Constraining the isotopic endmembers contributing to 1.1 Ga Keweenawan large igneous province magmatism

Rooney, Tyrone O.; Konter, J. G.; Finlayson, Valerie; LaVigne, Andrew; Brown, Eric L.; Stein, Carol A.; Stein, Seth; Moucha, R.

doi:10.1007/s00410-022-01907-8

Cited by 7 publications

(2 citation statements)

References 131 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These large outpourings of lava are the result of the most significant mass transfers from the mantle to the crust on the planet and yet a significant amount of the magma generated remains trapped in the crust as crystal cumulates (Bryan et al, 2010). While there has been a wealth of studies aimed at understanding the source of these voluminous magmas (Beccaluva et al, 2009;Heinonen et al, 2016;Ivanov et al, 2008;Melluso et al, 2006;Rooney et al, 2022;Xu et al, 2007), a growing number of studies have begun to focus on the differentiation of the magmas as they interact with the lithosphere (Davis et al, 2021;Grant et al, 2020;Heinonen et al, 2019;Jean, 2013;Steiner et al, 2021;Yu et al, 2015). Many CFB provinces preserve a temporal sequence of outputs of the magma plumbing system (lava flows) and thus provide a unique opportunity to evaluate the temporal chemical evolution of these mass transfer systems as they traverse and become modified by the lithosphere.…”

Section: Introductionmentioning

confidence: 99%

Magma Evolution During Main‐Phase Continental Flood Basalt Volcanism: A Case for Recharge‐Evacuation‐Assimilation‐Fractional Crystallization in the Ethiopian Low‐Ti Province

Krans,

Rooney,

Kappelman

et al. 2024

Geochem Geophys Geosyst

Self Cite

View full text Add to dashboard Cite

Lavas erupted in Continental Flood Basalt (CFB) provinces are not primary magmas; they are differentiated products that result from large volumes of melt migrating and stalling in the lithosphere prior to eruption, resulting in complex liquid lines of descent. Geochemical models can be used to constrain the various influencers of magma differentiation (recharge, assimilation, fractional crystallization (FC), eruption, and mixing). Temporal constraints for changes in plumbing system dynamics are recorded in the petrography and stratigraphy of the erupted lava flows. This study focuses on the flow‐stratigraphy preserved within the Oligocene Ethiopian low‐Ti flood basalt province, located on the NW Ethiopian Plateau. We present new bulk rock geochemistry from 107 lavas and interpret these data within a petrostratigraphic framework. Our model results suggest that both a deep (∼0.6 GPa) and shallow (<0.2 GPa) magmatic system are active throughout the main phase of volcanism. Our recharge evacuation assimilation and fractional crystallization models (REAFC) show that during the main phase of magmatism evacuation from both the deep (65%) and shallow (55%) systems reached an apex. During the terminal phases, magma evacuation from the deeper system ceases while evacuation from the shallow system is much reduced (25%). The degree of crustal contamination predicted by REAFC (4%–10%) is lower than previous estimates determined for this region using assimilation with FC only models (12%–25%). Our study highlights the importance of evaluating petrography while interpreting geochemical models in CFB.

show abstract

Section: Introductionmentioning

confidence: 99%

Magma Evolution During Main‐Phase Continental Flood Basalt Volcanism: A Case for Recharge‐Evacuation‐Assimilation‐Fractional Crystallization in the Ethiopian Low‐Ti Province

Krans,

Rooney,

Kappelman

et al. 2024

Geochem Geophys Geosyst

Self Cite

View full text Add to dashboard Cite

show abstract

“…Chapter 2 proposed an iron-rich tholeiitic picrite as parental magma for Americano do Brasil Complex, therefore in an effort to find a reasonable starting liquid composition for modeling the evolution of the Mangabal Complex and test a comagmatic affinity between the two complexes, we used a similar tholeiitic basalt. Both of the model compositions we have used were obtained from data for similar-aged Proterozoic Fe-rich tholeiites from the Mid-Continent Rift of North America (Lightfoot et al, 1999;Rooney et al, 2022). Cooling the parental basalt under isobaric conditions at 2.5 kbar and fO2 0.5 log units above the fayalite-magnetite-quartz (FMQ) solid oxygen buffer produced a model sequence of crystallization and modal proportions of solids similar to the observed bulk-rock and mineral compositions of most of the cumulate rocks of the complex.…”

Section: Modeling Of Cumulate Formation and Nature Of The Parental Magmamentioning

confidence: 99%

Petrogenesis of Mafic-Ultramafic Intrusions in the Southern Goiás Magmatic Arc, Central Brazil

Augustin¹

View full text Add to dashboard Cite

The Americano do Brasil and Mangabal Complexes belong to a cluster of Neoproterozoic mafic-ultramafic intrusions in the southern Goiás Magmatic Arc in Brazil that lies within the Brasília Belt, a complex, long-lived Neoproterozoic Orogen that formed during the amalgamation of the São Francisco/Congo, Amazonian, and Paranapanema Cratons in western Gondwana. Although deformed and partially recrystallized by a regional metamorphic overprint, the rocks of both complexes still preserve igneous textures. The rocks in both complexes show cumulate textures that range from adcumulate to orthocumulate. Petrography, geochemistry, geochronology, and petrological modeling were carried out to constrain the petrogenesis of the complexes.Modeling indicates that the parental magma for the Americano do Brasil Complex had an OIB-like Fe-rich picrite composition, while the parental magma of the Mangabal Complex could have been a tholeiitic basalt. Considering the temporal and spatial correlations, decompression melting of upwelling asthenosphere triggered by rollback subduction and/or influence of a mantle plume are plausible mechanisms to explain the petrogenesis of these mafic-ultramafic intrusions in the vicinities of the eastern Arenópolis arc and westernmost Anápolis-Itauçu belt. The complexes have experienced a protracted metamorphic evolution with peaks indicating amphibolite facies. The rock from both complexes shows late-stage alteration associated with metasomatism by CO2-Ca-S-rich fluids.

show abstract

Post-Archean Nb-REE-U enrichment in the Superior craton recorded in metasomatised mantle rocks erupted in the 1.1 Ga Midcontinental Rift event

Legros,

Czas,

Luo

et al. 2023

Miner Deposita

View full text Add to dashboard Cite

Constraining the isotopic endmembers contributing to 1.1 Ga Keweenawan large igneous province magmatism

Cited by 7 publications

References 131 publications

Magma Evolution During Main‐Phase Continental Flood Basalt Volcanism: A Case for Recharge‐Evacuation‐Assimilation‐Fractional Crystallization in the Ethiopian Low‐Ti Province

Magma Evolution During Main‐Phase Continental Flood Basalt Volcanism: A Case for Recharge‐Evacuation‐Assimilation‐Fractional Crystallization in the Ethiopian Low‐Ti Province

Petrogenesis of Mafic-Ultramafic Intrusions in the Southern Goiás Magmatic Arc, Central Brazil

Post-Archean Nb-REE-U enrichment in the Superior craton recorded in metasomatised mantle rocks erupted in the 1.1 Ga Midcontinental Rift event

Contact Info

Product

Resources

About