Geochronology is the science of determining the age of rocks and sediments using signatures inherent in the rocks themselves. Absolute geochronology can be accomplished through radioactive isotopes, whereas relative geochronology is provided by such as palaeomagnetism. By combining multiple geochronological indicators the precision of the age can be improved. Biostratigraphy does not directly provide an absolute age determination of a rock, both disciplines work together hand in hand however, to the point where they share the same system of naming rock layers and the time spans utilized to classify layers within a stratum. By measuring the amount of decay of a radioactive isotope with a known half-life. A number of isotopes are used for this purpose. More slowly decaying isotopes are useful for longer periods of time, two or more radiometric methods can be used in concert to achieve more robust results. Some of the commonly used techniques are, Radiocarbon dating and this technique measures the decay of carbon-14 in organic material and can be best applied to samples younger than about 60,000 years.
This technique measures the ratio of two isotopes to the amount of uranium in a mineral or rock. Often applied to the mineral zircon in igneous rocks, this method is one of the two most commonly used for geologic dating. Monazite geochronology is another example of U-Pb dating, employed for dating metamorphism in particular, uranium-lead dating is applied to samples older than about 1 million years. This technique is used to date speleothems, corals and its range is from a few years to about 700,000 years. These techniques date metamorphic and volcanic rocks and they are used to date volcanic ash layers within or overlying paleoanthropologic sites. The younger limit of the method is a few thousand years. Electron spin resonance dating A series of related techniques for determining the age at which a surface was created. Exposure dating uses the concentration of exotic nuclides produced by cosmic rays interacting with Earth materials as a proxy for the age at which a surface, such as an alluvial fan, was created.
Burial dating uses the radioactive decay of 2 cosmogenic elements as a proxy for the age at which a sediment was screened by burial from further cosmic rays exposure. Luminescence dating techniques observe light emitted from such as quartz, feldspar
Ste. Genevieve, Missouri
Genevieve is a city in Ste. Genevieve Township and is the county seat of Ste, the population was 4,410 at the 2010 census. Founded in 1735 by French Canadian colonists and settlers from east of the river, founded around 1812 by Canadien settlers and migrants from settlements in the Illinois Country just east of the Mississippi River, Ste. Geneviève is the oldest permanent European settlement in Missouri and it was named for Saint Genevieve, the patron saint of Paris, the capital of France. While most residents were of French-Canadian descent, many of the families had been in the Illinois Country for two or three generations. It is one of the oldest colonial settlements west of the Mississippi River and this area was known as New France, Illinois Country, or the Upper Louisiana territory. Traditional accounts suggested a founding of 1735 or so, but the historian Carl Ekberg has documented a more likely founding about 1750, the population to the east of the river needed more land, as the soils in the older villages had become exhausted.
Improved relations with hostile Native Americans, such as the Osage, prior to the French Canadian settlers, indigenous peoples known as the Mississippian culture and earlier cultures had been living in the region for more than a thousand years. At the time of settlement, however, no Indian tribe lived nearby on the west bank, jacques-Nicolas Bellins map of 1755, the first to show Ste. Genevieve in the Illinois Country, showed the Kaskaskia natives on the east side of the river, Osage hunting and war parties did enter the area from the north and west. The region had been abandoned by 1500, likely due to environmental exhaustion, after the peak of Mississippian-culture civilization at Cahokia. At the time of its founding, Genevieve was the last of a triad of French Canadian settlements in this area of the mid-Mississippi Valley region. About five miles northeast of Ste, Genevieve on the east side of the river was Fort de Chartres, it stood as the official capital of the area. Kaskaskia, which became Illinois’ first capital upon statehood, was located five miles southeast.
