Microscale effects of melt infiltration into the lithospheric mantle: Peridotite xenoliths from Xilong, South China

Lu, Jianggu; Zheng, Jianping; Griffin, William L.; O’Reilly, Suzanne Y.; Pearson, Norman J.

doi:10.1016/j.lithos.2015.06.013

Cited by 20 publications

(5 citation statements)

References 71 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We interpret this halo as a reaction rim between incoming melt and the original host phase. The textural and chemical character of these reaction rims is independent of whether the inclusion is of the 'carbonate-rich' or 'silicaterich' type and is similar to the spongy rims commonly observed around the outside of cpx grains in mantlederived xenoliths (Taylor and Neal 1989;Ionov 1998;Carpenter et al 2002;Su et al 2012;Lu et al 2015). Similarly, Cr-pyropes display a kelyphitic reaction zone around polymineralic inclusions of both types.…”

Section: Polymineralic Inclusions As Snapshots Of Melt-rock Reactionsupporting

confidence: 52%

The evolution of calcite-bearing kimberlites by melt-rock reaction: evidence from polymineralic inclusions within clinopyroxene and garnet megacrysts from Lac de Gras kimberlites, Canada

Bussweiler

Stone

Pearson

et al. 2016

Contrib Mineral Petrol

View full text Add to dashboard Cite

inclusion trails surround the inclusions. In Cr-pyropes, the inclusions additionally contain Al-spinel, clinopyroxene, and dolomite. The major and trace element compositions of the inclusion phases are generally consistent with the early stages of kimberlite differentiation trends. Extensive chemical exchange between the host phases and the inclusions is indicated by enrichment of the inclusions in major components of the host crystals, such as Cr 2 O 3 and Al 2 O 3 . This chemical evidence, along with phase equilibria constraints, supports the proposal that the inclusions within Cr-diopside record the decarbonation reaction: dolomitic melt + diopside → forsterite + calcite + CO 2 , yielding the observed inclusion mineralogy and producing associated (CO 2 -rich) fluid inclusions. Our study of polymineralic inclusions in megacrysts provides clear mineralogical and chemical evidence for an origin of kimberlite that involves the reaction of high-pressure dolomitic melt with diopside-bearing mantle assemblages producing a lower-pressure melt that crystallizes a calcite-dominated assemblage in the crust.

show abstract

Section: Polymineralic Inclusions As Snapshots Of Melt-rock Reactionsupporting

confidence: 52%

The evolution of calcite-bearing kimberlites by melt-rock reaction: evidence from polymineralic inclusions within clinopyroxene and garnet megacrysts from Lac de Gras kimberlites, Canada

Bussweiler

Stone

Pearson

et al. 2016

Contrib Mineral Petrol

View full text Add to dashboard Cite

show abstract

“…This explains the positive Eu anomalies in secondary Cpx3 of orthopyroxene reaction zones. Such positive Eu anomalies in the secondary clinopyroxenes from reaction rims are reported for peridotite xenolith from Cenozoic alkaline basalts in Xilong, South China [2], though generally the positive Eu anomaly in clinopyroxene is unusual.…”

Section: Compositional Changes In Rocks Due To the Basanite-lherzolit...mentioning

confidence: 51%

Interaction of Lherzolite Xenoliths with Basanite is not Isochemical: Evidence from Tumusun Volcano, Baikal Rift Zone

