Principle of lateral continuity

The principle of lateral continuity states that layers of sediment initially extend laterally in all directions; in other words, they are laterally continuous. As a result, rocks that are otherwise similar, but are now separated by a valley or other erosional feature, can be assumed to be originally continuous.
Layers of sediment do not extend indefinitely; rather, the limits can be recognized and are controlled by the amount and type of sediment available and the size and shape of the sedimentary basin. As long as sediment is transported to an area, it will eventually be deposited. However, as the amount of material lessens away from the source, the layer of that material will become thinner.
Often, coarser-grained material can no longer be transported to an area because the transporting medium has insufficient energy to carry it to that location. In its place, the particles that settle from the transporting medium will be finer-grained, and there will be a lateral transition from coarser- to finer-grained material. The lateral variation in sediment within a stratum is known as sedimentary facies.
If sufficient sedimentary material is available, it will be deposited up to the limits of the sedimentary basin. Often, the sedimentary basin is within rocks that are very different from the sediments that are being deposited. In those cases, the lateral limits of the sedimentary layer will be marked by an abrupt change in rock type.


Owens Valley Group

The Owens Valley Group is a geologic group in California. It preserves fossils dating back to the Permian period.


Liesegang rings (geology)

Liesegang rings () (also called Liesegangen rings or Liesegang bands) are colored bands of cement observed in sedimentary rocks that typically cut-across bedding. These secondary (diagenetic) sedimentary structures exhibit bands of (authigenic) minerals that are arranged in a regular repeating pattern. Liesegang rings are distinguishable from other sedimentary structures by their concentric or "ring-like" appearance. The precise mechanism from which Liesegang rings form is not entirely known and is still under research, however there is a precipitation process that is thought to be the catalyst for Liesegang ring formation referred to as the Ostwald-Liesegang supersaturation-nucleation-depletion cycle. Though Liesegang rings are considered a frequent occurrence in sedimentary rocks, rings composed of iron oxide can also occur in permeable igneous and metamorphic rocks that have been chemically weathered.
History.
In 1896, a German Chemist named Raphael E. Liesegang first described Liesegang "banding" in his observations from the results of an experiment, and Wilhelm Ostwald provided the earliest explanation for the phenomenon. The purpose of Liesegang's experiment was to observe precipitate formation resulting from the chemical reaction produced when a drop of silver nitrate solution was placed onto the surface of potassium dichromate gel. The resultant precipitate of silver dichromate formed a concentric pattern of rings. Liesegang and successive other workers observed the behavior of precipitates forming rings in sedimentary rocks, hence these features became known as "Liesegang rings".
Mechanism for development.
The process by which Liesegang rings develop is not completely understood. Liesegang rings may form from the chemical segregation of iron oxides and other minerals during weathering. One popular mechanism suggested by geochemists is that Liesegang rings develop when there is a lack of convection (advection) and has to do with the inter-diffusion of reacting species such as oxygen and ferrous iron that precipitate in separate discrete bands which become spaced apart in a geometric pattern. A process of precipitation known as the Ostwald-Liesegang supersaturation-nucleation-depletion cycle is known by the geologic community as a probable mechanism for Liesegang ring formation in sedimentary rocks. In this process the "...diffusion of reactants leads to supersaturation and nucleation; this precipitation results in localized band formation and depletion of reactants in adjacent zones." As Ostwald suggests, there is a localized formation of crystal seeds that occurs when the right level of supersaturation is reached, and once the crystal seeds form, the growth of the crystals is believed to lower the supersaturation level of fluids in pore spaces surrounding the crystals, thus mineralization that occurs after the initial crystal growth in the surrounding areas develops in bands or "rings". One classic example based on the Ostwald-Liesegang hypothesis is observed in water and rock interactions where iron hydroxide precipitates in sandstone through pore space.
Occurrence in the environment.
Liesegang ring patterns are considered to be secondary (diagenetic) sedimentary structures, though they are also found in permeable igneous and metamorphic rocks that have been chemically weathered. Chemical weathering of rocks that leads to the formation of Liesegang rings typically involves the diffusion of oxygen in subterranean water into pore space containing soluble ferrous iron. Liesegang rings usually cut across layers of stratification and occur in many types of rock, some of which more commonly include sandstone and chert. Though there is a high occurrence of Liesegang rings in sedimentary rocks, relatively few scientists have studied their mineralogy and texture in enough detail to write more about them. Liesegang rings are referred to as examples of geochemical self-organization, meaning that their distribution in the rock does not seem to be directly related to features that were established prior to Liesegang ring formation. For instance, in certain types of sedimentary rocks such as carbonate siltstones (calcisiltites), Liesegang ring patterns can be misinterpreted for faults; the rings may appear to be "offset," however the laminae in the rock exhibit an unbroken pattern, therefore the "observed" offset is attributed to pseudofaulting. Pseudofaults are the result of Liesegang rings developing within areas of the rock that are adjacent to each other but at varying stratigraphic levels. Liesegang rings can have the appearance of fine lamination and can be mistaken for laminae when parallel or subparallel to the bedding plane, and are more easily differentiated from laminae when the rings are observed cutting across beds or lamination.


Cabano Formation

The Cabano Formation is a geologic formation in Quebec. It preserves fossils dating back to the Silurian period.


Uriconian

Uriconian rocks are volcanic rocks found in parts of Shropshire, United Kingdom. The name relates to "Uriconio", the Latin name for an Iron Age hillfort on the summit of the Wrekin, a hill formed of Uriconian rock.
The Uriconian rocks of Shropshire (Wrekin Terrane) are thought to be potentially related to the Longmyndian Supergroup of the Stretton Hills, Shropshire, United Kingdom. Current geological profiling of the terranes suggests that the Uriconian rocks are of Precambrian age (Neoproterozoic Phases 2 and 3). The Uriconian Rocks outcrop to the southeast of the Long Mynd area of the Welsh Borderland Fault System and beyond the Church Stretton Fault which trends northeast-southwest across the area. The Stretton Hills are composed primarily of arenaceous (quartz rich sand) beds assigned to the Longmyndian Supergroup. The Longmyndian rocks are a c.6 km thick group of volcaniclastic and bentonitic sediment horizons. The Uriconian have long thought to be older than the Longmyndian and generally outcrop to the southeast of the latter within northeast-southwest trending lineaments suggesting basement influence for the regional structure.
The Uriconian rocks outcrop in areas from Wellington, Shropshire to Primrose Hill on the southwest side of The Wrekin, east of Caer Caradoc and in the Craven Arms Inlier. Primarily the strata exist as fault-bounded slices within splays of, and to the southeast of, the main Church Stretton fault system.
The Uriconian rocks comprise both intermediate to acidic and basic (bimodal) volcanic suites that reflect largely intraplate origins for the complex although some subduction signatures have been identified. Further work has led to suggest that the locality of this kind of volcanism is related to marginal basin volcanicity (behind the main arc) influenced by trans-tension brought about by oblique subduction.
The Neoproterozoic sediments were deposited on Avalonia in various strike-slip faulted basins and they comprise predominantly volcaniclastic and siliciclastic sediments.
Overview.
Britain during this period (late Precambrian/early Cambrian) lay about 70 degrees south of the equator at the margin of a large ocean (to the north) and with a large continental plate to the south, the ocean is accepting sediment from the continental block. The oceanic plate is subducting southwards underneath the continental block which is being buoyed by the rock which is subsequently being melted (partial melting) by the high temperatures and pressures associated with the process. As with all subduction zones an island arc is formed above the subducting plate (due to rising rock melt) with a back-arc basin existing between the island arc and the continental edge.
A large continental block existed with oceanic crust subducting underneath it. In front of the block and above the subducting oceanic plate are volcanoes emitting a range of varied deposits that give a spectrum of signatures (basaltic eruption, intermediate eruptions and acidic eruptions, as the material melting and rising changes over the period of the subduction). These volcanic deposits get mixed up with the sediment from the continent (now in the form of a back arc basin). These are the volcaniclastic deposits that we can see today at places such as The Wrekin.
During the formation of the volcanoes and their associated deposits of basalt and rhyolite there are melts that never reach the surface and these shallow level intrusions are notable in the forms of their non-extrusive equivalents such as granophyre and rhyolite. Granophyre is quite evident in the Ercall Quarries. The sediments and volcaniclastic sediments are of Precambrian Uriconian age and were deposited in rifts and basins that would have been sub-parallel to the back arc basin as subduction continued. Deep basins will have formed and sediments will have infilled the open space. Significant temperature and pressures are applied to these "infill sediments" and as such they were transformed to schist and gneiss (Primrose Hill Gneiss and Rushton Schist are examples).
The Uriconian Mountains were formed during this process to the northwest of the continental margin. The significant Longmyndian Supergroup sediments were deposited.
Geological relationships.
There is much uncertainty about the exact age of the Uriconian rocks primarily due to the complex structure of the folded and faulted rocks. All contacts are discordant, hence no direct relationships with the Longmyndian Supergroup can de deduced, and a relative age has not been established.
Relationships to other potential lateral equivalents (from the eastern part of the Avalonia palaeo micro-continent known as the Monian Terrane) are still conjectural albeit to varying degrees. The following relationships are all interpreted from figures presented in Brenchley (2006). The relationship to the Longmyndian Supergroup is generally accepted as coeval for the Shropshire/South Wales area. Other Neoproterozoic Phase II (NP2) rocks of similar age are the Warren House Formation of the Malvern Hills (566 +/-2 Ma), South Charnwood Diorites (of the Charnwood Terrane – these stretch back into NP1 though), Fachwen & Minfordd Formations (Arfon/Llyn area), and the blueschist metamorphosed Aethwy Terrane Blueschists.
Other notes.
Given the steep dip of the Uriconian rocks relative to the shallow inclination of the Cambrian, the Uriconian the tectonic events can be classed as pre-Atdabanian (Stage 2, Lower Cambrian). Zircon dating has given similar ages of 566.6+/-2.9Ma from the Longmyndian Supergroup and 566+/-2Ma for the Uriconian Volcanics.
This leads to suggest that the area was affected by (Uriconian) volcanism and associated events between 570-550 Ma including the intrusion of the Ercall Granophyre. This potentially created a thermal extension of the area allowing sedimentation to occur within the basin.


