Fell July 15, 1878
49° 36′ N., 17° 7′ E. A single 27.4 kg stone was seen and heard to fallMeteorite seen to fall. Such meteorites are usually collected soon after falling and are not affected by terrestrial weathering (Weathering = 0). Beginning in 2014 (date needs confirmation), the NomComm adopted the use of the terms "probable fall" and "confirmed fall" to provide better insight into the meteorite's history. If Click on Term to Read More at 1:45 in the afternoon in Prostejov, Jihomoravsky, Czechoslovakia. Analysis was conducted at the Museum of the Technical High School of Brünn, and Tieschitz was classified as an unbrecciated, unequilibrated ordinary chondriteWork in Progress Ordinary chondrites (OCs) are the largest meteorite clan, comprising approximately 87% of the global collection and 78% of all falls (Meteoritical Society database 2018)1. Meteorites & the Early Solar System: page 581 section 6.1 OC of type 5 or 6 with an apparent shock stage of S1, Click on Term to Read More with a shock stageA petrographic assessment, using features observed in minerals grains, of the degree to which a meteorite has undergone shock metamorphism. The highest stage observed in 25% of the indicator grains is used to determine the stage. Also called "shock level". Click on Term to Read More of S1/S2. This meteoriteWork in progress. A solid natural object reaching a planet’s surface from interplanetary space. Solid portion of a meteoroid that survives its fall to Earth, or some other body. Meteorites are classified as stony meteorites, iron meteorites, and stony-iron meteorites. These groups are further divided according to their mineralogy and Click on Term to Read More has preserved the early record of large-grained, pristine chondritesChondrites are the most common meteorites accounting for ~84% of falls. Chondrites are comprised mostly of Fe- and Mg-bearing silicate minerals (found in both chondrules and fine grained matrix), reduced Fe/Ni metal (found in various states like large blebs, small grains and/or even chondrule rims), and various refractory inclusions (such Click on Term to Read More.
Tieschitz does not follow the ordinary chondriteChondrites are the most common meteorites accounting for ~84% of falls. Chondrites are comprised mostly of Fe- and Mg-bearing silicate minerals (found in both chondrules and fine grained matrix), reduced Fe/Ni metal (found in various states like large blebs, small grains and/or even chondrule rims), and various refractory inclusions (such Click on Term to Read More
metal–silicateThe most abundant group of minerals in Earth's crust, the structure of silicates are dominated by the silica tetrahedron, SiO44-, with metal ions occurring between tetrahedra). The mesodesmic bonds of the silicon tetrahedron allow extensive polymerization and silicates are classified according to the amount of linking that occurs between the
trends in that it has an anomalous Fe content intermediate between the H and L groups, and it has a lower K content than is typical for both of those groups. In addition, Fe is more highly depleted compared to Ni. The Sm–Nd age of ~2 b.y. is evidence that a partial resetting event took place on the parent bodyThe body from which a meteorite or meteoroid was derived prior to its ejection. Some parent bodies were destroyed early in the formation of our Solar System, while others like the asteroid 4-Vesta and Mars are still observable today. Click on Term to Read More
at that time, possibly occurring during an aqueous alteration phase. The chemical composition of Tieschitz can support two petrogenetic scenarios—one in which formation occurred on a parent body unique from that of the H- and L-group ordinary chondrites, and another in which Fe was lost from an H-type chondritic body without disrupting the balance of other elemental systematics.