Prairie du Rocher and Cahokia, Illinois were early local French colonial settlements on the east side of the river, the Spanish moved the capital of Upper Louisiana from Fort de Chartres fifty miles upriver to St. Louis. They ruled with a hand and often through mostly French-speaking officials. Although under Spanish control for more than 40 years, Genevieve retained its French language and character. French-speaking people from Canada and settlers east of the Mississippi went west to escape British rule, Genevieve after George III issued the Royal Proclamation of 1763
The basin is elongate, extending approximately 400 miles northwest-southeast, and 200 miles southwest-northeast. The New Madrid Seismic Zone and the Wabash Valley Seismic Zone intersect the southern portion of the basin, the basement rocks deep below the sedimentary rocks of the basin are Proterozoic granites and rhyolite of the Eastern Granite–Rhyolite Province which dates to around 1.55 Ga. The rocks of the Illinois Basin are sources of coal, bituminous coal is present in Pennsylvanian rocks in the basin, deposited in freshwater swamp environments. Over the years, the Illinois Basin has produced more than eight tons of coal in Southern Illinois, particularly in the Harrisburg Coal Field. Coal production was 99 million short tons in 2008, roughly divided between Illinois and western Kentucky. The basin provided 8% of US coal production in 2008, the Illinois Basin has produced more than four billion barrels of petroleum. Major oil production began in 1905, and from 1907 through 1912, oil production peaked in 1908 at 34 million barrels per year, and declined steadily to 5 million barrels in 1933. A new wave of exploration brought oil production to a new high of 140 million barrels in 1940, waterflooding of old reservoirs caused a third peak of oil production in the 1950s.
Much recent drilling activity has targeted shale gas in the Devonian-Mississippian New Albany Shale, within the basin, deposits valuable for lead, coal balls and fluorite are mined in Hardin and Pope counties and Crittenden and Livingston counties, Kentucky. The deposits are in the form of veins and limestone replacement deposits in Mississippian sedimentary rocks, ore minerals are fluorite and sphalerite. Gangue minerals include common quartz and calcite, and minor barite and chalcopyrite, in 2009, Archer Daniels Midland Corp. began pilot testing the carbon sequestration potential of the Mt. Simon formation beneath its ethanol manufacturing facility in Illinois. As of January 2015, one million tons of carbon dioxide had been sequestered in the Illinois Basin-Decatur Project. GA Mansoori, N Enayati, LB Agyarko, Sources, Legislation, Illinois as Model State, World Sci
Kentucky, officially the Commonwealth of Kentucky, is a state located in the east south-central region of the United States. Kentucky is one of four U. S. states constituted as a commonwealth, originally a part of Virginia, in 1792 Kentucky became the 15th state to join the Union. Kentucky is the 37th most extensive and the 26th most populous of the 50 United States, Kentucky is known as the Bluegrass State, a nickname based on the bluegrass found in many of its pastures due to the fertile soil. One of the regions in Kentucky is the Bluegrass Region in central Kentucky. In 1776, the counties of Virginia beyond the Appalachian Mountains became known as Kentucky County, the precise etymology of the name is uncertain, but likely based on an Iroquoian name meaning the meadow or the prairie. Kentucky is situated in the Upland South, a significant portion of eastern Kentucky is part of Appalachia. Kentucky borders seven states, from the Midwest and the Southeast, West Virginia lies to the east, Virginia to the southeast, Tennessee to the south, Missouri to the west and Indiana to the northwest, and Ohio to the north and northeast.
Only Missouri and Tennessee, both of which border eight states, touch more, Kentuckys northern border is formed by the Ohio River and its western border by the Mississippi River. The official state borders are based on the courses of the rivers as they existed when Kentucky became a state in 1792, for instance, northbound travelers on U. S.41 from Henderson, after crossing the Ohio River, will be in Kentucky for about two miles. Ellis Park, a racetrack, is located in this small piece of Kentucky. Waterworks Road is part of the land border between Indiana and Kentucky. Kentucky has a part known as Kentucky Bend, at the far west corner of the state. It exists as an exclave surrounded completely by Missouri and Tennessee, Road access to this small part of Kentucky on the Mississippi River requires a trip through Tennessee. The epicenter of the powerful 1811–12 New Madrid earthquakes was near this area, much of the outer Bluegrass is in the Eden Shale Hills area, made up of short and very narrow hills.
