Carbonaceous Chondrite (CM2)

A 430 g meteorite was noticed on or about 29 April 1986, but was not collected until after a rain and subsequent discovery of a meteorite-produced hole in the roof. Sayama is a CM (Mighei-like) Carbonaceous Chondrite. The CMs are distinguished by small chondrules, refractory inclusions, abundant fine-grained matrix, and abundant hydrated minerals. Sayama’s matrix is unusually pervasive even for a CM meteorite. Evidence of hydrous alteration abounds — serpentine is often pseudomorphic after olivine while magnetite forms rinds around sulfides. Textural, isotopic, and kinetic considerations suggest that Sayama experienced slightly higher temperatures than other CMs during pre-terrestrial metamorphic aqueously driven alteration. Still, the fact that Sayama was not retrieved until after a rain merits a cautionary pause.

Pre-terrestrial alteration and subsequent minor terrestrial weathering have not erased some remarkable primordial features. While the phases were not directly observed, the signatures of both Diamond and silicon carbide are found in Sayama’s Ne isotopes anomalies. In addition, Ba isotopes indicate the presence of live Cs-135 in the early solar system.

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Standard Detailed Gallery Strunz Chemical Elements

Mineral List

ⓘ 'Apatite'

ⓘ 'Fayalite-Forsterite Series'

ⓘ Magnetite

ⓘ Pentlandite

ⓘ Pyrrhotite

ⓘ 'Serpentine Subgroup'

6 valid minerals.

Meteorite/Rock Types Recorded

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

Select Rock List Type

Alphabetical List Tree Diagram

ⓘ CM2 chondrite meteorite

Detailed Mineral List:

ⓘ 'Apatite'

Formula: Ca₅(PO₄)₃(Cl/F/OH)

References:

Takaoka et al., (2001) Sayama CM2 Chondrite: Fresh but Heavily Altered (abs. #1645). Lunar and Planetary Science Conference XXXII: Houston, Texas. (Mar 2001)

ⓘ Calcite

Formula: CaCO₃

References:

Takaoka et al., (2001) Sayama CM2 Chondrite: Fresh but Heavily Altered (abs. #1645). Lunar and Planetary Science Conference XXXII: Houston, Texas. (Mar 2001)

ⓘ 'Chlorite Group'

Description: a minor partner in the phyllosilicate mix

References:

Nakamura, T., Noguchi, T. & Yoneda, S. (2003). The Conditions of Aqueous Alteration Reactions Recorded in the Sayama CM2 Chondrite (abs. #5080). Meteoritics & Planetary Science 38 (7, Supplement), p. A47. (July 2003)

ⓘ Chromite

Formula: Fe²⁺Cr³⁺₂O₄

References:

Takaoka et al., (2001) Sayama CM2 Chondrite: Fresh but Heavily Altered (abs. #1645). Lunar and Planetary Science Conference XXXII: Houston, Texas. (Mar 2001)

ⓘ Dolomite

Formula: CaMg(CO₃)₂

Description: major carbonate of both matrix & chondrules

References:

Takaoka et al., (2001) Sayama CM2 Chondrite: Fresh but Heavily Altered (abs. #1645). Lunar and Planetary Science Conference XXXII: Houston, Texas. (Mar 2001)

ⓘ 'Fayalite-Forsterite Series'

Description: Forsterite-rich [Fa 0-23]

References:

Grossman, J. N. & Zipfel, J. (2001). The Meteoritical Bulletin, No. 85, 2001 September. Meteoritics & Planetary Science 36 (9), A293-A322. (Sept 2001)

Takaoka et al., (2001) Sayama CM2 Chondrite: Fresh but Heavily Altered (abs. #1645). Lunar and Planetary Science Conference XXXII: Houston, Texas. (Mar 2001)

ⓘ Magnetite

Formula: Fe²⁺Fe³⁺₂O₄

Description: Forms rinds on Pentlandite and Pyrrhotite

References:

Takaoka et al., (2001) Sayama CM2 Chondrite: Fresh but Heavily Altered (abs. #1645). Lunar and Planetary Science Conference XXXII: Houston, Texas. (Mar 2001)

ⓘ Pentlandite

Formula: (Ni_xFe_y)_Σ9S₈

Description: In matrix

References:

Takaoka et al., (2001) Sayama CM2 Chondrite: Fresh but Heavily Altered (abs. #1645). Lunar and Planetary Science Conference XXXII: Houston, Texas. (Mar 2001)

ⓘ Pyrrhotite

Formula: Fe_1-xS

Description: In matrix (rare)

References:

Takaoka et al., (2001) Sayama CM2 Chondrite: Fresh but Heavily Altered (abs. #1645). Lunar and Planetary Science Conference XXXII: Houston, Texas. (Mar 2001)

ⓘ 'Serpentine Subgroup'

Formula: D₃[Si₂O₅](OH)₄

Description: Abundant; Commonly pseudomorphic after olivine

References:

Takaoka et al., (2001) Sayama CM2 Chondrite: Fresh but Heavily Altered (abs. #1645). Lunar and Planetary Science Conference XXXII: Houston, Texas. (Mar 2001)

