Abstract This work focuses on the Olenekian-Anisian (Early-Middle Triassic) continental record of the Central-Eastern Pyrenean basin (NE Spain), a near-equator (10°-14°N) basin located in the western peri-Tethys margin, inside the Variscan fold-belt. Due to the mass mortality of the end-Permian and the subsequent Smithian-Spathian Boundary (SSB) crisis, the Early Triassic and its transition to the Middle Triassic was a time period with intermittent stages of environmental instability that affected fauna and flora intensely. Compared to other crisis, a remarkable feature is the longer time required to achive life recovery during this time-interval and the fact that continental environments have been less globally studied than their marine counterparts. Furthermore, in SW Europe there is almost no sedimentary continental record from the beginning of the Triassic. This multidisciplinary study, embracing sedimentology, mineralogy, palaeontology, palaeopedology and palaeogeography, of 10 complete and well dated Early-Middle Triassic field sections has allowed (1) the location and characterization of the oldest Mesozoic sedimentary record in the basin, which is of late Smithian age and overlies the late-middle Permian continental rocks and of (2) the Smithian-Spathian transition (SST), (3) the timing of life recovery during the late Spathian-Anisian, (4) the characterization of the first incursion of the Tethys sea into the basin, and (5) the comparison of the evolution of this basin with other basins of the same age in SW Europe. The SST coincides with hyper-arid climate conditions, evolving to semi-arid in the late Spathian and semi-arid to semi-humid in Anisian times. Poorly sorted breccias and conglomerate alluvial sheets with aeolian reworking dominate the SST, as a result of these environmental changes and tectonicsA broader comparison, based on stratigraphic studies by other authors, indicates less aridity in the basin studied compared to other SW Europe basins in the same period, maybe due to its greater proximity to the equator. Sedimentary characteristics changed during the late Spathian, when sandy braided fluvial systems developed and the first dispersed plants, pollen assemblages and paleosols appeared. Well-developed floodplains and associated paleosols and plants developed during the early Anisian, when more humid conditions prevailed. The occurrence of aluminium phosphate-sulphate (APS) minerals might be considered as evidence of environmental acidification during the Olenekian with an amelioration during the early Anisian, as described in neighboring basins, although in the Pyrenean basin this acidification was probably less intensive. The first incursion of the Tethys sea reached the Central-Eastern Pyrenean basin during the Anisian-Ladinian transition, about 3 My later than in neighbouring Southwestern Europe basins. General comparison with other Early-Middle Triassic continental records of Western Europe basins indicates contrasting trends of climate and sedimentary evolution, probably related to the still prevailing great paleorelief of the Variscan foldbelt, where part of the study basin could constitute an elevated area during some time-intervals, possibly related to the so-called Ebro High.

中文翻译：

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Olenekian-Anisian 大陆记录的逐渐变化和比利牛斯山脉中东部盆地的生物意义，西班牙东北部

摘要 这项工作的重点是中东比利牛斯盆地（西班牙东北部）的 Olenekian-Anisian（早中三叠世）大陆记录，该盆地是位于西特提斯边缘西部的近赤道（10°-14°N）盆地。 ，在 Variscan 折叠带内。由于二叠纪末的大规模死亡和随后的史密斯-斯巴达边界 (SSB) 危机，早三叠世及其向中三叠世的过渡是一个间歇性环境不稳定阶段的时期，对动植物群产生了强烈影响。与其他危机相比，一个显着的特点是在这个时间间隔内实现生命恢复所需的时间更长，而且大陆环境的全球研究少于海洋环境。此外，在欧洲西南部，几乎没有三叠纪初期的大陆沉积记录。这项多学科研究包括沉积学、矿物学、古生物学、古土壤学和古地理学，对 10 个完整且年代久远的早-中三叠世野外剖面进行了 (1) 盆地中最古老的中生代沉积记录的位置和表征，该记录是晚期史密斯时代并覆盖在晚中二叠世大陆岩石和 (2) 史密斯-斯帕阶 (SST) 过渡 (SST)，(3) 斯巴达阶-阿尼西亚晚期生命恢复的时间，(4) 首次入侵的特征特提斯海进入盆地，以及（5）该盆地与西欧其他同龄盆地的演化比较。SST 恰逢超干旱气候条件，在斯帕西亚晚期演变为半干旱，在阿尼西亚时代演变为半干旱至半湿润。由于这些环境变化和构造，分类不良的角砾岩和带有风成作用的砾岩冲积层在 SST 占主导地位。基于其他作者的地层学研究的更广泛的比较表明，与同一地区的其他西欧盆地相比，该盆地的干旱程度较低期间，可能是因为它更靠近赤道。沉积特征在晚期 Spathian 发生了变化，当时沙质辫状河流系统发育，出现了第一批分散的植物、花粉组合和古土壤。发育良好的洪泛平原和相关的古土壤和植物在阿尼世早期发展起来，当时更潮湿的条件盛行。磷酸-硫酸铝 (APS) 矿物的出现可能被认为是 Olenekian 时期环境酸化的证据，而在早期 Anisian 时期有所改善，如邻近盆地所述，尽管在比利牛斯盆地，这种酸化可能不那么强烈。在 Anisian-Ladinian 过渡期间，特提斯海的第一次入侵到达了中东部比利牛斯盆地，比邻近的西南欧盆地晚了大约 3 My。与西欧盆地其他早-中三叠世大陆记录的总体比较表明气候和沉积演化的对比趋势，可能与仍然盛行的 Variscan 褶皱带的大古地貌有关，其中研究盆地的一部分可能在一段时间内构成一个升高的区域- 间隔，