The Jackson Purchase and western Pennyrile are home to several bald cypress/tupelo swamps, located within the southeastern interior portion of North America, Kentucky has a climate that can best be described as a humid subtropical climate. Temperatures in Kentucky usually range from daytime summer highs of 87 °F to the low of 23 °F. The average precipitation is 46 inches a year, Kentucky experiences four distinct seasons, with substantial variations in the severity of summer and winter. The highest recorded temperature was 114 °F at Greensburg on July 28,1930 while the lowest recorded temperature was −37 °F at Shelbyville on January 19,1994, due to its location, Kentucky has a moderate humid subtropical climate, with abundant rainfall
A formation or geological formation is the fundamental unit of lithostratigraphy. A formation consists of a number of rock strata that have a comparable lithology. Formations are not defined on the thickness of the strata they consist of. The concept of formally defined layers or strata is central to the discipline of stratigraphy. Formations can be divided into members and are themselves frequently parcelled together in groups, the definition and recognition of formations allow geologists to correlate geologic strata across wide distances between outcrops and exposures of rock strata. Formations were initially described to be the essential geologic time markers based on relative ages, the divisions of the geological time scale were the formations described and put in chronological order by the geologists and stratigraphers of the 18th and 19th centuries. Geologic formations are sedimentary rock layers, but may be metamorphic rocks. Igneous intrusive rocks are not divided into formations. Formations are the only formal lithostratigraphic units into which the stratigraphic column everywhere should be divided completely on the basis of lithology, Formations must be able to be delineated at the scale of geologic mapping practiced in the region.
The thickness of formations may range from less than a meter to several thousand meters, geologic formations are typically named for the geographic area in which they were first described. Strictly, formations cannot be defined on any other criteria except primary lithology, sequence stratigraphy is a concept which challenges the idea of strict lithostratigraphic units by defining units based on events in sedimentary basins such as oceanic regressions and transgressions. The term formation is used informally to refer to a specific grouping of rocks. Formation is used informally to describe the sometimes odd shapes that rocks acquire through erosional or depositional processes, such a formation is said to be abandoned when it is no longer affected by the geologic agent that produced it. Some well known cave formations include stalactites and stalagmites, geochronology List of Rock Formations List of Chinese geological formations List of fossil sites
The Mesozoic Era is an interval of geological time from about 252 to 66 million years ago. This Era is called from a paleobotanist view the Age of Conifers, Mesozoic means middle life, deriving from the Greek prefix meso-/μεσο- for between and zōon/ζῷον meaning animal or living being. It is one of three eras of the Phanerozoic Eon, preceded by the Paleozoic and succeeded by the Cenozoic. The era is subdivided into three periods, the Triassic and Cretaceous, which are further subdivided into a number of epochs. The Mesozoic was a time of significant tectonic and evolutionary activity, the era witnessed the gradual rifting of the supercontinent Pangaea into separate landmasses that would eventually move into their current positions. The climate of the Mesozoic was varied, alternating between warming and cooling periods, however, the Earth was hotter than it is today. Birds first appeared in the Jurassic, having evolved from a branch of theropod dinosaurs, the first mammals appeared during the Mesozoic, but would remain small—less than 15 kg —until the Cenozoic.
Following the Paleozoic, the Mesozoic extended roughly 186 million years and this time frame is separated into three geologic periods. It is known as the Great Dying because it is considered the largest mass extinction in the Earths history, the upper boundary of the Mesozoic is set at the Cretaceous–Paleogene extinction event, which may have been caused by the impactor that created Chicxulub Crater on the Yucatán Peninsula. Towards the Late Cretaceous large volcanic eruptions are believed to have contributed to the Cretaceous–Paleogene extinction event. Approximately 50% of all genera became extinct, including all of the non-avian dinosaurs, the Triassic ranges roughly from 252 million to 201 million years ago. The Triassic is a time in Earths history bracketed between the Permian Extinction and the Triassic–Jurassic extinction event, two of the big five, and precedes the Jurassic Period and it has three major epochs, the Early Triassic, the Middle Triassic and the Late Triassic. The Early Triassic was between about 252 million to 247 million years ago and was dominated by deserts as Pangaea had not yet broken up, thus the interior was nothing, the Earth had just witnessed a massive die-off in which 95% of all life became extinct.