Deer Butte Formation

The Deer Butte Formation is a geologic formation in Oregon. It preserves fossils dating back to the Neogene period.


Beaver Bay Group

The Beaver Bay Group is a geologic group in Alaska. It preserves fossils dating back to the Paleogene period.


Eiss Formation

The Eiss Formation is a geologic formation in Kansas. It preserves fossils dating back to the Permian period.


Limestone Mountain Formation

The Limestone Mountain Formation is a geologic formation in Alaska. It preserves fossils dating back to the Devonian period.


Swarbrick Formation

The Swarbrick Formation is a geologic formation in Nevada. It preserves fossils dating back to the Cambrian period.


Marsh Farm Formation

The Marsh Farm Formation is a geologic formation in England. It preserves fossils dating back to the Paleogene period.


Conglomerate Mesa Formation

The Conglomerate Mesa Formation is a geologic formation in California. It preserves fossils dating back to the Permian period.


Paleobiota of the Kristianstad Basin

The Kristianstad Basin is a Cretaceous-age structural basin and geological formation in northeastern Skåne, the southernmost province of Sweden. The sediments in the basin preserves a wide assortment of taxa represented in its fossil record, including the only non-avian dinosaur fossils in Sweden and one of the world's most diverse mosasaur faunas.
Though a majority of the taxa listed below lived during the latest early Campanian ( 80.5 million years ago; fossils from the site Ivö Klack alone from this time compromise about 40 vertebrate species and more than 200 invertebrate species), the Kristianstad Basin preserves fossils ranging in age from the early Santonian ( 86.3 million years ago) to the early Maastrichtian ( 72.1 million years ago); some of the animals in the list were not contemporaries, but separated from each other in time by several million years. The timespans from which fossils have been recovered is included for each species in the list.
Crocodylomorphs.
In addition to the remains referred to "Aigialosuchus", detached and unidentified crocodylomorph scutes have also been discovered in Campanian-age deposits at Ivö Klack.
Dinosaurs.
Birds.
In addition to the fossils described below, indeterminate hesperornithiform remains have also been recovered from Åsen.
Plesiosaurs.
The last comprehensive review of the plesiosaur fauna in the Kristianstad Basin was done by paleontologist Per-Ove Persson in the 1960s and his taxonomy is still used with caution, pending a much-needed new review.
Pterosaurs.
Possible pterosaur bone fragments have been recovered from earliest Campanian-age deposits at Ullstorp, though they remain unpublished.
Scincomorpha.
Fossils of terrestrial scincomorph lizards have been recovered in the Kristianstad Basin, but are as of yet unpublished.
Turtles.
In addition to the fossils described below, indeterminate turtle remains, including limb bones and carapace fragments, have also been recovered from Ivö Klack, Ugnsmunnarna, Ignaberga and Åsen.
Invertebrates.
Bivalves.
The bivalves are the most species-rich group present in the Kristianstad Basin, with Surlyk & Sørenson (2010) stating that close to 70 distinct species were present at Ivö Klack alone.
Brachiopods.
According to Surlyk & Sørenson (2010) there were 27 distinct species of brachiopods present at Ivö Klack alone.
Bryozoans.
Fossils of bryozoans are common in several sites throughout the Kristianstad Basin.
Cephalopods.
Ammonites.
According to Surlyk & Sørenson, a large species of ammonite is also known from Ivö Klack.
Corals.
Fossils of corals are common in several sites throughout the Kristianstad Basin. The list below only accounts for the recently revised diversity of corals found at Ivö Klack.
Crinoids.
Fossils of crinoids have been found at several sites throughout the Kristianstad Basin.
Echinoids.
According to Surlyk & Sørenson (2010) there were 18 distinct species of echinoids present at Ivö Klack alone.
Gastropods.
According to Surlyk & Sørenson (2010), 19 species of gastropods could be identified from fossils just from the latest Early Campanian of Ivö Klack. Their subsequent 2011 study on the gastropods of the site only listed the 15 species accounted for below.
Polychaetes.
In addition to the diverse polychaete worm fauna of Ivö Klack listed below, encrusters of serpulid polychaetes have also been discovered at Åsen, though they are considerably fewer in number there and as of yet unpublished.
Sponges.
Fossil sponges have been recovered at fossil sites in the Kristianstad Basin.
Starfish.
Fossils of starfish have been found at several sites in the Kristianstad Basin. According to Surlyk & Sørenson (2010) there were 16 distinct species of starfish present at Ivö Klack alone.


Admire Group

The Admire Group is a geologic group in Nebraska. It preserves fossils dating back to the Carboniferous period.


Dell Beds Formation

The Dell Beds Formation is a geologic formation in Montana. It preserves fossils dating back to the Paleogene period.


Caprock

Caprock or cap rock is a harder or more resistant rock type overlying a weaker or less resistant rock type. Common types of caprock are sandstone and mafic rock types. An analogy of caprock could be the outer crust on a cake that is a bit harder than the underlying layer. Common caprock locations are escarpments, mesa formations, and salt domes. In the petroleum industry, caprock is generalized to any nonpermeable formation that may prevent oil, gas, or water from migrating to the surface.
Description.
Caprock is a harder or more resistant rock type overlying a weaker or less resistant rock type. Common types of caprock are sandstone and mafic rock types. An analogy of caprock could be the outer crust on a cake that is a bit harder than the underlying layer. In processes such as scarp retreat, the caprock controls the rate of erosion of the scarp. As the softer rock is cut away, periodically the caprock shears off. Caprock is also found on the top of mesa formations.
The Niagara Escarpment, over which Niagara Falls flows, is an example of a scarp or escarpment. At Niagara Falls, the caprock is the riverbed above the falls, and is what prevents the river from eroding the face of the falls very quickly. In the photo, the dark thin layer in the foreground where water is not yet running, is the caprock. The Niagara caprock is made of dolomitic limestone.
Petroleum.
In the petroleum industry, "caprock" is any nonpermeable formation that may trap oil, gas or water, preventing it from migrating to the surface. This caprock or "trap" can create a "reservoir" of oil, gas or water beneath it and is a primary target for the petroleum industry.
Salt dome caprock.
The tops of salt domes such as in the Gulf of Mexico dissolve in a characteristic manner, and can range between 0–1500 ft thick. The halite (salt) is removed first, leaving behind gypsum and anhydrite. The anhydrite and gypsum react with organic material to form calcite. The classic Murray 1966 paper describes the generalized sequence as sediments-calcite-gypsum-anhydrite-salt.


Ihmert Formation

The Ihmert Formation is a geologic formation in Germany. It preserves fossils dating back to the Devonian period.


Halomonadaceae

Halomonadaceae is a family of halophilic Proteobacteria.
History.
The family was originally described in 1988 to contain the genera "Halomonas" and "Deleya".
In 1989, "Chromobacterium marismortui" was reclassified as "Chromohalobacter marismortui" forming a third genus in the family Halomonadaceae.
Subsequently, in 1990 a species was discovered and was originally proposed to be called "Volcaniella eurihalina" forming a new genus in the "Halomonadaceae", but was later (in 1995) reclassified as a member of the genus "Halomonas".
The species "Carnimonas nigrificans" (sole member of genus) was not placed in the family due to the lack of two out of 15 descriptive 16S rRNA signature sequences, but it has been proposed to reclassify it into the family.
In 1996, the family was later reorganised by unifying genera "Deleya", "Halomonas" and "Halovibrio" and the species "Paracoccus halodenitrificans" into "Halomonas" and placing "Zymobacter" in this family. However, it was later discovered that the strain of "Halovibrio variabilis" DSM 3051 and DSM 3050 differed and the latter was made type strain of the "Halovibrio", which remains still in use. and now comprising two species (the other being Halovibrio denitrificans)
In 2002, "Halomonas marina" was transferred to its own genus "Cobetia", and in 2009 "Halomonas marisflavi", "Halomonas indalinina". and "Halomonas avicenniae" were transferred to a new genus called "Kushneria" (5 species)
Several singleton genera were created recently: in 2007, "Halotalea alkalilenta" was described, "Aidingimonas halophila" in 2009, "Halospina denitrificans" in 2006, "Modicisalibacter tunisiensis" in 2009 "Salinicola socius" in 2009. To the latter genus two species were transferred "Halomonas salaria" as "Salinicola salarius" and "Chromohalobacter salarius" as "Salinicola halophilus".
The family also contain the recently discovered but uncultured bacterium "Candidatus Portiera aleyrodidarum" (primary endosymbionts of whiteflies).
Genera.
Note: Species of "Deleya" and "Halovibrio" are now "Halomonas"
Etymology.
The names derives from Halomonas, which is the type genus of the family, plus the suffix -aceae, ending to denote a family
Research.
Geomicrobiologist Felisa Wolfe-Simon with a NASA funded team is researching a particular strain the family Halomonadaceae, named GFAJ-1, isolated and cultured from sediments collected along the shore of Mono Lake, near Yosemite National Park in eastern California. This GFAJ-1 strain of Halomonadaceae can grow in the presence of high concentrations of arsenic.


