Carbonaceous Chondrite (CR-an; S1/2; W0/1)
Find, 2000; 114 kg

Over thirteen months a total of 27 stones were found by two different members of a search party in Niger. The stones share a basic lithology — dominant constituents are largely equilibrated olivine (very roughly 50 vol%), frequently accompanied by pyroxene in relic chondrules (roughly 30 vol%) with accessory Fe-Ni metal and interstial plagioclase. However, textures, relative abundances of phases, and oxygen isotope signatures vary significantly with different stones. Matrix plagioclase has a general andesine composition (~An46), but plagioclase in relic chondrules is closer to oligoclase (~An46). Larger Fe-Ni metal grains are largely kamacite while smaller grains are often taenite-rich and accompanied by sulfides. Attempts to explain these characteristics have usually attributed these features as due to incomplete metamorphism of some originally very diverse components within the region of the solar nebula where the CR original homeworld(s) originated.

As Tafassasset is by far the most massive of the meteorites classified as CR (Renazzo-like) carbonaceous chondrites, it is — of course — quite understandable that understanding the relationships between Tafassasset's different constituents and the relationships between Tafassasset and other CR chondrites has taken center stage. A frequent suggestion has been that the CB, CH, and CR carbonaceous chondrite groups constitute a subclass (or 'clan') among the larger carbonaceous chondrite class with its 8 defined groups. Tafassasset provides plenty of material which might contribute to a more definitive understanding of the origins of these relatively metal-rich groups within the overall carbonaceous chondrite class.

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Standard Detailed Gallery Strunz Chemical Elements

Mineral List

6 valid minerals.

Meteorite/Rock Types Recorded

Note: data is currently VERY limited. Please bear with us while we work towards adding this information!

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Alphabetical List Tree Diagram

ⓘ Primitive achondrite meteorite

Detailed Mineral List:

ⓘ Chromite

Formula: Fe²⁺Cr³⁺₂O₄

References:

Russell, S.S., Zipfel, J., Grossman, J.N. & Grady, M.M. (2002). The Meteoritical Bulletin, No. 86, 2002 July. Meteoritics & Planetary Science 37 (7,Suppl.): pp. A157-A184. (July 2002).

Bourot-Denise, M., Zanda, B. & M. Javoy, M. (2012) Tafassasset: An Equilibrated CR Chondrite. 33rd Annual Lunar and Planetary Science Conference, March 11-15, 2002, Houston, Texas, abstract no.1611. (Mar 2012).

ⓘ 'Clinopyroxene Subgroup'

References:

Russell, S.S., Zipfel, J., Grossman, J.N. & Grady, M.M. (2002). The Meteoritical Bulletin, No. 86, 2002 July. Meteoritics & Planetary Science 37 (7,Suppl.): pp. A157-A184. (July 2002).

ⓘ 'Fayalite-Forsterite Series'

Description: Olivine composition — Fa29.3.

References:

Russell, S.S., Zipfel, J., Grossman, J.N. & Grady, M.M. (2002). The Meteoritical Bulletin, No. 86, 2002 July. Meteoritics & Planetary Science 37 (7,Suppl.): pp. A157-A184. (July 2002).

ⓘ Iron

Formula: Fe

Description: Kamacite (6% Ni, 0.6% Co).

References:

Russell, S.S., Zipfel, J., Grossman, J.N. & Grady, M.M. (2002). The Meteoritical Bulletin, No. 86, 2002 July. Meteoritics & Planetary Science 37 (7,Suppl.): pp. A157-A184. (July 2002).

ⓘ Iron var. Kamacite

Formula: (Fe,Ni)

Description: Kamacite (6% Ni, 0.6% Co).

References:

Russell, S.S., Zipfel, J., Grossman, J.N. & Grady, M.M. (2002). The Meteoritical Bulletin, No. 86, 2002 July. Meteoritics & Planetary Science 37 (7,Suppl.): pp. A157-A184. (July 2002).

ⓘ Iron var. Martensite

Formula: Fe

References:

Russell, S.S., Zipfel, J., Grossman, J.N. & Grady, M.M. (2002). The Meteoritical Bulletin, No. 86, 2002 July. Meteoritics & Planetary Science 37 (7,Suppl.): pp. A157-A184. (July 2002).

ⓘ Merrillite

Formula: Ca₉NaMg(PO₄)₇

References:

ⓘ 'Orthopyroxene Subgroup'

References:

Russell, S.S., Zipfel, J., Grossman, J.N. & Grady, M.M. (2002). The Meteoritical Bulletin, No. 86, 2002 July. Meteoritics & Planetary Science 37 (7,Suppl.): pp. A157-A184. (July 2002).

ⓘ Pentlandite

Formula: (Ni_xFe_y)_Σ9S₈

References:

Russell, S.S., Zipfel, J., Grossman, J.N. & Grady, M.M. (2002). The Meteoritical Bulletin, No. 86, 2002 July. Meteoritics & Planetary Science 37 (7,Suppl.): pp. A157-A184. (July 2002).

ⓘ 'Plagioclase'

Formula: (Na,Ca)[(Si,Al)AlSi₂]O₈

Description: An46.4Or2.2 in matrix; An26.6Or5.2 in chondrule relics.

References:

Russell, S.S., Zipfel, J., Grossman, J.N. & Grady, M.M. (2002). The Meteoritical Bulletin, No. 86, 2002 July. Meteoritics & Planetary Science 37 (7,Suppl.): pp. A157-A184. (July 2002).

ⓘ 'Pyroxene Group'

Formula: ADSi₂O₆

Description: Pyroxene composition — Fs24.3.