Gornova¹,

Belyaev²,

Karimov³

et al. 2023

Preprint

View full text Add to dashboard Cite

To investigate the process and chemistry of reaction zone formation, we conducted detailed petrographic observations and major-trace element analysis of rocks and minerals of lherzolite xenoliths from basanites of Tumusun volcano (Baikal Rift Zone). The reaction zones gradually disappear from contact toward center of xenoliths. This indicates their formation as a result of lherzolite-basanite interaction. The influence of basanite melt on major-trace element composition of secondary minerals of reaction zones is notable only at distance up to 100-200 μm from the contact. The major-trace element composition of secondary clinopyroxenes from orthopyroxene reaction zone indicates their formation from a melt formed by dissolution of orthopyroxene and influenced by element diffusion from basanite melt. Inside xenoliths the secondary minerals have Mg# values equal to or higher than Mg# of primary minerals. The secondary clinopyroxenes inherit their depleted or enriched REE pattern from primary pyroxenes. The major-trace element variations in secondary clinopyroxenes testify melt heterogeneity. Secondary clinopyroxene has slightly higher LILE and similar abundances of other trace elements compared to unreacted part of clinopyroxene grain. This is consistent with model developed from experimental studies: due to the interaction with basanite, incongruent dissolution of orthopyroxene occurs to form a melt which circulates in lherzolite and leads to pyroxenes and spinel dissolution. Non-dissolved centers of minerals are homogenous and similar in major-trace element composition to primary minerals. The process of peridotite-basanite interaction is not isochemical: even the centers of large xenoliths become enriched in LILE.

show abstract

“… Distribution of predicted Mg# in the lithospheric mantle (black) and mantle xenoliths data (red) (Hao et al., 2016; Liu et al., 2012; Liu, Zhang, et al., 2017; Lu et al., 2015; Xu et al., 2000; Zheng et al., 2015). Green solid lines represent the means of accepted models from inversion, and green dashed lines are their standard deviations.…”

Section: Discussionmentioning

confidence: 99%

Thermochemical Structure and Melting Distribution of the Upper Mantle Beneath Intraplate Volcanic Areas in Eastern South China Block

Zhang,

Guo,

Dai

et al. 2023

JGR Solid Earth

View full text Add to dashboard Cite

The Eastern South China Block (SCB) has experienced complex Mesozoic‐Cenozoic tectonism and intraplate volcanism. However, due to a lack of exhaustive exploration of the upper mantle's thermochemical structure, it is difficult to determine the extent of the lithospheric modification and the mechanisms by which the volcanism generate. Here, we jointly invert Rayleigh wave dispersion, surface heat flow, geoid height, and elevation data to provide a comprehensive thermal and compositional structure of the upper mantle beneath eastern SCB and infer regions of partial melting. Our model reveals widespread lithospheric thinning in the eastern SCB and large variations of lithospheric composition with a more fertile eastern Lower Yangtze lithosphere than the lithosphere elsewhere, suggesting the lithosphere of the eastern Lower Yangtze is more severely modified than the rest of the SCB. Moreover, two high‐temperature anomalies are revealed: one beneath the eastern Lower Yangtze and the other beneath the Pearl River Delta region, associated with the Pacific plate subduction and Hainan plume, respectively. The high‐degree partial melting (∼6%) in the asthenosphere beneath the Lower Yangtze is responsible for the strong ongoing lithospheric modification and the young intraplate volcanism in the Nvshan and Subei areas. Small‐scale upper mantle convections triggered by the large mantle upwellings created a low value of ∼3% melts, possibly responsible for the intraplate volcanism in the coastal CB and less severe lithospheric modification. We demonstrate that the lithospheric thickness and its thermochemical state are the key factors that influence the composition and evolution of intraplate volcanism in the eastern SCB.

show abstract

Microscale effects of melt infiltration into the lithospheric mantle: Peridotite xenoliths from Xilong, South China

Cited by 20 publications

References 71 publications

The evolution of calcite-bearing kimberlites by melt-rock reaction: evidence from polymineralic inclusions within clinopyroxene and garnet megacrysts from Lac de Gras kimberlites, Canada

The evolution of calcite-bearing kimberlites by melt-rock reaction: evidence from polymineralic inclusions within clinopyroxene and garnet megacrysts from Lac de Gras kimberlites, Canada

Interaction of Lherzolite Xenoliths with Basanite is not Isochemical: Evidence from Tumusun Volcano, Baikal Rift Zone

Thermochemical Structure and Melting Distribution of the Upper Mantle Beneath Intraplate Volcanic Areas in Eastern South China Block

Contact Info

Product

Resources

About