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Meadowcroft Rockshelter
Meadowcroft Rockshelter is an archaeological site located near Avella in Jefferson Township, Pennsylvania. The site is a rock shelter in a bluff overlooking Cross Creek (a tributary of the Ohio River), and contains evidence that the area may have been continually inhabited for more than 19,000 years. If accurately dated, it would be one of the earliest known sites with evidence of a human presence and continuous human occupation in the New World. The site is located 27 miles west-southwest of Pittsburgh in the Pittsburgh metropolitan area. The site operates as a division of the Heinz History Center of Pittsburgh and has a museum and a reconstruction of a circa 1570s Monongahela Culture Indian village. Meadowcroft Rockshelter is recognized as a National Historic Landmark, a Pennsylvania Commonwealth Treasure, and as an official project of Save America's Treasures. Geology and location The rockshelter is a natural formation beneath an overhanging cliff of Morgantown-Connellsv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jefferson Township, Washington County, Pennsylvania
Jefferson Township is a township in Washington County, Pennsylvania. The population was 1,116 at the 2020 census. History The Meadowcroft Rockshelter and Pine Bank Covered Bridge are listed on the National Register of Historic Places. Geography According to the United States Census Bureau, U.S. Census Bureau, the township has a total area of , of which is land and 0.04% of which is water. Surrounding communities Jefferson Township has five borders: the townships of Hanover Township, Washington County, Pennsylvania, Hanover to the north, Smith Township, Washington County, Pennsylvania, Smith to the northeast, Cross Creek Township, Washington County, Pennsylvania, Cross Creek from the east to south-southeast, and Independence Township, Washington County, Pennsylvania, Independence to the south, and Brooke County, West Virginia to the west. Demographics At the 2000 United States census, 2000 census, there were 1,218 people, 469 households, and 354 families living in the townshi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mercyhurst University
(Seize the day) , former_names = Mercyhurst College (1926–2012) , established = , type = Private university , religious_affiliation = Roman Catholic (Sisters of Mercy) , endowment = $31.8 million , faculty = 136 full-time , administrative_staff = 434 , president = Kathleen Getz , students = 2,759 , city = Erie , state = Pennsylvania , country = U.S. , campus = Urban, , athletics_affiliations = , colors = Blue, green, & white , sports_nickname = Lakers , mascot = Luke the Laker , academic_affiliations = Conference for Mercy Higher Education ACCU NAICU , accreditation = MSCHE , footnotes = , website = Mercyhurst University, formerly Mercyhurst College, is a private Roman Catholic university in Erie, Pennsylvania. History On September 20, 1926, Mercyhurst College opened its doors just a few blocks away from the city's southern boundary. It was founded by the Sisters of Mercy of the Diocese of Erie, who were led by Mother M. Borgia Egan, who beca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clovis Culture
The Clovis culture is a prehistoric Paleoamerican culture, named for distinct stone and bone tools found in close association with Pleistocene fauna, particularly two mammoths, at Blackwater Locality No. 1 near Clovis, New Mexico, in 1936 and 1937 (though Paleoindian artifacts had been found at the site since the 1920s). It appears around 11,500–11,000 uncalibrated years before present (YBP)"Clovis Culture" entry in the ''Concise Oxford Dictionary of Archaeology'': "9,500–9,000 BC". at the end of the last glacial period and is characterized by the manufacture of " Clovis points" and distinctive bone and ivory tools. Archaeologists' most precise determinations at present suggest this radiocarbon age is equal to roughly 13,200 to 12,900 calendar years ago. The only human burial that has been directly associated with tools from the Clovis culture included the remains of an infant boy researchers named Anzick-1. Paleogenetic analyses of Anzick-1's ancient nuclear, mitoc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiocarbon Dating
Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon. The method was developed in the late 1940s at the University of Chicago by Willard Libby. It is based on the fact that radiocarbon () is constantly being created in the Earth's atmosphere by the interaction of cosmic rays with atmospheric nitrogen. The resulting combines with atmospheric oxygen to form radioactive carbon dioxide, which is incorporated into plants by photosynthesis; animals then acquire by eating the plants. When the animal or plant dies, it stops exchanging carbon with its environment, and thereafter the amount of it contains begins to decrease as the undergoes radioactive decay. Measuring the amount of in a sample from a dead plant or animal, such as a piece of wood or a fragment of bone, provides information that can be used to calc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cucurbita Pepo
''Cucurbita pepo'' is a cultivated plant of the genus ''Cucurbita''. It yields varieties of winter squash and pumpkin, but the most widespread varieties belong to the subspecies ''Cucurbita pepo'' subsp. ''pepo'', called summer squash. It has been domesticated in the Americas for thousands of years. Some authors maintain that ''C. pepo'' is derived from '' C. texana'', while others suggest that ''C. texana'' is merely feral ''C. pepo''. They have a wide variety of uses, especially as a food source and for medical conditions. ''C. pepo'' seems more closely related to '' C. fraterna'', though disagreements exist about the exact nature of that connection, too. It is a host species for the melonworm moth, the squash vine borer, and the pickleworm. They are also the preferred pollen for squash bees. History ''C. pepo'' is one of the oldest, if not the oldest domesticated species. The oldest known locations are in southern Mexico in Oaxaca 8,000–10,000 years ago and Ocampo, T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maize
Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. The leafy stalk of the plant produces pollen inflorescences (or "tassels") and separate ovuliferous inflorescences called ears that when fertilized yield kernels or seeds, which are fruits. The term ''maize'' is preferred in formal, scientific, and international usage as a common name because it refers specifically to this one grain, unlike ''corn'', which has a complex variety of meanings that vary by context and geographic region. Maize has become a staple food in many parts of the world, with the total production of maize surpassing that of wheat or rice. In addition to being consumed directly by humans (often in the form of masa), maize is also used for corn ethanol, animal feed and other maize products, such as corn starch and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jasper
Jasper, an aggregate of microgranular quartz and/or cryptocrystalline chalcedony and other mineral phases,Kostov, R. I. 2010. Review on the mineralogical systematics of jasper and related rocks. – Archaeometry Workshop, 7, 3, 209-213PDF/ref> is an opaque, impure variety of silica, usually red, yellow, brown or green in color; and rarely blue. The common red color is due to iron(III) inclusions. Jasper breaks with a smooth surface and is used for ornamentation or as a gemstone. It can be highly polished and is used for items such as vases, seals, and snuff boxes. The specific gravity of jasper is typically 2.5 to 2.9. Jaspillite is a banded-iron-formation rock that often has distinctive bands of jasper. Etymology and history The name means "spotted or speckled stone," and is derived via Old French ''jaspre'' (variant of Anglo-Norman ''jaspe'') and Latin ''iaspidem'' (nom. ''iaspis'') from Greek ἴασπις ''iaspis'' (feminine noun), from an Afroasiatic language (cf. H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flint
Flint, occasionally flintstone, is a sedimentary cryptocrystalline form of the mineral quartz, categorized as the variety of chert that occurs in chalk or marly limestone. Flint was widely used historically to make stone tools and start fires. It occurs chiefly as nodules and masses in sedimentary rocks, such as chalks and limestones.''The Flints from Portsdown Hill'' Inside the nodule, flint is usually dark grey, black, green, white or brown in colour, and often has a glassy or waxy appearance. A thin layer on the outside of the nodules is usually different in colour, typically white and rough in texture. The nodules can often be found along s and |
Lanceolate
The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular or irregular, may be smooth or bearing hair, bristles or spines. For more terms describing other aspects of leaves besides their overall morphology see the leaf article. The terms listed here all are supported by technical and professional usage, but they cannot be represented as mandatory or undebatable; readers must use their judgement. Authors often use terms arbitrarily, or coin them to taste, possibly in ignorance of established terms, and it is not always clear whether because of ignorance, or personal preference, or because usages change with time or context, or because of variation between specimens, even specimens from the same plant. For example, whether to call leaves on the same tree "acuminate", "lanceolate", or "linear" could ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamellar Blade
A ''lamella'' (plural ''lamellae'') is a small plate or flake, from the Latin, and may also be used to refer to collections of fine sheets of material held adjacent to one another, in a gill-shaped structure, often with fluid in between though sometimes simply a set of 'welded' plates. The term is used in biological contexts to describe thin membranes of plates of tissue. In context of materials science, the microscopic structures in bone and nacre are called lamellae. Moreover, the term lamella is often used as a way to describe crystal structure of some materials. Uses of the term In surface chemistry (especially mineralogy and materials science), lamellar structures are fine layers, alternating between different materials. They can be produced by chemical effects (as in eutectic solidification), biological means, or a deliberate process of lamination, such as pattern welding. Lamellae can also describe the layers of atoms in the crystal lattices of materials such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biface
A hand axe (or handaxe or Acheulean hand axe) is a Prehistory, prehistoric stone tool with two faces that is the longest-used tool in human history, yet there is no academic consensus on what they were used for. It is made from stone, usually flint or chert that has been "reduced" and shaped from a larger piece by knapping, or hitting against another stone. They are characteristic of the lower Acheulean and middle Palaeolithic (Mousterian) periods, roughly 1.6 million years ago to about 100,000 years ago, and used by ''Homo erectus'' and other early humans, but rarely by ''Homo sapiens''. Their technical name (biface) comes from the fact that the archetypical model is a generally bifacial (with two wide sides or faces) and almond-shaped (amygdaloidal) lithic flake. Hand axes tend to be Symmetry, symmetrical along their longitudinal Symmetry axis, axis and formed by pressure or percussion. The most common hand axes have a pointed end and rounded base, which gives them their char ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