Tieschitz is texturally unique in that it contains both an opaque (black) matrixFine grained primary and silicate-rich material in chondrites that surrounds chondrules, refractory inclusions (like CAIs), breccia clasts and other constituents. Click on Term to Read More
component and a transparent (white) matrix component. The white matrix material fills the interstitialTerm applied to ions or atoms occupying sites between lattice points. Click on Term to Read More
space between chondrulesRoughly spherical aggregate of coarse crystals formed from the rapid cooling and solidification of a melt at ~1400 ° C. Large numbers of chondrules are found in all chondrites except for the CI group of carbonaceous chondrites. Chondrules are typically 0.5-2 mm in diameter and are usually composed of olivine Click on Term to Read More
and clasts, and is comprised of an amorphousMaterial without the regular, ordered structure of crystalline solids. Amorphous substances, like glass, lack a definite repeating pattern in their atomic structures (crystallinity). There may be small regions of order, but, overall there is disorder. Click on Term to Read More
phase primarily composed of albitic plagioclaseAlso referred to as the plagioclase feldspar series. Plagioclase is a common rock-forming series of feldspar minerals containing a continuous solid solution of calcium and sodium: (Na1-x,Cax)(Alx+1,Si1-x)Si2O8 where x = 0 to 1. The Ca-rich end-member is called anorthite (pure anorthite has formula: CaAl2Si2O8) and the Na-rich end-member is albite Click on Term to Read More
(Al-, Na-, and Ca-rich) containing nanometer scale inclusions of Ca-rich pyroxeneA class of silicate (SiO3) minerals that form a solid solution between iron and magnesium and can contain up to 50% calcium. Pyroxenes are important rock forming minerals and critical to understanding igneous processes. For more detailed information, please read the Pyroxene Group article found in the Meteoritics & Classification Click on Term to Read More
(Dobrică and Brearley, 2011, 2014, 2016). The white matrix is theorized to have precipitated from a leachate of chondruleRoughly spherical aggregate of coarse crystals formed from the rapid cooling and solidification of a melt at ~1400 ° C. Large numbers of chondrules are found in all chondrites except for the CI group of carbonaceous chondrites. Chondrules are typically 0.5-2 mm in diameter and are usually composed of olivine Click on Term to Read More
feldspathic mesostasisLast material to crystallize/solidify from a melt. Mesostasis can be found in both chondrules, in the matrix around chondrules, and in achondrites as interstitial fine-grained material such as plagioclase, and/or as glass between crystalline minerals. Click on Term to Read More
glass that was dissolved by an aqueous, halogenated, metasomatic fluid (Dobrică and Brearley, 2014 and references therein). This scenario is consistent with the numerous voids found in ~30% of the chondrules and the observation that the white matrix shares a similar mineralogy with the altered ‘bleached’ chondrules.
The low-alkali black matrix component of Tieschitz also shows the effects of metasomatism (Dobrică and Brearley, 2011). The black matrix contains micron-scale voids and veins, sometimes incorporating a polycrystalline fibrous mineralInorganic substance that is (1) naturally occurring (but does not have a biologic or man-made origin) and formed by physical (not biological) forces with a (2) defined chemical composition of limited variation, has a (3) distinctive set of of physical properties including being a solid, and has a (4) homogeneous Click on Term to Read More
lining the walls which was determined to be sodic-calcic amphibole, a secondary mineralMineral that forms through processes such as weathering, and in the case of meteorites can also include pre-terrestrial alteration. Secondary minerals in meteorites that formed during terrestrial weathering include oxides and hydroxides formed directly from metallic Fe-Ni by oxidation, phosphates formed by the alteration of schreibersite, and sulfates formed by Click on Term to Read More
never before reported in an ordinary chondrite (Dobrică and Brearley, 2014). In addition, elongated ferroan olivineGroup of silicate minerals, (Mg,Fe)2SiO4, with the compositional endpoints of forsterite (Mg2SiO4) and fayalite (Fe2SiO4). Olivine is commonly found in all chondrites within both the matrix and chondrules, achondrites including most primitive achondrites and some evolved achondrites, in pallasites as large yellow-green crystals (brown when terrestrialized), in the silicate portion Click on Term to Read More
crystals are present within the voids, which were demonstrated to have formed under conditions of low pressure and low water:rock ratios. Both the amphibole and the olivine were precipitated from an aqueous fluid, probably during the same hydrothermal event that produced the voids in the chondrule mesostasis.