Small carbonaceous fossil

Small carbonaceous fossils (SCFs) are sub-millimetric organic remains of organisms preserved in sedimentary strata.
This category of fossils has traditionally included robust or thick-walled entities such as plant spores, acritarchs and chitinozoa, but the term 'SCFs' is usually applied to more fragile remnants of animals that can only be extracted through a delicate maceration technique. SCFs are relatively widespread and abundant, and can potentially preserve both mineralized and non-mineralized parts of organisms. Since SCFs can preserve the remains of non-biomineralized organisms, they have been viewed as a relatively untapped record of animal evolution, which has the potential to circumvent some of the biases of the shelly fossil record.
Extraction.
SCFs are typically preserved in fine-grained siliciclastic rocks, and are too small to be fruitfully examined on bedding planes. Instead, they are extracted by dissolving the rock in acid. Traditional palynological preparations involve high-energy steps such as centrifuging that destroy large and fragile fossils. In the more delicate technique pioneered by Butterfield, individual microfossils are picked from sieved acid residues by hand. The sieving stage removes crystalline residue, making it easier to extract fossils, but introduces a filter: the smallest fossils (<~40 µm) pass through the sieve and are lost. Once extracted, fossils can be mounted for light or scanning electron microscopy: transmitted light illuminates internal microstructures, whereas SEM picks out surface features.
Preservation.
SCFs are best preserved in environments that had anoxic conditions and where the sediments have not been subject to high temperatures (limited thermal maturity); the presence of oxygen is particularly deleterious at high temperatures.
Biota.
Traditional palynological methods are designed for extracting fossilized plant spores and other resistant organic microfossils such as acritarchs and chitinozoa. By using the modified SCFs extraction technique, more delicate fossil structures can also be recovered, including fragments of animals. In particular, this technique has been applied to sediments deposited during the Cambrian Period, since there is great interest in tracking how soft-bodied animals evolved during this time interval. Animal SCFs extracted from Cambrian sediments include the minute scales of priapulid worms, "Wiwaxia" sclerites, and arthropod feeding parts, for example. These organisms are not represented in the conventional (shelly) fossil record, and so the SCFs record provides data on their distribution and evolution that would not otherwise be available. Lagerstätten such as the Burgess Shale provide isolated snapshots of Palaeozoic life, whereas SCFs provide a more continuous record, albeit blighted by the fragmentary (and consequently enigmatic) nature of many of its constituents. As such, SCFs can help to fill in some of the details of the fossil record outside the rare Lagerstätten sites: for instance, highlighting the rapid nature of the Cambrian explosion.


Soda straw

A soda straw (or simply straw) is a speleothem in the form of a hollow mineral cylindrical tube. They are also known as tubular stalactites. Soda straws grow in places where water leaches slowly through cracks in rock, such as on the roofs of caves. Soda straws in caves rarely grow more than a few millimetres per year and may average one tenth of a millimetre per year. A soda straw can turn into a stalactite if the hole at the bottom is blocked, or if the water begins flowing on the outside surface of the hollow tube. Soda straws can also form outside the cave environment on exposed concrete surfaces as a type of calthemite, growing significantly faster than those formed on rock.
Formation.
These tubes form when calcium carbonate or calcium sulfate dissolved in the water comes out of solution and is deposited. In soda straws, as each drop hovers at the tip, it deposits a ring of mineral at its edge. It then falls and a new drop takes its place. Each successive drop of water deposits a little more mineral before falling, and eventually a tube is built up. Stalagmites or flowstone may form where the water drops hit the cave floor.
Soda straws are some of the most fragile of speleothems. Like helictites, they can be easily crushed or broken by the slightest touch. Because of this, soda straws are rarely seen within arms' reach in show caves or others with unrestricted access. Kartchner Caverns in southern Arizona has well-preserved soda straws because of its recent discovery in 1974 and highly regulated traffic.
Outside the cave environment.
Straws can also form beneath man-made structures and grow significantly faster than in the natural cave environment. These forms are classified as calthemites as opposed to the speleothems growing in natural environments. Their chemistry differs from those found in caves because they are derived from concrete, lime, mortar or other calcareous material.
Calthemite soda straws have been recorded as growing up to per day in length, which is hundreds of times faster than speleothem soda straw growth rates typically averaging 2 mm or less per year.
Calthemite straws are on average just 40% the mass per unit length of speleothem straws of equivalent external diameter. This is because calthemite straws have a thinner wall thickness and less-dense calcium carbonate structure compared to speleothem straws.
A calthemite straw can vary in outside diameter as it grows in length. Changes in diameter can take a matter of days or weeks and are due to changes in drip rate over time. Slow dripping calthemite straws tend to be slightly larger in diameter than fast-dripping straws. As a comparison, because of the much "slower growth rate of speleothem (cave) straws, there is more chance that fluctuation in drip rate may be averaged out and the straw external diameter remains reasonably constant."


Larry Soderblom

Laurence A. Soderblom (born 1944) is a geophysicist with the Astrogeology Science center at the United States Geological Survey in Flagstaff, Arizona where he has served as Chief of the Branch of Astrogeology. Soderblom is best known for his work in imaging science.
He earned Bachelor of Science degrees in geology and physics from the New Mexico Institute of Mining and Technology and a PhD in planetary science and geophysics from Caltech.
Soderblom has been involved in several JPL planetary missions. As an Associate Investigator on the Mariner 6, 7, and Mariner 9, and Viking program teams. He is best known for his leadership in imaging science on the Voyager, Magellan, "Galileo", Mars Global Surveyor, Mars Pathfinder, and Mars Exploration Rovers. He also served on the science teams of the Deep Space 1 and "Cassini–Huygens" missions. He has participated in missions ranging from Venus to Neptune and each of the planets in between.
Soderblom has also appeared on "" and "The Planets" (1999) discussing his work with the Voyager team.


Mearim River

The Mearim River is a river in Maranhão state of northern Brazil. The river originates in the southern part of Maranhão, and drains north into the Baía de São Marcos, an estuary that also receives the Pindaré and Grajaú rivers, which are sometimes considered tributaries of the Mearim. The lower Mearim is known for its pororoca, or tidal bore.
The Mearim is approximately 800 kilometers long, flowing through the marshlands of the Atlantic Coastal Plain. It meets the Atlantic Ocean at the Sao Marcos Bay, where it forms a common estuary with another river, Pindare. The Mearim's primary source of water is rain. The river's upper and middle courses are characterized by rapids. Only the lower sections of the Mearim are suitable for navigation.
The river defines the southern boundary of the Tocantins-Araguaia-Maranhão moist forests ecoregion.


Alan Grant (Jurassic Park)


Gelli Formation

The Gelli Formation is a geologic formation in Wales. It preserves fossils dating back to the Ordovician period.


Essen Formation

The Essen Formation is a geologic formation in Germany. It preserves fossils dating back to the Carboniferous period.


Ovda Regio

Ovda Regio is a Venusian crustal plateau located near the equator in the western highland region of Aphrodite Terra that stretches from 10°N to 15°S and 50°E to 110°E. Known as the largest crustal plateau in Venus, the regio covers an area of approximately and is bounded by regional plains to the north, Salus Tessera to the west, Thetis Regio to the east, and Kuanja as well as Ix Chel chasmata to the south. The crustal plateau serves as a place to hold the localized tessera terrains in the planet, which makes up roughly 8% of Venus' surface area. The kinematic evolution of crustal plateaus on Venus has been a debated topic in the planetary science community. Understanding its complex evolution is expected to contribute to a better knowledge of the geodynamic history of Venus. It is named after a Marijian forest spirit that can appear as both male and female.
Structural geology.
Extensive research has been conducted to describe the structural geology of Ovda Regio. Synthetic aperture radar (SAR) images from the NASA Magellan mission have been analyzed to recognize the distribution of its structural features. The distribution was then mapped to find its temporal and spatial relation to find insight into the Regio's deformation and formation mechanisms. The challenge in this process is to find the ideal temporal and spatial relationships, which hold a prominent role in comprehending the tectonic processes. In terms of structural setting, the Regio is characterized mainly by ribbons, folds, and a complex of graben.
Western Ovda.
Folds and a distinct compositional layering generally characterize the western part of Ovda Regio. Compositional layering means that the structural layers differ from each other in terms of their chemical compositions. In particular, the layers are differentiated based on their tone and textural recognition from SAR images. The folds observed in this part of the Regio are concentric, associated with plunges, and share a common axis that is trending in an east–west fashion. Another feature that is observed in this part is ribbons structures. Ribbons can be described as structures that are steep with long depression of about 1–3 km in width and shallow depths of less than 500 m. In contrast to the folding structures, the ribbons in the western part are randomly distributed.
Central Ovda.
Central Ovda is distinguishable by ridges exhibiting east–west orientations similar to those of western Ovda. These ridges are common on the northern margin and often share a common axis with the fold structures. Other structural features observed in this part of Ovda are imbricate stack and duplex formation on the southern margin. A more detailed analysis was conducted in this part indicate that central Ovda hosts a strike-slip tectonic regime where the deformation is accompanied by three different structures: folds, normal faults, and strike-slip faults.
Eastern Ovda.
In the eastern part of Ovda, the structural setting is defined mainly by wide folds and ribbons structures. The wide folds are observed to have amplitudes up to 25 km and several hundred km in length. While the ribbons structures generally hold a radial pattern. Some of the ribbons structures on this part of Ovda are quite difficult to interpret due to the SAR images' limited resolution. A good number of grabens are also present in this part, although the grabens are not highly distinguishable and are limited to fold crests.
Kinematic evolution.
There are a few ideas being continuously discussed in the planetary science community regarding the tectonic evolution of Ovda Regio:
Regional kinematic evolution.
Regionally, there are two separate phases of tectonic evolution. Initially, the Regio was at a stable state where there are no stresses acting on the crustal plateaus. This state was then followed by the first phase in which the north–south-oriented compressional stresses acted on the Regio and produced an east–west folding pattern. This pattern provides the primary structural framework in Ovda Regio. Then, the second phase took place in which the compressional stresses intensified and developed significant mega shear zones.
Marginal kinematic evolution.
There are generally two different phases of structural evolution that describe the Regio's crustal plateau margins. The initial phase preceded the first phase and the last phase concluded the second phase. The initial phase was when all the material being set in place, which would then construct the tessera terrain. During the first phase, the thrust faults and fold belts started to develop parallel to the margins. At the beginning of the first phase, these faults and folds made an impact on the tessera terrain, but later on it made an impact on the intratessera volcanic plains. On second phase, all the thrust faults and fold belts experienced a perpendicular extension. Furthermore, the last phase occurred when the extensional events continuously carried out the deformed structures from the plateau and affecting the volcanic units.
Dynamic development.
There are several models that have been debated to explain crustal plateau formation in Venus, particularly in Ovda Regio:
Downwelling model.
This model describes that the mantle downwelling flow assisted the development of crustal thickening and shortening of the ductile crust because of compression and accretion of thin lithosphere. However, this model needs a lot amount of time of crustal thickening (1-4 billion years). There are also a few constraints for this model. The first one is that this model provides no explanation for the contractional structures and the second one is that the timing of the extensional structures does not correlate well with the known cross-cutting relationships.
Upwelling model.
This second model describes the upwelling of a mantle flow (plume) that accommodates the formation of crustal thickening by magmatic underplating and volcanic activities associated with the thin lithosphere. Planetary scientists that support this model identify two categories of extensional structures: long-narrow graben, referred to as a ribbons, and more widely spaced graben. The sequence of formation for these structures is still debatable. Some scientists believe that the ribbons were formed first, followed later on by the wide spaced graben. But there are other scientists who believe the reverse sequence.
Impact model.
Under the impact model, the crustal plateaus were formed by lava ponds from mantle melting due to meteor impacts to the planet's thin lithosphere. Based on this model, the crustal plateaus would be uplifted by isostasy because the mantle underneath the lava ponds are depleted with residual melts as compared to the neighboring undepleted mantle. However, there are a few issues accompanying this model. The first issue is that scientists are not confident that meteor impacts have the capabilities to melt a significant portion of the planet's lithosphere and generate enough magma that would cause isostasy. The second issue is the planet's large folds need a high amount of stresses to pass the thin brittle layer, but the underlying magma is not capable of transferring enough stresses through the layer.


