1.
Utah
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Utah is a state in the western United States. It became the 45th state admitted to the U. S. on January 4,1896, Utah is the 13th-largest by area, 31st-most-populous, and 10th-least-densely populated of the 50 United States. Utah has a population of more than 3 million, approximately 80% of whom live along the Wasatch Front, Utah is bordered by Colorado to the east, Wyoming to the northeast, Idaho to the north, Arizona to the south, and Nevada to the west. It also touches a corner of New Mexico in the southeast, approximately 62% of Utahns are reported to be members of The Church of Jesus Christ of Latter-day Saints or LDS, which greatly influences Utahn culture and daily life. The LDS Churchs world headquarters is located in Salt Lake City, Utah is the only state with a majority population belonging to a single church. The state is a center of transportation, education, information technology and research, government services, mining, in 2013, the U. S. Census Bureau estimated that Utah had the second fastest-growing population of any state. St. George was the metropolitan area in the United States from 2000 to 2005. Utah also has the 14th highest median income and the least income inequality of any U. S. state. A2012 Gallup national survey found Utah overall to be the best state to live in based on 13 forward-looking measurements including various economic, lifestyle, the name Utah is derived from the name of the Ute tribe. It means people of the mountains in the Ute language, according to other sources Utah is derived from the Apache name Yudah which means Tall. These Native American tribes are subgroups of the Ute-Aztec Native American ethnicity and were sedentary, the Ancestral Pueblo people built their homes through excavations in mountains, and the Fremont people built houses of straw before disappearing from the region around the 15th century. Another group of Native Americans, the Navajo, settled in the region around the 18th century, in the mid-18th century, other Uto-Aztecan tribes, including the Goshute, the Paiute, the Shoshone, and the Ute people, also settled in the region. These five groups were present when the first European explorers arrived, the southern Utah region was explored by the Spanish in 1540, led by Francisco Vásquez de Coronado, while looking for the legendary Cíbola. A group led by two Catholic priests—sometimes called the Dominguez-Escalante Expedition—left Santa Fe in 1776, hoping to find a route to the coast of California, the expedition traveled as far north as Utah Lake and encountered the native residents. The Spanish made further explorations in the region, but were not interested in colonizing the area because of its desert nature, in 1821, the year Mexico achieved its independence from Spain, the region became known as part of its territory of Alta California. European trappers and fur traders explored some areas of Utah in the early 19th century from Canada, the city of Provo, Utah was named for one, Étienne Provost, who visited the area in 1825. The city of Ogden, Utah was named after Peter Skene Ogden, in late 1824, Jim Bridger became the first known English-speaking person to sight the Great Salt Lake. Due to the salinity of its waters, Bridger thought he had found the Pacific Ocean
2.
United States
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Forty-eight of the fifty states and the federal district are contiguous and located in North America between Canada and Mexico. The state of Alaska is in the northwest corner of North America, bordered by Canada to the east, the state of Hawaii is an archipelago in the mid-Pacific Ocean. The U. S. territories are scattered about the Pacific Ocean, the geography, climate and wildlife of the country are extremely diverse. At 3.8 million square miles and with over 324 million people, the United States is the worlds third- or fourth-largest country by area, third-largest by land area. It is one of the worlds most ethnically diverse and multicultural nations, paleo-Indians migrated from Asia to the North American mainland at least 15,000 years ago. European colonization began in the 16th century, the United States emerged from 13 British colonies along the East Coast. Numerous disputes between Great Britain and the following the Seven Years War led to the American Revolution. On July 4,1776, during the course of the American Revolutionary War, the war ended in 1783 with recognition of the independence of the United States by Great Britain, representing the first successful war of independence against a European power. The current constitution was adopted in 1788, after the Articles of Confederation, the first ten amendments, collectively named the Bill of Rights, were ratified in 1791 and designed to guarantee many fundamental civil liberties. During the second half of the 19th century, the American Civil War led to the end of slavery in the country. By the end of century, the United States extended into the Pacific Ocean. The Spanish–American War and World War I confirmed the status as a global military power. The end of the Cold War and the dissolution of the Soviet Union in 1991 left the United States as the sole superpower. The U. S. is a member of the United Nations, World Bank, International Monetary Fund, Organization of American States. The United States is a developed country, with the worlds largest economy by nominal GDP. It ranks highly in several measures of performance, including average wage, human development, per capita GDP. While the U. S. economy is considered post-industrial, characterized by the dominance of services and knowledge economy, the United States is a prominent political and cultural force internationally, and a leader in scientific research and technological innovations. In 1507, the German cartographer Martin Waldseemüller produced a map on which he named the lands of the Western Hemisphere America after the Italian explorer and cartographer Amerigo Vespucci
3.