Although a Sm–Nd study (Smoliar et al.
, 2004) suggests that a late alteration event occurred ~2.0 b.y. ago, necessarily involving an impact heating event, the Ar–Ar chronometer has not been disturbed (4.45 [±0.05] b.y.; Turner et al.
, 1978). Upon consideration of all the evidence, Dobrică and Brearley (2014) argue that the metasomatic process that produced the amphibole-filled voids in the black matrix, and which led to the precipitation of the albitic white matrix, most likely occurred during primary metamorphism on the parent body of Tieschitz through radiogenic heating.
A native Cu assemblage has been identified by Komorowski et al.
(2009, 2010, 2012) consisting of nm-sized metallic Hg spherules and HgS (cinnabar), associated with CuS (covellite) and native Cu. This first occurrence of native Hg in a meteorite likely reflects equilibration with subsequent sulfidation processes during accretionAccumulation of smaller objects into progressively larger bodies in the solar nebula leading to the eventual formation of asteroids, planetesimals and planets. The earliest accretion of the smallest particles was due to Van der Waals and electromagnetic forces. Further accretion continued by relatively low-velocity collisions of smaller bodies in the Click on Term to Read More
of fine-grained dust at low temperatures (<< 300°C) within the nebulaAn immense interstellar, diffuse cloud of gas and dust from which a central star and surrounding planets and planetesimals condense and accrete. The properties of nebulae vary enormously and depend on their composition as well as the environment in which they are situated. Emission nebula are powered by young, massive Click on Term to Read More
. It has been demonstrated that these volatile-rich assemblages are not associated with shock-generated remobilization–condensation scenarios on the parent asteroid.
A wide variety of chondrule types are present in Tieschitz including BO, RP, and POP. Unlike other H3 chondrules, the porphyritic chondrules in Tieschitz have accretionary, fine-grained, dark rims, possibly formed by fine dust from impacts prior to planetary accumulation and lithification. Metal–troiliteBrass colored non-magnetic Fe sulfide, FeS, found in a variety of meteorites.
assemblages also occur in chondrule rims. Flat trace elementSubstance composed of atoms, each of which has the same atomic number (Z) and chemical properties. The chemical properties of an element are determined by the arrangement of the electrons in the various shells (specified by their quantum number) that surround the nucleus. In a neutral atom, the number of Click on Term to Read More
abundance patterns of refractory lithophiles in nonporphyritic chondrules suggest that they originated by direct nebular condensation, which was followed by metasomatic processes (Engler et al.
, 2003). A cooling rate of 18°C/m.y. was calculated for Tieschitz based upon cloudy taeniteLess common than kamacite, both taenite and kamacite are Ni-Fe alloys found in iron meteorites. Taenite, γ-(Fe,Ni), has 27-65 wt% Ni, and forms small crystals that appear as highly reflecting thin ribbons on the etched surface of a meteorite; the name derives from the Greek word for "ribbon." Click on Term to Read More
particle size (Scott et al.
, 2013). This cooling rate, along with other literature cooling rate data for a broad spectrum of meteorite groups having a wide range of metamorphicRocks that have recrystallized in a solid state due to changes in temperature, pressure, and chemical environment. Click on Term to Read More
grades, led to the conclusion that an onion shell model was not appropriate for the ordinary chondrites; instead, thorough impact-generated mixing of all the metamorphic layers after cooling is considered a more scenario.
Anomalous grains including presolar Al-rich oxide grains have been identified in Tieschitz. Most of these anomalous grains are known to originate in red giantGiant and highly luminous red star in the later stages of stellar evolution after it has left the main sequence. These red stars have a relatively cool surface whose core has burned most of its hydrogen. Red giants lose parts of their atmospheres and thus provide new elements into interstellar Click on Term to Read More
stars located ~100 AUThe astronomical unit for length is described as the "mean" distance (average of aphelion and perihelion distances) between the Earth and the Sun. Though most references state the value for 1 AU to be approximately 150 million kilometers, the currently accepted precise value for the AU is 149,597,870.66 km. The Click on Term to Read More
from the solar nebulaThe primitive gas and dust cloud around the Sun from which planetary materials formed.