Nevada Group

The Nevada Group is an abandoned term for a geologic group in Nevada. The group, reflected a collection of rocks then thought to preserve fossils dating back to the Devonian period.
The term was abandoned as a geologic unit because it is "a collection of distinctive rock units deposited in variety of depositional environments."


Terra Nivium

Terra Nivium (Latin for "Land of Snows") is a roughly triangular highland region on the Moon. In his "Almagestum novum", the notable selenographer Giovanni Riccioli named the various highland regions terrae. However, unlike his naming scheme for craters and lunar maria, his nomenclature for the continental areas of the Moon never came into common use.
It lies to the north of the Mare Vaporum and is bounded along the northwest by the rugged Montes Apenninus range, and to the northeast by the less impressive Montes Haemus mountains. Portions of this area have been penetrated by flows of magma that connect to the Mare Vaporum.
This irregular area contains a number of smaller depressions that have become covered in flows of basaltic lavas. These form what are essentially miniature lunar maria. They are clustered near the southern borders of the area, and fill much of the terrain between Mare Vaporum and the Montes Haemus. These mare-like features are generally irregular in shape, and many are joined together through gaps between the more rugged islands of continental terrain.
These areas are listed in the table below, ordered from west to east. The listed diameter corresponds to the smallest circle that fully contains the feature.


Farisita Formation

The Farisita Formation is a geologic formation in Colorado. It preserves fossils dating back to the Paleogene period.


Burlingame Formation

The Burlingame Formation is a geologic formation in Kansas. It preserves fossils dating back to the Carboniferous period.


Severn River Formation

The Severn River Formation is a geologic formation in Quebec. It preserves fossils dating back to the Silurian period.


Hillard Limestone

The Hillard Limestone is a geologic formation in Alaska. It preserves fossils dating back to the Cambrian period.


Rajdeep Dasgupta

Rajdeep Dasgupta is a professor of Earth, Environmental, and Planetary Sciences at Rice University. In his research, he studies the role of subsurface melting and magma on the origin and evolution of the Earth and other terrestrial planets.
Career.
Rajdeep Dasgupta earned his B.Sc. in 1998 and his M.Sc. in 2000 from Jadavpur University in Kolkata, India and completed his Ph.D. in geology at the University of Minnesota in 2006. Dasgupta was a postdoctoral research associate at the University of Minnesota, and then was a postdoctoral fellow at Lamont-Doherty Earth Observatory at Columbia University. He joined the faculty of Rice University in 2008 where he is now a professor. Dasgupta also is a visiting scientist with the Lunar and Planetary Institute and an associate editor with "Geochimica et Cosmochimica Acta". He is a member of the American Geophysical Union, the Mineralogical Society of America, the Geochemical Society, and the Geological Society of America.
In 2011, Dasgupta received the F.W. Clarke Medal from the Geochemical Society, an award given to an early-career scientist for a single outstanding contribution to geochemistry or cosmochemistry. The American Geophysical Union awarded him the James B. Macelwane Medal in 2014. In 2012, he won the Hisashi Kuno award, given annually to an AGU member who has made outstanding contributions to the fields of volcanology, geochemistry or petrology.
Research Initiatives.
Rajdeep Dasgupta is an expert on the deep carbon cycle and his research centers on how carbon, oxygen, and hydrogen in the mantle affect magma melting processes. He has created new models for how rocks melt in carbon-rich environments and calculated carbon’s solubility in the core. Dasgupta has developed a way to use major elements in magmas to estimate their source region and composition in the mantle. He also is researching sulfur solubility, to understand sulfur transport in subduction zones.


Nehou Formation

The Nehou Formation is a geologic formation in France. It preserves fossils dating back to the Devonian period.


Werfen

Werfen () is a market town in the district of St. Johann im Pongau, in the Austrian state of Salzburg. It is mainly known for medieval Hohenwerfen Castle and the Eisriesenwelt ice cave, the largest in the world.
Geography.
Werfen is located in the northwest of the historic Pongau region, about south of the city of Salzburg. The settlement is situated in the Salzach valley south of the Lueg Pass, between the Berchtesgaden Alps (Hagen Mountains and the Hochkönig massif) in the west and the Tennen Mountains in the east. The Salzburg-Tyrol Railway line ("Giselabahn") and the Tauern Autobahn run parallel to the river. The region is known as the type locality of the geologic Werfen Formation, a Triassic stone layer of the Limestone Alps.
The municipality comprises the cadastral communities ("Katastralgemeinden") of Reitsam, Scharten, Sulzau, Werfen Markt, and Wimm.
History.
Important trade routes passed through the Salzach valley since ancient times, when the area was part of the Roman Noricum province. "Werven" was first mentioned about 1140 AD. The settlement arose south of Hohenwerfen Castle, erected from 1075 at the behest of the Archbishop Gebhard of Salzburg during the Investiture Controversy with King Henry IV of Germany. It is one of the oldest markets in the former Archbishopric of Salzburg, with market privileges documented since 1425. At about the same time, the nearby parish of Pfarrwerfen was established, like the neighbouring settlement of Werfenweng in the east.
As the seat of the local administration, Werfen and the castle were heavily attacked during the German Peasants' War in 1525/26. From 1675 onwards, numerous people in the environment of the local knacker Barbara Koller and her son Jakob were sentenced and executed in the Zaubererjackl witch trials. Werfen was also a centre of the expulsion of Salzburg Protestants under the rule of Prince-Archbishop Count Leopold Anton von Firmian in 1731. In the late 18th century, a large limonite deposit was developed in Sulzau, which from 1770 became the most important ironworks ("Konkordiahütte") in the Salzburg archbishopric.
With the lands of the secularised prince-archbishopric, Werfen finally fell to the Austrian Empire by resolution of the Vienna Congress in 1816. The Salzburg-Tyrol Railway line from Salzburg to Wörgl opened in 1875, with stations in Sulzau, Tenneck, and Werfen.
The secluded above the village of Tenneck is the site of the Baroque , a former hunting lodge of Archbishop Wolf Dietrich Raitenau, which in 1908 was acquired by Archduke Franz Ferdinand of Austria. After the archduke's assassination in 1914, the Habsburg-Lorraine dynasty sold the castle to the German Krupp industrial magnates. The Krupp dynasty held the premises until the death of Arndt von Bohlen und Halbach in 1986, today the estates are privately owned by Frederick R. Koch.
A small portion of a picnic scene from "The Sound of Music" was filmed on a hillside of the village of Werfen. Julie Andrews and crew filmed the opening shots of the "Do-Re-Mi" sequence with Hohenwerfen Castle in the background. Hohenwerfen was also the location for some filming of "Where Eagles Dare".
Politics.
Seats in the municipal council ("Gemeinderat") as of 2019 local elections:


Gaptank Formation

The Gaptank Formation is a geologic formation in Texas. It preserves fossils dating back to the Carboniferous period.


Hogeye Tuff

The Hogeye Tuff is a geologic group in Texas. It preserves fossils dating back to the Paleogene period.


Calcaires et marnes schisteuses

The Calcaires et marnes schisteuses is a geologic formation in France. It preserves fossils dating back to the Ordovician period.


Buffalo Canyon Formation

The Buffalo Canyon Formation is a geologic formation in Nevada. It preserves fossils dating back to the Neogene period.


Quebec Group

The Quebec Group is a geologic group in Quebec. It preserves fossils dating back to the Silurian period.


Goodhue Formation

The Goodhue Formation is a geologic formation in California. It preserves fossils dating back to the Permian period.


Kasseler Meeressand Formation

The Kasseler Meeressand Formation is a geologic formation in Germany. It preserves fossils dating back to the Paleogene period.


Garber Formation

The Garber Formation is a geologic formation in Oklahoma. It preserves fossils dating back to the Permian period.


Hales Limestone

The Hales Limestone is a geologic formation in Nevada. It preserves fossils dating back to the Cambrian period.


Carmarthen Group

The Carmarthen Group is a geologic group in Wales. It preserves fossils dating back to the Ordovician period.


