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Chert (/ tʃ ɜːr t /) is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, [1] the mineral form of silicon dioxide (SiO 2). [2] Chert is characteristically of biological origin, but may also occur inorganically as a chemical precipitate or a diagenetic replacement, as in petrified wood.
Tree remains that have undergone petrifaction, as seen in Petrified Forest National Park. In geology, petrifaction or petrification (from Ancient Greek πέτρα (pétra) 'rock, stone') is the process by which organic material becomes a fossil through the replacement of the original material and the filling of the original pore spaces with minerals.
In 1768, in the 12th volume of Systema Naturae, he included G. sagittarius and G. scalaris, respectively a possible plant fossil and a possible graptolite. In his 1751 Skånska Resa, he included a figure of a "fossil or graptolite of a strange kind" currently thought to be a type of Climacograptus (a genus of biserial graptolites).
Fossil wood is wood that is preserved in the fossil record. Wood is usually the part of a plant that is best preserved (and most easily found). Fossil wood may or may not be petrified. The fossil wood may be the only part of the plant that has been preserved; [101] therefore such wood may get a special kind of botanical name.
Different techniques are also required for blade creation; a soft punch or hammerstone is necessary for creating a blade. The long sharp edges of blades made them useful for a variety of purposes. After blades are flaked, they are often incorporated as parts of larger tools, such as spears. Other times, the simple shape and sharpness serves the ...
A large coprolite of a carnivorous dinosaur found in Harding County, South Dakota, US A large Miocene coprolite from South Carolina, US Coprolites found on the Blahnita riverbed, Romania, showing a seed inclusion (right specimen) A large coprolite from South Carolina, US Age: White River Oligocene; Location: Northwest Nebraska; Dimensions: Varies (25 mm × 20 mm); Weight: 8-10 g; Features ...
Kimberly Cooley-Reyes, 66, falls into that category. An avid gardener, Cooley-Rees found human composting after her best friend passed away several years ago and had a green burial.
A Triarthrus eatoni with preserved appendages. From upper New York, United States. The preservational regime of Beecher's Trilobite Bed (Upper Ordovician) and other similar localities [1] involves the replacement of soft tissues with pyrite, producing a three-dimensional fossil replicating the anatomy of the original organism. [2]