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73-754: Loves Park is a city in Boone and Winnebago counties in the U.S. state of Illinois . Most of the city is in Winnebago County, with a tiny sliver in the east located in Boone County. The population was 23,397 at the 2020 census. Loves Park is part of the Rockford Metropolitan Statistical Area . Malcolm Love, an industrialist in Rockford, Illinois , purchased 236 acres of land in this area in 1901 and set up

146-600: A dense rock equivalent volume of as much as 1,140 cubic kilometres (270 cu mi). Remarkably, this appears to have had little impact on life. There was vigorous tectonic activity along northwest margin of Gondwana during the Floian, 478 Ma, recorded in the Central Iberian Zone of Spain. The activity reached as far as Turkey by the end of Ordovician. The opposite margin of Gondwana, in Australia, faced

219-603: A biogeographic affinity with Gondwana, and the Alborz margin of Gondwana was linked biogeographically to South China. Southeast Asia's fauna also maintained strong affinities to Gondwana's. North China was biogeographically connected to Laurentia and the Argentinian margin of Gondwana. A Celtic biogeographic province also existed, separate from the Laurentian and Baltican ones. However, tropical articulate brachiopods had

292-468: A burst of volcanic activity that deposited new silicate rocks, which draw CO 2 out of the air as they erode. Another possibility is that bryophytes and lichens, which colonized land in the middle to late Ordovician, may have increased weathering enough to draw down CO 2 levels. The drop in CO 2 selectively affected the shallow seas where most organisms lived. It has also been suggested that shielding of

365-590: A deep embayment between Siberia and the Central Mongolian terranes . Most of the terranes of central Asia were part of an equatorial archipelago whose geometry is poorly constrained by the available evidence. The period was one of extensive, widespread tectonism and volcanism. However, orogenesis (mountain-building) was not primarily due to continent-continent collisions. Instead, mountains arose along active continental margins during accretion of arc terranes or ribbon microcontinents. Accretion of new crust

438-639: A dispute between followers of Adam Sedgwick and Roderick Murchison , who were placing the same rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it

511-607: A distinct band around the Earth, and that the breakup of the parent body may have formed a ring system for a period of about 40 million years, with frequent falling debris causing these craters. The Ordovician was a time of calcite sea geochemistry in which low-magnesium calcite was the primary inorganic marine precipitate of calcium carbonate . Carbonate hardgrounds were thus very common, along with calcitic ooids , calcitic cements, and invertebrate faunas with dominantly calcitic skeletons. Biogenic aragonite , like that composing

584-466: A female householder with no husband present, and 27.8% were non-families . 23.3% of all households were made up of individuals, and 13.0% had someone living alone who was 65 years of age or older. The average household size was 2.82 and the average family size was 3.33. The county's age distribution consisted of 24.7% under the age of 18, 9.4% from 18 to 24, 23.1% from 25 to 44, 27.1% from 45 to 64, and 15.6% who were 65 years of age or older. The median age

657-549: A gathering place that came to be known as Love's Park. The city of Loves Park was incorporated in 1947 . When the city's economy was negatively affected by the early 1980s recession , City Hall was moved from the Grand Avenue fire station into the Marshall Middle School to save money. In 2001, Danfoss moved their plant from Rockford to Loves Park, becoming one of the town's largest employers. Loves Park

730-464: A given landmass were severely affected. Tropical lifeforms were hit particularly hard in the first wave of extinction, while cool-water species were hit worst in the second pulse. Those species able to adapt to the changing conditions survived to fill the ecological niches left by the extinctions. For example, there is evidence the oceans became more deeply oxygenated during the glaciation, allowing unusual benthic organisms (Hirnantian fauna) to colonize

803-693: A more cosmopolitan distribution , with less diversity on different continents. During the Middle Ordovician, beta diversity began a significant decline as marine taxa began to disperse widely across space. Faunas become less provincial later in the Ordovician, partly due to the narrowing of the Iapetus Ocean, though they were still distinguishable into the late Ordovician. Trilobites in particular were rich and diverse, and experienced rapid diversification in many regions. Trilobites in

