δ18O, δ13C, trace elements and REE in situ measurements coupled with U–Pb ages to reconstruct the diagenesis of upper triassic atoll-type carbonates from the Panthalassa Ocean

In situ U-Pb Dating of Calcite from the South China Antimony Metallogenic Belt

“…Post-ore Cal-III gray calcite veinlets crosscut both Dol-I and Cal-II crystals with an immediate contact, which rules out the alteration and reprecipitation during the latest hydrothermal event ( Roberts et al., 2020 ). Because of Fe 2+ serving as the dominant luminescence quencher ( Peyrotty et al., 2020 ), Cal-II with lower Fe concentration exhibits bright CL responses in calcite as being different from that of Cal-III, which is supported by the in situ element data ( Table 1 ).…”

Sedimentology and biostratigraphy of the upper Triassic carbonates from the Shiriya cape, North Kitakami Belt, Japan

“…As first suggested by Sano et al (2009) and on the basis of facies interpretation, the Shiriya limestone are defined as remnants of an atoll‐type system developed on a basaltic seamount in the Panthalassa Ocean during the Norian (Late Triassic). Accreted during the Late Jurassic into the Shiriya accretionary complex, and then recycled in the trench to be incorporated again in the prism during the Early Cretaceous (Ueda et al, 2018), the Shiriya limestone is part of the numerous similar Triassic systems accreted on Jurassic‐Cretaceous complexes and distributed on the west Circum‐Pacific region (Chablais et al, 2011; Chablais, Martini, Samankassou, et al, 2010; Chablais, Onoue, & Martini, 2010; Kiessling & Flügel, 2000; Onoue et al, 2009; Peybernes et al, 2015; Peybernes, Chablais, Onoue, Escarguel, & Martini, 2016; Peybernes, Chablais, Onoue, & Martini, 2016; Peyrotty, Brigaud, & Martini, 2020; Peyrotty, Rigaud, et al, 2020; Peyrotty, Ueda, et al, 2020). These accreted carbonate systems present the same characteristics as the Shiriya limestone: (i) They crop out over a limited area within the accretionary complex, indicating a restricted lateral extension of the system, which is compatible with an atoll morphology.…”

“…Following Ueda et al (2018), we used the term conglomerate which better take into account the observed gradation from sandstone including lithologically diversified grains (i.e., limestone, quartz, volcanics, chert) to conglomerate containing the same lithologies. However, in other Japanese accretionary complexes, similar block‐in‐matrix rock bodies have often been referred to as breccia (e.g., Peybernes, Chablais, Onoue, Escarguel, & Martini, 2016; Peybernes, Chablais, Onoue, & Martini, 2016; Peyrotty, Brigaud, & Martini, 2020; Peyrotty, Rigaud, et al, 2020). For instance, in the Sambosan accretionary complex (SAC) in southwest Japan (Figure 1), two main types of breccia are observed: the first (B1) is characterized by limestone and basaltic clasts embedded in volcaniclastic matrix (VCM) whereas the second (B2) is characterized by association of limestone, chert, basalt and siliceous mudstone clasts set in siliceous mudstone matrix (Peybernes, 2016).…”

“…One noticeable difference is the presence of sandstone grains in Shiriya conglomerate that were not observed in the SAC breccia. According to former studies, conglomerate and breccia could form: (i) on the slopes of the carbonate system either during the deposition or its dismantling after the drowning of the atoll; (ii) within the trench or (iii) during the accretion process (Chablais, 2010; Onoue & Stanley, 2008; Peybernes, Chablais, Onoue, & Martini, 2016; Peyrotty, Brigaud, & Martini, 2020; Sano, 1989; Sano & Kanmera, 1991; Ueda et al, 2018; Wakita & Metcalfe, 2005).…”

“…Their sedimentological, biostratigraphical and diagenetical investigations shed light on the development, evolution and demise of shallow‐water carbonate systems out of Tethyan domain (Figure 1). Accordingly, these studies provided new perspectives about ecology, environmental conditions, fauna dispersion within the immense Panthalassa Ocean (Bucur et al, 2020; Chablais, Martini, & Onoue, 2010; Chablais, Martini, Samankassou, et al, 2010; Chablais, Onoue, & Martini, 2010; Chablais et al, 2011; Del Piero et al, 2020; Del Piero, Rigaud, & Martini, 2022; Del Piero, Rigaud, Peybernes, et al, 2022; Forel et al, 2022; Peybernes et al, 2015; Peybernes, Chablais, Onoue, Escarguel, & Martini, 2016; Peybernes, Chablais, Onoue, & Martini, 2016; Peybernes et al, 2020; Peyrotty, Rigaud, et al, 2020; Peyrotty, Brigaud, & Martini, 2020; Peyrotty, Ueda, et al, 2020; Rigaud et al, 2010, 2012, 2016; Rigaud, Martini, & Rettori, 2013; Rigaud, Blau, et al, 2013; Rigaud, Vachard, & Martini, 2015; Rigaud, Martini, & Vachard, 2015). Although the majority of these Panthalassan relics have been studied, some outcrops are still under‐explored regarding petrography and sedimentology.…”