Stratigraphic cycles preserved in sedimentary successions are controlled by the interaction of tectonics, climate, sediment supply and sea-level variations. Understanding the influence of these drivers on sedimentary systems dynamics is crucial to understand and extract information from sedimentary archives. In the deep marine deposits of the Ainsa foreland basin (lower to middle Eocene, southern central Pyrenees, Spain), the origin of well-preserved cyclicity between channelized sandy submarine fans and hemipelagic deposits remains subject to debate because of the absence of chronostratigraphic constraints on high resolution geochemical proxies. Here, we contrast a combination of newly acquired and legacy geochemical datasets (carbon and oxygen stable isotopes, organic matter content, major and trace elements and the mineralogical composition of bulk hemipelagic sediments) tuned by a new age model to global “target” curves to discuss the possible drivers of the stratigraphic cycles found in the deep marine sediment gravity flow deposits of the Hecho Group. Our new age model is based on magnetostratigraphic and biostratigraphic datasets acquired on a composite section going from the Banaston system to the distal deposits of the Sobrarbe deltaic complex. Four major polarity zones are identified in the studied succession covering the time span from C21n (lower members of the Banaston system) to C19r (Sobrarbe deltaic complex). Our age model is corroborated by the identification of the nannoplankton zone NP16 in the Guaso system (C20n).

Comparison between global carbon isotope curve and local isotope dataset shows some differences, suggesting the preservation of a local isotope signal modulated by eustatism, changes in the environment of deposition and/or restriction in water circulation in the Ainsa basin. Yet, comparison of the stratigraphic record with global sea-level curves highlights that sands are mainly delivered to the basin during lowstands, pointing to the important role of eustasy even in an active foreland tectonic context. The exception to the rule is the Banaston member II, whose deposition during a sea-level highstand seems to be controlled by the growth of tectonic structures.

沉积层序中保存的地层旋回受构造、气候、沉积物供应和海平面变化的相互作用控制。了解这些驱动因素对沉积系统动力学的影响对于理解和提取沉积档案中的信息至关重要。在 Ainsa 前陆盆地（下始新世，中始新世，西班牙比利牛斯山脉中南部）的深海沉积物中，由于缺乏年代地层学限制，河道化沙质海底扇和半远洋沉积物之间保存完好的旋回性的起源仍然存在争议。高分辨率地球化学代理。在这里，我们对比了新获得的和遗留的地球化学数据集（碳和氧稳定同位素、有机物含量、主要和微量元素以及大块半远洋沉积物的矿物组成）通过新时代模型调整到全球“目标”曲线，以讨论在 Hecho 群深海沉积物重力流沉积物中发现的地层旋回的可能驱动因素。我们的新时代模型基于在从 Banaston 系统到 Sobrarbe 三角洲复合体的远端沉积物的复合剖面上获得的磁地层和生物地层数据集。在研究的序列中确定了四个主要极性带，涵盖从 C21n（班纳斯顿系统的下层成员）到 C19r（Sobrarbe 三角洲复合体）的时间跨度。我们的年龄模型得到了 Guaso 系统 (C20n) 中纳米浮游生物区 NP16 的证实。

全球碳同位素曲线与局部同位素数据集之间的比较显示出一些差异，表明在安萨盆地中存在由浮游生物、沉积环境变化和/或水循环限制所调制的局部同位素信号。然而，地层记录与全球海平面曲线的比较突出显示，沙子主要在低位期间输送到盆地，即使在活跃的前陆构造背景下，也表明了eustasy的重要作用。该规则的例外是 Banaston II 段，其在海平面高位期间的沉积似乎受构造结构的生长控制。