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876-728: A period known as the Ordovician meteor event . It has been theorized that this increase in impacts may originate from a ring system that formed around Earth at the time. In 2008, the ICS erected a formal international system of subdivisions for the Ordovician Period and System. Pre-existing Baltoscandic, British, Siberian, North American, Australian, Chinese, Mediterranean and North- Gondwanan regional stratigraphic schemes are also used locally. The Ordovician Period in Britain

949-674: A record high of 109 °F (43 °C) was recorded in July 1936. Average monthly precipitation ranged from 1.29 inches (33 mm) in February to 4.56 inches (116 mm) in June. As of the 2020 United States Census , there were 53,448 people, 18,799 households, and 13,580 families residing in the county. The population density was 189.5 inhabitants per square mile (73.2/km ). There were 20,157 housing units at an average density of 71.5 per square mile (27.6/km ). The racial makeup of

1022-541: A set of island arcs. The accretion of these arcs to the eastern margin of Gondwana was responsible for the Benambran Orogeny of eastern Australia. Subduction also took place along what is now Argentina (Famatinian Orogeny) at 450 Ma. This involved significant back arc rifting. The interior of Gondwana was tectonically quiet until the Triassic . Towards the end of the period, Gondwana began to drift across

1095-568: Is a county located in the U.S. state of Illinois . As of the 2020 census , the population was 53,448. Its county seat is Belvidere . Boone County is included in the Rockford , IL Metropolitan Statistical Area . Unlike most of Illinois, much of Northern Illinois was not submerged in a shallow prehistoric sea . As a result, bedrock found in the area now bounded as Boone County is almost entirely Ordovician , as opposed to nearby counties like McHenry and Carroll which contain large areas of later Silurian bedrock. Till and outwash from

1168-565: Is divided into these nine townships : Boone County is located in the Boone-Winnebago County Regional Office of Education #4. Boone County, with neighboring Winnebago County , is located in Illinois's 17th Judicial Circuit . The entirety of Boone County, along with portions of southeastern Winnebago County, is in the third subcircuit. As a historic Yankee settlement, Boone County in its early years

1241-489: Is located at 42°19′34″N 89°1′33″W  /  42.32611°N 89.02583°W  / 42.32611; -89.02583 (42.326227, -89.025739). According to the 2021 census gazetteer files, Loves Park has a total area of 16.85 square miles (43.64 km), of which 16.33 square miles (42.29 km) (or 96.86%) is land and 0.53 square miles (1.37 km) (or 3.14%) is water. As of the 2020 census there were 23,397 people, 9,608 households, and 6,138 families residing in

1314-489: Is marked by a sudden abundance of hard substrate trace fossils such as Trypanites , Palaeosabella , Petroxestes and Osprioneides . Bioerosion became an important process, particularly in the thick calcitic skeletons of corals, bryozoans and brachiopods, and on the extensive carbonate hardgrounds that appear in abundance at this time. Green algae were common in the Late Cambrian (perhaps earlier) and in

1387-506: Is now Boone County. When the New England settlers arrived in what is now Boone County there was nothing but a dense virgin forest and wild prairie. In the late 1870s immigrants began arriving from Germany and Ireland . According to the U.S. Census Bureau , the county has a total area of 282.039 square miles (730.48 km ) (99.5%), of which 280.741 square miles (727.12 km ) is land and 1.298 square miles (3.36 km ) (0.5%)

1460-478: Is water. Logan Avenue county route 40 Genoa Road (T-40) Garden Prairie Road county route 41 Poplar Grove Road county route 32 Capron Road (T-41) In recent years, average temperatures in the county seat of Belvidere have ranged from a low of 11 °F (−12 °C) in January to a high of 85 °F (29 °C) in July, although a record low of −29 °F (−34 °C) was recorded in January 1979 and

1533-518: The Cambrian , reef -forming corals appeared in the early Ordovician, including the earliest known octocorals , corresponding to an increase in the stability of carbonate and thus a new abundance of calcifying animals. Brachiopods surged in diversity, adapting to almost every type of marine environment. Even after GOBE, there is evidence suggesting that Ordovician brachiopods maintained elevated rates of speciation. Molluscs , which appeared during

