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Skolithos
''Skolithos'' (formerly spelled ''Scolithus'' or ''Skolithus'') is a common trace fossil ichnogenus that is, or was originally, an approximately vertical cylindrical burrow. It is produced by a variety of organisms in shallow marine environments globally and appear as lineated features in sedimentary rocks. Depositional environments ''Skolithos'' burrows range in age from early Cambrian to the present and are found throughout the world. They occur in sediments and sedimentary rocks, primarily sands and sandstones. They are typically marine in origin, and are commonly associated with high-energy environments close to the shoreline. They have also been reported from freshwater lacustrine settings, but have rarely been described from carbonate rocks. Vertical ''Skolithos'' burrows can also occur in alluvial sediments such as braided river deposits, where the periodic fluctuation of water is an important factor in the formation of this structure. This periodic water fluctuation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skolithos In Dakota Formation
''Skolithos'' (formerly spelled ''Scolithus'' or ''Skolithus'') is a common trace fossil ichnogenus that is, or was originally, an approximately vertical cylindrical burrow. It is produced by a variety of organisms in shallow marine environments globally and appear as lineated features in sedimentary rocks. Depositional environments ''Skolithos'' burrows range in age from early Cambrian to the present and are found throughout the world. They occur in sediments and sedimentary rocks, primarily sands and sandstones. They are typically marine in origin, and are commonly associated with high-energy environments close to the shoreline. They have also been reported from freshwater lacustrine settings, but have rarely been described from carbonate rocks. Vertical ''Skolithos'' burrows can also occur in alluvial sediments such as braided river deposits, where the periodic fluctuation of water is an important factor in the formation of this structure. This periodic water fluctuation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trace Fossil
A trace fossil, also known as an ichnofossil (; from el, ἴχνος ''ikhnos'' "trace, track"), is a fossil record of biological activity but not the preserved remains of the plant or animal itself. Trace fossils contrast with body fossils, which are the fossilized remains of parts of organisms' bodies, usually altered by later chemical activity or mineralization. The study of such trace fossils is ichnology and is the work of ichnologists. Trace fossils may consist of impressions made on or in the substrate by an organism. For example, burrows, borings (bioerosion), urolites (erosion caused by evacuation of liquid wastes), footprints and feeding marks and root cavities may all be trace fossils. The term in its broadest sense also includes the remains of other organic material produced by an organism; for example coprolites (fossilized droppings) or chemical markers (sedimentological structures produced by biological means; for example, the formation of stromatolites). H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burrow Fossils
Burrow fossils are the remains of burrows - holes or tunnels excavated into the ground or seafloor - by animals to create a space suitable for habitation, temporary refuge, or as a byproduct of locomotion preserved in the rock record. Because burrow fossils represent the preserved byproducts of behavior rather than physical remains, they are considered a kind of trace fossil. One common kind of burrow fossil is known as Skolithos, and the similar Trypanites, Ophiomorpha and Diplocraterion. Vertebrate burrows Fish burrows Fossil Lungfish burrows are preserved in the Rocky Point Member of the Chinle Formation in Canyonlands National Park. Invertebrate burrows Examples are Treptichnus pedum ''Treptichnus'' (formerly named ''Phycodes'', ''Manykodes'' by J. Dzik, and also known as ''Trichophycus''See e.gfossiilid.info: paleodiversity in Baltoscandia: Trichophycus pedum/ref>) is the preserved burrow of an animal. As such, it is regar ... and Arenicolites franconicus. Footnotes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophiomorpha
''Ophiomorpha'' is an ichnotaxon, usually interpreted as a burrow of an organism (specifically a crustacean) living in the near-shore environment. The burrow lining is more or less smooth on the inside, and densely to strongly mammalated or nodose on the outside, due to the packing of fecal pellets for support of the burrow. Branching is irregular but Y-shaped where present. It (particularly ''O. nodosa'') is often considered part of the Skolithos ichnofacies, where it has occurred (i.e. nearshore environments) since the early Permian, though it (particularly ''O. rudis'') has also occurred in deep water settings (Nereites ichnofacies) since the Late Jurassic, such as well-oxygenated turbidites. More generally ''Ophiomorpha ''and other crustacean-generated burrows first become prominent in the Jurassic. See also * Trace fossil A trace fossil, also known as an ichnofossil (; from el, ἴχνος ''ikhnos'' "trace, track"), is a fossil record of biological activity but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thrust Fault
