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Paria Canyon-Vermilion Cliffs Wilderness
The Paria Canyon-Vermilion Cliffs Wilderness is a National Wilderness Preservation System, wilderness area located in northern Arizona and southern Utah, United States, within the arid Colorado Plateau region. The wilderness is composed of broad plateaus, tall escarpments, and deep canyons. The Paria River flows through the wilderness before joining the Colorado River at Lee's Ferry, Arizona. The U.S. Congress designated the wilderness area in 1984 and it was largely incorporated into the new Vermilion Cliffs National Monument proclaimed in 2000 by Executive order (United States), executive order of President of the United States, President Bill Clinton. Both the wilderness area and the U.S. National Monument, National Monument are administered by the federal Bureau of Land Management. The Colorado Plateau and its river basins are of immense value in the Earth sciences, specifically chronostratigraphy, as the region contains multiple terrain features exposing Law of Superposi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coconino County, Arizona
Coconino County is a County (United States), county in the North Central Arizona, North-Central part of the U.S. state of Arizona. Its population was 145,101 at the 2020 United States census, 2020 census. The county seat is Flagstaff, Arizona, Flagstaff. The county takes its name from ''Cohonino'', a name applied to the Havasupai people. It is the List of the largest counties in the United States by area, second-largest county by area in the contiguous United States, behind San Bernardino County, California. It has , or 16.4% of Arizona's total area, and is larger than the nine smallest states in the U.S. Coconino County comprises the Flagstaff metropolitan statistical area, Grand Canyon National Park, the federally recognized Havasupai Nation, and parts of the federally recognized Navajo Nation, Navajo, Hualapai, and Hopi nations. As a result, its relatively large Native Americans in the United States, Native American population makes up nearly 30% of the county's total popu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
President Of The United States
The president of the United States (POTUS) is the head of state and head of government of the United States. The president directs the Federal government of the United States#Executive branch, executive branch of the Federal government of the United States, federal government and is the Powers of the president of the United States#Commander-in-chief, commander-in-chief of the United States Armed Forces. The power of the presidency has grown since the first president, George Washington, took office in 1789. While presidential power has ebbed and flowed over time, the presidency has played an increasing role in American political life since the beginning of the 20th century, carrying over into the 21st century with some expansions during the presidencies of Presidency of Franklin D. Roosevelt, Franklin D. Roosevelt and Presidency of George W. Bush, George W. Bush. In modern times, the president is one of the world's most powerful political figures and the leader of the world's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bighorn Sheep
The bighorn sheep (''Ovis canadensis'') is a species of Ovis, sheep native to North America. It is named for its large Horn (anatomy), horns. A pair of horns may weigh up to ; the sheep typically weigh up to . Recent genetic testing indicates three distinct subspecies of ''Ovis canadensis'', one of which is endangered: Sierra Nevada bighorn sheep, ''O. c. sierrae''. Sheep originally crossed to North America over the Beringia, Bering Land Bridge from Siberia; the population in North America peaked in the millions, and the bighorn sheep entered into the mythology of Indigenous peoples of the Americas, Native Americans. By 1900, the population had crashed to several thousand due to diseases introduced through European livestock and overhunting. Taxonomy and genetics ''Ovis canadensis'' is one of two species of mountain Ovis, sheep in North America; the other species being ''O. dalli'', the Dall sheep. Wild sheep crossed the Bering land bridge from Siberia into Alaska during the Pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancestral Puebloan
The Ancestral Puebloans, also known as Ancestral Pueblo peoples or the Basketmaker-Pueblo culture, were an ancient Native American culture of Pueblo peoples spanning the present-day Four Corners region of the United States, comprising southeastern Utah, northeastern Arizona, northwestern New Mexico, and southwestern Colorado. They are believed to have developed, at least in part, from the Oshara tradition, which developed from the Picosa culture. The Ancestral Puebloans lived in a range of structures that included small family pit houses, larger structures to house clans, grand pueblos, and cliff-sited dwellings for defense. They had a complex network linking hundreds of communities and population centers across the Colorado Plateau. They held a distinct knowledge of celestial sciences that found form in their architecture. The kiva, a congregational space that was used mostly for ceremonies, was an integral part of the community structure. Archaeologists continue to d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petroglyphs
A petroglyph is an image created by removing part of a rock surface by incising, picking, carving, or abrading, as a form of rock art. Outside North America, scholars often use terms such as "carving", "engraving", or other descriptions of the technique to refer to such images. Petroglyphs, estimated to be 20,000 years old are classified as protected monuments and have been added to the tentative list of UNESCO's World Heritage Sites. Petroglyphs are found worldwide, and are often associated with prehistoric peoples. The word comes from the Greek prefix , from meaning "stone", and meaning "carve", and was originally coined in French as . In scholarly texts, a ''petroglyph'' is a rock engraving, whereas a '' petrograph'' (or ''pictograph'') is a rock painting. In common usage, the words are sometimes used interchangeably. Both types of image belong to the wider and more general category of rock art or parietal art. Petroforms, or patterns and shapes made by many large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologic Record