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1606-455: The Devonian . The first land plants are known from this period. The Great Ordovician Biodiversification Event considerably increased the diversity of life. Fish , the world's first true vertebrates , continued to evolve, and those with jaws may have first appeared late in the period. About 100 times as many meteorites struck the Earth per year during the Ordovician compared with today in

1679-684: The Erie Canal . They consisted entirely of settlers from New England . These were " Yankee " settlers, that is to say they were descended from the English Puritans who settled New England in the colonial era. They were primarily members of the Congregational Church though due to the Second Great Awakening many of them had converted to Methodism and some had become Baptists before coming to what

1752-463: The Illinoian glaciation covers area bedrock to a depth of several hundred feet. The county's proximity to the driftless area protected the region somewhat from the more recent Wisconsin glaciation . As a result, the county's northern townships resemble a driftless-like area, with higher peak elevations and more surface detail compared to the southern townships dominated by the broad flood plains of

1825-822: The Kishwaukee River and its tributaries. By the time of the first identified human settlements, the region was made up of thickly wooded forested hills and grassy prairie plains. Archeological study at the Koster Site seems to indicate that humans had established complex societies ten thousand years ago along the river basins of the Illinois and Mississippi. By the time of European exploration, Upper Mississippian culture collapsed; westward expansion forced many Algonquin -speaking nations into conflict with each other as they moved after encroachment of their lands. Potowatomi and Mascouten tribes were still living in

1898-766: The Rheic Ocean between Gondwana and Avalonia. Avalonia collided with Baltica towards the end of Ordovician. Other geographic features of the Ordovician world included the Tornquist Sea , which separated Avalonia from Baltica; the Aegir Ocean, which separated Baltica from Siberia; and an oceanic area between Siberia, Baltica, and Gondwana which expanded to become the Paleoasian Ocean in Carboniferous time. The Mongol-Okhotsk Ocean formed

1971-471: The endocerid cephalopods died out completely, except for possible rare Silurian forms. The Ordovician–Silurian extinction events may have been caused by an ice age that occurred at the end of the Ordovician Period, due to the expansion of the first terrestrial plants , as the end of the Late Ordovician was one of the coldest times in the last 600 million years of Earth's history. On the whole,

2044-460: The Cambrian or even the Ediacaran , became common and varied, especially bivalves , gastropods , and nautiloid cephalopods. Cephalopods diversified from shallow marine tropical environments to dominate almost all marine environments. Graptolites, which evolved in the preceding Cambrian period, thrived in the oceans. This includes the distinctive Nemagraptus gracilis graptolite fauna, which

2117-472: The Cambrian were succeeded by those that dominated the rest of the Paleozoic, such as articulate brachiopods, cephalopods , and crinoids . Articulate brachiopods, in particular, largely replaced trilobites in shelf communities. Their success epitomizes the greatly increased diversity of carbonate shell-secreting organisms in the Ordovician compared to the Cambrian. Ordovician geography had its effect on

2190-967: The Dapingian and the early Darriwilian. The Llanvirn corresponds to the late Darriwilian. The Caradoc covers the Sandbian and the first half of the Katian. The Ashgill represents the second half of the Katian, plus the Hirnantian . The Ashgill Epoch, the last epoch of the British Ordovician, is made of four ages: the Hirnantian Age, the Rawtheyan Age, the Cautleyan Age, and the Pusgillian Age. These ages make up

2263-848: The Early Eocene Climatic Optimum. Carbon dioxide levels were very high at the Ordovician period's beginning. By the late Early Ordovician, the Earth cooled, giving way to a more temperate climate in the Middle Ordovician, with the Earth likely entering the Early Palaeozoic Ice Age during the Sandbian, and possibly as early as the Darriwilian or even the Floian. The Dapingian and Sandbian saw major humidification events evidenced by trace metal concentrations in Baltoscandia from this time. Evidence suggests that global temperatures rose briefly in