The most common life on earth were Lystrosaurus, labyrinthodonts. Temnospondyls evolved during this time and would be the dominant predator for much of the Triassic, the Middle Triassic spans roughly from 247 million to 237 million years ago. The Middle Triassic featured the beginnings of the breakup of Pangaea, the ecosystem had recovered from the devastation that was the Great Dying. Algae, sponge and crustaceans all had recovered, new aquatic reptiles evolved, such as ichthyosaurs and nothosaurs. Meanwhile, on land, pine forests flourished, as did groups of insects like mosquitoes, the first ancient crocodilians evolved, which sparked competition with the large amphibians that had since ruled the freshwater world
The Paleocene or Palaeocene, the old recent, is a geologic epoch that lasted from about 66 to 56 million years ago. It is the first epoch of the Paleogene Period in the modern Cenozoic Era, as with many geologic periods, the strata that define the epochs beginning and end are well identified, but the exact ages remain uncertain. The Paleocene Epoch brackets two major events in Earths history and it started with the mass extinction event at the end of the Cretaceous, known as the Cretaceous–Paleogene boundary. This was a marked by the demise of non-avian dinosaurs, giant marine reptiles and much other fauna. The die-off of the dinosaurs left unfilled ecological niches worldwide, the Paleocene ended with the Paleocene–Eocene Thermal Maximum, a geologically brief interval characterized by extreme changes in climate and carbon cycling. The name Paleocene comes from Ancient Greek and refers to the old new fauna that arose during the epoch. The K–Pg boundary that marks the separation between Cretaceous and Paleocene is visible in the record of much of the Earth by a discontinuity in the fossil fauna.
There is evidence of abrupt changes in flora and fauna. There is some evidence that a substantial but very short-lived climatic change may have happened in the early decades of the Paleocene. The end of the Paleocene was marked by a time of major change, the Paleocene–Eocene Thermal Maximum upset oceanic and atmospheric circulation and led to the extinction of numerous deep-sea benthic foraminifera and a major turnover in mammals on land. The Paleocene is divided into three stages, the Danian, the Selandian and the Thanetian, as shown in the table above, the Paleocene is divided into six Mammal Paleogene zones. The early Paleocene was cooler and dryer than the preceding Cretaceous, in many ways, the Paleocene continued processes that had begun during the late Cretaceous Period. During the Paleocene, the continued to drift toward their present positions. The Laramide orogeny of the late Cretaceous continued to uplift the Rocky Mountains in the American west, africa was heading north towards Europe, slowly closing the Tethys Ocean, and India began its migration to Asia that would lead to a tectonic collision and the formation of the Himalayas.
The inland seas in North America and Europe had receded by the beginning of the Paleocene, making way for new land-based flora, warm seas circulated throughout the world, including the poles. The earliest Paleocene featured a low diversity and abundance of marine life, tropical conditions gave rise to abundant marine life, including coral reefs. With the demise of marine reptiles at the end of the Cretaceous, at the end of the Cretaceous, the ammonites and many species of foraminifera became extinct. Marine fauna came to resemble modern fauna, with only the marine mammals, terrestrial Paleocene strata immediately overlying the K–Pg boundary is in places marked by a fern spike, a bed especially rich in fern fossils
Sandstone is a clastic sedimentary rock composed mainly of sand-sized minerals or rock grains. Most sandstone is composed of quartz or feldspar because these are the most common minerals in the Earths crust, like sand, sandstone may be any color, but the most common colors are tan, yellow, grey, pink and black. Since sandstone beds often form highly visible cliffs and other topographic features, quartz-bearing sandstone is converted into quartzite through heating and pressure, usually related to tectonic compression within orogenic belts. They are formed from cemented grains that may either be fragments of a rock or be mono-minerallic crystals. The cements binding these grains together are typically calcite, grain sizes in sands are defined within the range of 0.0625 mm to 2 mm. The formation of sandstone involves two principal stages, first, a layer or layers of sand accumulates as the result of sedimentation, either from water or from air. Typically, sedimentation occurs by the settling out from suspension.