Grand Staircase
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Dutton divided this layer cake of Earth history into five steps from the youngest rocks, Pink Cliffs, Grey Cliffs, White Cliffs, Vermilion Cliffs, and Chocolate Cliffs. Since then, modern geologists have further divided Duttons steps into rock formations. The nearly 40 identified rock layers of Grand Canyon form one of the most studied geologic columns in the world, see geology of the Grand Canyon area for details. The oldest exposed formation in Zion National Park is the youngest exposed formation in the Grand Canyon – the ~240‑million-year-old Kaibab Limestone, the Bryce Canyon area to the northeast continues where the Zion area leaves off by presenting Cenozoic-aged rocks that are 100 million years younger. In fact the youngest formation seen in the Zion area is the oldest exposed formation in Bryce Canyon – the Dakota Sandstone, there are, however, shared rock units between all three, creating a super-sequence of formations that geologists call the Grand Staircase. Bryce Canyons formations are the youngest known units in the Grand Staircase, younger rock units, if they ever existed, have been removed by erosion. See geology of the Zion Canyon area and geology of the Bryce Canyon area for details, the major canyons of the region did not start to form until about five to six million years ago when the Gulf of California opened up and thus lowered the rivers base level. In the 1880s, many large dinosaur skeletons were excavated from southern Utah in regions north of the Grand Staircase, following these discoveries there was little interest in further exploration. Southern Utah has continued to reward researchers owing to its sweet spot for exposing fossil remnants for observation and collection at the surface. At locations south, in Arizona, the climate is so dry that erosion is relatively slow, further north, the wetter climates encourage growth of forests, which destroy fossils by the actions of roots and soil bacteria. Geology of the Grand Canyon area Grand Staircase-Escalante National Monument The Salt Lake Tribune, May 21,2006, not found 4/8/08 Grand Staircase-Escalante National Monument Official Website for the Bureau of Land Management Grand Staircase-Escalante National Monument USGS. gov, Photo tour of Grand Staircase
4.
Canyons of the Escalante
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The Canyons of the Escalante is a collective name for the erosional landforms created by the Escalante River and its tributaries—the Escalante River Basin. Located in southern Utah in the western United States, these features include high vertical canyon walls, numerous slot canyons, waterpockets, domes, hoodoos. The headwaters of the Escalante River are located on the slopes of the Aquarius Plateau, in Utahs Garfield County, the Escalante River begins at the confluence of Birch Creek and North Creek, with the flow of Pine Creek added just below the town. The river runs a distance of 80 mi from the Birch/North Creek confluence before emptying into the Colorado River in Kane County. The lower section of the river, southeast of Coyote Gulch, is now beneath the surface of Lake Powell, numerous side canyons also feed the main river, accounting for the large size of the basin. Most of these creeks flow from the top of the Kaiparowits Plateau or from the base of its eastern edge. Streams from the flow from Boulder Mountain, while those from the northeast originate in the Circle Cliffs area. The sandstone layers now exposed in the Canyons of the Escalante were deposited during the Mesozoic era,180 to 225 million years ago, when this area was part of a large area of sand dunes. Near the end of the Cretaceous period, about 80 million years ago, the western section of North America entered an era of uplift and mountain-building. More recently, additional uplift formed the Colorado Plateau province and these episodes of uplift raised the Aquarius Plateau to the extent that there were strong erosional forces acting on the Escalante River Basin. Wetter climates during the recent ice ages of the Pleistocene period contributed to deep cutting of the canyon walls, Sandstone exposed in canyons nearer to the Colorado River are typically from the Glen Canyon Group. The dark red cliffs of Coyote Gulch, for example, are composed of Navajo Sandstone, the lighter sandstone domes of Dance Hall Rock and Sooner Rocks are formed from the higher Entrada sandstone layer. Due to tilting of layers throughout the area, sandstone exposed at higher elevations near the town of Escalante may actually be from a lower layer, Wingate Sandstone. Kelsey, ISBN 0-944510-11-6 Canyons of the Escalante, Trails Illustrated Map, ISBN 0-925873-98-5 Escalante Canyon at Utah. com History of the Escalante area
5.