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2336-532: The Early Ordovician, leveling off somewhat during the middle of the period. Locally, some regressions occurred, but the sea level rise continued in the beginning of the Late Ordovician. Sea levels fell steadily due to the cooling temperatures for about 3 million years leading up to the Hirnantian glaciation. During this icy stage, sea level seems to have risen and dropped somewhat. Despite much study,

2409-559: The Great Ordovician Biodiversification Event) was no less remarkable; marine faunal genera increased fourfold, resulting in 12% of all known Phanerozoic marine fauna. Several animals also went through a miniaturization process, becoming much smaller than their Cambrian counterparts. Another change in the fauna was the strong increase in filter-feeding organisms. The trilobite, inarticulate brachiopod, archaeocyathid , and eocrinoid faunas of

2482-507: The Hirnantian glaciation. As with North America and Europe , Gondwana was largely covered with shallow seas during the Ordovician. Shallow clear waters over continental shelves encouraged the growth of organisms that deposit calcium carbonates in their shells and hard parts. The Panthalassic Ocean covered much of the Northern Hemisphere , and other minor oceans included Proto-Tethys , Paleo-Tethys , Khanty Ocean , which

2555-469: The Ordovician of Wisconsin have been found with an age of about 460 million years ago, a time when the land flora most likely only consisted of plants similar to non-vascular bryophytes . Though stromatolites had declined from their peak in the Proterozoic, they continued to exist in localised settings. The Ordovician came to a close in a series of extinction events that, taken together, comprise

2628-421: The Ordovician were very different from their predecessors in the Cambrian. Many trilobites developed bizarre spines and nodules to defend against predators such as primitive eurypterids and nautiloids while other trilobites such as Aeglina prisca evolved to become swimming forms. Some trilobites even developed shovel-like snouts for ploughing through muddy sea bottoms. Another unusual clade of trilobites known as

2701-582: The Ordovician, when at least two volcanic island arcs collided with Laurentia to form the Appalachian Mountains . Laurentia was otherwise tectonically stable. An island arc accreted to South China during the period, while subduction along north China (Sulinheer) resulted in the emplacement of ophiolites. The ash fall of the Millburg/Big Bentonite bed, at about 454 Ma, was the largest in the last 590 million years. This had

2774-428: The Ordovician. The ice age was possibly not long-lasting. Oxygen isotopes in fossil brachiopods show its duration may have been only 0.5 to 1.5 million years. Other researchers (Page et al.) estimate more temperate conditions did not return until the late Silurian. The late Ordovician glaciation event was preceded by a fall in atmospheric carbon dioxide (from 7000 ppm to 4400 ppm). The dip may have been caused by

2847-557: The Ordovician. Terrestrial plants probably evolved from green algae, first appearing as tiny non- vascular forms resembling liverworts , in the middle to late Ordovician. Fossil spores found in Ordovician sedimentary rock are typical of bryophytes. Among the first land fungi may have been arbuscular mycorrhiza fungi ( Glomerales ), playing a crucial role in facilitating the colonization of land by plants through mycorrhizal symbiosis , which makes mineral nutrients available to plant cells; such fossilized fungal hyphae and spores from

2920-634: The Republican Party towards an expanded Southern and Western base, and particularly its growing strength with social conservatives, alienated the Yankee North during the 1990s and 2000s, but Boone County remained in Republican hands. The candidacy of Ross Perot in 1992 and 1996 caused George H. W. Bush and Bob Dole both to win Boone County with mere pluralities against Bill Clinton , and in 2008, Illinois resident Barack Obama became

2993-613: The South Pole. This contributed to the Hibernian glaciation and the associated extinction event. The Ordovician meteor event is a proposed shower of meteors that occurred during the Middle Ordovician Epoch, about 467.5 ± 0.28 million years ago, due to the break-up of the L chondrite parent body. It is not associated with any major extinction event. A 2024 study found that craters from this event cluster in

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3066-564: The Wuliuan, exploded in diversity during the Tremadocian, quickly becoming globally widespread. Several groups of endobiotic symbionts appeared in the Ordovician. In the Early Ordovician, trilobites were joined by many new types of organisms, including tabulate corals, strophomenid , rhynchonellid , and many new orthid brachiopods, bryozoans, planktonic graptolites and conodonts, and many types of molluscs and echinoderms, including

