Abstract Due to their accretion on the Circum–Pacific area during the Jurassic and the Cretaceous, Upper Triassic carbonates from the Panthalassa occur very scarcely and with relatively poor preservation in accretionary complexes. However, they represent a unique opportunity to improve our knowledge of the depositional conditions in tropical regions of the Panthalassa. Recognized as a cradle of life, shallow–water carbonates are also of great importance to understand of how life evolved out of the Tethyan domain during the Triassic. Since 2007, several sedimentological and biostratigraphic studies, focused on the Upper Triassic shallow water limestone from the Circum–Pacific area, have been carried out as part of the REEFCADE project at the University of Geneva. Carbonates were thus reported in the southern part of Japan and in the Russian Far East. Hokkaido Island, in northern Japan, represents the missing link between those two areas. To fill this gap, five limestone outcrops, so far poorly described in the literature, were identified and sampled in the Pippu and Esashi areas (central and northern part of Hokkaido Island, respectively). Their related microfacies are presented in detail as well as their foraminiferal associations. The obtained age, based on foraminiferal biostratigraphy from both areas, is defined as Carnian and the facies similarities, associated with specific modes of occurrence, identify the outcrops from the two areas as part of the same depositional system. Based on microfacies interpretations, a hypothetical depositional model is presented. It corresponds to a intra–oceanic depositional system developed on the flanks of an emergent volcanic seamount. The strong similarity with synchronous systems from the Sambosan Accretionary Complex (southwestern Japan) is discussed.

中文翻译：

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来自北海道（日本）内泽增生杂岩的上三叠统浅水碳酸盐岩：来自 Panthalassa 的新见解

摘要 泛太平洋上三叠统碳酸盐岩在侏罗纪和白垩纪期间在环太平洋地区增生，在增生杂岩中很少出现，保存相对较差。然而，它们代表了一个独特的机会，可以提高我们对 Panthalassa 热带地区沉积条件的了解。被公认为生命的摇篮，浅水碳酸盐岩对于了解生命如何在三叠纪从特提斯地区演化出来也非常重要。自 2007 年以来，作为日内瓦大学 REEFCADE 项目的一部分，已经开展了多项沉积学和生物地层学研究，重点是环太平洋地区的上三叠统浅水石灰岩。因此，在日本南部和俄罗斯远东地区报告了碳酸盐。日本北部的北海道岛代表了这两个地区之间缺失的一环。为了填补这一空白，在 Pippu 和 Esashi 地区（分别是北海道岛的中部和北部）确定并取样了五个迄今为止文献中描述得很少的石灰岩露头。详细介绍了它们的相关微相以及它们的有孔虫关联。根据两个地区的有孔虫生物地层学，获得的年龄被定义为 Carnian，并且与特定发生模式相关的相相似性将两个地区的露头识别为同一沉积系统的一部分。基于微相解释，提出了一个假设的沉积模型。它对应于在一个新兴的火山海山侧翼发育的大洋内沉积系统。讨论了与来自 Sambosan 增生复合体（日本西南部）的同步系统的强烈相似性。