The Bursum Formation is a geologic formation in New Mexico . It preserves fossils dating back to the Early Permian period .
31-667: The Bursum Formation is primarily mudstone but with substantial limestone , particularly in its lower beds, with a thickness in excess of 100 m (330 ft). It rests disconformably on the Atrasado Formation and grades into the overlying Abo Formation . It represents the transitional zone between the marine Madera Group and the continental Abo Formation. The Red Tanks Member is composed mostly of variegated shale , mudstone, and siltstone of nonmarine origin, with some beds of marine limestone and shale forming six transgressive depositional sequences. Its type section
62-409: A buffer to stabilise it in the range 7.37–7.43: Exhaled CO 2 (g) depletes CO 2 (aq) , which in turn consumes H 2 CO 3 , causing the equilibrium of the first reaction to try to restore the level of carbonic acid by reacting bicarbonate with a hydrogen ion, an example of Le Châtelier's principle . The result is to make the blood more alkaline (raise pH). By the same principle, when
93-427: A grain size less than 0.063 millimetres (0.0025 in). Individual grains this size are too small to be distinguished without a microscope, which means that most classifications emphasize texture rather than mineral composition, and mudstones have historically received less attention from petrologists than have sandstones . The simplest definition is that a mudstone is a fine-grained clastic sedimentary rock that
124-457: A distinctive, widespread limestone horizon. These are unusual in being composed mostly of forams rather than cyanobacteria and are interpreted as having formed in a shelf environment below the euphotic zone or normal wave base but above the storm wave base. The Bursum Formation was first defined by R.H. Wilpolt and coinvestigators in 1946 for exposures near the Bursum triangulation point in
155-669: A further increase to the upper limit for the matrix size in order to bring it into line with the upper limit for silt (63 μm). On December 13, 2016, NASA reported further evidence supporting habitability on the planet Mars as the Curiosity rover climbed higher, studying younger layers, on Mount Sharp . Also reported, the very soluble element boron was detected for the first time on Mars. In June 2018 , NASA reported that Curiosity had detected kerogen and other complex organic compounds from mudstone rocks approximately 3.5 billion years old. Carbonate A carbonate
186-587: A model with fractional bonds and delocalized charges: Metal carbonates generally decompose on heating, liberating carbon dioxide leaving behind an oxide of the metal. This process is called calcination , after calx , the Latin name of quicklime or calcium oxide , CaO, which is obtained by roasting limestone in a lime kiln : As illustrated by its affinity for Ca , carbonate is a ligand for many metal cations. Transition metal carbonate and bicarbonate complexes feature metal ions covalently bonded to carbonate in
217-401: A mudstone is to incorrectly estimate the volume of 'grains' in the sample - in consequence, misidentifying mudstone as wackestone and vice versa. The original Dunham classification (1962) defined the matrix as clay and fine-silt size sediment <20 μm in diameter. This definition was redefined by Embry & Klovan (1971 ) to a grain size of less than or equal to 30 μm. Wright (1992 ) proposed
248-406: A variety of bonding modes. Lithium , sodium , potassium , rubidium , caesium , and ammonium carbonates are water-soluble salts, but carbonates of 2+ and 3+ ions are often poorly soluble in water. Of the insoluble metal carbonates, CaCO 3 is important because, in the form of scale , it accumulates in and impedes flow through pipes. Hard water is rich in this material, giving rise to
279-532: Is a salt of carbonic acid , ( H 2 CO 3 ), characterized by the presence of the carbonate ion , a polyatomic ion with the formula CO 2− 3 . The word "carbonate" may also refer to a carbonate ester , an organic compound containing the carbonate group O=C(−O−) 2 . The term is also used as a verb, to describe carbonation : the process of raising the concentrations of carbonate and bicarbonate ions in water to produce carbonated water and other carbonated beverages – either by
310-448: Is a sedimentary rock in which neither silt, clay, nor coarser grains is predominant. Rock of this composition that does show laminations or fissility is sometimes described as mudshale rather than mudstone . The lack of fissility or layering in mudstone may be due to either original texture or the disruption of layering by burrowing organisms in the sediment prior to lithification . Mudstone looks like hardened clay and, depending upon
