extinct in the Late Cretaceous. The first radiation of the diatoms (generally siliceous shelled, rather than calcareous ) in the oceans occurred during the Cretaceous; freshwater diatoms did not appear until the Miocene . Calcareous nannoplankton were important components of the marine microbiota and important as biostratigraphic markers and recorders of environmental change. The Cretaceous

8436-464: The impact of a large asteroid that formed the Chicxulub crater in the Gulf of Mexico. The end of the Cretaceous is defined by the abrupt Cretaceous–Paleogene boundary (K–Pg boundary), a geologic signature associated with the mass extinction that lies between the Mesozoic and Cenozoic Eras . The Cretaceous as a separate period was first defined by Belgian geologist Jean d'Omalius d'Halloy in 1822 as

8550-491: 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 Conglomerate that can be found in

8664-741: The last epoch of the Jurassic, the Tithonian, continued into the Berriasian, the first age of the Cretaceous. The North Atlantic seaway opened and enabled the flow of cool water from the Boreal Ocean into the Tethys. There is evidence that snowfalls were common in the higher latitudes during this age, and the tropics became wetter than during the Triassic and Jurassic. Glaciation was restricted to high- latitude mountains, though seasonal snow may have existed farther from

8778-564: The late Valanginian (~ 134 million years ago) found in Israel and Italy, initially at low abundance. Molecular clock estimates conflict with fossil estimates, suggesting the diversification of crown-group angiosperms during the Late Triassic or the Jurassic, but such estimates are difficult to reconcile with the heavily sampled pollen record and the distinctive tricolpate to tricolporoidate (triple grooved) pollen of eudicot angiosperms. Among

8892-465: The late Cretaceous, and all else that depended on them suffered, as well. Herbivorous animals, which depended on plants and plankton as their food, died out as their food sources became scarce; consequently, the top predators , such as Tyrannosaurus rex , also perished. Yet only three major groups of tetrapods disappeared completely; the nonavian dinosaurs , the plesiosaurs and the pterosaurs . The other Cretaceous groups that did not survive into

9006-563: The latest Albian. Approximately 94 Ma, the Cenomanian-Turonian Thermal Maximum occurred, with this hyperthermal being the most extreme hothouse interval of the Cretaceous and being associated with a sea level highstand. Temperatures cooled down slightly over the next few million years, but then another thermal maximum, the Coniacian Thermal Maximum, happened, with this thermal event being dated to around 87 Ma. Atmospheric CO 2 levels may have varied by thousands of ppm throughout

9120-406: The lowest temperature recorded was −42 °F (−41.1 °C) on December 22, 2022 . As of the census of 2010, there were 55,316 people, 22,794 households, and 14,237 families residing in the city. The population density was 2,056.4 inhabitants per square mile (794.0/km ). There were 24,536 housing units at an average density of 912.1 per square mile (352.2/km ). The racial makeup of the city

9234-674: The l’Arboudeyesse Thermal Event (ATE) a million years later. Following these two hyperthermals was the Amadeus Thermal Maximum around 106 Ma, during the middle Albian. Then, around a million years after that, occurred the Petite Verol Thermal Event (PVTE). Afterwards, around 102.5 Ma, the Event 6 Thermal Event (EV6) took place; this event was itself followed by the Breistroffer Thermal Maximum around 101 Ma, during

9348-508: The middle Cretaceous, becoming the dominant group of land plants by the end of the period, coincident with the decline of previously dominant groups such as conifers. The oldest known fossils of grasses are from the Albian , with the family having diversified into modern groups by the end of the Cretaceous. The oldest large angiosperm trees are known from the Turonian (c. 90 Mya) of New Jersey, with

9462-679: The middle of the Cretaceous. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Earth by the end of the Cretaceous, coincident with the decline and extinction of previously widespread gymnosperm groups. The Cretaceous (along with the Mesozoic) ended with the Cretaceous–Paleogene extinction event , a large mass extinction in which many groups, including non-avian dinosaurs, pterosaurs , and large marine reptiles , died out, widely thought to have been caused by

9576-408: The most promising candidates for fixing the Jurassic–Cretaceous boundary. In particular, the first appearance Calpionella alpina , coinciding with the base of the eponymous Alpina subzone, has been proposed as the definition of the base of the Cretaceous. The working definition for the boundary has often been placed as the first appearance of the ammonite Strambergella jacobi , formerly placed in

9690-493: 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. Around 300 million years ago, the sinking suddenly reversed, and the sediment-covered granite began to uplift , giving rise to the Ancestral Rocky Mountains . Over the next 150 million years, during

9804-484: The next 35 million years, the Cretaceous seaway repeatedly widened as far as Utah and Wisconsin and narrowed to near closure. 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

9918-495: The north and east, is the main avenue of transportation to and from the city. The towns immediately adjacent to Casper are Mills , Evansville , and Bar Nunn . Unincorporated areas include Allendale, Dempsey Acres, Red Buttes, Indian Springs, and several others. According to the United States Census Bureau , the city has a total area of 27.24 square miles (70.55 km ), of which 26.90 square miles (69.67 km )