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 2 - Sulphides and Sulfosalts
ⓘ	Pentlandite	2.BB.15	(Ni_xFe_y)_Σ9S₈
ⓘ	Pyrrhotite	2.CC.10	Fe_1-xS
Group 4 - Oxides and Hydroxides
ⓘ	Chromite	4.BB.05	Fe²⁺Cr³⁺₂O₄
ⓘ	Magnetite	4.BB.05	Fe²⁺Fe³⁺₂O₄
Group 5 - Nitrates and Carbonates
ⓘ	Calcite	5.AB.05	CaCO₃
ⓘ	Dolomite	5.AB.10	CaMg(CO₃)₂
Unclassified
ⓘ	'Chlorite Group'	-
ⓘ	'Fayalite-Forsterite Series'	-
ⓘ	'Serpentine Subgroup'	-	D₃[Si₂O₅](OH)₄
ⓘ	'Apatite'	-	Ca₅(PO₄)₃(Cl/F/OH)

List of minerals for each chemical element

H	Hydrogen
H	ⓘ Serpentine Subgroup	D₃[Si₂O₅](OH)₄
H	ⓘ Apatite	Ca₅(PO₄)₃(Cl/F/OH)
C	Carbon
C	ⓘ Calcite	CaCO₃
C	ⓘ Dolomite	CaMg(CO₃)₂
O	Oxygen
O	ⓘ Calcite	CaCO₃
O	ⓘ Chromite	Fe²⁺Cr₂³⁺O₄
O	ⓘ Dolomite	CaMg(CO₃)₂
O	ⓘ Magnetite	Fe²⁺Fe₂³⁺O₄
O	ⓘ Fayalite-Forsterite Series
O	ⓘ Serpentine Subgroup	D₃[Si₂O₅](OH)₄
O	ⓘ Apatite	Ca₅(PO₄)₃(Cl/F/OH)
F	Fluorine
F	ⓘ Apatite	Ca₅(PO₄)₃(Cl/F/OH)
Mg	Magnesium
Mg	ⓘ Dolomite	CaMg(CO₃)₂
Mg	ⓘ Fayalite-Forsterite Series
Si	Silicon
Si	ⓘ Fayalite-Forsterite Series
Si	ⓘ Serpentine Subgroup	D₃[Si₂O₅](OH)₄
P	Phosphorus
P	ⓘ Apatite	Ca₅(PO₄)₃(Cl/F/OH)
S	Sulfur
S	ⓘ Pentlandite	(Ni_xFe_y)_Σ9S₈
S	ⓘ Pyrrhotite	Fe_1-xS
Cl	Chlorine
Cl	ⓘ Apatite	Ca₅(PO₄)₃(Cl/F/OH)
Ca	Calcium
Ca	ⓘ Calcite	CaCO₃
Ca	ⓘ Dolomite	CaMg(CO₃)₂
Ca	ⓘ Apatite	Ca₅(PO₄)₃(Cl/F/OH)
Cr	Chromium
Cr	ⓘ Chromite	Fe²⁺Cr₂³⁺O₄
Fe	Iron
Fe	ⓘ Chromite	Fe²⁺Cr₂³⁺O₄
Fe	ⓘ Magnetite	Fe²⁺Fe₂³⁺O₄
Fe	ⓘ Pentlandite	(Ni_xFe_y)_Σ9S₈
Fe	ⓘ Pyrrhotite	Fe_1-xS
Fe	ⓘ Fayalite-Forsterite Series
Ni	Nickel
Ni	ⓘ Pentlandite	(Ni_xFe_y)_Σ9S₈

Other Regions, Features and Areas containing this locality

AsiaContinent

Eurasian Plate

Northern Japan ForearcAccretionary Complex

Japan

Honshu IslandIsland

Okhotsk PlateTectonic Plate

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References

Grossman, J. N. & Zipfel, J. (2001). The Meteoritical Bulletin, No. 85, 2001 September. Meteoritics & Planetary Science 36 (9), A293-A322. (Sept 2001)

Takaoka et al., (2001) Sayama CM2 Chondrite: Fresh but Heavily Altered (abs. #1645). Lunar and Planetary Science Conference XXXII: Houston, Texas. (Mar 2001)

Hidaka, H. & Yoneda, S. (2013). Radioactive Cs capture in the early solar system. Nature Scientific Reports, Vol. 3, id. 1330 (2013). (Feb 2013)

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Sayama meteorite, Sayama City, Saitama Prefecture, JapaniRegional Level TypesSayama meteoriteMeteorite Fall Location Sayama CityCity Saitama PrefecturePrefecture JapanCountry function showexplain() { $("#locexplain").toggle(); if (typeof movemap === "function") movemap(); }

Select Mineral List Type

Mineral List

Meteorite/Rock Types Recorded

Select Rock List Type

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

Sayama meteorite, Sayama City, Saitama Prefecture, Japan i
Regional Level Types
Sayama meteorite Meteorite Fall Location
Sayama City City
Saitama Prefecture Prefecture
Japan Country