Ultramafic xenoliths from aillikites in the Tarim large igneous province: Implications for Alaskan-type affinity and role of subduction

Petrology, Age, and Rift Origin of Ultramafic Lamprophyres (Aillikites) at Mount Webb, a New Alkaline Province in Central Australia

“…Several explanations have been proposed for the cause of MLDs, including (a) layers of partial melt (Kumar et al, 2012;Thybo, 2006;Thybo & Perchuć, 1997), (b) elastically accommodated grain boundary sliding (Karato, 2012;Karato et al, 2015), (c) accumulation of hydrous-seismically slow minerals, including pargasite and phlogopite (Aulbach et al, 2017;Kovacs et al, 2017;Kovács et al, 2021;Rader et al, 2015;Saha et al, 2021;Selway et al, 2015;Smart et al, 2021;Sudholz et al, 2023), (d) high density fluids such as brines (Aulbach, 2018;Bettac et al, 2023) and (e) thermal anomalies related to lithological changes and melt-wall rock interactions (Z. Liu et al, 2021). A pargasite-amphibole model for the MLD has received petrological support in recent years because the high-pressure stability limit of pargasite (amphibole) occurs at a depth similar to most seismic MLDs (80-120 km), and the formation of pargasite is known to take place beneath the metasomatized roots of cratons (Mandler & Grove, 2016;Niida & Green, 1999).…”

“…Research into aillikites has broadly focused on their regional geodynamic context, the compositional relationship they share with carbonatites and kimberlites, and the mechanisms of lithospheric contribution to magmatism (I. Ashchepkov et al., 2020; Foley et al., 2009; Nosova et al., 2018; Tappe et al., 2006, 2008, 2009; Veter et al., 2017; Wang et al., 2021). Like kimberlites and related deep‐seated volcanics (i.e., lamproites and lamprophyres), aillikites also provide important insights into the underlying lithospheric mantle through the mantle cargo they bring to the surface during their rapid magmatic ascent (I. Ashchepkov et al., 2020; Hutchison et al., 2018; L. Liu et al., 2021; Tappe et al., 2008; Wang et al., 2021).…”

“…Like kimberlites and related deep-seated volcanics (i.e., lamproites and lamprophyres), aillikites also provide important insights into the underlying lithospheric mantle through the mantle cargo they bring to the surface during their rapid magmatic ascent (I. Ashchepkov et al, 2020;Hutchison et al, 2018;L. Liu et al, 2021;Tappe et al, 2008;Wang et al, 2021).…”

Tracing Deep Carbon Cycling by Zinc Isotopes in a Peralkaline‐Carbonatite Suite

“…The carbonate‐rich aillikite shows heterogranular porphyritic texture with abundant phenocrysts of olivine, spinel, clinopyroxene, amphibole and phlogopite, and mafic‐ultramafic xenoliths (Liu et al., 2021; Wang et al., 2021). Nephelinite exhibits a porphyritic texture with phenocrysts composed of olivine, clinopyroxene, nepheline and alkali feldspar with minor apatite and sodalite (Cheng et al., 2015), whereas the nepheline‐bearing syenites are medium‐ to fine‐grained and composed of alkali feldspar, nepheline and clinopyroxene with minor titanite, apatite, Fe‐Ti oxide and biotite (Kong et al., 2022).…”

Reconciling the Cretaceous breakup and demise of the Phoenix Plate with East Gondwana orogenesis in New Zealand

“…Moreover, while plateau arrivals at intra-oceanic trenches may cause a polarity reversal (and ongoing subduction), e.g., during the arrival of the Ontong Java Plateau at the Vitiaz trench triggering the formation of the New Hebrides trench and the South Solomon trench (Auzende et al, 1995;Petterson et al, 1997;Quarles van Ufford and Cloos, 2005;Knesel et al, 2008;Lallemand and Arcay, 2021), there is no record of LIP arrival at a trench causing subduction cessation or a plate reorganization on the scale as observed here. Instead, LIP subduction is physically straightforward, even though it may cause shallow dipping slabs (e.g., Yang et al, 2020;Liu et al, 2021). LIP subduction has, for example, been ongoing in the Maracaïbo trench of the southern Caribbean region for more than 50 Ma (White et al, 1999;Boschman et al, 2014), and even the Hikurangi Plateau itself is subducting today at the Hikurangi trench (Collot and Davy, 1998;Reyners et al, 2011Reyners et al, , 2017Fig.…”