Environment and taphonomy of an intrabasinal upland flora preserved in lower Permian volcaniclastic sediments
Environment and taphonomy of an intrabasinal upland flora preserved in lower Permian volcaniclastic sediments
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下二叠统火山碎屑沉积物中盆地内高地植物群的环境和埋藏学
DOI：
10.1127/njgpa/2021/0992
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Rößler
中科院分区：
文献类型：
--
作者：
Trümper;Luthardt;Rößler
在德国西南部温魏莱尔附近的田野上发现的硅化木为晚古生代裸子植物的解剖提供了独特的三维视角。然而，对化石的起源知之甚少，阻碍了进一步的研究。本文根据Zuckerwald地区的发掘资料，对石化茎段的寄主岩石和古植物学性质进行了研究，以重建其古环境、古生态和古生物学特征。化石木材代表部分硅化的碎片茎和根，这是嵌入在冲积扇碎屑上Schallodenbach成员（Donnersberg组，萨尔-Nahe盆地）。Walchian针叶树的小枝，Cordaites叶印，罕见的Calamites铸件以及蕨类植物和Dicranophyllum的叶印伴随着茎。生物地层学研究表明，植物碎屑是在沟道化泥石流的前缘运移的。流行的3D保存可能得益于快速的主岩固结和快速但逐步硅化来自火山岩内。古电流数据，沉积学和树木年轮分析表明，温魏莱尔组合复杂的火山Donnersberg圆顶，这是由一个季节性干燥适应植物群落植被的盆地内高地景观。结果表明，质量流埋藏群落在重建晚古生代内陆盆地，这是超出了有限的盆地中央埋藏窗口的干旱-高地生态系统的潜力。
Silicified woods found on fields near Winnweiler, SW-Germany, provide unique threedimensional insights into the anatomy of late Palaeozoic gymnosperms. However, little is known about the fossils’ origin impeding further research. Based on an excavation at the Zuckerwald locality, we characterise the host rocks and palaeobotanical nature of the petrified stem fragments to reconstruct their palaeoenvironments, palaeoecology and fossilisation. The fossil woods represent partially silicified fragmentary stems and roots, which were embedded in alluvial-fan debrites of the upper Schallodenbach Member (Donnersberg Formation, Saar-Nahe Basin). Twigs of Walchian conifers, Cordaites leaf impressions, rare Calamites casts as well as leaf impressions of pteridophylls and Dicranophyllum accompany the stems. Biostratinomy indicates that the phytodebris was transported at the front of channelised debris-flows. Prevalent 3D-preservation probably benefited from rapid host-rock consolidation and quick but stepwise silicification sourced from volcanic intraclasts. Palaeo current data, sedimentology and tree-ring analysis reveal that the Winnweiler Assemblage Complex derived from an intrabasinal upland landscape of the volcanic Donnersberg Dome, which was vegetated by a seasonally-dry adapted floral community. Results demonstrate the potential of mass-flow taphocoenoses in reconstructing dry-upland ecosystems of late Palaeozoic intramontane basins, which are beyond the restricted basin-central taphonomic windows.