The most common cementing materials are silica and calcium carbonate, which are derived either from dissolution or from alteration of the sand after it was buried. Colours will usually be tan or yellow, a predominant additional colourant in the southwestern United States is iron oxide, which imparts reddish tints ranging from pink to dark red, with additional manganese imparting a purplish hue. Red sandstones are seen in the Southwest and West of Britain, as well as central Europe. The regularity of the latter favours use as a source for masonry, either as a building material or as a facing stone. These physical properties allow the grains to survive multiple recycling events. Quartz grains evolve from rock, which are felsic in origin. Feldspathic framework grains are commonly the second most abundant mineral in sandstones, Feldspar can be divided into two smaller subdivisions, alkali feldspars and plagioclase feldspars. The different types of feldspar can be distinguished under a petrographic microscope, below is a description of the different types of feldspar.
Alkali feldspar is a group of minerals in which the composition of the mineral can range from KAlSi3O8 to NaAlSi3O8. Plagioclase feldspar is a group of solid solution minerals that range in composition from NaAlSi3O8 to CaAl2Si2O8. Lithic framework grains are pieces of ancient source rock that have yet to weather away to individual mineral grains, accessory minerals are all other mineral grains in a sandstone, commonly these minerals make up just a small percentage of the grains in a sandstone
Indiana /ɪndiˈænə/ is a U. S. state located in the midwestern and Great Lakes regions of North America. Indiana is the 38th largest by area and the 16th most populous of the 50 United States and its capital and largest city is Indianapolis. Indiana was admitted to the United States as the 19th U. S. state on December 11,1816, before becoming a territory, varying cultures of indigenous peoples and historic Native Americans inhabited Indiana for thousands of years. Indiana has an economy with a gross state product of $298 billion in 2012. Indiana has several areas with populations greater than 100,000. The states name means Land of the Indians, or simply Indian Land and it stems from Indianas territorial history. On May 7,1800, the United States Congress passed legislation to divide the Northwest Territory into two areas and named the section the Indiana Territory. In 1816, when Congress passed an Enabling Act to begin the process of establishing statehood for Indiana, a resident of Indiana is officially known as a Hoosier.
The first inhabitants in what is now Indiana were the Paleo-Indians, divided into small groups, the Paleo-Indians were nomads who hunted large game such as mastodons. They created stone tools made out of chert by chipping and flaking, the Archaic period, which began between 5000 and 4000 BC, covered the next phase of indigenous culture. The people developed new tools as well as techniques to cook food, such new tools included different types of spear points and knives, with various forms of notches. They made ground-stone tools such as axes, woodworking tools. During the latter part of the period, they built mounds and middens. The Archaic period ended at about 1500 BC, although some Archaic people lived until 700 BC, the Woodland period took place in Indiana, where various new cultural attributes appeared. During this period, the people created ceramics and pottery, an early Woodland period group named the Adena people had elegant burial rituals, featuring log tombs beneath earth mounds. In the middle portion of the Woodland period, the Hopewell people began developing long-range trade of goods, nearing the end of the stage, the people developed highly productive cultivation and adaptation of agriculture, growing such crops as corn and squash.
The Woodland period ended around 1000 AD, the Mississippian culture emerged, lasting from 1000 until the 15th century, shortly before the arrival of Europeans. During this stage, the people created large urban settlements designed according to their cosmology, with mounds and plazas defining ceremonial
The Carboniferous is a geologic period and system that spans 60 million years from the end of the Devonian Period 358.9 million years ago, to the beginning of the Permian Period,298.9 Mya. The name Carboniferous means coal-bearing and derives from the Latin words carbō and ferō, and was coined by geologists William Conybeare and William Phillips in 1822. Based on a study of the British rock succession, it was the first of the system names to be employed. The Carboniferous is often treated in North America as two periods, the earlier Mississippian and the Pennsylvanian. Terrestrial life was established by the Carboniferous period. Amphibians were the dominant land vertebrates, of one branch would eventually evolve into amniotes. Arthropods were common, and many were much larger than those of today. Vast swaths of forest covered the land, which would eventually be laid down, the atmospheric content of oxygen reached their highest levels in geological history during the period, 35% compared with 21% today, allowing terrestrial invertebrates to evolve to great size.