Ob (river)

The Ob (: Ob') is a major river in Russia. It is in western Siberia; and is the world's seventh-longest river, at . It forms at the confluence of the Biya and Katun which have their origins in the Altai Mountains. It is the westernmost of the three great Siberian rivers that flow into the Arctic Ocean (the other two being the Yenisei and the Lena). Its flow is north-westward, then northward then these directions are repeated over greater distance.
The main city on its banks is Novosibirsk, the largest city in Siberia, and the third-largest city in Russia. It is where the Trans-Siberian Railway crosses the river.
The Gulf of Ob is the world's longest estuary.
Names.
The internationally known name of the river is based on the Russian name "Обь" ("Obʹ" ). Possibly from Proto-Indo-Iranian "*Hā́p-", "river, water" (compare Vedic "áp-", Persian "āb", Tajik "ob", and Pashto "obə", "water"). Katz (1990) proposes Komi "ob" 'river' as the immediate source of derivation for the Russian name. Katz's proposal of a common Finno-Ugric root, loaned early on from a pre-Indo-Iranian source related to Sanskrit "ambhas-" 'water' is deemed improbable by Rédei (1992), who prefers to analyze this as a later loan from a descendant of the non-nasal root form "*Hā́p-".
The Ob is known to the Khanty people as the "As" (the source of the name "Ostyak"), "Yag", "Kolta" and "Yema"; to the Nenets people as the "Kolta" or "Kuay"; and to the Siberian Tatars as the "Umar" or "Omass".
Geography.
The Ob forms southwest of Biysk in Altai Krai at the confluence of the Biya and Katun rivers. Both these streams have their origin in the Altay Mountains, the Biya issuing from Lake Teletskoye, the Katun, long, bursting out of a glacier on Mount Byelukha.
The Ob itself is in Russia. Its tributaries extend into northern Kazakhstan, a western corner of China and a tiny upland parcel of the western tip of Mongolia, where the wider borders match the drainage basin almost precisely. The river splits into more than one arm after the large Irtysh flows into it at about 69° E. Originating in China, the Irtysh is the furthest source of the Ob. From their respective sources to the confluence, the Irtysh measures 4,248 kilometers (2,640 mi) and the Ob 2,538 km (1,577 mi). Other noteworthy tributaries are: from the east, the Tom, Chulym, Ket, Tym and Vakh rivers; and, from the west and south, the Vasyugan, Irtysh (with the Ishim and Tobol rivers), and Severnaya Sosva.
The Ob zigzags west and north until it reaches 55° N, where it curves to the northwest, and again north, wheeling finally eastwards into the Gulf of Ob, a bay of the Kara Sea, separating the Yamal Peninsula from the Gyda Peninsula.
The combined Ob-Irtysh system, the fourth-longest river system of Asia (after Yenisei, and China's Yangzi and Yellow rivers), is long, and the area of its basin .
The river basin of the Ob consists mostly of steppe, taiga, swamps, tundra, and semi-desert topography. The floodplains of the Ob are characterized by many tributaries and lakes.
The Ob is icebound at southern Barnaul from early in November to near the end of April, and at northern Salekhard, above its mouth, from the end of October to the beginning of June.
The Ob River crosses several climatic zones. The upper Ob valley, in the south, supports grapes, melons and watermelons, whereas the lower reaches of the Ob are Arctic tundra. The most temperate climates on the Ob are at Biysk, Barnaul, and Novosibirsk.
Human use.
The Ob provides irrigation, drinking water, hydroelectric energy, and fishing (the river hosts more than 50 species of fish).
There are several hydroelectric power plants along the Ob river, the largest being Novosibirskaya GES.
The navigable waters within the Ob basin reach a total length of .
The importance of navigation in the Ob basin for transportation was particularly great before the completion of the Trans-Siberian Railway, since, despite the general south-to-north direction of the flow of Ob and most of its tributaries, the width of the Ob basin provided for (somewhat indirect) transportation in the east–west direction as well.
Until the early 20th century, a particularly important western river-port was
Tyumen, located on the Tura, a tributary of the Tobol. Reached by an extension of the Yekaterinburg-Perm railway in 1885, and thus obtaining a rail link to the Kama and Volga rivers in the heart of Russia, Tyumen became an important railhead for some years until the railway extended further east. In the eastern reaches of the Ob basin, Tomsk on the Tom functioned as an important terminus.
Tyumen had its first steamboat in 1836, and steamboats have navigated the middle reaches of the Ob since 1845. The first steamboat on the Ob, Nikita Myasnikov's "Osnova", was launched in 1844; the early starts were difficult, and it was not until 1857 that steamboat shipping started developing in the Ob system in a serious way. Steamboats started operating on the Yenisei in 1863, on the Lena and Amur in the 1870s. In 1916, there were 49 steamers on the Ob; 10 on the Yenisei.
In an attempt to extend the Ob navigable system even further, a system of canals, utilizing the Ket, long in all, was built in the late 19th-century to connect the Ob with the Yenisei, but soon abandoned as being uncompetitive with the railway.
The Trans-Siberian Railway, once completed, provided for more direct, year-round transportation in the east–west direction. But the Ob river-system still remained important for connecting the huge expanses of Tyumen Oblast and Tomsk Oblast with the major cities along the Trans-Siberian route, such as Novosibirsk or Omsk. In the second half of the 20th century, construction of rail links to Labytnangi, Tobolsk, and the oil and gas cities of Surgut, and Nizhnevartovsk provided more railheads, but did not diminish the importance of the waterways for reaching places still not served by the rail.
A dam built near Novosibirsk in 1956 created the then-largest artificial lake in Siberia, called Novosibirsk Reservoir.
From the 1960s through 1980s, Soviet engineers and administrators contemplated a gigantic project to divert some of the waters of Ob and Irtysh to Kazakhstan and the Soviet Central Asian republics, replenishing the Aral Sea as well. The project never left the drawing board, abandoned in 1986 for economic and environmental considerations.
Pollution.
In its early years of operation, the Mayak nuclear plant released vast quantities of radioactively contaminated water into several small lakes near the plant. These lakes drain into the Techa, whose waters ultimately flow into the Ob near the end of its path.
Tributaries.
The Irtysh is the major tributary of the Ob. The larger tributaries along its course are:
In addition, the Nadym and the Pur River flow into the Gulf of Ob and the Taz into the Taz Estuary, a side arm of the Gulf of Ob.
Cities.
Cities along the river include:
Bridges.
From a confluence to a source:


Cymerig Limestone

The Cymerig Limestone is a geologic formation in Wales. It preserves fossils dating back to the Ordovician period.


Ely Limestone

The Ely Limestone is a geologic formation in Nevada and Utah. It preserves fossils dating back to the Carboniferous period.


Sheep Track Pumice

Sheep Track Pumice or Sheep Track Member by Canadian volcanologist Jack Souther, is the name for a pumice deposit in northern British Columbia, Canada. It lies in the Snowshoe Lava Field and is thought to have formed in the Holocene period.


Ettrain Formation

The Ettrain Formation is a geologic formation in Yukon. It preserves fossils dating back to the Carboniferous period.


Chapelton Formation

The Chapelton Formation is a geologic formation in Jamaica. It preserves fossils dating back to the Paleogene period, Eocene epoch. Fossils of the possible species "Charactosuchus kugleri" have been found in the formation.


Pipe Creek Sinkhole

Pipe Creek Sinkhole near Swayzee in Grant County, Indiana, is one of the most important paleontological sites in the interior of the eastern half of North America. It is preserved because it was buried by glacial till. Uncovered in 1996 by workers at the Pipe Creek Junior limestone quarry, the sinkhole has yielded a diverse array of fossils from the Pliocene epoch, dating back five million years. Discoveries have been made there of the remains of camelids, bears, beavers, frogs, snakes, turtles, and several previously unknown species of rodents. Two fish taxa, bullhead ("Ameiurus") and sunfish ("Centrarchidae"), have also been found there.
Origin and importance.
Pipe Creek Sinkhole preserves an ancient wetland. It was created by the collapse of a limestone cave in a Silurian reef formation. That left a steep-sided depression about long, wide and deep. When water collected in the depression, it became the habitat of the plants and animals whose remains were preserved there when the sinkhole was buried by glacial outwash and till during the Pleistocene Epoch, two million to 11,000 years ago.
While the ecology of the Pliocene in North America is well-known from fossil discoveries in other places, notably coastal sites, the Pleistocene glaciers destroyed or scattered most of the fossil remains in the continent's interior. Pipe Creek Sinkhole, however, was "buried" by the glaciers and the debris they left, making it the only known Pliocene example in the central part of the eastern half of the continent.
The sinkhole's ecology.
The ancient wetland was home to a large and dense plant and animal population that includes both extinct and extant forms. The climate was warm and temperate, but somewhat dry, possibly supporting a grassland-forest transitional zone. The preserved vertebrate fauna are dominated by aquatic species, particularly leopard frogs, which are still common throughout the United States. Mammalian finds include an early rhinoceros ("Teleoceras", possibly from the Miocene epoch), canids, peccaries and short-faced bear.
Backed by a grant from the National Science Foundation, researchers from the Indiana State Museum and several universities substantially completed field work at the sinkhole in the summer of 2004, but there was about one weeklong dig a year from 2005 to 2011. What probably was the last work at the site took place in 2014, with scientists and volunteers screening soil previously removed from the sinkhole.


Loma Candela Formation

The Loma Candela Formation is a geologic formation in Cuba. It preserves fossils dating back to the Paleogene period.
Description.
The formation consists of limestones, yellowish calcareous marls and coastal conglomerates and fine calcareous sandstones. The Loma Candela Formation was deposited in a marine environment. It overlies the Universidad Formation and is correlated with the Tallahassee and Lake City Formations of Florida.


Borolanite

Borolanite is an historical petrological name for a pyroxene-melanite bearing nepheline syenite variety which contains nepheline-alkali feldspar pseudomorphs interpreted to be after leucite which occur as conspicuous white spots in the dark rock matrix.
The rock occurs in the Borralan Igneous Complex or Loch Borralan Complex which is an alkalic igneous complex near Loch Borralan in northwest Scotland.
The 1911 Britannica described borolanite as: one of the most remarkable rocks of the British Isles, found on the shores of Loch Borolan (Loch Borralan) in Sutherland, after which it has been named. In this locality there is a considerable area of granite rich in red alkali feldspar, and passing, by diminution in the amount of its quartz, into quartz-syenites and syenites. At the margins of the outcrop patches of nepheline syenite occur; usually the nepheline is decomposed, but occasionally it is well-preserved; the other ingredients of the rock are brown garnet (melanite) and aegirine. The abundance of melanite is very unusual in igneous rocks, though some syenites, leucitophyres, and aegirine-felsites resemble borolanite in this respect. In places the nepheline syenite assumes the form of a dark rock with large rounded white spots. These last consist of an intermixture of nepheline or sodalite and alkali-feldspar. From the analogy of certain leucite syenites which are known in Arkansas, it is very probable that these spots represent original leucites which have been changed into aggregates of the above-named minerals. They resemble leucite in their shape, but have not yet been proved to have its crystalline outlines. The pseudo-leucites, as they have been called, measure one-quarter to three-quarters of an inch across. The dark matrix consists of biotite, aegirine-augite and melanite. Connected with the borolanite there are other types of nepheline syenite and pegmatite. In Finland, melanite bearing nepheline rocks have been found and described as ijolite, but the only other locality for melanite-leucite-syenite is Magnet Cove igneous complex in Arkansas.