Grand Staircase-Escalante National Monument
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The Grand Staircase-Escalante National Monument is a U. S. National Monument protecting 1,880,461 acres of land in southern Utah. President Bill Clinton designated the area as a monument in 1996 using his authority under the Antiquities Act. Grand Staircase-Escalante encompasses the largest land area of all U. S. National Monuments, the Monument is managed by the Bureau of Land Management rather than the National Park Service. This was the first National Monument managed by the BLM, visitor centers are located in Cannonville, Big Water, Escalante, and Kanab. The Monument stretches from the towns of Big Water, Glendale and Kanab, Utah on the southwest, to the towns of Escalante, encompassing 1.9 million acres, the Monument is slightly larger in area than the state of Delaware. The western part of the Monument is dominated by the Paunsaugunt Plateau and the Paria River and this section shows the geologic progression of the Grand Staircase. Features include the slot canyons of Bull Valley Gorge, Willis Creek, the center section is dominated by a single long ridge, called Kaiparowits Plateau from the west, and called Fifty-Mile Mountain when viewed from the east. Fifty-Mile Mountain stretches southeast from the town of Escalante to the Colorado River in Glen Canyon, the eastern face of the mountain is a steep,2200 foot escarpment. The western side is a slope descending to the south. East of Fifty-Mile Mountain are the Canyons of the Escalante, the Monument is bounded by Glen Canyon National Recreation Area on the east and south. The popular hiking, backpacking and canyoneering areas include the slot canyons of Peekaboo, Spooky and Brimstone Canyons, the Devils Garden is also located in this area. Access is via the Hole-in-the-Rock Road which extends southeast from the town of Escalante, the road was constructed to facilitate Mormon settlement of southeastern Utah, including the town of Bluff. The road is used by ranchers to access the flat desert at the base of Fifty Mile Mountain for grazing cattle. Since 2000, numerous fossils over 75 million years old have been found at Grand Staircase-Escalante. In 2002, a volunteer at the Monument discovered a 75-million-year-old dinosaur near the Arizona border, on October 3,2007, the dinosaurs name, Gryposaurus monumentensis was announced in the Zoological Journal of the Linnean Society. G. monumentensis was at least 30 feet long and 10 feet tall, many of the specimens from the Kaiparowits Formation are reposited at the Natural History Museum of Utah in Salt Lake City. Two ceratopsid dinosaurs, also discovered at the Monument, were introduced by the Utah Geological Survey in 2007 and they were uncovered in the Wahweap formation, which is just below the Kaiparowits formation where the duckbill was extracted. They lived about 80 million or 81 million years ago, the two fossils are called the Last Chance skull and the Nipple Butte skull
6.
Colorado River
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The Colorado River is one of the principal rivers of the Southwestern United States and northern Mexico. The 1, 450-mile-long Colorado River drains an expansive, arid watershed that encompasses parts of seven U. S. starting in the central Rocky Mountains in the U. S. After entering Mexico, the Colorado approaches the mostly dry Colorado River Delta at the tip of the Gulf of California between Baja California and Sonora. Known for its dramatic canyons, whitewater rapids, and eleven U. S. National Parks, the Colorados large flow and steep gradient are used for generating hydroelectric power, and its major dams regulate peaking power demands in much of the Intermountain West. Intensive water consumption has dried up the lower 100 miles of the river, beginning with small bands of nomadic hunter-gatherers, Native Americans have inhabited the Colorado River basin for at least 8,000 years. Most native peoples that inhabit the basin today are descended from groups that settled in the region beginning about 1,000 years ago. Europeans first entered the Colorado Basin in the 16th century, when explorers from Spain began mapping and claiming the area, early contact between Europeans and Native Americans was generally limited to the fur trade in the headwaters and sporadic trade interactions along the lower river. After most of the Colorado River basin became part of the U. S. in 1846, several expeditions charted the Colorado in the mid-19th century – one of which, led by John Wesley Powell, was the first to run the rapids of the Grand Canyon. American explorers collected valuable information that would later be used to develop the river for navigation, lesser numbers settled in the upper basin, which was the scene of major gold strikes in the 1860s and 1870s. Large engineering works began around the start of the 20th century, with guidelines established in a series of international. The U. S. federal government was the driving force behind the construction of dams and aqueducts in the river system, although many state. Most of the dams in the river basin were built between 1910 and 1970, the system keystone, Hoover Dam, was completed in 1935. The Colorado is now considered among the most controlled and litigated rivers in the world, as demands for Colorado River water continue to rise, the level of human development and control of the river continues to generate controversy. The Colorado begins at La Poudre Pass in the Southern Rocky Mountains of Colorado, after a short run south, the river turns west below Grand Lake, the largest natural lake in the state. As it flows southwest, it gains strength from many tributaries, as well as larger ones including the Blue, Eagle. In a few areas, such as the marshy Kawuneeche Valley near the headwaters, arcing northwest, the Colorado begins to cut across the eponymous Colorado Plateau, a vast area of high desert centered at the Four Corners of the southwestern United States. In Utah, the Colorado flows primarily through the slickrock country and this is one of the most inaccessible regions of the continental United States. Here, the San Juan River, carrying runoff from the slope of Colorados San Juan Mountains, joins the Colorado from the east. S
7.
