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Fossil Wood
Fossil wood, also known as fossilized tree, is wood that is preserved in the fossil record. Over time the wood will usually be the part of a plant that is best preserved (and most easily found). Fossil wood may or may not be petrified, in which case it is known as ''petrified wood'' or ''petrified tree''. The study of fossil wood is sometimes called palaeoxylology, and a palaeoxylologist is somebody who studies fossil wood. The fossil wood may be the only part of the plant that has been preserved, with the rest of the plant completely unknown: therefore such wood may get a special kind of botanical name. This will usually include "xylon" and a term indicating its presumed (not necessarily certain) affinity, such as '' Araucarioxylon'' (wood similar to that of extant ''Araucaria'' or some related genus like Agathis or Wollemia), '' Palmoxylon'' (wood similar to that of modern Arecaeae), or '' Castanoxylon'' (wood similar to that of modern chinkapin or chestnut tree). T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permineralization
Permineralization is a process of fossilization of bones and tissues in which mineral deposits form internal Casting, casts of organisms. Carried by water, these minerals fill the spaces within organic tissue. Because of the nature of the casts, permineralization is particularly useful in studies of the internal structures of organisms, usually of plants. Process Permineralization, a type of fossilization, involves deposits of minerals within the cells of organisms. Water from the ground, lakes, or oceans seeps into the pores of organic tissue and forms a crystal cast with deposited minerals. Crystals begin to form in the porous cell walls. This process continues on the inner surface of the walls until the central cavity of the cell, the Lumen (anatomy), lumen, is completely filled. The cell walls themselves remain intact surrounding the crystals. Silicification In silicification, the weathering of rocks releases silicate minerals and the silica makes its way into a body of still ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lignite
Lignite (derived from Latin ''lignum'' meaning 'wood'), often referred to as brown coal, is a soft, brown, combustible sedimentary rock formed from naturally compressed peat. It has a carbon content around 25–35% and is considered the lowest rank of coal due to its relatively low heat content. When removed from the ground, it contains a very high amount of moisture, which partially explains its low carbon content. Lignite is mined all around the world and is used almost exclusively as a fuel for steam-electric power generation. Lignite combustion produces less heat for the amount of carbon dioxide and sulfur released than other ranks of coal. As a result, lignite is the most harmful coal to human health. Depending on the source, various toxic heavy metals, including naturally occurring radioactive materials, may be present in lignite and left over in the coal fly ash produced from its combustion, further increasing health risks. Characteristics Lignite is brownish-bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleobotany
Paleobotany or palaeobotany, also known as paleophytology, is the branch of botany dealing with the recovery and identification of plant fossils from geological contexts, and their use for the biological reconstruction of past environments ( paleogeography), and the evolutionary history of plants, with a bearing upon the evolution of life in general. It is a component of paleontology and paleobiology. The prefix ''palaeo-'' or ''paleo-'' means "ancient, old", and is derived from the Greek adjective , . Paleobotany includes the study of land plants, as well as the study of prehistoric marine photoautotrophs such as photosynthetic algae, seaweeds or kelp. A closely related field is palynology, which is the study of fossilized and extant spores and pollen. Paleobotany is important in the reconstruction of ancient ecological and climate systems, known as paleoecology and paleoclimatology respectively. It is fundamental to the study of green plant development and evolution ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jet (gemstone)
Jet is a type of lignite, the lowest rank of coal, and is a gemstone. Unlike many gemstones, jet is not a mineral, but is rather a mineraloid. It is derived from wood that has changed under extreme pressure. The English noun ''jet'' derives from the French word for the same material, (modern French ), ultimately referring to the ancient town of Gagae. Jet is either black or dark brown, but may contain pyrite inclusions which are of brassy colour and metallic lustre. The adjective " jet-black", meaning as dark a black as possible, derives from this material. Origin Jet is a product of decomposition of wood from millions of years ago, commonly the wood of trees of the family Araucariaceae. Jet is found in two forms, hard and soft. Hard jet is the result of carbon compression and salt water; soft jet may be the result of carbon compression and fresh water. Despite the name they both occupy the same area of the Mohs scale with the difference being that soft jet is more likely to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dendrochronology