10032-824: The oceans. Extinction was more severe among animals living in the water column than among animals living on or in the seafloor. Animals in the water column are almost entirely dependent on primary production from living phytoplankton, while animals living on or in the ocean floor feed on detritus or can switch to detritus feeding. The largest air-breathing survivors of the event, crocodilians and champsosaurs , were semiaquatic and had access to detritus. Modern crocodilians can live as scavengers and can survive for months without food and go into hibernation when conditions are unfavorable, and their young are small, grow slowly, and feed largely on invertebrates and dead organisms or fragments of organisms for their first few years. These characteristics have been linked to crocodilian survival at

10146-629: The oldest records of Angiosperm macrofossils are Montsechia from the Barremian aged Las Hoyas beds of Spain and Archaefructus from the Barremian-Aptian boundary Yixian Formation in China. Tricolpate pollen distinctive of eudicots first appears in the Late Barremian, while the earliest remains of monocots are known from the Aptian. Flowering plants underwent a rapid radiation beginning during

10260-644: 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. 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. Over

10374-452: The poles. Many of the dominant taxonomic groups present in modern times can be ultimately traced back to origins in the Cretaceous. During this time, new groups of mammals and birds appeared, including the earliest relatives of placentals & marsupials ( Eutheria and Metatheria respectively), and the earliest crown group birds. Acanthomorph fish, the most diverse group of modern vertebrates, appeared in aquatic habitats around

10488-508: The poles. After the end of the first age, however, temperatures began to increase again, with a number of thermal excursions, such as the middle Valanginian Weissert Thermal Excursion (WTX), which was caused by the Paraná-Etendeka Large Igneous Province's activity. It was followed by the middle Hauterivian Faraoni Thermal Excursion (FTX) and the early Barremian Hauptblatterton Thermal Event (HTE). The HTE marked

10602-433: The population were Hispanic or Latino of any race. There were 20,343 households, out of which 31.8% had children under the age of 18 living with them, 49.6% were married couples living together, 11.1% had a female householder with no husband present, and 35.4% were non-families. Of all households 29.1% were made up of individuals, and 10.2% had someone living alone who was 65 years of age or older. The average household size

10716-536: The present-day Front Range was home to ancient mountain ranges, deserts, beaches, and even oceans. The name "Front Range" is also applied to the Front Range urban corridor , the populated region of Colorado and Wyoming just east of the mountain range and extending from Cheyenne, Wyoming south to Pueblo, Colorado . This urban corridor benefits from the weather-moderating effect of the Front Range mountains, which help block prevailing storms. About 1 billion years ago,

10830-412: The principal food of mosasaurs , a group of giant marine lizards related to snakes that became extinct at the boundary. Omnivores , insectivores , and carrion -eaters survived the extinction event, perhaps because of the increased availability of their food sources. At the end of the Cretaceous, there seem to have been no purely herbivorous or carnivorous mammals . Mammals and birds that survived

10944-547: The punctuation mark at the end of a progressive decline in biodiversity during the Maastrichtian age. The result was the extinction of three-quarters of Earth's plant and animal species. The impact created the sharp break known as the K–Pg boundary (formerly known as the K–T boundary). Earth's biodiversity required substantial time to recover from this event, despite the probable existence of an abundance of vacant ecological niches . Despite

11058-744: The rise of angiosperms, during the Jurassic and the Early Cretaceous, the higher flora was dominated by gymnosperm groups, including cycads , conifers , ginkgophytes , gnetophytes and close relatives, as well as the extinct Bennettitales . Other groups of plants included pteridosperms or "seed ferns", a collective term that refers to disparate groups of extinct seed plants with fern-like foliage, including groups such as Corystospermaceae and Caytoniales . The exact origins of angiosperms are uncertain, although molecular evidence suggests that they are not closely related to any living group of gymnosperms. The earliest widely accepted evidence of flowering plants are monosulcate (single-grooved) pollen grains from

11172-522: The roads that run through the Front Range, the Union Pacific Railroad operates two rail lines through the mountains. The first Overland Route , transiting southern Wyoming, runs parallel to I-80 for much of its way. The second is the former Denver & Rio Grande Western Railroad Moffat Route, which runs parallel to the Colorado River and through the 6.5-mile-long Moffat Tunnel . Originally

11286-447: The severity of the K-Pg extinction event, there were significant variations in the rate of extinction between and within different clades . Species that depended on photosynthesis declined or became extinct as atmospheric particles blocked solar energy . As is the case today, photosynthesizing organisms, such as phytoplankton and land plants , formed the primary part of the food chain in

11400-486: 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. 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

11514-422: The strong regionality of most biostratigraphic markers, and the lack of any chemostratigraphic events, such as isotope excursions (large sudden changes in ratios of isotopes ) that could be used to define or correlate a boundary. Calpionellids , an enigmatic group of planktonic protists with urn-shaped calcitic tests briefly abundant during the latest Jurassic to earliest Cretaceous, have been suggested as

