Eagle Station group

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Eagle Station group
  Group  
Eagle Station pallasite, Mineralogisches Museum, Bonn.jpg
Eagle Station meteorite, type specimen for the group
Type Stony-iron
Class Pallasite
Composition Meteoric iron, silicates
Total known specimens5

The Eagle Station group (abbreviated PES - Pallasite Eagle Station) is a set of pallasite meteorite specimen that do not fit into any of the other defined pallasite groups. In meteorite classification five meteorites have to be found, so they can be defined as their own group. [1] Currently only five Eagle Station type meteorites have been found, which is just enough for a separate group. [2]

Contents

Naming and history

The Eagle Station group is named after the Eagle Station meteorite, the type specimen of the group. It is in turned named after Eagle Station, Carroll County Kentucky where it was found. [3]

Description

The Eagle Station group has a composition similar to Main group pallasites. Diagnostic differences are that the olivine is richer in iron and calcium. The group also has a distinct oxygen isotope signature. [1]

The meteoric iron is similar to the IIF iron meteorites. This might indicate that Eagle station group and IIF formed close to each other in the solar nebula. [1]

Parent body

The trace elements in the phosphates of the Eagle Station group are distinct from other pallasites. Most pallasites are believed to be derived from the core-mantle boundary. Trace elements indicate that the Eagle Station group came from shallower depths of their parent body. [4]

Notable specimen

Only five specimen have been found so far: [2]

See also

Related Research Articles

<span class="mw-page-title-main">Kamacite</span> Alloy of iron and nickel found in meteorites

Kamacite is an alloy of iron and nickel, which is found on Earth only in meteorites. According to the International Mineralogical Association (IMA) it is considered a proper nickel-rich variety of the mineral native iron. The proportion iron:nickel is between 90%:10% and 95%:5%; small quantities of other elements, such as cobalt or carbon may also be present. The mineral has a metallic luster, is gray and has no clear cleavage although its crystal structure is isometric-hexoctahedral. Its density is about 8 g/cm3 and its hardness is 4 on the Mohs scale. It is also sometimes called balkeneisen.

<span class="mw-page-title-main">Peridot</span> Green gem-quality mineral

Peridot, sometimes called chrysolite, is a deep yellowish-green transparent variety of olivine. Peridot is one of the few gemstones that occurs in only one color.

<span class="mw-page-title-main">Meteorite classification</span> Systems of grouping meteorites based on shared characteristics

In meteoritics, a meteorite classification system attempts to group similar meteorites and allows scientists to communicate with a standardized terminology when discussing them. Meteorites are classified according to a variety of characteristics, especially mineralogical, petrological, chemical, and isotopic properties.

<span class="mw-page-title-main">Chondrite</span> Class of stony meteorites made of round grains

A chondrite is a stony (non-metallic) meteorite that has not been modified, by either melting or differentiation of the parent body. They are formed when various types of dust and small grains in the early Solar System accreted to form primitive asteroids. Some such bodies that are captured in the planet's gravity well become the most common type of meteorite by arriving on a trajectory toward the planet's surface. Estimates for their contribution to the total meteorite population vary between 85.7% and 86.2%.

<span class="mw-page-title-main">Carbonaceous chondrite</span> Class of chondritic meteorites

Carbonaceous chondrites or C chondrites are a class of chondritic meteorites comprising at least 8 known groups and many ungrouped meteorites. They include some of the most primitive known meteorites. The C chondrites represent only a small proportion (4.6%) of meteorite falls.

<span class="mw-page-title-main">Pallasite</span> Class of stony–iron meteorite

The pallasites are a class of stony–iron meteorite.