Lake Powell
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Lake Powell is a reservoir on the Colorado River, straddling the border between Utah and Arizona. It is a vacation spot that around two million people visit every year. It is the second largest man-made reservoir by water capacity in the United States behind Lake Mead. Lake Powell was created by the flooding of Glen Canyon by the Glen Canyon Dam, which led to the creation of Glen Canyon National Recreation Area. The reservoir is named for explorer John Wesley Powell, a one-armed American Civil War veteran who explored the river via three wooden boats in 1869, in 1972, Glen Canyon National Recreation Area was established. It is public land managed by the National Park Service, and it lies in parts of Garfield, Kane, and San Juan counties in southern Utah, and Coconino County in northern Arizona. The northern limits of the lake extend at least as far as the Hite Crossing Bridge, a map centered at the confluence of the Escalante River 37°17′22″N 110°52′20″W with the Colorado River gives a good view of the extent of the lake. Lake Powell is a storage facility for the Upper Basin states of the Colorado River Compact. The Compact specifies that the Upper Basin states are to provide an annual flow of 7,500,000 acre feet to the Lower Basin states. In the 1940s and early 1950s, the U. S. Bureau of Reclamation planned to construct a series of Colorado River dams in the rugged Colorado Plateau province of Colorado, Utah, and Arizona. Glen Canyon Dam was born of a controversial damsite the Bureau selected in Echo Park, by agreeing to a relocated damsite near Lees Ferry between Glen and Grand Canyons, however, Brower did not realize what he had gambled away. At the time, Brower had not actually been to Glen Canyon, when he later saw Glen Canyon on a river trip, Brower discovered that it had the kind of scenic, cultural, and wilderness qualities often associated with Americas national parks. Over 80 side canyons in the colorful Navajo Sandstone contained clear streams, abundant wildlife, arches, natural bridges, by then, however, it was too late to stop the Bureau and its commissioner Floyd Dominy from building Glen Canyon Dam. Brower believed the river should remain free, and would forever after consider the loss of Glen Canyon his lifes ultimate disappointment. Construction on Glen Canyon Dam began with a demolition blast keyed by the push of a button by President Dwight D. Eisenhower at his desk in the Oval Office on October 1,1956, the first blast started clearing tunnels for water diversion. On February 11,1959, water was diverted through the tunnels so dam construction could begin, later that year, the bridge was completed, allowing trucks to deliver equipment and materials for the dam, and also for the new town of Page, Arizona. Concrete placement started around the clock on June 17,1960, the last bucket of concrete was poured on September 13,1963. Over 5 million cubic yards of concrete make up Glen Canyon Dam, the Dam is 710 feet high, with the surface elevation of the water at full pool being approximately 3700 feet
8.