Astoria Formation

The Astoria Formation is a geologic formation in Oregon. It preserves fossils dating back to the Neogene period.


Volga

The Volga (; ) is the longest river in Europe. It is situated in Russia, and flows through Central Russia to Southern Russia and into the Caspian Sea. Volga has a length of , and a catchment area of . It is also Europe's largest river in terms of discharge and drainage basin. It is widely regarded as the national river of Russia. The old Russian state, the Rus' Khaganate, arose along the Volga between the late-8th and mid-9th centuries AD. Historically, it was an important meeting place of Eurasian civilizations.
The river flows in Russia through forests, forest-steppes and steppes. Four of the ten largest cities of Russia, including the nation's capital, Moscow, are located in the Volga's drainage basin.
Some of the largest reservoirs in the world are located along the Volga. The river has a symbolic meaning in Russian culture and is often referred to as Волга-матушка "Volga-Matushka" (Mother Volga) in Russian literature and folklore.
Nomenclature.
The Russian hydronym "Volga" () derives from Proto-Slavic *"vòlga" "wetness, moisture", which is preserved in many Slavic languages, including Ukrainian "volóha" () "moisture", Russian "vlaga" () "moisture", Bulgarian "vlaga" () "moisture", Czech "vláha" "dampness", Serbian "vlaga" (влага) "moisture", Croatian "vlaga" "moisture", Slovene "vlaga" "moisture", and Macedonian vlaga "moisture", among others.
The Scythian name for the Volga was "Rā" (), literally "wetness". This is related to the Avestan name for the river; "Raŋha" (derived from Proto-Indo-European "*h1res-" or "*h1ers-", "wet" or "moisture"), or "mythical stream" (also compare the derivation Sogdian "r’k" "vein, blood vessel" (*"raha-ka"), Persian رگ "rag" "vein" and Vedic Sanskrit "rasā́" (रसा) "dew, liquid, juice; mythical river"). The Scythian name survives in modern Mordvin "Rav" () "Volga".
The Turkic peoples living along the river formerly referred to it as "Itil" or "Atil". In modern Turkic languages, the Volga is known as "İdel" () in Tatar, Атӑл ("Atăl") in Chuvash, "Idhel" in Bashkir, "Edil" in Kazakh, and "İdil" in Turkish. The Turkic names go back to the ancient Turkic form “Etil/ Ertil”, the origin and meaning of which are not clear. Perhaps this form has a connection with the hydronym "Irtesh".
The Turkic peoples associated the Itil's origin with the Kama. Thus, a left tributary to the Kama was named the "Aq Itil" "White Itil" which unites with the "Kara Itil" "Black Itil" at the modern city of Ufa. The name "Indyl" ("Indɨl") is used in Adyge (Cherkess) language.
In Asia the river was known by its other Turkic name "Sarı-su" "yellow water", but the Oirats also used their own name, "Ijil mörön" or "adaptation river". Presently the Mari, another Uralic group, call the river "Jul" (), meaning "way" in Tatar. Formerly, they called the river "Volgydo", a borrowing from Old East Slavic.
Description.
The Volga is the longest river in Europe, and its catchment area is almost entirely inside Russia, though the longest river in Russia is the Ob–Irtysh river system.
It belongs to the closed basin of the Caspian Sea, being the longest river to flow into a closed basin. Rising in the Valdai Hills above sea level northwest of Moscow and about southeast of Saint Petersburg, the Volga heads east past Lake Sterzh, Tver, Dubna, Rybinsk, Yaroslavl, Nizhny Novgorod, and Kazan. From there it turns south, flows past Ulyanovsk, Tolyatti, Samara, Saratov and Volgograd, and discharges into the Caspian Sea below Astrakhan at below sea level. At its most strategic point, it bends toward the Don ("the big bend"). Volgograd, formerly Stalingrad, is located there.
The Volga has many tributaries, most importantly the rivers Kama, the Oka, the Vetluga, and the Sura. The Volga and its tributaries form the Volga river system, which flows through an area of about in the most heavily populated part of Russia. The Volga Delta has a length of about and includes as many as 500 channels and smaller rivers. The largest estuary in Europe, it is the only place in Russia where pelicans, flamingos, and lotuses may be found. The Volga freezes for most of its length for three months each year.
The Volga drains most of Western Russia. Its many large reservoirs provide irrigation and hydroelectric power. The Moscow Canal, the Volga–Don Canal, and the Volga–Baltic Waterway form navigable waterways connecting Moscow to the White Sea, the Baltic Sea, the Caspian Sea, the Sea of Azov and the Black Sea. High levels of chemical pollution have adversely affected the river and its habitats.
The fertile river valley provides large quantities of wheat, and also has many mineral riches. A substantial petroleum industry centers on the Volga valley. Other resources include natural gas, salt, and potash. The Volga Delta and the Caspian Sea are fishing grounds. Astrakhan, at the delta, is the center of the caviar industry.
Reservoirs (downstream to upstream).
A number of large hydroelectric reservoirs were constructed on the Volga during the Soviet era. They are:
Human history.
The Volga-Oka region has been occupied for at least 9,000 years, and supported a bone and antler industry for producing bone arrowheads, spearheads, lanceheads, daggers, hunters knives, and awls. The makers also used local quartz, and imported flints.
The area around the Volga was inhabited by the Slavic tribes of Vyatichs and Buzhans, by Finno-Ugrics, Scandinavians and Balts, by Huns and Turkic peoples (Tatars, Kipchaks) in the first millennium AD, replacing the Scythians. Furthermore, the river played a vital role in the commerce of the Byzantine people. The ancient scholar Ptolemy of Alexandria mentions the lower Volga in his "Geography" (Book 5, Chapter 8, 2nd Map of Asia). He calls it the "Rha", which was the Scythian name for the river. Ptolemy believed the Don and the Volga shared the same upper branch, which flowed from the Hyperborean Mountains. Between 2nd and 5th centuries Baltic people were very widespread in today's European Russia. Baltic people were widespread from Sozh River till today's Moscow and covered much of today's Central Russia and intermingled with the East Slavs. The Russian ethnicity in Western Russia and around the Volga river evolved to a very large extent, next to other tribes, out of the East Slavic tribe of the Buzhans and Vyatichis. The Vyatichis were originally concentrated on the Oka river. Furthermore, several localities in Russia are connected to the Slavic Buzhan tribe, like for example Sredniy Buzhan in the Orenburg Oblast, Buzan and the Buzan river in the Astrakhan Oblast. Buzhan (Persian: بوژان, also Romanized as Būzhān; also known as Būzān) is also a village in Nishapur, Iran. In late 8th century the Russian state Russkiy Kaganate is recorded in different Northern and Oriental sources. The Volga was one of the main rivers of the Rus' Khaganates culture.
Subsequently, the river basin played an important role in the movements of peoples from Asia to Europe. A powerful polity of Volga Bulgaria once flourished where the Kama joins the Volga, while Khazaria controlled the lower stretches of the river. Such Volga cities as Atil, Saqsin, or Sarai were among the largest in the medieval world. The river served as an important trade route connecting Scandinavia, Finno-Ugric areas with the various Slavic tribes and Turkic, Germanic, Finnic and other people in Old Rus', and Volga Bulgaria with Khazaria, Persia and the Arab world.
From 6th till 8th century the Alans settled in the Middle Volga region and in the steppes of Russia's southern region in the Pontic–Caspian steppe.
Khazars were replaced by Kipchaks, Kimeks and Mongols, who founded the Golden Horde in the lower reaches of the Volga. Later their empire divided into the Khanate of Kazan and Khanate of Astrakhan, both of which were conquered by the Russians in the course of the 16th century Russo-Kazan Wars. The Russian people's deep feeling for the Volga echoes in national culture and literature, starting from the 12th-century Lay of Igor's Campaign. The Volga Boatman's Song is one of many songs devoted to the national river of Russia.
Construction of Soviet Union-era dams often involved enforced resettlement of huge numbers of people, as well as destruction of their historical heritage. For instance, the town of Mologa was flooded for the purpose of constructing the Rybinsk Reservoir (then the largest artificial lake in the world). The construction of the Uglich Reservoir caused the flooding of several monasteries with buildings dating from the 15th and 16th centuries. In such cases the ecological and cultural damage often outbalanced any economic advantage.
20th-century conflicts.
During the Russian Civil War, both sides fielded warships on the Volga. In 1918, the Red Volga Flotilla participated in driving the Whites eastward, from the Middle Volga at Kazan to the Kama and eventually to Ufa on the Belaya.
During World War II, the city on the big bend of the Volga, currently known as Volgograd, witnessed the Battle of Stalingrad, possibly the bloodiest battle in human history, in which the Soviet Union and the German forces were deadlocked in a stalemate battle for access to the river. The Volga was (and still is) a vital transport route between central Russia and the Caspian Sea, which provides access to the oil fields of the Apsheron Peninsula. Hitler planned to use access to the oil fields of Azerbaijan to fuel future German conquests. Apart from that, whoever held both sides of the river could move forces across the river, to defeat the enemy's fortifications beyond the river. By taking the river, Hitler's Germany would have been able to move supplies, guns, and men into the northern part of Russia. At the same time, Germany could permanently deny this transport route by the Soviet Union, hampering its access to oil and to supplies via the Persian Corridor.
For this reason, many amphibious military assaults were brought about in an attempt to remove the other side from the banks of the river. In these battles, the Soviet Union was the main offensive side, while the German troops used a more defensive stance, though much of the fighting was close quarters combat, with no clear offensive or defensive side.
Ethnic groups.
Many different ethnicities lived on the Volga river. Numerous were the Eastern Slavic Vyatchi tribes which took a decisive role in the development of modern Russians. Among the first recorded people along the upper Volga were also the Finno-Ugric people Mari (Мари) and their west ethnic group named Merya (Мäрӹ). Where the Volga flows through the steppes the area was also inhabited by the Iranian people of the Sarmatians from 200 BC. Since ancient times, even before Rus' states developed, the Volga river was an important trade route where not only Slavic, Turkic and Finno-Ugric people lived, but also Arab world of the Middle East met the Varangian people of the Nordic countries through trading. In the 8th and 9th centuries colonization also began from Kievan Rus'. Slavs from Kievan Rus' brought Christianity to the upper Volga, and a portion of non-Slavic local people adopted Christianity and gradually became East Slavs. The remainder of the Mari people migrated to the east far inland. In the course of several centuries the Slavs assimilated the indigenous Finnic populations, such as the Merya and Meshchera peoples. The surviving peoples of Volga Finnic ethnicity include the Maris and Mordvins of the middle Volga. Also Khazar and Bulgar peoples inhabited the upper, middle and lower of the Volga River basin.
Apart from the Huns, the earliest Turkic tribes arrived in the 7th century and assimilated some Finnic and Indo-European population on the middle and lower Volga. The Muslim Tatars are descendants of the population of medieval Volga Bulgaria. Another Turkic group, the Nogais, formerly inhabited the lower Volga steppes.
The Volga region is home to a German minority group, the Volga Germans. Catherine the Great had issued a Manifesto in 1763 inviting all foreigners to come and populate the region, offering them numerous incentives to do so. This was partly to develop the region but also to provide a buffer zone between the Russians and the Mongols to the East. Because of conditions in German territories, Germans responded in the largest numbers. Under the Soviet Union a slice of the region was turned into the Volga German Autonomous Soviet Socialist Republic.
Navigation.
The Volga, widened for navigation purposes with construction of huge dams during the years of Joseph Stalin's industrialization, is of great importance to inland shipping and transport in Russia: all the dams in the river have been equipped with large (double) ship locks, so that vessels of considerable dimensions can travel from the Caspian Sea almost to the upstream end of the river.
Connections with the river Don and the Black Sea are possible through the Volga–Don Canal. Connections with the lakes of the North (Lake Ladoga, Lake Onega), Saint Petersburg and the Baltic Sea are possible through the Volga–Baltic Waterway; and commerce with Moscow has been realised by the Moscow Canal connecting the Volga and the Moskva River.
This infrastructure has been designed for vessels of a relatively large scale (lock dimensions of on the Volga, slightly smaller on some of the other rivers and canals) and it spans many thousands of kilometers. A number of formerly state-run, now mostly privatized, companies operate passenger and cargo vessels on the river; Volgotanker, with over 200 petroleum tankers, is one of them.
In the later Soviet era, up to the modern times, grain and oil have been among the largest cargo exports transported on the Volga.
 Until recently access to the Russian waterways was granted to foreign vessels on a very limited scale. The increasing contacts between the European Union and Russia have led to new policies with regard to the access to the Russian inland waterways. It is expected that vessels of other nations will be allowed on Russian rivers soon.
Cultural significance.
Literature:
Cinema:


E. Bruce Watson

Edward Bruce Watson (born 16 October 1950) is an American geochemist at Rensselaer Polytechnic Institute in Troy, New York.
Education and career.
Watson received in 1972 his bachelor's degree in geology from the University of New Hampshire and in 1976 his Ph.D. from the Massachusetts Institute of Technology in geochemistry. As a postdoc, he worked at the Carnegie Institution of Washington. In 1977 became an assistant professor of geochemistry at Rensselaer Polytechnic Institute and was subsequently promoted to associate professor and full professor. Since 2011 he has also held a professorship of materials science and engineering. He was a visiting researcher in 1980 at Macquarie University in Sydney and in 1984 at the Max Planck Institute for Chemistry in Mainz.
Watson's research deals (mostly but not exclusively) with the geochemistry of the deep Earth inaccessible to drilling or other direct observation. He studies the chemical composition and materials present in these deep regions and their changes over geologic time. The geochemistry of Earth's deep crust and upper mantle (down to depths of about 150 kilometers) are studied in his laboratory through the design and execution of experiments involving high temperatures and high pressures.
His research has included the following topics:


Lueders Formation

The Lueders Formation is a geologic formation in Texas. It preserves fossils dating back to the Permian period.


Overstep

An overstep is a geological form that has a deposition of a stratum across inclined, progressively older rocks.
The Indira Gandhi National Open University syllabus definition is: "The term "overstep" is used to describe the relationship of beds in an unconformable sequence where the younger series rests upon progressively older members of the underlying series."
An onlap is a more general term than overstep, in which the younger beds overlap onto successively older beds.


Hertha Formation

The Hertha Formation is a geologic formation in Missouri. It preserves fossils dating back to the Carboniferous period.


Western Geophysical

Western Geophysical was an international oil exploration company founded in California in 1933 by Henry Salvatori for the purpose of using reflection seismology to explore for petroleum.
The company prospered and was sold by Salvatori to Litton Industries in 1960. In 1987, Litton and Dresser Industries formed a joint venture comprising Western and Dresser Atlas. The joint venture, Western Atlas, was spun off as a public company in 1994. Western then purchased Halliburton Geophysical Services, which had been formed from Geophysical Service Incorporated, Geosource and several other companies. In 1998, Western Atlas was acquired by Baker Hughes. In 2000, Western Geophysical became part of a joint venture between Baker Hughes and Schlumberger called WesternGeco and ceased to exist as a separate entity. In May 2006, Schlumberger bought Baker Hughes' 30% share of the company.
Western Geophysical built a number of significant seismic survey vessels over the years, in different classes depending on the role. The majority of Western Geophysical vessels were named for geographic features, such as:
More recent vessels including the Western Trident and Western Neptune passed to WesternGeco when the new company was formed.
The company was often referred to as "Westerns" and was affectionately known over many years by many of its employees as the "circus without a tent".
Dean Walling was the operating President of Western Geophysical for his entire working life and retired when the company was sold to Litton Industries in 1960.


Pyroclastic fall

A pyroclastic fall is a uniform deposit of material which has been ejected from a volcanic eruption or plume such as an ash fall or tuff. Pyroclastic air fall deposits are a result of:
Structures.
The deposits of pyroclastic falls follow a well sorted and well bedded trend. They exhibit mantle bedding—the deposits directly overlie pre-existing topography and maintain a uniform thickness over relatively short distances. Sorting by size is more pronounced than pyroclastic surge or pyroclastic flows. Early settling of crystals and lithic fragments near an eruptive vent and of glassy fragments further away is a common trend witnessed during many eruptions. The St Vincent eruption in 1902 ejected a large eruption column which when settled near the vent contained 73% crystals, and ash deposited in Jamaica 1,600 km away consisted entirely of glass dust.
Dispersal.
The distribution of pyroclastic ash depends largely on the direction of wind at intermediate and high altitudes between approximately 4.5 – 13 km. The general trend of pyroclastic dispersal is shown using isopachs (which are analogous to topographic map contours though they illustrate lines of equal thickness rather than elevation) and show the dispersal as elongated with wind direction.
The Krakatoa (Indonesia) eruption of 1883 produced an eruption column which rose to more than 50 km. An ash flow from this explosion was recognised 2,500 km west of the volcano. The total area of recognisable pyroclastic fall was greater than 800,000 km². The pyroclastic ash encircled the globe in 13.5 days and at altitudes of between 30 and 50 km the average velocity was 12 km/h. The ash remained in the upper atmosphere and produced brilliant sunsets for many years, lowered the global temperature by 0.5 °C for at least five years.
The 1912 eruption in the Valley of Ten Thousand Smokes (Alaska) covered an area greater than 100,000 km² to a depth of six mm.
Composition variations.
Pyroclastic falls exhibit lateral and commonly vertical variations in the nature and size of fragments. This is commonly known as an inversion of the magma chamber.
The 79 AD eruption of Mount Vesuvius produced the Pompeii Pumice which is an example of lateral and vertical variations. The deposit is well sorted with density and size of pumice, and the content and size of the lithic fragments increasing upwards. The bottom layer of the pumice is white felsic rich pumice with a darker grey mafic pumice overlying it. These changes represent the increasing vigour of the eruption. The mafic upper part of the deposit reflects the increasing depth of the origin or compositionally zoned magma chamber (mafic lava is denser and settles to the bottom of the chamber as well as crystals which settle out, e.g., olivine). This unit represents an inversion of the magma chamber as progressively deeper materials from the chamber were tapped as the eruption progressed.