3139-516: The city was $ 57,096, and the median income for a family was $ 66,914. Males had a median income of $ 49,182 versus $ 28,021 for females. The per capita income for the city was $ 31,504. About 9.9% of families and 14.7% of the population were below the poverty line , including 27.9% of those under age 18 and 6.3% of those age 65 or over. RMTD provides bus service on Routes 16, 17, 18, 20 and 22 connecting Loves Park to downtown Rockford and other destinations. Boone County, Illinois Boone County

3212-430: The city. The population density was 1,388.22 inhabitants per square mile (535.99/km). There were 10,640 housing units at an average density of 631.30 per square mile (243.75/km). The racial makeup of the city was 79.42% White , 5.48% African American , 0.30% Native American , 3.59% Asian , 0.03% Pacific Islander , 2.92% from other races , and 8.25% from two or more races. Hispanic or Latino of any race were 8.89% of

3285-475: The county was 72.5% white, 2.3% black or African American, 1.2% Asian, 0.9% American Indian, 11.6% from other races, and 11.4% from two or more races. Those of Hispanic or Latino origin made up 24.1% of the population. The most common reported ancestries were German (23.7%), Irish (11.7%), Italian (7.4%), and Swedish (7.4%). Of the 18,799 households, 31.7% had children under the age of 18 living with them, 55.5% were married couples living together, 10.6% had

3358-750: The county's vote, and in the century up to 1960 no Democrat reached thirty percent – a degree of GOP loyalty comparable to such famous bastions as Owsley County in Kentucky, Grant County in West Virginia, or Avery County in North Carolina. Even Barry Goldwater , who alienated the Yankee Northeast so much as to lose all but one county there, still won Boone County by 15.6 percentage points, and between 1968 and 1988 no Democrat did better than Jimmy Carter ’s 40.2 percent. The shift of

3431-456: The depths. These organisms were cosmopolitan in distribution and present at most latitudes. At the end of the second event, melting glaciers caused the sea level to rise and stabilise once more. The rebound of life's diversity with the permanent re-flooding of continental shelves at the onset of the Silurian saw increased biodiversity within the surviving Orders. Recovery was characterized by an unusual number of "Lazarus taxa", disappearing during

3504-473: The details remain unresolved. In particular, some researches interpret the fluctuations in sea level as pre-Hibernian glaciation, but sedimentary evidence of glaciation is lacking until the end of the period. There is evidence of glaciers during the Hirnantian on the land we now know as Africa and South America, which were near the South Pole at the time, facilitating the formation of the ice caps of

3577-422: The diversity of fauna; Ordovician invertebrates displayed a very high degree of provincialism. The widely separated continents of Laurentia and Baltica, then positioned close to the tropics and boasting many shallow seas rich in life, developed distinct trilobite faunas from the trilobite fauna of Gondwana, and Gondwana developed distinct fauna in its tropical and temperature zones. The Tien Shan terrane maintained

3650-559: The early Katian (Boda Event), depositing bioherms and radiating fauna across Europe. The early Katian also witnessed yet another humidification event. Further cooling during the Hirnantian, at the end of the Ordovician, led to the Late Ordovician glaciation . The Ordovician saw the highest sea levels of the Paleozoic, and the low relief of the continents led to many shelf deposits being formed under hundreds of metres of water. The sea level rose more or less continuously throughout

3723-425: The extinction and reappearing well into the Silurian, which suggests that the taxa survived in small numbers in refugia . An alternate extinction hypothesis suggested that a ten-second gamma-ray burst could have destroyed the ozone layer and exposed terrestrial and marine surface-dwelling life to deadly ultraviolet radiation and initiated global cooling. Recent work considering the sequence stratigraphy of

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3796-485: The fauna that emerged in the Ordovician were the template for the remainder of the Palaeozoic. The fauna was dominated by tiered communities of suspension feeders, mainly with short food chains. The ecological system reached a new grade of complexity far beyond that of the Cambrian fauna, which has persisted until the present day. Though less famous than the Cambrian explosion , the Ordovician radiation (also known as