A major marine and terrestrial extinction event, the Carboniferous rainforest collapse, occurred in the middle of the period, the half of the period experienced glaciations, low sea level, and mountain building as the continents collided to form Pangaea. In the United States the Carboniferous is usually broken into Mississippian and Pennsylvanian subperiods, the Silesian is roughly contemporaneous with the late Mississippian Serpukhovian plus the Pennsylvanian. In Britain the Dinantian is traditionally known as the Carboniferous Limestone, the Namurian as the Millstone Grit, and the Westphalian as the Coal Measures and Pennant Sandstone. There was a drop in south polar temperatures, southern Gondwanaland was glaciated throughout the period and these conditions apparently had little effect in the deep tropics, where lush swamps, to become coal, flourished to within 30 degrees of the northernmost glaciers. Mid-Carboniferous, a drop in sea level precipitated a major extinction, one that hit crinoids.
This sea level drop and the unconformity in North America separate the Mississippian subperiod from the Pennsylvanian subperiod. This happened about 323 million years ago, at the onset of the Permo-Carboniferous Glaciation, the Carboniferous was a time of active mountain-building, as the supercontinent Pangaea came together. The southern continents remained tied together in the supercontinent Gondwana, which collided with North America–Europe along the present line of eastern North America, in the same time frame, much of present eastern Eurasian plate welded itself to Europe along the line of the Ural mountains. Most of the Mesozoic supercontinent of Pangea was now assembled, although North China, the Late Carboniferous Pangaea was shaped like an O. There were two major oceans in the Carboniferous—Panthalassa and Paleo-Tethys, which was inside the O in the Carboniferous Pangaea, other minor oceans were shrinking and eventually closed - Rheic Ocean, the small, shallow Ural Ocean and Proto-Tethys Ocean
The Campanian is, in the ICS geologic timescale, the fifth of six ages of the Late Cretaceous epoch. The Campanian spans the time from 83.6 ±0.7 Ma to 72.1 ±0.6 Ma and it is preceded by the Santonian and it is followed by the Maastrichtian. The Campanian was introduced in literature by Henri Coquand in 1857. It is named after the French village of Champagne in the département Charente-Maritime, the original type locality was an outcrop near the village of Aubeterre-sur-Dronne in the same region. Due to changes of the definitions, this section is now part of the Maastrichtian stage. The base of the Campanian stage is laid at the extinction of crinoid species Marsupites testudinarius, a GSSP had not yet been ratified in 2009. One possible candidate is in a section near a dam at Waxahachie, the top of the Campanian is defined as the place in the stratigraphic column were the ammonite Pachydiscus neubergicus first appears. The Campanian is sometimes subdivided into Lower and Upper subages, in the Tethys domain, the Campanian encompasses six ammonite biozones.
In North America, for example, the number of dinosaur genera rises from 4 at the base of the Campanian to 48 in the upper part. This development is referred to as the Campanian Explosion. However, it is not yet if the event is artificial. The generally warm climates and large area covered in shallow sea during the Campanian probably favoured the dinosaurs. In the following Maastrichtian stage, the number of North American dinosaur genera found is 30% less than in the upper Campanian, & Smith, A. G.2004, A Geologic Time Scale 2004, Cambridge University Press. Late Cretaceous oviraptorosaur dinosaurs from Montana, pp. 42–57 in D. H. Tanke and K. Carpenter, Mesozoic Vertebrate Life. Le Loueff, J. Xu, X. Zhao, X. Sahni, A. Gomani,2004, Dinosaur distribution, in, Weishampel, D. B. The Dinosauria, University of California Press, Berkeley, ISBN 0-520-24209-2, pp 517–606