; one particular 17
O-rich grain has a composition consistent with an origin from a supernovaStellar explosion that expels much or all of the stellar material with great force, driving a blast wave into the surrounding space, and leaving a supernova remnant. Supernovae are classified based on the presence or absence of features in their optical spectra taken near maximum light. They were first categorized Click on Term to Read More
. Another 17
O-depleted grain has a composition more representative of a low mass starSelf-luminous object held together by its own self-gravity. Often refers to those objects which generate energy from nuclear reactions occurring at their cores, but may also be applied to stellar remnants such as neutron stars.
like the SunOur parent star. The structure of Sun's interior is the result of the hydrostatic equilibrium between gravity and the pressure of the gas. The interior consists of three shells: the core, radiative region, and convective region. Image source: http://eclipse99.nasa.gov/pages/SunActiv.html. The core is the hot, dense central region in which the
. Also present are circumstellar grains of graphiteOpaque form of carbon (C) found in some iron and ordinary chondrites and in ureilite meteorites. Each C atom is bonded to three others in a plane composed of fused hexagonal rings, just like those in aromatic hydrocarbons. The two known forms of graphite, α (hexagonal) and β (rhombohedral), have Click on Term to Read More
, corundumCrystalline form of aluminium oxide, Al2O3, found in Ca-Al-rich inclusions (CAIs). Corundum-bearing CAI are a rare class of high-temperature condensates from the inner regions of the protoplanetary disk1. Click on Term to Read More
, and spinelMg-Al oxide, MgAl2O4, found in CAIs.
, and an abundance of SiC grains; these grains have anomalous isotopic ratios and are considered to have condensed around AGB or J-type stars. The few SiC X-grains present in Tieschitz were probably formed in type II supernovae. From their study of O-isotopic anomalies of the Sun, Lee et al.
(2008) inferred that the Sun must have formed within a stellar cluster coeval with a massive star.
It was demonstrated by Szurgot (2016) that the mean atomic weightMass of a neutral atom of a nuclide - also called "atomic weight." The atomic weight of an element is the weighted average of each isotope. Click on Term to Read More
) of meteorites can be used to resolve the OC groups, including the intermediate groups L/LL and H/L. Amean
values can also be predicted through various equations based on other parameters such as atomic Fe/Si
ratio and grain densityMass of an object divided by its volume. Density is a characteristic property of a substance (rock vs. ice, e.g.). Some substances (like gases) are easily compressible and have different densities depending on how much pressure is exerted upon them. The Sun is composed of compressible gases and is much Click on Term to Read More
, and these Amean
values, as well as the magnetic susceptibility values derived from X-ray fluorescenceEmission of electromagnetic radiation, especially of light, that results from bombardment of a substance with other forms of electromagnetic radiation. This spontaneously emitted radiation ceases immediately after excitation ceases. Click on Term to Read More
(XRF) scanning, all consistently resolve these groups into the ordered sequence LL < L/LL < L < H/L < H. Tieschitz has Amean
values of 24.32 (chemical composition), 24.14 (Fe/Si
atomic ratio), and 24.30 (grain density). The magnetic susceptibility value for Tieschitz (logχ
= 4.91) corresponds to an Amean
value of 23.92 utilizing the equation [Amean
= 1.49 × logχ
+ 16.6]. The magnetic susceptibility values determined for both the historical and transitional OC groups are consistent with the ordered sequence above. Furthermore, it was demonstrated that Amean
values are lower for unequilibrated type 3 samples than for equilibrated samples within each OC group due to the presence of water; Amean
values for petrologic types 4–6 are indistinguishable within each group.