3869-578: The first rugose corals appeared. The planktonic graptolites remained diverse, with the Diplograptina making their appearance. One of the earliest known armoured agnathan (" ostracoderm ") vertebrates, Arandaspis , dates from the Middle Ordovician. During the Middle Ordovician there was a large increase in the intensity and diversity of bioeroding organisms. This is known as the Ordovician Bioerosion Revolution. It

3942-502: The globe. At the start of the period, the continents of Laurentia (in present-day North America ), Siberia , and Baltica (present-day northern Europe) were separated from Gondwana by over 5,000 kilometres (3,100 mi) of ocean. These smaller continents were also sufficiently widely separated from each other to develop distinct communities of benthic organisms. The small continent of Avalonia had just rifted from Gondwana and began to move north towards Baltica and Laurentia, opening

4015-532: The only Democrat to carry the county since James K. Polk in 1844. The 2010s have seen a reversal of this Democratic trend due to concern over employment declines in the “ Rust Belt ." 42°20′N 88°49′W  /  42.33°N 88.81°W  / 42.33; -88.81 Ordovician The Ordovician, named after the Welsh tribe of the Ordovices , was defined by Charles Lapworth in 1879 to resolve

4088-548: The ophiuroids ("brittle stars") and the first sea stars . Nevertheless, the arthropods remained abundant; all the Late Cambrian orders continued, and were joined by the new group Phacopida . The first evidence of land plants also appeared (see evolutionary history of life ). In the Middle Ordovician, the trilobite-dominated Early Ordovician communities were replaced by generally more mixed ecosystems, in which brachiopods, bryozoans, molluscs, cornulitids , tentaculitids and echinoderms all flourished, tabulate corals diversified and

4161-399: The population. There were 9,608 households, out of which 31.0% had children under the age of 18 living with them, 43.69% were married couples living together, 15.02% had a female householder with no husband present, and 36.12% were non-families. 29.20% of all households were made up of individuals, and 12.39% had someone living alone who was 65 years of age or older. The average household size

4234-518: The region when white settlers arrived and statehood was declared in 1818. As a political institution, Boone County was formed in March 3, 1836 out of Winnebago County . It was named for Kentucky frontiersman Daniel Boone . The first non-Native American settlers arrived in what is now Boone County in 1835. They arrived as a result of the end of the Black Hawk War as well as the completion of

4307-400: The sea level dropped, and the vast shallow intra-continental Ordovician seas withdrew, which eliminated many ecological niches. When they returned, they carried diminished founder populations that lacked many whole families of organisms. They then withdrew again with the next pulse of glaciation, eliminating biological diversity with each change. Species limited to a single epicontinental sea on

4380-426: The sea, and about 49% of genera of fauna disappeared forever; brachiopods and bryozoans were greatly reduced, along with many trilobite , conodont and graptolite families. The most commonly accepted theory is that these events were triggered by the onset of cold conditions in the late Katian, followed by an ice age , in the Hirnantian faunal stage, that ended the long, stable greenhouse conditions typical of

4453-512: The second largest of the five major extinction events in Earth's history in terms of percentage of genera that became extinct. The only larger one was the Permian–Triassic extinction event . The extinctions occurred approximately 447–444 million years ago and mark the boundary between the Ordovician and the following Silurian Period. At that time all complex multicellular organisms lived in

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4526-425: The shells of most molluscs , dissolved rapidly on the sea floor after death. Unlike Cambrian times, when calcite production was dominated by microbial and non-biological processes, animals (and macroalgae) became a dominant source of calcareous material in Ordovician deposits. The Early Ordovician climate was very hot, with intense greenhouse conditions and sea surface temperatures comparable to those during

4599-492: The sun's rays from the proposed Ordovician ring system, which also caused the Ordovician meteor event , may have also led to the glaciation. As the southern supercontinent Gondwana drifted over the South Pole, ice caps formed on it, which have been detected in Upper Ordovician rock strata of North Africa and then-adjacent northeastern South America, which were south-polar locations at the time. As glaciers grew,