341-590: Is at Carrizo Arroyo ( 34°46′45″N 107°06′25″W / 34.7790683°N 107.1068066°W / 34.7790683; -107.1068066 ). It is also present at Abo Pass. The Bursum Formation has a more consistently marine character further south. The fact that the transgressive sequences are fewer in number than the cyclothems of the Pennsylvanian - Permian boundary in the North American mid-continent shows that tectonics had more influence on
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#1732801207481372-402: Is double bonded. These compounds are also known as organocarbonates or carbonate esters, and have the general formula R−O−C(=O)−O−R′ , or RR′CO 3 . Important organocarbonates include dimethyl carbonate , the cyclic compounds ethylene carbonate and propylene carbonate , and the phosgene replacement, triphosgene . Three reversible reactions control the pH balance of blood and act as
403-408: Is not laminated or fissile . Most definitions also include a requirement that the rock contain significant amounts of both silt- and clay-sized grains. One common requirement is that a mudstone is a mudrock (a rock containing more than 50% silt- to clay-sized particles) in which between a third and two-thirds of the mud (silt and clay) fraction is clay particles. Another definition is that mudstone
434-441: Is related to the disparate lattice energies of solids composed of mono- vs dianions, as well as mono- vs dications. In aqueous solution , carbonate, bicarbonate, carbon dioxide, and carbonic acid participate in a dynamic equilibrium . In strongly basic conditions, the carbonate ion predominates, while in weakly basic conditions, the bicarbonate ion is prevalent. In more acid conditions, aqueous carbon dioxide , CO 2 (aq) ,
465-444: Is the main form, which, with water, H 2 O , is in equilibrium with carbonic acid – the equilibrium lies strongly towards carbon dioxide. Thus sodium carbonate is basic, sodium bicarbonate is weakly basic, while carbon dioxide itself is a weak acid. In organic chemistry a carbonate can also refer to a functional group within a larger molecule that contains a carbon atom bound to three oxygen atoms, one of which
496-453: Is the simplest oxocarbon anion . It consists of one carbon atom surrounded by three oxygen atoms, in a trigonal planar arrangement, with D 3h molecular symmetry . It has a molecular mass of 60.01 g/mol and carries a total formal charge of −2. It is the conjugate base of the hydrogencarbonate (bicarbonate) ion, HCO − 3 , which is the conjugate base of H 2 CO 3 , carbonic acid . The Lewis structure of
527-503: The Dunham classification (Dunham, 1962 ) system of limestones , a mudstone is defined as a mud-supported carbonate rock that contains less than 10% grains. Most recently, this definition has been clarified as a matrix-supported carbonate-dominated rock composed of more than 90% carbonate mud (<63 μm) component . A recent study by Lokier and Al Junaibi (2016) has highlighted that the most common problems encountered when describing
558-666: The Joyita Hills. He also correlated the formation with the Laborcita Formation and Red Tanks Formation (which he regarded as a separate formation). Mudstone Mudstone , a type of mudrock , is a fine-grained sedimentary rock whose original constituents were clays or muds . Mudstone is distinguished from shale by its lack of fissility . The term mudstone is also used to describe carbonate rocks ( limestone or dolomite ) that are composed predominantly of carbonate mud. However, in most contexts,
589-512: The addition of carbon dioxide gas under pressure or by dissolving carbonate or bicarbonate salts into the water. In geology and mineralogy , the term "carbonate" can refer both to carbonate minerals and carbonate rock (which is made of chiefly carbonate minerals), and both are dominated by the carbonate ion, CO 2− 3 . Carbonate minerals are extremely varied and ubiquitous in chemically precipitated sedimentary rock . The most common are calcite or calcium carbonate , CaCO 3 ,
620-506: The base of the Permian as the first appearance of the conodont Streptognathus isolatus pushes the earliest part of the formation, and the associated North American Wolfcampian Stage back into the latest Pennsylvanian. The Red Tanks Member also contains biogenic carbonate nodules ( oncolites ) at Cibola Spring ( 34°13′52″N 106°40′44″W / 34.231151°N 106.6787895°W / 34.231151; -106.6787895 ) in