Diagram credit: M. Szurgot, 47th LPSC, #2180
based on chemical composition (Eq. 1), Fe/Si
atomic ratio (Eq. 2), and grain density (Eq. 3) A hypothesis was presented by Trigo-Rodríguez and Williams (2016) to explain the notable coincidence in the timing of the four known H/L chondrite falls—all occurring within a three month period: Bremervorde on May 13, 1855; Famenin on June 27, 2015; Cali on July 6, 2007; and Tieschitz on July 15, 1878. The probability that all of the H/L meteorite falls would occur within this specific timeframe completely by chance was calculated to be only 6%. Trigo-Rodríguez and Williams (2016) consider that these H/L chondrites could be associated with the Bejar bolideA very bright fireball that breaks apart in the atmosphere with a minimum brightness approximately equivalent to the full moon. Click on Term to Read More
that was tracked by the Spanish MeteorHow long Sonic booms Of the several 10s of tons of cosmic material entering Earth's atmosphere each day, only about one ton reaches the surface. An object's chance of survival depends on its initial mass, speed and angle of entry, and friability (tendency to break up). Micrometeoroids radiate heat so Click on Term to Read More
Network above Salamanca, Spain on July 11, 2008, and also fortuously photographed
from Madrid by Javier Pérez Vallejo. Based on the available data, an orbital solution was constructed for this bolide which is consistent with a high-inclination orbitThe elliptical path of one body around another, typically the path of a small body around a much larger body. However, depending on the mass distribution of the objects, they may rotate around an empty spot in space • The Moon orbits around the Earth. • The Earth orbits around Click on Term to Read More
, and it is considered that it could represent material from the disruption of cometConglomeration of frozen water and gases (methane, ammonia, CO2) and silicates that that formed in the outer solar system and orbits the Sun. In recent years, the description of comets has shifted from dirty snowballs to snowy dirtballs with more dust than ice. However, the ratio is less than 10-to-1. Click on Term to Read More
C/1919 Q2 Metcalf (see diagram below). They also propose that the Bejar bolide along with the H/L chondrites could be associated with the Omicron Draconids meteor streamRelatively narrow band of meteoroids stretched out along the orbital path of a comet. It consists of dust released from the nucleus of a comet during its perihelion passage. The dust grains escape the weak gravity of the nucleus and travel on their own independent, heliocentric orbits. Although these orbits
which was shown by A. Cook to follow a similar orbit as comet C/1919 Q2 Metcalf. As demonstrated by Martínez-Jiménez et al.
(2016) in their study of the Cali meteorite, not all H/L chondrites show such obvious features of aqueous alteration as those present in Tieschitz. Therefore, the H/L parent asteroid could be heterogeneous with respect to aqueous alteration, or alternatively, it could be a rubble pile composed of a broad diversity of material with variable densitiesMass of an object divided by its volume. Density is a characteristic property of a substance (rock vs. ice, e.g.). Some substances (like gases) are easily compressible and have different densities depending on how much pressure is exerted upon them. The Sun is composed of compressible gases and is much Click on Term to Read More
and metamorphic histories.
Diagram credit: Josep M. Trigo-Rodríguez/SPMN Other meteorites assigned to this intermediate chondrite group include Famenin [3.8–3.9], Bremervörde [3.9], NWA 1955 [3–4], Haxtun , Yamato 74645 , Cali , and Yamato 8424; initial studies of Dhofar 008 indicate that it might also belong to this group. The specimen of Tieschitz shown above is a 4.8 g interior cut fragment, and the bottom image is an excellent petrographic thin sectionThin slice or rock, usually 30 µm thick. Thin sections are used to study rocks with a petrographic microscope.
micrograph of Tieschitz, shown courtesy of Peter Marmet. click on image for a magnified view
Photo courtesy of Peter Marmet