4672-577: The time period from c. 450 Ma to c. 443 Ma. The Rawtheyan, the second last of the Ashgill ages, was from c. 449 Ma to c. 445 Ma. It is in the Katian Age of the ICS's Geologic Time Scale . During the Ordovician, the southern continents were assembled into Gondwana , which reached from north of the equator to the South Pole . The Panthalassic Ocean, centered in the northern hemisphere, covered over half

4745-399: The trinucleids developed a broad pitted margin around their head shields. Some trilobites such as Asaphus kowalewski evolved long eyestalks to assist in detecting predators whereas other trilobite eyes in contrast disappeared completely. Molecular clock analyses suggest that early arachnids started living on land by the end of the Ordovician. Although solitary corals date back to at least

4818-401: Was 2.94 and the average family size was 2.41. The city's age distribution consisted of 21.7% under the age of 18, 9.4% from 18 to 24, 25.6% from 25 to 44, 25.8% from 45 to 64, and 17.5% who were 65 years of age or older. The median age was 38.0 years. For every 100 females, there were 95.5 males. For every 100 females age 18 and over, there were 90.2 males. The median income for a household in

4891-455: Was 38.7 years. For every 100 females, there were 99.0 males. The median income for a household in the county was $ 70.396 and the median income for a family was $ 84,450. Males had a median income of $ 50,213 versus $ 30,219 for females. The per capita income for the county was $ 32,659. About 5.0% of families and 8.2% of the population were below the poverty line , including 10.5% of those under age 18 and 6.8% of those age 65 or over. Boone County

4964-495: Was a major base for the Free Soil Party , being one of nine Illinois counties to vote for Martin van Buren in 1848. Its Free Soil affinities meant Boone became one of the first strongholds of the Republican Party and remained overwhelmingly Republican for the following century, although it did vote for Progressive Theodore Roosevelt in 1912 when the Republican Party was severely split. Between at least 1892 and 1928 no Democratic presidential candidate ever managed twenty percent of

5037-481: Was adopted as an official period of the Paleozoic Era by the International Geological Congress . Life continued to flourish during the Ordovician as it had in the earlier Cambrian Period, although the end of the period was marked by the Ordovician–Silurian extinction events . Invertebrates, namely molluscs and arthropods , dominated the oceans, with members of the latter group probably starting their establishment on land during this time, becoming fully established by

5110-482: Was closed off by the Late Ordovician, Iapetus Ocean , and the new Rheic Ocean . For most of the Late Ordovician life continued to flourish, but at and near the end of the period there were mass-extinction events that seriously affected conodonts and planktonic forms like graptolites . The trilobites Agnostida and Ptychopariida completely died out, and the Asaphida were much reduced. Brachiopods , bryozoans and echinoderms were also heavily affected, and

5183-439: Was distributed widely during peak sea levels in the Sandbian. Some new cystoids and crinoids appeared. It was long thought that the first true vertebrates (fish — Ostracoderms ) appeared in the Ordovician, but recent discoveries in China reveal that they probably originated in the Early Cambrian . The first gnathostome (jawed fish) may have appeared in the Late Ordovician epoch. Chitinozoans, which first appeared late in

5256-495: Was limited to the Iapetus margin of Laurentia; elsewhere, the pattern was of rifting in back-arc basins followed by remerger. This reflected episodic switching from extension to compression. The initiation of new subduction reflected a global reorganization of tectonic plates centered on the amalgamation of Gondwana. The Taconic orogeny , a major mountain-building episode, was well under way in Cambrian times. This continued into

5329-532: Was traditionally broken into Early (Tremadocian and Arenig ), Middle ( Llanvirn (subdivided into Abereiddian and Llandeilian) and Llandeilo ) and Late ( Caradoc and Ashgill) epochs. The corresponding rocks of the Ordovician System are referred to as coming from the Lower, Middle, or Upper part of the column. The Tremadoc corresponds to the ICS's Tremadocian. The Arenig corresponds to the Floian, all of

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