Evidence from Antarctic mantle peridotite xenoliths for changes in mineralogy, geochemistry and geothermal gradients beneath a developing rift

Foley, Stephen F.; Andronikov, A. V.; Jacob, Dorrit E.; Melzer, Stefan

doi:10.1016/j.gca.2006.03.010

Cited by 85 publications

(90 citation statements)

References 77 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Furthermore, the very high Al 2 O 3 content typically observed in pyroxenes in kelyphites (5-15 wt%; cf. Mukhopadhyay 1991; Foley et al 2006;Špaček et al 2013) is also reproduced by our model (Fig. 6b).…”

Section: Kelyphite Formation Around Garnets: Heating Decompression Osupporting

confidence: 78%

Application of thermodynamic modelling to natural mantle xenoliths: examples of density variations and pressure–temperature evolution of the lithospheric mantle

Ziberna

Klemme

2016

Contrib Mineral Petrol

View full text Add to dashboard Cite

low-temperature peridotites (spinel and spinel + garnet harzburgites and lherzolites), are linked to a cooling event in the mantle which occurred long before the eruption of the host basalts. In addition, our phase equilibria calculations show that kelyphitic rims around garnets, as those observed in the high-temperature garnet peridotites from Pali-Aike, can be explained simply by decompression and do not require additional metasomatic fluid or melt.

show abstract

Section: Kelyphite Formation Around Garnets: Heating Decompression Osupporting

confidence: 78%

Application of thermodynamic modelling to natural mantle xenoliths: examples of density variations and pressure–temperature evolution of the lithospheric mantle

Ziberna

Klemme

2016

Contrib Mineral Petrol

View full text Add to dashboard Cite

show abstract

“…The mantle-and sporadically lower rust-parts of these geotherms are based on temperature-depths data yielded by the xenoliths (e.g. Pearson et al 1991a, b;O'Reilly and Griffin 1996;Werling and Altherr 1997;Foley et al 2006). Thus, they show the real mantle temperatures at the time of sampling by volcanic eruptions.…”

Section: Geological Considerationsmentioning

confidence: 99%

Lithosphere thermal structure at the eastern margin of the Bohemian Massif: a case petrological and geophysical study of the Niedźwiedź amphibolite massif (SW Poland)

Puziewicz

Czechowski

Krysiński

et al. 2011

Int J Earth Sci (Geol Rundsch)

View full text Add to dashboard Cite

The crustal section beneath amphibolite Niedźwiedź Massif (Fore-Sudetic Block in NE Bohemian Massif), modelled on the basis of geological and seismic data, is dominated by gneisses with subordinate granites (upper and middle crust) and melagabbros (lower crust). The geotherm was calculated based on the chemical analyses of the heat-producing elements in the rocks forming the crust and the measurements of their density and heat conductivity. The results were verified by heat flow calculations based on temperature measurements from 1,600 m deep well in the Niedźwiedź Massif and by temperaturedepth estimates in mantle xenoliths coming from the nearby ca. 4.5 My basanite plug in Lutynia. The paleoclimate-corrected heat flow in the Niedźwiedź Massif is 69.5 mW m -2 , and the mantle heat flow is 28 mW m -2 . The mantle beneath the Massif was located marginally relative to the areas of intense Cenozoic thermal rejuvenation connected with alkaline volcanism. This results in geotherm which is representative for lithosphere parts located at the margins of zones of continental alkaline volcanism and at its waning stages. The lithosphereasthenosphere boundary (LAB) beneath Niedźwiedź is located between 90 and 100 km depth and supposedly the rheological change at LAB is not related to the appearance of melt.

show abstract

“…5 Page 2 of 17 Altherr and Kalt 1996;Godard and Martin 2000;Keankeo et al 2000;Foley et al 2006;Degi et al 2009;Obata 2011;Obata et al 2013;Spacek et al 2013). Familiar examples of symplectite formation involving composition change are myrmekites, where a vermicular intergrowth of sodic plagioclase and quartz replaces K-feldspar (Phillips 1974;Abart et al 2014) pseudoleucites, where vermicular nepheline-Kfeldspar intergrowths pseudomorphically replace leucite (Gittins et al 1980); scapolite-quartz symplectites replacing K-feldspar (Harley and Santosh 1995) or scapolite-clinopyroxene symplectites replacing garnet (Abart et al 2001).…”

mentioning

confidence: 99%

Synthesis of monticellite–forsterite and merwinite–forsterite symplectites in the CaO–MgO–SiO2 model system: influence of temperature and water content on microstructure evolution

Remmert

Heinrich

Wunder

et al. 2017

Contrib Mineral Petrol

View full text Add to dashboard Cite

Homogeneous single crystals of synthetic monticellite with the composition Ca 0.88 Mg 1.12 SiO 4 (Mtc I) were annealed in a piston-cylinder apparatus at temperatures between 1000 and 1200• C , pressures of 1.0-1.4 GPa, for run durations from 10 min to 24 h and applying bulk water contents ranging from 0.0 to 0.5 wt% of the total charge. At these conditions, Mtc I breaks down to a fine-grained, symplectic intergrowth. Thereby, two types of symplectites are produced: a first symplectite type (Sy I) is represented by an aggregate of rod-shaped forsterite immersed in a matrix of monticellite with end-member composition (Mtc II), and a second symplectite type (Sy II) takes the form of a lamellar merwinite-forsterite intergrowth. Both symplectites may form simultaneously, where the formation of Sy I is favoured by the presence of water. Sy I is metastable with respect to Sy II and is successively replaced by the latter. For both symplectite types, the characteristic spacing of the symplectite phases is independent of run duration and is only weeakly influenced by the water content, but it is strongly temperature dependent. It varies from about 400 nm at 1000• C to 1200 nm at 1100• C in Sy I, and from 300 nm at 1000 • C to 700 nm at 1200• C in Sy II. A thermodynamic analysis reveals that the temperature dependence of the characteristic spacing of the symplectite phases is due to a relatively high activation energy for chemical segregation by diffusion within the reaction front as compared to the activation energy for interface reactions at the reaction front. The temperature dependence of the characteristic lamellar spacing and the temperature-time dependence of overall reaction progress have potential for applications in geo-thermometry and geo-speedometry.

show abstract

Evidence from Antarctic mantle peridotite xenoliths for changes in mineralogy, geochemistry and geothermal gradients beneath a developing rift

Cited by 85 publications

References 77 publications

Application of thermodynamic modelling to natural mantle xenoliths: examples of density variations and pressure–temperature evolution of the lithospheric mantle

Application of thermodynamic modelling to natural mantle xenoliths: examples of density variations and pressure–temperature evolution of the lithospheric mantle

Lithosphere thermal structure at the eastern margin of the Bohemian Massif: a case petrological and geophysical study of the Niedźwiedź amphibolite massif (SW Poland)

Synthesis of monticellite–forsterite and merwinite–forsterite symplectites in the CaO–MgO–SiO2 model system: influence of temperature and water content on microstructure evolution

Contact Info

Product

Resources

About