11628-611: The terrestrial fauna of the late Cretaceous Hell Creek Formation . Other important Cretaceous exposures occur in Europe (e.g., the Weald ) and China (the Yixian Formation ). In the area that is now India, massive lava beds called the Deccan Traps were erupted in the very late Cretaceous and early Paleocene. Palynological evidence indicates the Cretaceous climate had three broad phases:

11742-650: The three high schools. Casper has a public library , a branch of the Natrona County Public Library System. Casper is served by one print newspaper, the Casper Star-Tribune , a daily, and until recently the Casper Journal , published weekly. Casper is also home to WyoFile, an online publication focusing on state issues and Oil City News, an online news and media site. Casper is served by 30 radio stations on FM and AM . KTWO 1030 AM

11856-483: The trunk having a preserved diameter of 1.8 metres (5.9 ft) and an estimated height of 50 metres (160 ft). During the Cretaceous, ferns in the order Polypodiales , which make up 80% of living fern species, would also begin to diversify. On land, mammals were generally small sized, but a very relevant component of the fauna , with cimolodont multituberculates outnumbering dinosaurs in some sites. Neither true marsupials nor placentals existed until

11970-751: The ultimate end of the Tithonian-early Barremian Cool Interval (TEBCI). During this interval, precession was the dominant orbital driver of environmental changes in the Vocontian Basin. For much of the TEBCI, northern Gondwana experienced a monsoonal climate. A shallow thermocline existed in the mid-latitude Tethys. The TEBCI was followed by the Barremian-Aptian Warm Interval (BAWI). This hot climatic interval coincides with Manihiki and Ontong Java Plateau volcanism and with

12084-400: 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

12198-628: The very end, but a variety of non-marsupial metatherians and non-placental eutherians had already begun to diversify greatly, ranging as carnivores ( Deltatheroida ), aquatic foragers ( Stagodontidae ) and herbivores ( Schowalteria , Zhelestidae ). Various "archaic" groups like eutriconodonts were common in the Early Cretaceous, but by the Late Cretaceous northern mammalian faunas were dominated by multituberculates and therians , with dryolestoids dominating South America . The apex predators were archosaurian reptiles , especially dinosaurs , which were at their most diverse stage. Avians such as

12312-518: The winter and early to mid-spring months, and usually falls in May and October. Precipitation is greatest in spring and early summer, but even then it is not high. Highs reach 90 °F (32.2 °C) on 37.8 days per year and fail to surpass freezing on 41.3. Lows drop to 0 °F (−17.8 °C) on an average of 14.6 nights annually. The highest temperature recorded in Casper was 104 °F (40.0 °C) on July 12, 1954, July 16, 2005, and July 29, 2006, while

12426-523: The years. As recently as the early 1980s, the city was near or home to three refineries. The surviving one, operated by Sinclair Oil Corporation , is located nearby in Evansville. Development of Wyoming coal and uranium fields in recent decades has helped Casper continue its role as a center in the energy industry. Casper Wind Farm began operations near Casper in Natrona County and has 11 turbines with

12540-408: Was 2.38 and the average family size was 2.94. In the city, the population was spread out, with 25.9% under the age of 18, 10.5% from 18 to 24, 27.7% from 25 to 44, 22.3% from 45 to 64, and 13.6% who were 65 years of age or older. The median age was 36 years. For every 100 females, there were 95.0 males. For every 100 females age 18 and over, there were 91.6 males. The median income for a household in

12654-419: Was 92.3% White , 1.0% African American , 0.9% Native American , 0.8% Asian , 2.3% from other races , and 2.6% from two or more races. Hispanic or Latino people of any race were 7.4% of the population. There were 22,794 households, of which 31.5% had children under the age of 18 living with them, 46.1% were married couples living together, 11.2% had a female householder with no husband present, 5.2% had

12768-432: Was a period with a relatively warm climate , resulting in high eustatic sea levels that created numerous shallow inland seas . These oceans and seas were populated with now- extinct marine reptiles , ammonites , and rudists , while dinosaurs continued to dominate on land. The world was largely ice-free, although there is some evidence of brief periods of glaciation during the cooler first half, and forests extended to

12882-630: Was followed by the Aptian-Albian Cold Snap (AACS) that began about 118 Ma. A short, relatively minor ice age may have occurred during this so-called "cold snap", as evidenced by glacial dropstones in the western parts of the Tethys Ocean and the expansion of calcareous nannofossils that dwelt in cold water into lower latitudes. The AACS is associated with an arid period in the Iberian Peninsula . Temperatures increased drastically after

12996-504: Was laid out by the Pioneer Town Site Company in 1888 and was known as Strouds, but the name Casper soon prevailed. While the name is derived from Fort Caspar and Lt. Caspar Collins, it is officially named "Casper" due to a typo occurring during the official registration. Casper was an early commercial rival to both Bessemer and Douglas, Wyoming . The absence of a railhead doomed Bessemer in favor of Casper, while Douglas, also

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