Intracrystalline Cation Distribution in Natural Clinopyroxenes of Tholeiitic, Transitional, and Alkaline Basaltic Rocks

Negro, A. Dal; Carbonin, S.; Molin, Gianmario; Cundari, A.; Piccirillo, E. M.

doi:10.1007/978-1-4612-5683-0_3

Cited by 91 publications

(30 citation statements)

References 14 publications

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“…As may be inferred from the microprobe analysis (Table 1), the tetrahedral site is mainly occupied by Si (Si = 1.989 a.p.f.u.). This is consistent with the very short mean bond length of the tetrahedron (< Si43 > = 1.637 ,/~, Table 3), one of the lowest observed values in lunar and terrestrial cpx (Dal Negro et al, 1982, 1984Takeda, 1972;Manoli and Molin, 1988).…”

Section: Silicate Crystal Chemistrysupporting

confidence: 84%

“…2). The two bond lengths are related (direct and inverse relationship respectively) to the Ca and R 3+ ion content in terrestrial pyroxenes (Dal Negro et al, 1982). The Zaoyang cpx plot in the field of transitional basalts and is close to the field of some basaltic andesites.…”

Section: Silicate Crystal Chemistrymentioning

confidence: 74%

“…), while the total content of trivalent ions R 3 + (R 3 + = AlW+Fe3++Cr3++Ti 4+) is very low (0.034 a.p.f.u.). The M1 site volume (a structural parameter strongly related to the crystallization environment) of 11.88 ~3 is a common value in terrestrial cpx from volcanic transitional basalts (Dal Negro et al, 1982) and in alkali basalt to latite lavas (Faraone et al, 1988).…”

Section: Silicate Crystal Chemistrymentioning

confidence: 99%

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Zaoyang chondrite cooling history from Fe²⁺-Mg intracrystalline ordering in pyroxenes

1994

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The crystal chemistry of clinopyroxene, orthopyroxene and olivine from a crushed fragment of the H5 Zaoyang chondrite has been investigated by X-ray structure refinement and detailed microprobe analysis. The meteoritic pyroxenes have cell and polyhedral volumes which compare well with such data from terrestrial pyroxenes that typically crystallize at low-pressure. Fe 2+ and Mg are rather disordered in M1 and M2 sites of clino-and orthopyroxenes; the closure temperatures of the exchange reaction are 600 and 512~ respectively, which is consistent with a reasonably fast cooling rate, estimated to be of the order of l~The closure temperature for the intercrystalline Ca-Mg exchange reaction for clino-and orthopyroxenes is 900~ as calculated from clino-and orthopyroxene intergrowth.The cooling rates obtained from Fe 2 +-Mg intracrystalline partitioning suggest a cooling of the order of degrees per day at temperatures of 600-500~ due to a strong loss of heat by irradiation.

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Section: Silicate Crystal Chemistrysupporting

confidence: 84%

Section: Silicate Crystal Chemistrymentioning

confidence: 74%

Section: Silicate Crystal Chemistrymentioning

confidence: 99%

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Zaoyang chondrite cooling history from Fe²⁺-Mg intracrystalline ordering in pyroxenes

1994

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“…Similar disequilibrium textures and compositions are observed in mildly alkalic basalts from the Mont Crozier Section of the Kerguelen Archipelago in the SE Indian Ocean by Damasceno et al (2002). Estimated temperatures for clinopyroxenes (using the constraints described by Dal Negro et al 1982;Malgarotto et al 1993;Nimis 1995) range from 8888C to 9158C. The trachyandesite lava flow gave the highest temperature (9158C) and the quartz-micromonzonite dykes the lowest (8888C).…”

Section: Fe-ti Oxidessupporting

confidence: 55%

“…The crystallization pressures calculated using the compositions of clinopyroxenes (Dal Negro et al 1982;Nimis 1995) range from 1 kbar (in the trachyandesite) to 6 kbar (in the basaltic trachyandesite). The relative distribution of Al between the tetrahedral and octahedral sites in the clinopyroxene structure is related to the physicochemical conditions of crystallization.…”

