Research output: Contribution to journal › Article › peer-review
A mantle origin for sulfates in the unusual "salty" Udachnaya-East kimberlite from sulfur abundances, speciation and their relationship with groundmass carbonates. / D'Eyrames, Elisabeth; Thomassot, Emilie; Kitayama, Yumi et al.
In: Bulletin de la Societe Geologique de France, Vol. 188, No. 1-2, 6, 01.01.2017.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - A mantle origin for sulfates in the unusual "salty" Udachnaya-East kimberlite from sulfur abundances, speciation and their relationship with groundmass carbonates
AU - D'Eyrames, Elisabeth
AU - Thomassot, Emilie
AU - Kitayama, Yumi
AU - Golovin, Alexander
AU - Korsakov, Andrey
AU - Ionov, Dmitri
PY - 2017/1/1
Y1 - 2017/1/1
N2 - The Udachnaya-East pipe in Yakutia in Siberia hosts a unique dry (serpentine-free) body of hypabyssal kimberlite (<0.64wt% H2O), associated with a less dry type of kimberlite and a serpentinized kimberlitic breccia. The dry kimberlite is anomalously rich in salts (Na2O and Cl both up to 6wt%) whereas the slightly less dry and the breccia kimberlite are salt free. Yet the Udachnaya kimberlite is a group-1 kimberlite, as is the archetypical kimberlite from Kimberley, South Africa. Samples were studied from the three different types of kimberlite (dry-salty, n=8, non-salty, n=5 and breccia, n=3) regarding their mineralogy, geochemistry, and more specifically their sulfur content. Our results show the salty kimberlite is unprecedentedly rich in sulfur (0.13-0.57wt%) compared to the non-salty kimberlite (0.04-0.12wt%) and the breccia (0.29-0.33wt%). In the salty kimberlite, most of the sulfur is present as sulfates (up to 97% of Stotal) and is disseminated throughout the groundmass in close association with Na-K-bearing carbonates. Sulfates occur within the crystal structure of these Na-K-bearing carbonates as the replacement of (CO3) by (SO3) groups, or as Na- and K-rich sulfates (e.g. aphtitalite, (K,Na)3Na(SO4)2). The associated sulfides are djerfisherite; also Na- and K-rich species. The close association of sulfates and carbonates in these S-rich alkaline rocks suggests that the sulfates crystallized from a mantle-derived magma, a case that has strong implication for the oxygen fugacity of kimberlite magmatism and more generally for the global S budget of the mantle.
AB - The Udachnaya-East pipe in Yakutia in Siberia hosts a unique dry (serpentine-free) body of hypabyssal kimberlite (<0.64wt% H2O), associated with a less dry type of kimberlite and a serpentinized kimberlitic breccia. The dry kimberlite is anomalously rich in salts (Na2O and Cl both up to 6wt%) whereas the slightly less dry and the breccia kimberlite are salt free. Yet the Udachnaya kimberlite is a group-1 kimberlite, as is the archetypical kimberlite from Kimberley, South Africa. Samples were studied from the three different types of kimberlite (dry-salty, n=8, non-salty, n=5 and breccia, n=3) regarding their mineralogy, geochemistry, and more specifically their sulfur content. Our results show the salty kimberlite is unprecedentedly rich in sulfur (0.13-0.57wt%) compared to the non-salty kimberlite (0.04-0.12wt%) and the breccia (0.29-0.33wt%). In the salty kimberlite, most of the sulfur is present as sulfates (up to 97% of Stotal) and is disseminated throughout the groundmass in close association with Na-K-bearing carbonates. Sulfates occur within the crystal structure of these Na-K-bearing carbonates as the replacement of (CO3) by (SO3) groups, or as Na- and K-rich sulfates (e.g. aphtitalite, (K,Na)3Na(SO4)2). The associated sulfides are djerfisherite; also Na- and K-rich species. The close association of sulfates and carbonates in these S-rich alkaline rocks suggests that the sulfates crystallized from a mantle-derived magma, a case that has strong implication for the oxygen fugacity of kimberlite magmatism and more generally for the global S budget of the mantle.
KW - Kimberlite
KW - Mantle
KW - Siberia
KW - Sulfates
KW - Sulfides
KW - Udachnaya
KW - SOUTH-AFRICA
KW - PETROGENESIS
KW - YAKUTIA
KW - ALKALI CHLORIDES
KW - UNALTERED KIMBERLITES
KW - PIPE
KW - GROUP-I
KW - MELT INCLUSIONS
KW - RUSSIA
KW - MAGMA EVOLUTION
UR - http://www.scopus.com/inward/record.url?scp=85026663687&partnerID=8YFLogxK
U2 - 10.1051/bsgf/2017007
DO - 10.1051/bsgf/2017007
M3 - Article
AN - SCOPUS:85026663687
VL - 188
JO - Bulletin - Societie Geologique de France
JF - Bulletin - Societie Geologique de France
SN - 0037-9409
IS - 1-2
M1 - 6
ER -
ID: 10069970