Arizona
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Arizona is a state in the southwestern region of the United States. It is also part of the Western United States and the Mountain West states and it is the sixth largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix, Arizona is one of the Four Corners states. It has borders with New Mexico, Utah, Nevada, California, and Mexico, Arizonas border with Mexico is 389 miles long, on the northern border of the Mexican states of Sonora and Baja California. Arizona is the 48th state and last of the states to be admitted to the Union. Historically part of the territory of Alta California in New Spain, after being defeated in the Mexican–American War, Mexico ceded much of this territory to the United States in 1848. The southernmost portion of the state was acquired in 1853 through the Gadsden Purchase, Southern Arizona is known for its desert climate, with very hot summers and mild winters. There are ski resorts in the areas of Flagstaff, Alpine, in addition to the Grand Canyon National Park, there are several national forests, national parks, and national monuments. To the European settlers, their pronunciation sounded like Arissona, the area is still known as alĭ ṣonak in the Oodham language. Another possible origin is the Basque phrase haritz ona, as there were numerous Basque sheepherders in the area, There is a misconception that the states name originated from the Spanish term Árida Zona. See also lists of counties, islands, rivers, lakes, state parks, national parks, Arizona is in the Southwestern United States as one of the Four Corners states. Arizona is the sixth largest state by area, ranked after New Mexico, of the states 113,998 square miles, approximately 15% is privately owned. The remaining area is public forest and park land, state trust land, Arizona is well known for its desert Basin and Range region in the states southern portions, which is rich in a landscape of xerophyte plants such as the cactus. This regions topography was shaped by volcanism, followed by the cooling-off. Its climate has hot summers and mild winters. The state is well known for its pine-covered north-central portion of the high country of the Colorado Plateau. Like other states of the Southwest United States, Arizona has an abundance of mountains, despite the states aridity, 27% of Arizona is forest, a percentage comparable to modern-day France or Germany. The worlds largest stand of pine trees is in Arizona
9.
Utah State Route 12
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The 30-mile long portion of the highway that ascends and descends Boulder Mountain on the Aquarius Plateau is known as Boulder Mountain Highway. The Average Daily Traffic on SR-12 is at its greatest at its junction with US-89. At its other end, at the junction with SR-24, the bottoms out at 435. The road from Bryce Canyon Junction to Tropic was added to the highway system in 1914. That same year, a new State Route 120 was created, continuing the road from Tropic to Henrieville, another road was also added to the state highway system in 1914, connecting SR-22 at Widtsoe with Escalante, and it was numbered State Route 23 in 1927. An extension took SR-23 northeast to Boulder in 1941, and in 1947 SR-54 absorbed SR-23, with the Widtsoe-Escalante road dropped in favor of Henrieville-Escalante. State Route 117, running southeast from SR-24 near Teasdale to Grover, became a highway in 1931. In 1969, SR-54 became part of SR-12, but most of former SR-117 was dropped, leaving SR-12 to stretch from Bryce Canyon Junction to the limit of Boulder. This spur became a new SR-63 in 1975, and in 1985 the route was extended north from Boulder to SR-24. Paunsaugunt Plateau Map and more from the DOTs American Byways website State of Utahs website for the highway Historic American Engineering Record No. UT-83, Red Canyon Tunnel, Through Rock Fin on State Highway 12,5 miles east of U. S.89, Panguitch, Garfield County, UT,3 photos,1 color transparency,2 photo caption pages HAER No. UT-80, Escalante River Bridge, Spanning Escalante River at State Route 12,9.5 miles East of Escalante, Escalante, Garfield County, UT,11 photos,16 data pages,1 photo caption page
10.
Pinus monophylla
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Pinus monophylla, the single-leaf pinyon, is a pine in the pinyon pine group, native to the United States and northwest Mexico. The range is in southernmost Idaho, western Utah, Arizona, southwest New Mexico, Nevada, eastern and southern California and it occurs at moderate altitudes from 1, 200-metre -2, 300-metre, rarely as low as 950-metre and as high as 2, 900-metre. It is widespread and often abundant in this region, forming open woodlands. Single-leaf Pinyon is the worlds only 1-needled pine, Pinus monophylla is a small to medium size tree, reaching 10-metre -20-metre tall and with a trunk diameter of up to 80-centimetre rarely more. The bark is furrowed and scaly. The leaves are, uniquely for a pine, usually single, stout, 4-centimetre - 6-centimetre long, the cones thus grow over a two-year cycle, so that newer green and older, seed-bearing or open brown cones are on the tree at the same time. The cones open to 6-centimetre - 9-centimetre broad when mature, holding the seeds on the scales after opening, the seeds are 11-millimetre - 16-millimetre long, with a thin shell, a white endosperm, and a vestigial 1-millimetre - 2-millimetre wing. Empty pine nuts with undeveloped seeds are a tan color. The pine nuts are dispersed by the pinyon jay, which plucks the seeds out of the cones, choosing only the dark ones. The jay, which uses the seeds as a food resource, some of these stored seeds are not used and are able to grow into new trees. Indeed, Pinyon seeds will germinate in the wild unless they are cached by jays or other animals. There are three subspecies, Pinus monophylla subsp, most of the range, except for the areas below. Needles more stout, bright blue-green, with 2-7 resin canals, cones are 5. 5-centimetre - 8-centimetre long, often longer than broad. Southernmost Nevada, southwest through southeastern California to 29°N in northern Baja California, needles less stout, gray-green, with 8-16 resin canals and 13-18 stomatal lines. Cones are 4. 5-centimetre - 6-centimetre long, broader than long, slopes of the lower Colorado River valley and adjacent tributaries from St. George, Utah to the Hualapai Mountains, and along the lower flank of the Mogollon Rim to Silver City, New Mexico. Needles less stout, gray-green, with 2-3 resin canals and 8-16 stomatal lines, cones are 4. 5-centimetre - 6-centimetre long, broader than long. It is most closely related to the Colorado pinyon, which hybridises with it occasionally where their ranges meet in western Arizona and it also hybridises extensively with Parry pinyon. Fallax/Pinus edulis zones as growing more single needle fascicles after dry years and they have recently been shown to be a two-needled variant of single-leaf pinyon from chemical and genetic evidence
11.