The geologic record in stratigraphy, paleontology and other natural sciences refers to the entirety of the layers of rock strata. That is, deposits laid down by volcanism or by deposition of sediment derived from weathering detritus (clays, sands etc.). This includes all its fossil content and the information it yields about the history of the Earth: its past climate, geography, geology and the evolution of life on its surface. According to the law of superposition, sedimentary and volcanic rock layers are deposited on top of each other. They harden over time to become a solidified ( competent) rock column, that may be intruded by igneous rocks and disrupted by tectonic events. Correlating the rock record At a certain locality on the Earth's surface, the rock column provides a cross section of the natural history in the area during the time covered by the age of the rocks. This is sometimes called the ''rock history'' and gives a window into the natural history of the locatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratum
In geology and related fields, a stratum (: strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as either '' bedding surfaces'' or ''bedding planes''.Salvador, A. ed., 1994. ''International stratigraphic guide: a guide to stratigraphic classification, terminology, and procedure. 2nd ed.'' Boulder, Colorado, The Geological Society of America, Inc., 215 pp. . Prior to the publication of the International Stratigraphic Guide, older publications have defined a stratum as being either equivalent to a single bed or composed of a number of beds; as a layer greater than 1 cm in thickness and constituting a part of a bed; or a general term that includes both ''bed'' and '' lamina''.Neuendorf, K.K.E., Mehl, Jr., J.P., and Jackson, J.A. , eds., 2005. ''Glossary of Geology'' 5th ed. Alexandria, Virginia, American Geological Institute. 779 pp. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleobiology
Paleobiology (or palaeobiology) is an interdisciplinary field that combines the methods and findings found in both the earth sciences and the life sciences. An investigator in this field is known as a paleobiologist. Paleobiology is closely related to the field of paleontology, although the latter focuses primarily on the study and taxonomic classification of fossil records, while paleobiology incorporates a broader ecological, evolutionary and geological perspectives of the history of life on Earth. It is also not to be confused with geobiology, which focuses more on the contemporary interactions between the modern biosphere and the physical Earth. Paleobiological research uses biological field research of current biota and of fossil evidence millions of years old to draw parallel and answer questions about the molecular evolution and the evolutionary history of life. In this scientific quest, macrofossils, microfossils and trace fossils are typically analyzed. H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologist
A geologist is a scientist who studies the structure, composition, and History of Earth, history of Earth. Geologists incorporate techniques from physics, chemistry, biology, mathematics, and geography to perform research in the Field research, field and the laboratory. Geologists work in the Energy industry, energy and mining sectors to exploit Natural resource, natural resources. They monitor environmental hazards such as earthquakes, volcanoes, tsunamis and landslides. Geologists are also important contributors to climate change discussions. History James Hutton is often viewed as the first modern geologist. In 1785 he presented a paper entitled ''Theory of the Earth'' to the Royal Society of Edinburgh. In his paper, he explained his theory that the Earth must be much older than had previously been supposed to allow enough time for mountains to be eroded and for sediments to form new rocks at the bottom of the sea, which in turn were raised up to become dry land. Hutton pub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologic Time Scale
The geologic time scale or geological time scale (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronology (a scientific branch of geology that aims to determine the age of rocks). It is used primarily by Earth scientists (including geologists, paleontologists, geophysicists, geochemists, and paleoclimatologists) to describe the timing and relationships of events in geologic history. The time scale has been developed through the study of rock layers and the observation of their relationships and identifying features such as lithologies, paleomagnetic properties, and fossils. The definition of standardised international units of geological time is the responsibility of the International Commission on Stratigraphy (ICS), a constituent body of the International Union of Geological Sciences (IUGS), whose primary objective is to preci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Law Of Superposition
The law of superposition is an axiom that forms one of the bases of the sciences of geology, archaeology, and other fields pertaining to geological stratigraphy. In its plainest form, it states that in undeformed stratigraphic sequences, the oldest strata will lie at the bottom of the sequence, while newer material stacks upon the surface to form new deposits over time. This is paramount to stratigraphic dating, which requires a set of assumptions, including that the law of superposition holds true and that an object cannot be older than the materials of which it is composed. To illustrate the practical applications of superposition in scientific inquiry, sedimentary rock that has not been deformed by more than 90° will exhibit the oldest layers on the bottom, thus enabling paleontologists and paleobotanists to identify the relative ages of any fossils found within the strata, with the remains of the most archaic lifeforms confined to the lowest. These findings can inform t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terrain Feature
A landform is a land feature on the solid surface of the Earth or other planetary body. They may be natural or may be anthropogenic (caused or influenced by human activity). Landforms together make up a given terrain, and their arrangement in the landscape is known as topography. Landforms include hills, mountains, canyons, and valleys, as well as shoreline features such as bays, peninsulas, and seas, including submerged features such as mid-ocean ridges, volcanoes, and the great oceanic basins. Physical characteristics Landforms are categorized by characteristic physical attributes such as elevation, slope, orientation, structure stratification, rock exposure, and soil type. Gross physical features or landforms include intuitive elements such as berms, cliffs, hills, mounds, peninsulas, ridges, rivers, valleys, volcanoes, and numerous other structural and size-scaled (e.g. ponds vs. lakes, hills vs. mountains) elements including various kinds of inland and oceanic waterbodi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
