The impact of volcanic activity and trophic state on the preservation of plant remains from two Triassic palaeolake deposits in western Gondwana is investigated. Six taphonomic modes are identified for the Potrerillos–Cacheuta sequence and the Los Rastros Formation, along with proposed taphonomic pathways for each mode. The taphonomic pathways were compared with those proposed for the Agua de la Zorra Formation, a coeval lacustrine-deltaic succession. In all three cases, plant preservation in off-shore lacustrine facies was enhanced by anoxic bottom conditions. In the more proximal near-shore facies, a high sedimentation rate would have been factor that enhanced the preservation. Variation in relative abundance and taxonomic diversity between the three successions are attributed to ecological differences rather than taphonomic differences among the lake systems. No evidence was recorded that the preserved plant material was produced by volcanic trauma. The preservation of the cuticle recorded in the Cacheuta Formation was likely enhanced by the apparently low thermal maturation of the rock and the presence of tuffaceous horizons. In the three successions, the abundance and distribution of remains throughout the sections suggest that the trophic state of the lake did not influence the preservation of the plant.

中文翻译：

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冈瓦纳西部三叠纪湖泊-三角洲系统火山活动和营养状态对植物埋藏过程的影响

研究了火山活动和营养状态对冈瓦纳西部两个三叠纪古湖沉积物中植物遗骸保存的影响。Potrerillos-Cacheuta 序列和 Los Rastros 组确定了六种埋藏模式，以及每种模式的拟议埋藏路径。将埋葬路径与为 Agua de la Zorra 组提出的路径进行了比较，Agua de la Zorra 组是一个同时代的湖泊 - 三角洲序列。在所有三种情况下，缺氧底部条件都增强了近海湖泊相中的植物保存。在更近的近岸相中，高沉积速率可能是增强保存的因素。三个演替之间的相对丰度和分类多样性的变化归因于生态差异而不是湖泊系统之间的埋葬差异。没有证据表明保存的植物材料是由火山创伤产生的。Cacheuta 组中记录的角质层的保存可能由于岩石明显低的热成熟度和凝灰质层的存在而得到加强。在三个演替中，整个剖面中遗骸的丰度和分布表明湖泊的营养状态并未影响植物的保存。Cacheuta 组中记录的角质层的保存可能由于岩石明显低的热成熟度和凝灰质层的存在而得到加强。在三个演替中，整个剖面中遗骸的丰度和分布表明湖泊的营养状态并未影响植物的保存。Cacheuta 组中记录的角质层的保存可能由于岩石明显低的热成熟度和凝灰质层的存在而得到加强。在三个演替中，整个剖面中遗骸的丰度和分布表明湖泊的营养状态并未影响植物的保存。