A thrust fault is a break in the Earth's crust, across which older rocks are pushed above younger rocks. Thrust geometry and nomenclature Reverse faults A thrust fault is a type of reverse fault that has a dip of 45 degrees or less. If the angle of the fault plane is lower (often less than 15 degrees from the horizontal) and the displacement of the overlying block is large (often in the kilometer range) the fault is called an ''overthrust'' or ''overthrust fault''. Erosion can remove part of the overlying block, creating a ''fenster'' (or ''window'') – when the underlying block is exposed only in a relatively small area. When erosion removes most of the overlying block, leaving island-like remnants resting on the lower block, the remnants are called ''klippen'' (singular ''klippe''). Blind thrust faults If the fault plane terminates before it reaches the Earth's surface, it is referred to as a ''blind thrust'' fault. Because of the lack of surface evidence, blind thr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleozoic Life Of British Columbia
The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ''zōḗ'' (), "life", meaning "ancient life" ). It is the longest of the Phanerozoic eras, lasting from , and is subdivided into six geologic periods (from oldest to youngest): # Cambrian # Ordovician # Silurian # Devonian # Carboniferous # Permian The Paleozoic comes after the Neoproterozoic Era of the Proterozoic Eon and is followed by the Mesozoic Era. The Paleozoic was a time of dramatic geological, climatic, and evolutionary change. The Cambrian witnessed the most rapid and widespread diversification of life in Earth's history, known as the Cambrian explosion, in which most modern phyla first appeared. Arthropods, molluscs, fish, amphibians, reptiles, and synapsids all evolved during the Paleozoic. Life began in the ocean but even ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleozoic Life Of Alberta
The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ''zōḗ'' (), "life", meaning "ancient life" ). It is the longest of the Phanerozoic eras, lasting from , and is subdivided into six geologic periods (from oldest to youngest): # Cambrian # Ordovician # Silurian # Devonian # Carboniferous # Permian The Paleozoic comes after the Neoproterozoic Era of the Proterozoic Eon and is followed by the Mesozoic Era. The Paleozoic was a time of dramatic geological, climatic, and evolutionary change. The Cambrian witnessed the most rapid and widespread diversification of life in Earth's history, known as the Cambrian explosion, in which most modern phyla first appeared. Arthropods, molluscs, fish, amphibians, reptiles, and synapsids all evolved during the Paleozoic. Life began in the ocean but even ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rheology
Rheology (; ) is the study of the flow of matter, primarily in a fluid ( liquid or gas) state, but also as "soft solids" or solids under conditions in which they respond with plastic flow rather than deforming elastically in response to an applied force. Rheology is a branch of physics, and it is the science that deals with the deformation and flow of materials, both solids and liquids.W. R. Schowalter (1978) Mechanics of Non-Newtonian Fluids Pergamon The term ''rheology'' was coined by Eugene C. Bingham, a professor at Lafayette College, in 1920, from a suggestion by a colleague, Markus Reiner.The Deborah Number The term was inspired by the of |
Loch Eriboll
__NOTOC__ Loch Eriboll (Scottish Gaelic: "Loch Euraboil") is a long sea loch on the north coast of Scotland, which has been used for centuries as a deep water anchorage as it is safe from the often stormy seas of Cape Wrath and the Pentland Firth. Bronze Age remains can be found in the area, including a souterrain and a very well preserved wheelhouse on the hillside above the west shore. A small scale lime industry developed here in the 19th century and Ard Neakie, a promontory on the eastern shore of the loch, had four large lime kilns developed in around 1870.Ard Neackie, Limekilns, Quarry Canmore. Retrieved 11 April 2021. Before the development of the coast road around the loch in 1890, the Heilam ferry ran from the quay at |
Foliation (geology)
Foliation in geology refers to repetitive layering in metamorphic rocks.Marshak, Stephen, ''Essentials of Geology,'' W. W. Norton 3rd Ed, 2009 Each layer can be as thin as a sheet of paper, or over a meter in thickness. The word comes from the Latin ''folium'', meaning "leaf", and refers to the sheet-like planar structure. It is caused by shearing forces (pressures pushing different sections of the rock in different directions), or differential pressure (higher pressure from one direction than in others). The layers form parallel to the direction of the shear, or perpendicular to the direction of higher pressure. Nonfoliated metamorphic rocks are typically formed in the absence of significant differential pressure or shear. Foliation is common in rocks affected by the regional metamorphic compression typical of areas of mountain belt formation (orogenic belts). More technically, foliation is any penetrative planar fabric present in metamorphic rocks. Rocks exhibiting foliat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vein (geology)
In geology, a vein is a distinct sheetlike body of crystallized minerals within a rock. Veins form when mineral constituents carried by an aqueous solution within the rock mass are deposited through precipitation. The hydraulic flow involved is usually due to hydrothermal circulation. Veins are classically thought of as being the ones in the body not the rock veins and arteries planar fractures in rocks, with the crystal growth occurring normal to the walls of the cavity, and the crystal protruding into open space. This certainly is the method for the formation of some veins. However, it is rare in geology for significant open space to remain open in large volumes of rock, especially several kilometers below the surface. Thus, there are two main mechanisms considered likely for the formation of veins: ''open-space filling'' and ''crack-seal growth''. Open space filling Open space filling is the hallmark of epithermal vein systems, such as a stockwork, in greisens or in cert ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