References:

ⓘ Taenite

Formula: (Fe,Ni)

Description: Taenite (up to 36% Ni, 0.2% Co) with martensite cores.

References:

Russell, S.S., Zipfel, J., Grossman, J.N. & Grady, M.M. (2002). The Meteoritical Bulletin, No. 86, 2002 July. Meteoritics & Planetary Science 37 (7,Suppl.): pp. A157-A184. (July 2002).

ⓘ Troilite

Formula: FeS

References:

Russell, S.S., Zipfel, J., Grossman, J.N. & Grady, M.M. (2002). The Meteoritical Bulletin, No. 86, 2002 July. Meteoritics & Planetary Science 37 (7,Suppl.): pp. A157-A184. (July 2002).

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 1 - Elements
ⓘ	Iron	1.AE.05	Fe
ⓘ	var. Kamacite	1.AE.05	(Fe,Ni)
ⓘ	var. Martensite	1.AE.05	Fe
ⓘ	Taenite	1.AE.10	(Fe,Ni)
Group 2 - Sulphides and Sulfosalts
ⓘ	Pentlandite	2.BB.15	(Ni_xFe_y)_Σ9S₈
ⓘ	Troilite	2.CC.10	FeS
Group 4 - Oxides and Hydroxides
ⓘ	Chromite	4.BB.05	Fe²⁺Cr³⁺₂O₄
Group 8 - Phosphates, Arsenates and Vanadates
ⓘ	Merrillite	8.AC.45	Ca₉NaMg(PO₄)₇
Unclassified
ⓘ	'Clinopyroxene Subgroup'	-
ⓘ	'Fayalite-Forsterite Series'	-
ⓘ	'Plagioclase'	-	(Na,Ca)[(Si,Al)AlSi₂]O₈
ⓘ	'Pyroxene Group'	-	ADSi₂O₆
ⓘ	'Orthopyroxene Subgroup'	-

List of minerals for each chemical element

O	Oxygen
O	ⓘ Chromite	Fe²⁺Cr₂³⁺O₄
O	ⓘ Merrillite	Ca₉NaMg(PO₄)₇
O	ⓘ Fayalite-Forsterite Series
O	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
O	ⓘ Pyroxene Group	ADSi₂O₆
Na	Sodium
Na	ⓘ Merrillite	Ca₉NaMg(PO₄)₇
Na	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
Mg	Magnesium
Mg	ⓘ Merrillite	Ca₉NaMg(PO₄)₇
Mg	ⓘ Fayalite-Forsterite Series
Al	Aluminium
Al	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
Si	Silicon
Si	ⓘ Fayalite-Forsterite Series
Si	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
Si	ⓘ Pyroxene Group	ADSi₂O₆
P	Phosphorus
P	ⓘ Merrillite	Ca₉NaMg(PO₄)₇
S	Sulfur
S	ⓘ Pentlandite	(Ni_xFe_y)_Σ9S₈
S	ⓘ Troilite	FeS
Ca	Calcium
Ca	ⓘ Merrillite	Ca₉NaMg(PO₄)₇
Ca	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
Cr	Chromium
Cr	ⓘ Chromite	Fe²⁺Cr₂³⁺O₄
Fe	Iron
Fe	ⓘ Chromite	Fe²⁺Cr₂³⁺O₄
Fe	ⓘ Iron	Fe
Fe	ⓘ Iron var. Kamacite	(Fe,Ni)
Fe	ⓘ Pentlandite	(Ni_xFe_y)_Σ9S₈
Fe	ⓘ Taenite	(Fe,Ni)
Fe	ⓘ Troilite	FeS
Fe	ⓘ Fayalite-Forsterite Series
Fe	ⓘ Iron var. Martensite	Fe
Ni	Nickel
Ni	ⓘ Iron var. Kamacite	(Fe,Ni)
Ni	ⓘ Pentlandite	(Ni_xFe_y)_Σ9S₈
Ni	ⓘ Taenite	(Fe,Ni)

Other Regions, Features and Areas containing this locality

AfricaContinent

African PlateTectonic Plate

East Niger Rift basinBasin
Tuareg Shield
- Eastern Hoggar BeltVolcanic Arc

North Africa

Sahara DesertDesert

West AfricaUN Subregion

This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.

References

www.lpi.usra.edu (n.d.) http://www.lpi.usra.edu/meteor/metbull.php?sea=Tafassasset&sfor=names&ants=&falls=&valids=&stype=contains&lrec=50&map=ge&browse=&country=All&srt=name&categ=All&mblist=All&rect=&phot=&snew=0&pnt=Normal%20table&code=23779

www.lpi.usra.edu (n.d.) http://www.lpi.usra.edu/meteor/get_original_photo.php?recno=5632046

www.lpi.usra.edu (n.d.) http://www.lpi.usra.edu/meetings/lpsc2002/pdf/1611.pdf

Russell, S.S., Zipfel, J., Grossman, J.N. & Grady, M.M. (2002). The Meteoritical Bulletin, No. 86, 2002 July. Meteoritics & Planetary Science 37 (7,Suppl.): pp. A157-A184. (July 2002).

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Mineral List

Meteorite/Rock Types Recorded

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Detailed Mineral List:

Gallery:

List of minerals arranged by Strunz 10th Edition classification

List of minerals for each chemical element

Other Regions, Features and Areas containing this locality

References

Tafassasset meteorite, Arlit, Agadez, Niger i
Regional Level Types
Tafassasset meteorite Meteorite Fall Location
Arlit Department
Agadez Region
Niger Country