651-459: The carbonate ion has two (long) single bonds to negative oxygen atoms, and one short double bond to a neutral oxygen atom. This structure is incompatible with the observed symmetry of the ion, which implies that the three bonds are the same length and that the three oxygen atoms are equivalent. As in the case of the isoelectronic nitrate ion, the symmetry can be achieved by a resonance among three structures: This resonance can be summarized by
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#1732801207481682-453: The chief constituent of limestone (as well as the main component of mollusc shells and coral skeletons); dolomite , a calcium-magnesium carbonate CaMg(CO 3 ) 2 ; and siderite , or iron(II) carbonate , FeCO 3 , an important iron ore . Sodium carbonate ("soda" or "natron"), Na 2 CO 3 , and potassium carbonate ("potash"), K 2 CO 3 , have been used since antiquity for cleaning and preservation, as well as for
713-434: The circumstances under which it was formed, it may show cracks or fissures, like a sun-baked clay deposit. When the mineral composition of mudstones has been determined, using such techniques as scanning electron microscopy , electron probe microanalysis , or X-ray diffraction analysis , they have been found to be composed primarily of clay minerals , quartz , and feldspars , with a variety of accessory minerals . In
744-476: The development of this formation than glacial cycles . Fossils found in the formation include the fusulinid Triticites from which its early Permian age is determined. The formation also preserves fossils of the forams Bradyina lucida and Eostaffella . There are two Lagerstätten in the Red Tanks Member at Carrizo Arroyo that are of early Asselian age, while the recent definition of
775-473: The long-term carbon cycle, due to the large number of marine organisms (especially coral) which are made of calcium carbonate. Increased solubility of carbonate through increased temperatures results in lower production of marine calcite and increased concentration of atmospheric carbon dioxide. This, in turn, increases Earth temperature. The amount of CO 2− 3 available is on a geological scale and substantial quantities may eventually be redissolved into
806-435: The manufacture of glass . Carbonates are widely used in industry, such as in iron smelting, as a raw material for Portland cement and lime manufacture, in the composition of ceramic glazes , and more. New applications of alkali metal carbonates include: thermal energy storage, catalysis and electrolyte both in fuel cell technology as well as in electrosynthesis of H 2 O 2 in aqueous media. The carbonate ion
837-412: The need for infrastructural water softening . Acidification of carbonates generally liberates carbon dioxide : Thus, scale can be removed with acid. In solution the equilibrium between carbonate, bicarbonate, carbon dioxide and carbonic acid is sensitive to pH, temperature, and pressure. Although di- and trivalent carbonates have low solubility, bicarbonate salts are far more soluble. This difference
868-781: The northern Jornada del Muerto and in the Los Pinos Mountains . They assigned the formation to the (now-defunct) Magdalena Group. M.L. Thompson later redefined the formation as including all Permian beds older than the Abo Formation, characterizing these as transitional beds between the marine beds of the Madera Group and the Abo Formation. D.A. Myers assigned the formation to the Madera Group in 1972. In his revision of Pennsylvanian stratigraphy in New Mexico in 2001, Barry S. Kues retained this assignment, except in
899-410: The pH is too high, the kidneys excrete bicarbonate ( HCO − 3 ) into urine as urea via the urea cycle (or Krebs–Henseleit ornithine cycle). By removing the bicarbonate, more H is generated from carbonic acid ( H 2 CO 3 ), which comes from CO 2 (g) produced by cellular respiration . Crucially, a similar buffer operates in the oceans. It is a major factor in climate change and
930-412: The sea and released to the atmosphere, increasing CO 2 levels even more. It is generally thought that the presence of carbonates in rock is strong evidence for the presence of liquid water. Recent observations of the planetary nebula NGC 6302 show evidence for carbonates in space, where aqueous alteration similar to that on Earth is unlikely. Other minerals have been proposed which would fit
961-438: The term refers to siliciclastic mudstone, composed mostly of silicate minerals. The NASA Curiosity rover has found deposits of mudstone on Mars that contain organic substances such as propane , benzene and toluene . There is not a single definition of mudstone that has gained general acceptance, though there is wide agreement that mudstones are fine-grained sedimentary rocks, composed mostly of silicate grains with