<span class="mw-page-title-main">Iron meteorite</span> Meteorite composed of iron-nickel alloy called meteoric iron

Iron meteorites, also known as siderites, or ferrous meteorites, are a type of meteorite that consist overwhelmingly of an iron–nickel alloy known as meteoric iron that usually consists of two mineral phases: kamacite and taenite. Most iron meteorites originate from cores of planetesimals, with the exception of the IIE iron meteorite group

<span class="mw-page-title-main">Allende meteorite</span>

The Allende meteorite is the largest carbonaceous chondrite ever found on Earth. The fireball was witnessed at 01:05 on February 8, 1969, falling over the Mexican state of Chihuahua. After it broke up in the atmosphere, an extensive search for pieces was conducted and over 2 tonnes were recovered. The availability of large quantities of samples of the scientifically-important chondrite class has enabled numerous investigations by many scientists; it is often described as "the best-studied meteorite in history." The Allende meteorite has abundant, large calcium–aluminium-rich inclusions (CAI), which are among the oldest objects formed in the Solar System.

<span class="mw-page-title-main">Pallasovka (meteorite)</span> Pallasite meterorite found during 1990 in southern Russia

Pallasovka is a pallasite meteorite found in 1990 near the town of Pallasovka, Russia.

<span class="mw-page-title-main">Mbozi meteorite</span>

Mbozi is an ungrouped iron meteorite found in Tanzania. It is one of the world's largest meteorites, variously estimated as the fourth-largest to the eighth-largest, it is located near the city of Mbeya in Tanzania's southern highlands. The meteorite is 3 metres (9.8 ft) long, 1 metre high, and weighs an estimated 16 metric tons.

<span class="mw-page-title-main">Lodranite</span> Type of meteorites

Lodranites are a small group of primitive achondrite meteorites that consists of meteoric iron and silicate minerals. Olivine and pyroxene make up most of the silicate minerals. Like all primitive achondrites lodranites share similarities with chondrites and achondrites.

Winonaites are a group of primitive achondrite meteorites. Like all primitive achondrites, winonaites share similarities with chondrites and achondrites. They show signs of metamorphism, partial melting, brecciation and relic chondrules. Their chemical and mineralogical composition lies between H and E chondrites.

The Brachina meteorite is the type specimen of the brachinites class of the asteroidal achondrites.

<span class="mw-page-title-main">IAB meteorite</span>

IAB meteorites are a group of iron meteorites according to their overall composition and a group of primitive achondrites because of silicate inclusions that show a strong affinity to winonaites and chondrites.

<span class="mw-page-title-main">IIICD meteorite</span>

IIICD meteorites are a group of primitive achondrites. They are classified in a clan together with the IAB meteorites and the winonaites.

<span class="mw-page-title-main">IVB meteorite</span>

IVB meteorites are a group of ataxite iron meteorites classified as achondrites. The IVB group has the most extreme chemical compositions of all iron meteorites, meaning that examples of the group are depleted in volatile elements and enriched in refractory elements compared to other iron meteorites.

<span class="mw-page-title-main">Eagle Station meteorite</span>

The Eagle Station meteorite is a pallasite and type specimen of the Eagle Station group.

IIG meteorites are a group of iron meteorites. The group currently has six members. They are hexahedrites with large amounts of schreibersite. The meteoric iron is composed of kamacite.

The Vermillion meteorite is a pallasite (stony-iron) meteorite and one of two members of the pyroxene pallasite grouplet.

This is a glossary of terms used in meteoritics, the science of meteorites.

References

  1. 1 2 3 D.S. Lauretta, H.Y. McSween, Jr., editors ; foreword by Richard P. Binze; M. K. Weisberg; T. J. McCoy, A. N. Krot (2006). "Systematics and Evaluation of Meteorite Classification". Meteorites and the early solar system II (PDF). Tucson: University of Arizona Press. pp. 19–52. ISBN   978-0816525621 . Retrieved 15 December 2012.{{cite book}}: |author= has generic name (help)CS1 maint: multiple names: authors list (link)
  2. 1 2 "Meteoritical Bulletin Database". Meteoritical Society.
  3. "Eagle Station". Meteoritical Society.
  4. Davis, Andrew M.; Olsen, Edward J. (17 October 1991). "Phosphates in pallasite meteorites as probes of mantle processes in small planetary bodies". Nature. 353 (6345): 637–640. Bibcode:1991Natur.353..637D. doi:10.1038/353637a0. S2CID   4301413.