Section: Fe-ti Oxidesmentioning

confidence: 99%

Mineral chemistry, crystallization conditions and magma mixing‐mingling at Orduzu volcano (Malatya), Eastern Anatolia, Turkey

Önal

2007

Geological Journal

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The Middle Miocene Orduzu volcanic suite, which is a part of the widespread Neogene Yamadag volcanism of Eastern Anatolia, consists of a rhyolitic lava flow, rhyolitic dykes, a trachyandesitic lava flow and basaltic trachyandesitic dykes. Existence of mafic enclaves and globules in some of the volcanic rocks, and microtextures in phenocrysts indicate that magma mingling and mixing between andesitic and basaltic melts played an important role in the evolution of the volcanic suite. Major and trace element characteristics of the volcanic rocks are similar to those formed in convergent margin settings. In particular, incompatible trace element patterns exhibit large depletions in high field strength elements (Nb and Ta) and strong enrichments in both large ion lithofile elements (Ba, Th and U) and light rare earth elements, indicating a strong subduction signature in the source of the volcanic rocks. Furthermore, petrochemical data obtained suggest that parental magmas of rhyolite lava and dykes, and trachyandesite lava and basaltic trachyandesite dykes were derived from subduction-related enriched lithospheric mantle and metasomatized mantle (AE asthenosphere), respectively. A detailed mineralogical study of the volcanic suite shows that plagioclase is the principal phenocryst phase in all of the rock units from the Orduzu volcano. The plagioclase phenocrysts are accompanied by quartz in the rhyolitic lava flows and by two pyroxenes in the trachyandesitic lava flows and basaltic trachyandesitic dykes. Oxide phases in all rocks are magnetite and ilmenite. Calculated crystallization temperatures range from 6508C to 8008C for plagioclase, 7458C-10548C for biotite, 8888C-9158C for pyroxene and 7368C-8418C for magnetite-ilmenite pairs. Calculated crystallization pressures of pyroxenes vary between 1.24-5.81 kb, and oxygen fugacity range from À14.47 to À12.39. The estimates of magmatic intensive parameters indicate that the initial magma forming the Orduzu volcanic unit began to crystallize in a high-level magma chamber and then was stored in a shallow reservoir where it underwent intermediate-mafic mixing. The rhyolitic lava flow and dykes evolved in relatively shallower crustal magma chambers.

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Architecture of the Magmatic System in the Main Ethiopian Rift

Nazzareni

Rossi

Petrelli

et al. 2020

Geophysical Monograph Series

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Intracrystalline Cation Distribution in Natural Clinopyroxenes of Tholeiitic, Transitional, and Alkaline Basaltic Rocks

Cited by 91 publications

References 14 publications

Zaoyang chondrite cooling history from Fe²⁺-Mg intracrystalline ordering in pyroxenes

Zaoyang chondrite cooling history from Fe²⁺-Mg intracrystalline ordering in pyroxenes

Mineral chemistry, crystallization conditions and magma mixing‐mingling at Orduzu volcano (Malatya), Eastern Anatolia, Turkey

Architecture of the Magmatic System in the Main Ethiopian Rift

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Intracrystalline Cation Distribution in Natural Clinopyroxenes of Tholeiitic, Transitional, and Alkaline Basaltic Rocks

Cited by 91 publications

References 14 publications

Zaoyang chondrite cooling history from Fe2+-Mg intracrystalline ordering in pyroxenes

Zaoyang chondrite cooling history from Fe2+-Mg intracrystalline ordering in pyroxenes

Mineral chemistry, crystallization conditions and magma mixing‐mingling at Orduzu volcano (Malatya), Eastern Anatolia, Turkey

Architecture of the Magmatic System in the Main Ethiopian Rift

Contact Info

Product

Resources

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Zaoyang chondrite cooling history from Fe²⁺-Mg intracrystalline ordering in pyroxenes

Zaoyang chondrite cooling history from Fe²⁺-Mg intracrystalline ordering in pyroxenes