Metallographic cooling rates and origin of IVA iron meteorites

Yang, Jijin; Goldstein, Joseph I.; Scott, E. R. D.

doi:10.1016/j.gca.2008.04.009

Cited by 85 publications

(151 citation statements)

References 61 publications

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“…according to Yang and Goldstein (2005), and the nucleation temperature for the kamacite precipitates is about 520°C (793 K) (Yang and Goldstein, 2006). The Fe-Ni and Fe-Ni-P phase diagrams, and the interdiffusion coefficients, which control the growth of the Widmanstätten pattern, are given by Yang et al (2008). The simulated result using the taenite profile matching method (Goldstein and Ogilvie, 1965) and the measured results (Fig.…”

Section: Fuzzy Creek (Iva)mentioning

confidence: 98%

“…In order to measure the cooling rates of Fuzzy Creek and EET, information about the nucleation process of the kamacite, the nucleation temperature, the effect of impingement by adjacent kamacite plates, the Fe-Ni and Fe-Ni-P phase diagrams, and the interdiffusion coefficients which control the growth of the Widmanstätten pattern are needed (Yang et al, 2008). The Ni profile matching method (Goldstein and Ogilvie, 1965) was used to obtain a cooling rate for individual measured taenite zoning profiles.…”

Section: Metallography and Cooling Ratesmentioning

confidence: 99%

“…Numerous studies have noted the large apparent range of metallographic cooling rates among IVA irons, which is inconsistent with a slowly cooled core, mantled by appreciable silicate rock or regolith (Goldstein and Short, 1967;Rasmussen et al, 1995;Haack et al, 1996;Yang et al, 2008). The variations in cooling rates have been accounted for in several ways.…”

Section: Introductionmentioning

confidence: 99%

“…Wasson et al (2006) speculated that the methodology to constrain metallographic cooling rates may be flawed, and that IVA cooling rates were actually generally constant. Yang et al (2008) concluded that the IVA irons cooled below 650°C at highly variable rates of 100-6600 K/Myr, where cooling rate decreased with increasing Ni content. To account for this they proposed inward crystallization of a metallic body of radius 150 ± 50 km with <1 km of silicate mantle.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Group IVA irons: New constraints on the crystallization and cooling history of an asteroidal core with a complex history

McCoy

Walker

Goldstein

et al. 2011

Geochimica et Cosmochimica Acta

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Section: Fuzzy Creek (Iva)mentioning

confidence: 98%

Section: Metallography and Cooling Ratesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Group IVA irons: New constraints on the crystallization and cooling history of an asteroidal core with a complex history

McCoy

Walker

Goldstein

et al. 2011

Geochimica et Cosmochimica Acta

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“…Poleg zna~ilnih razlik v hitrosti ohlajanja med kemijskimi skupinami so tudi znotraj posameznih skupin razponi v hitrosti ohlajanja precej veliki. Zelo veliki razponi so lahko posledica trkov velikih diferenciranih mati~nih teles z drugimi ve~jimi telesi, pri ~emer so prvotna mati~na telesa razpadla na ve~ manj{ih, ki so se razli~no hitro ohlajala (yanG et al, 2008;Goldstein et al, 2009;yanG et al, 2010). Na podlagi hitrosti ohlajanja posameznega meteorita je možno oceniti, v katerem delu jedra mati~nega telesa je le-ta nastal.…”