Dendrochronology (or tree-ring dating) is the scientific method of chronological dating, dating tree rings (also called growth rings) to the exact year they were formed in a tree. As well as dating them, this can give data for dendroclimatology, the study of climate and atmospheric conditions during different periods in history from the wood of old trees. Dendrochronology derives from the Ancient Greek (), meaning "tree", (), meaning "time", and (), "the study of". Dendrochronology is useful for determining the precise age of samples, especially those that are too recent for radiocarbon dating, which always produces a range rather than an exact date. However, for a precise date of the death of the tree a full sample to the edge is needed, which most trimmed timber will not provide. It also gives data on the timing of events and rates of change in the environment (most prominently climate) and also in wood found in archaeology or works of art and architecture, such as old pane ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amber
Amber is fossilized tree resin. Examples of it have been appreciated for its color and natural beauty since the Neolithic times, and worked as a gemstone since antiquity."Amber" (2004). In Maxine N. Lurie and Marc Mappen (eds.) ''Encyclopedia of New Jersey'', Rutgers University Press, . Amber is used in jewelry and as a healing agent in Traditional medicine, folk medicine. There are five classes of amber, defined on the basis of their chemical constituents. Because it originates as a soft, sticky tree resin, amber sometimes contains animal and plant material as Inclusion (mineral), inclusions. Amber occurring in coal seams is also called resinite, and the term ''ambrite'' is applied to that found specifically within New Zealand coal seams. Etymology The English word ''amber'' derives from Arabic from Middle Persian 𐭠𐭭𐭡𐭫 (''ʾnbl'' /ambar/, “ambergris”) via Medieval Latin, Middle Latin ''ambar'' and Middle French ''ambre''. The word referred to what is n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Level Rise
The sea level has been rising from the end of the last ice age, which was around 20,000 years ago. Between 1901 and 2018, the average sea level rose by , with an increase of per year since the 1970s. This was faster than the sea level had ever risen over at least the past 3,000 years. The rate accelerated to /yr for the decade 2013–2022. Climate change due to human activities is the main cause. Between 1993 and 2018, melting ice sheets and glaciers accounted for 44% of sea level rise, with another 42% resulting from thermal expansion of water. Sea level rise lags behind changes in the Earth's temperature by decades, and sea level rise will therefore continue to accelerate between now and 2050 in response to warming that has already happened. What happens after that depends on future human greenhouse gas emissions. If there are very deep cuts in emissions, sea level rise would slow between 2050 and 2100. The reported factors of increase in flood hazard potential are often e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine Transgression
A marine transgression is a geologic event where sea level rises relative to the land and the shoreline moves toward higher ground, resulting in flooding. Transgressions can be caused by the land sinking or by the ocean basins filling with water or decreasing in capacity. Transgressions and regressions may be caused by tectonic events like orogenies, severe climate change such as ice ages or isostatic adjustments following removal of ice or sediment load. During the Cretaceous, seafloor spreading created a relatively shallow Atlantic basin at the expense of a deeper Pacific basin. That reduced the world's ocean basin capacity and caused a rise in sea level worldwide. As a result of the sea level rise, the oceans transgressed completely across the central portion of North America and created the Western Interior Seaway from the Gulf of Mexico to the Arctic Ocean. The opposite of transgression is regression where the sea level falls relative to the land and exposes the form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Axel Heiberg Island
Axel Heiberg Island (, ) is an uninhabited island in the Qikiqtaaluk Region, Nunavut, Canada. Located in the Arctic Ocean, it is the 32nd largest island in the world and Canada's seventh largest island. According to Statistics Canada, it has an area of . It is named after Axel Heiberg. One of the larger members of the Arctic Archipelago, it is also a member of the Sverdrup Islands and Queen Elizabeth Islands. It is known for its unusual fossil forests, which date from the Eocene period. Owing to the lack of mineralization in many of the forest specimens, the traditional characterization of "fossilisation" fails for these forests and "mummification" may be a more precise description. The fossil records provide strong evidence that the Axel Heiberg forest was a high-latitude wetland forest. A holotype of the ammonite '' Otoceras gracile'' was found in the Griesbachian (Early Triassic) deposits of this island. History Axel Heiberg Island has been inhabited in the past by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ellesmere Island
Ellesmere Island (; ) is Canada's northernmost and List of Canadian islands by area, third largest island, and the List of islands by area, tenth largest in the world. It comprises an area of , slightly smaller than Great Britain, and the total length of the island is . Lying within the Arctic Archipelago, Ellesmere Island is considered part of the Queen Elizabeth Islands. Cape Columbia at is the most northerly point of land in Canada and one of the most northern points of land on the planet (the most northerly point of land on Earth is the nearby Kaffeklubben Island of Greenland). The Arctic Cordillera mountain system covers much of Ellesmere Island, making it the most mountainous in the Arctic Archipelago. More than one-fifth of the island is protected as Quttinirpaaq National Park. In 2021, the population of Ellesmere Island was recorded at 144. There are three settlements: Alert, Nunavut, Alert, Eureka, Nunavut, Eureka, and Grise Fiord. Ellesmere Island is administered as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
