Abstract The Olivares Formation, a lower Paleogene unit of the Subbetic Zone in Southern Spain, is mostly composed of calcarenites comprising 60–90% of resedimented Microcodium remains, which are intercalated in hemipelagic marls rich in planktonic foraminifera. Microcodium is formed on the roots of terrestrial plants adapted to live on carbonate-rich substrates, its occurrence in the Olivares Formation entailing a massive resedimentation from a subaerially exposed carbonate source area. New field observations demonstrate that the unit was deposited, at the base of a faulted slope, within a graben flanked by massifs of mostly Jurassic carbonates, while an ichnological analysis shows an abundant and moderately diverse trace fossil assemblage consisting of 30 ichnospecies belonging to 21 ichnogenera. The nongraphoglyptid assemblage (24 ichnospecies, 16 ichnogenera) is dominated by Chondrites, Ophiomorpha, Planolites, and Scolicia. Zoophycos isp. is common, while Cladichnus, Gordia, Helminthopsis, Multina, Nereites, Parahaentzscheliana, Polykampton, Spirophycus, Strobilorhaphe and Thalassinoides isp. are scarce or rare. In the graphoglyptid assemblage (6 ichnospecies, 5 ichnogenera), Helminthorhaphe is common/scarce and Belorhaphe, Desmograpton, Paleodictyon and Urohelmintoida are scarce/rare. This trace fossil assemblage, with abundant Scolicia and Nereites and frequent graphoglyptids, can be assigned to the deep-sea Nereites ichnofacies. Within the Nereites ichnofacies, the Ophiomorpha rudis and Paleodictyon subichnofacies are readily differentiated, and the Nereites subichnofacies probably also occurs, pointing to vertical changes in the turbiditic system most likely related to a coeval sea-level rise that eventually resulted in the flooding of the emergent Microcodium-producing carbonate massifs.

中文翻译：

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亚贝蒂带（西班牙东南部）的大年-下Selandian Microcodium 丰富的方解石：深海、坡底系统中的Nereites 地层相记录

摘要 Olivares 组是西班牙南部亚贝蒂带的下古近系单元，主要由钙质岩组成，其中 60-90% 的再沉积 Microcodium 残骸夹在富含浮游有孔虫的半远洋泥灰岩中。Microcodium 形成于适合生活在富含碳酸盐的基质上的陆生植物的根部，它在 Olivares 组中的出现需要从地下暴露的碳酸盐源区进行大规模的再沉积。新的实地观察表明，该单元沉积在断层斜坡底部，两侧是主要侏罗纪碳酸盐岩地块的地堑内，而地质学分析显示，有丰富且适度多样的痕迹化石组合，由属于 21 种属的 30 种物种组成. nongraphoglyptid 组合 (24 ichnospecies, 16 ichnogenera) 以球粒陨石、Ophiomorpha、Planolites 和 Scolicia 为主。Zoophycos isp。是常见的，而 Cladichnus、Gordia、蠕虫、Multina、Nereites、Parhaentzscheliana、Polykampton、Spirophycus、Strobilorhaphe 和 Thalassinoides isp。稀少或稀有。在graphoglyptid 组合（6 ichnospecies，5 ichnogenera）中，Helminthorhaphe 常见/稀少，而Belorhaphe、Desmograpton、Paleodictyon 和Urohelmintoida 则稀少/稀有。这种微量化石组合，具有丰富的 Scolicia 和 Nereites 以及频繁的graphoglyptids，可以归入深海 Nereites 地层相。在沙蚕地层相内，容易区分出Ophiomorpha rudis 和Paleodictyon 亚种相，也可能出现沙蚕亚种相，