Section: Hitrost Ohlajanja Meteorita Javorjeunclassified

Two years of the Javorje meteorite investigations

Miler¹,

Gosar²

2012

Geologija

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Klju~ne besede: železov meteorit Javorje, srednji oktaedrit IIIAB, sEM/EDs analiza, mineralna in kemijska sestava, hitrost ohlajanja, Poljanska dolina, slovenijaKey words: iron meteorite Javorje, medium octahedrite IIIAB, sEM/EDs analysis, mineral and chemical composition, cooling rate, Poljane Valley, slovenia Izvle~ekMeteorit Javorje je železov meteorit, natan~neje srednji oktaedrit iz kemijske skupine železovih meteoritov z oznako IIIAB s 7,83-odstotno vsebnostjo niklja. Najden je bil novembra 2009 blizu Javorij v Poljanski dolini. s skoraj petimi kilogrami predstavlja najve~ji in najtežji meteorit, kar so jih doslej na{li na ozemlju slovenije. Namen ~lanka je predstaviti glavne zna~ilnosti meteorita Javorje tudi slovenski geolo{ki javnosti. V ~lanku so povzeti rezultati že objavljene raziskave tega meteorita, dodane pa so nekatere novej{e ugotovitve in podrobnosti o glavnih, akcesornih in sekundarnih mineralih ter o hitrosti ohlajanja. AbstractMeteorite Javorje is a IIIAB medium octahedrite iron meteorite with 7.83 wt% Ni content. It was found in November 2009 near village Javorje in the Poljane Valley. With nearly five kilograms it represents the largest and heaviest meteorite found so far in the territory of slovenia. The purpose of this paper is to present general characteristics of meteorite Javorje to the slovenian geological community. This paper reviews results of already published research of this meteorite and provides some newer findings and details about major, accessory and secondary minerals, and also its cooling rate. UvodMeteorit Javorje je s skoraj petimi kilogrami najve~ji in najtežji meteorit izmed doslej najdenih na ozemlju slovenije, in prav je, da o izsledkih raziskav tega zanimivega predmeta seznanjamo tudi bralce Geologije, osrednje slovenske geolo{ke znanstvene revije. Pred dobrima dvema letoma je v bližini Javorij nad Poljansko dolino, zahodno od Škofje Loke, Vladimir Štibelj povsem po naklju~ju odkril meteorit, ki poleg železovega meteorita Av~e in kamnitega meteorita Jesenice, predstavlja tretji meteorit najden na ozemlju slovenije. Pri gradnji gozdne ceste je pozornost najditelja v novo skopanem cestnem useku na globini 65-70 cm pritegnila nenavadna gmota, ki se je po svojem videzu razlikovala od kamnine in tal v kateri je ležala. Ko jo je vzel v roke, je ugotovil, da je nenavadno težka. V trenutku je bil prepri~an, da je na{el izjemno najdbo in domneval, da je najdeni predmet meteorit. Domnevni meteorit je skrbno shranil ter o najdbi obvestil v Poljanski dolini dobro znanega geologa, nekdanjega sodelavca rudnika urana Žirovski vrh, Pavla A. Florjan~i~a. skupaj sta ugotovila, da je kos kovinski in da mo~no privla~i magnet. seveda pa tudi Pavle A. Florjan~i~ ni mogel brez analiz potrditi, da je najdba res meteorit. Zato sta za pomo~ prosila raziskovalce Geolo{kega zavoda slovenije. raziskave domnevnega meteorita so nam predstavljale velik raziskovalni izziv, saj se do takrat z materialom iz vesolja {e nismo sre~ali. Ko so preliminarne analize z vrsti~nim elektronskim mikroskopom v ...

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Core solidification and dynamo evolution in a mantle‐stripped planetesimal

et al. 2016

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The physical processes active during the crystallization of a low-pressure, low-gravity planetesimal core are poorly understood but have implications for asteroidal magnetic fields and large-scale asteroidal structure. We consider a core with only a thin silicate shell, which could be analogous to some M-type asteroids including Psyche, and use a parameterized thermal model to predict a solidification timeline and the resulting chemical profile upon complete solidification. We then explore the potential strength and longevity of a dynamo in the planetesimal's early history. We find that cumulate inner core solidification would be capable of sustaining a dynamo during solidification, but less power would be available for a dynamo in an inward dendritic solidification scenario. We also model and suggest limits on crystal settling and compaction of a possible cumulate inner core.Iron meteorites can also provide information on the cooling rate experienced after solidification. Yang et al. [2008] examined several irons in the IVA meteorite family and found a large range of cooling rates within Key Points: • The rate and structure of inward fractional crystallization are constrained • Crystal settling could form a cumulate inner core with significant trapped melt • Constraints are placed on dynamo strength and longevity during solidification

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Metallographic cooling rates and origin of IVA iron meteorites

Cited by 85 publications

References 61 publications

Group IVA irons: New constraints on the crystallization and cooling history of an asteroidal core with a complex history

Group IVA irons: New constraints on the crystallization and cooling history of an asteroidal core with a complex history

Two years of the Javorje meteorite investigations

Core solidification and dynamo evolution in a mantle‐stripped planetesimal

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