Fraser River

The Fraser River is the longest river within British Columbia, Canada, rising at Fraser Pass near Blackrock Mountain in the Rocky Mountains and flowing for , into the Strait of Georgia just south of the City of Vancouver. It is the 11th longest river in Canada. The river's annual discharge at its mouth is or , and it discharges 20 million tons of sediment into the ocean.
Naming.
The river is named after Simon Fraser, who led an expedition in 1808 on behalf of the North West Company from the site of present-day Prince George almost to the mouth of the river.
The river's name in the Halqemeylem (Upriver Halkomelem) language is ', often seen archaically as Staulo, and has been adopted by the Halkomelem-speaking peoples of the Lower Mainland as their collective name, . The river's name in the Dakelh language is '. The "Tsilhqot'in" name for the river, not dissimilar to the "Dakelh" name, is , meaning Sturgeon "()" River "()".
Course.
The Fraser drains a area. Its source is a dripping spring at Fraser Pass in the Canadian Rocky Mountains. The river then flows north to the Yellowhead Highway and west past Mount Robson to the Rocky Mountain Trench and the Robson Valley near Valemount. After running northwest past 54° north, it makes a sharp turn to the south at Giscome Portage, meeting the Nechako River at the city of Prince George, then continues south, progressively cutting deeper into the Fraser Plateau to form the Fraser Canyon from roughly the confluence of the Chilcotin River, near the city of Williams Lake, southwards. It is joined by the Bridge and Seton Rivers at the town of Lillooet, then by the Thompson River at Lytton, where it proceeds south until it is approximately north of the 49th parallel, which is Canada's border with the United States.
From Lytton southwards it runs through a progressively deeper canyon between the Lillooet Ranges of the Coast Mountains on its west and the Cascade Range on its east. Hell's Gate, located immediately downstream of the town of Boston Bar, is a famous portion of the canyon where the walls narrow dramatically, forcing the entire volume of the river through a gap only 35 metres (115 feet) wide. An aerial tramway takes visitors out over the river. Hells Gate is visible from Trans-Canada Highway 1 about south of the tramway. Simon Fraser was forced to portage the gorge on his trip through the canyon in June 1808.
At Yale, at the head of navigation on the river, the canyon opens up and the river widens, though without much adjoining lowland until Hope, where the river then turns west and southwest into the Fraser Valley, a lush lowland valley, and runs past Chilliwack and the confluence of the Harrison and Sumas Rivers, bending northwest at Abbotsford and Mission.
The Fraser then flows past Maple Ridge, Pitt Meadows, Port Coquitlam, and north Surrey. It turns southwest again just east of New Westminster, where it splits into the North Arm, which is the southern boundary of the City of Vancouver, and the South Arm, which divides the City of Richmond from the City of Delta to the south. Richmond is on the largest island in the Fraser, Lulu Island and also on Sea Island, which is the location of Vancouver International Airport, where the Middle Arm branches off to the south from the North Arm. The far eastern end of Lulu Island is named Queensborough and is part of the City of New Westminster. Also in the lowermost Fraser, among other smaller islands, is Annacis Island, an important industrial and port area, which lies to the southeast of the eastern end of Lulu Island. Other notable islands in the lower Fraser are Barnston Island, Matsqui Island, Nicomen Island and Sea Bird Island. Other islands lie on the outer side of the estuary, most notably Westham Island, a wildfowl preserve, and Iona Island, the location of the main sewage plant for the City of Vancouver.
After 100 kilometres (about 60 mi), the Fraser forms a delta where it empties into the Strait of Georgia between the mainland and Vancouver Island. The lands south of the City of Vancouver, including the cities of Richmond and Delta, sit on the flat flood plain. The islands of the delta include Iona Island, Sea Island, Lulu Island, Annacis Island, and a number of smaller islands. While the vast majority of the river's drainage basin lies within British Columbia, a small portion in the drainage basin lies across the international border in Washington in the United States, namely the upper reaches of the tributary Chilliwack and Sumas rivers. Most of lowland Whatcom County, Washington is part of the Fraser Lowland and was formed also by sediment deposited from the Fraser, though most of the county is not in the Fraser drainage basin.
Similar to the Columbia River Gorge east of Portland, Oregon, the Fraser exploits a topographic cleft between two mountain ranges separating a more continental climate (in this case, that of the British Columbia Interior) from a milder climate near the coast. When an Arctic high-pressure area moves into the British Columbia Interior and a relatively low-pressure area builds over the general Puget Sound and Strait of Georgia region, the cold Arctic air accelerates southwest through the Fraser Canyon. These outflow winds can gust up to and have at times exceeded . Such winds frequently reach Bellingham and the San Juan Islands, gaining strength over the open water of the Strait of Juan de Fuca.
The estuary at the river's mouth is a site of hemispheric importance in the Western Hemisphere Shorebird Reserve Network.
Discharge.
The Water Survey of Canada currently operates 17 gauge stations that measure discharge and water level along the majority of the mainstem from Red Pass just downstream of Moose Lake in the Mount Robson Provincial Park, to Steveston in Vancouver at the river mouth. With an average flow at the mouth of about , the Fraser is the largest river by discharge flowing into the Pacific seaboard of Canada and the fifth largest in the country. The average flow is highly seasonal; summer discharge rates can be ten times larger than the flow during the winter.
The Fraser's highest recorded flow, in June 1894, is estimated to have been at Hope. It was calculated using high-water marks near the hydrometric station at Hope and various statistical methods. In 1948 the Fraser River Board adopted the estimate for the 1894 flood. It remains the value specified by regulatory agencies for all flood control work on the river. Further studies and hydraulic models have estimated the maximum discharge of the Fraser River, at Hope during the 1894 flood, as within a range of about .
History.
On June 14, 1792, the Spanish explorers Dionisio Alcalá Galiano and Cayetano Valdés entered and anchored in the North Arm of the Fraser River, becoming the first Europeans to find and enter it. The existence of the river, but not its location, had been deduced during the 1791 voyage of José María Narváez, under Francisco de Eliza.
The upper reaches of the Fraser River were first explored by Sir Alexander Mackenzie in 1793, and fully traced by Simon Fraser in 1808, who confirmed that it was not connected with the Columbia River.
In 1828 George Simpson visited the river, mainly to examine Fort Langley and determine whether it would be suitable as the Hudson's Bay Company's main Pacific depot. Simpson had believed the Fraser River might be navigable throughout its length, even though Simon Fraser had described it as non-navigable. Simpson journeyed down the river and through the Fraser Canyon and afterwards wrote "I should consider the passage down, to be certain Death, in nine attempts out of Ten. I shall therefore no longer talk about it as a navigable stream". His trip down the river convinced him that Fort Langley could not replace Fort Vancouver as the company's main depot on the Pacific coast.
Much of British Columbia's history has been bound to the Fraser, partly because it was the essential route between the Interior and the Lower Coast after the loss of the lands south of the 49th Parallel with the Oregon Treaty of 1846. It was the site of its first recorded settlements of Aboriginal people ("see" Musqueam, , St'at'imc, Secwepemc and Nlaka'pamux), the route of multitudes of prospectors during the Fraser Canyon Gold Rush and the main vehicle of the province's early commerce and industry.
In 1998, the river was designated as a Canadian Heritage River for its natural and human heritage. It remains the longest river with that designation.
Uses.
The Fraser is heavily exploited by human activities, especially in its lower reaches. Its banks are rich farmland, its water is used by pulp mills, and a few dams on some tributaries provide hydroelectric power. The main flow of the Fraser has never been dammed partly because its high level of sediment flows would result in a short dam lifespan, but mostly because of strong opposition from fisheries and other environmental concerns. In 1858, the Fraser River and surrounding areas were occupied when the gold rush came to the Fraser Canyon and the Fraser River. It is also a popular fishing location for residents of the Lower Mainland.
The delta of the river, especially in the Boundary Bay area, is an important stopover location for migrating shorebirds.
The Fraser Herald, a regional position within the Canadian Heraldic Authority is named after the river.
Fishing.
The Fraser River is known for the fishing of white sturgeon, all five species of Pacific salmon (chinook, coho, chum, pink, sockeye), as well as steelhead trout. A typical white sturgeon catch can average about .
A large white sturgeon weighing an estimated and measuring was caught and released on the Fraser River in July 2012, but it was reportedly measured nose to tip of tail, not nose to fork as is the officially recognized method for accurate measurement of this species. Thus the "reported" length of this fish, and its estimated weight, were likely greater than what its actual measurements would have been if standard data collection had been utilized in this case. Regardless of this discrepancy, landing large sturgeon like this is reasonably uncommon, however fish nearing or achieving this size are caught on rod and reel in the Fraser river virtually every year, and reports of even larger fish being lost occur with fair regularity. A variety of guiding outfits throughout the Fraser valley and lower mainland offer services to pursue this magnificent sportfish.
Flooding.
After European settlement, the first disastrous flood in the Fraser Valley occurred in 1894. With no protection against the rising waters of the Fraser River, Fraser Valley communities from Chilliwack downstream were inundated with water. In the 1894 floods, the water mark at Mission reached .
After the 1894 flood, a dyking system was constructed throughout the Fraser Valley. The dyking and drainage projects greatly improved the flood problems, but unfortunately over time, the dykes were allowed to fall into disrepair and became overgrown with brush and trees. With some dykes constructed of a wooden frame, they gave way in 1948 in several locations, marking the second disastrous flood. Flooding since 1948 has been minor in comparison.
1948 flood.
1948 saw massive flooding in Chilliwack and other areas along the Fraser River. The high-water mark at Mission rose to . The peak flow was about 15,600 cubic meters per second.
Causes.
Cool temperatures in March, April, and early May had delayed the melting of the heavy snowpack that had accumulated over the winter season. Several days of hot weather and warm rains over the holiday weekend in late May hastened the thawing of the snowpack. Rivers and streams quickly swelled with spring runoff, reaching heights surpassed only in 1894. Finally, the poorly maintained dike systems failed to contain the water.
At the height of the 1948 flood, stood under water. Dykes broke at Agassiz, Chiliwack, Nicomen Island, Glen Valley and Matsqui. When the flood waters receded a month later, 16,000 people had been evacuated, with damages totaling $20 million, about $210 million in 2010 dollars.
Later flooding.
Due to record snowpacks on the mountains in the Fraser River catch basin which began melting, combined with heavy rainfall, water levels on the Fraser River rose in 2007 to a level not reached since 1972. Low-lying land in areas upriver such as Prince George suffered minor flooding. Evacuation alerts were given for the low-lying areas not protected by dikes in the Lower Mainland. However, the water levels did not breach the dikes, and major flooding was averted.
Tributaries.
Tributaries are listed from the mouth of the Fraser and going up river.


Systems tract


Newberria Formation

The Newberria Formation is a geologic formation in Germany. It preserves fossils dating back to the Devonian period.


Roof pendant

In structural geology, a roof pendant, which also known as a pendant, is a mass of country rock that projects downward into and is entirely surrounded by an igneous intrusion such as a batholith or other pluton. In lay terminology sometimes "rock hat" is used. A roof pendant is an erosional remnant that was created by the removal by erosion of the overlying country rock that formed the roof of the igneous intrusion that encloses it. If this downward protruding mass of roof rock still has a connection to the main, surrounding mass of country rock, they are known by structural geologists as either "septa" or "screens." Roof pendants typically have been strongly metamorphosed through the processes of contact metamorphism.
A classic, well-documented example of a roof pendant is the strata that comprise Mount Morrison within the Sierra Nevada in Mono and Fresno counties, California. It lies midway between Mono Lake on the north and Bishop, California, on the south. Mount Morrison consists of a roof pendant that underlies an area of . This roof pendant consists of a 15,000 m- (50,000 ft-) thick sequence of complexly folded and faulted metasedimentary strata and metavolcanic strata. The eastern two-thirds of this roof pendant consists of Cambrian to Silurian and Pennsylvanian to Permian metasedimentary strata. Metavolcanic rocks of Mesozoic age comprise the western third of the roof pendant. Mesozoic granitic rocks enclose and intrude the pendant rocks. These granitic rocks consist predominantly of quartz monzonite and granodiorite with local, minor, scattered bodies of granite, aplite, diorite and gabbro. These pendants are part of a discontinuous, -long, northwest-trending belt of roof pendants that are preserved within the granitic plutons of Sierra Nevada.


Phycosiphon

Phycosiphon is an ichnogenus of trace fossil. The first recorded fossil was found in Scunthorpe, United Kingdom.