Juniperus osteosperma
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Juniperus osteosperma is a shrub or small tree reaching 3–6 m tall. It is native to the southwestern United States, in Utah, Nevada, Arizona, western New Mexico, western Colorado, Wyoming, southern Montana, southern Idaho and eastern California. It grows at altitudes of 1, 300–2,600 metres, on dry soils. The shoots are fairly thick compared to most junipers,1. 5–2 mm diameter, the leaves are arranged in opposite decussate pairs or whorls of three, the adult leaves are scale-like, 1–2 mm long and 1–1.5 millimetres broad. The juvenile leaves are needle-like, 5–10 mm long, the cones are berry-like, 8–13 millimetres in diameter, blue-brown with a whitish waxy bloom, and contain a single seed, they are mature in about 18 months. The male cones are 2–4 millimetres long, and shed their pollen in early spring and it is largely monoecious with both sexes on the same plant, but around 10% of plants are dioecious, producing cones of only one sex. Seeds are dispersed by Jackrabbits rodents and to an extent by coyotes. Junipers of the World, The genus Juniperus, trafford Publishing ISBN 1-4120-4250-X J. C. Chambers, S. B. Vander Wall and E. W. Schupp. Seed and seedling ecology of piñon and juniper species in the woodlands of western North America. IUCN Red List of Threatened Species, international Union for Conservation of Nature. Interactive Distribution Map of Juniperus osteosperma
12.
Cretaceous
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The Cretaceous is a geologic period and system that spans 79 million years from the end of the Jurassic Period 145 million years ago to the beginning of the Paleogene Period 66 Mya. It is the last period of the Mesozoic Era, the Cretaceous Period is usually abbreviated K, for its German translation Kreide. The Cretaceous was a period with a 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, during this time, new groups of mammals and birds, as well as flowering plants, appeared. The Cretaceous ended with a mass extinction, the Cretaceous–Paleogene extinction event, in which many groups, including non-avian dinosaurs, pterosaurs. The end of the Cretaceous is defined by the abrupt Cretaceous–Paleogene boundary, the name Cretaceous was derived from Latin creta, meaning chalk. 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, Gallic and Senonian. A subdivision in eleven stages, all originating from European stratigraphy, is now used worldwide, in many parts of the world, alternative local subdivisions are still in use. As with other geologic periods, the rock beds of the Cretaceous are well identified. No great extinction or burst of diversity separates the Cretaceous from the Jurassic and this layer has been dated at 66.043 Ma. A140 Ma age for the Jurassic-Cretaceous boundary instead of the usually accepted 145 Ma was proposed in 2014 based on a study of Vaca Muerta Formation in Neuquén Basin. Víctor Ramos, one of the authors of the study proposing the 140 Ma boundary age sees the study as a first step toward formally changing the age in the International Union of Geological Sciences, due to the high sea level there was extensive space for such sedimentation. Because of the young age and great thickness of the system. Chalk is a type characteristic for the Cretaceous. It consists of coccoliths, microscopically small calcite skeletons of coccolithophores, the group 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 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, the Cretaceous is usually a marine system consisting of competent limestone beds or incompetent marls
