Abstract Las Violetas Fossil Forest of the Salamanca Formation was a mixed forest of Paleocene age located in the Golfo San Jorge Basin, central Patagonia of Argentina, which includes conifers (previously studied), dicots and palms. In the present work, the dicot fossil woods outcropping in one of the fossiliferous levels (L3) of the Salamanca Formation are described, taxonomically assigned, and their affinities are discussed. They are three new species, including a new genus related to the Myrtaceae and Laurales. The complete fossiliferous assemblage is used to infer the climate and environment of the fossil forest. This assemblage represents a parautochtonous fossil plant association that lived either on the margins of channels or exposed bars in well-drained soils, probably tropical red-soils, close to their depositional setting (tidal channels and bars of an estuary). Warm and humid conditions and porous host-rocks favored the silicification of woods and pigmentation with Fe, resulting in yellow-orange and green fossil woods. We apply growth ring analysis to the conifer woods. For the dicots, wood anatomical characters influenced by the environment were analyzed, and the Vulnerability and Mesomorphy indices were used. These methods, comparisons with extant forests and the sedimentology, suggest that the Las Violetas Fossil Forest was an evergreen forest that developed under uniform growing seasons that ended abruptly, with an abundant water supply and high mean annual temperatures.

中文翻译：

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古新世 Las Violetas 化石森林：木材解剖学和古气候学

摘要 Las Violetas Fossil Forest of the Salamanca Formation 是位于阿根廷巴塔哥尼亚中部 Golfo San Jorge 盆地的古新世混交林，包括针叶树（先前研究过）、双子叶植物和棕榈树。在目前的工作中，描述了在萨拉曼卡组的化石层 (L3) 之一中出露的双子叶植物化石木材，并对其进行了分类分配，并讨论了它们的亲缘关系。它们是三个新物种，包括一个与桃金娘科和月桂目有关的新属。完整的化石组合用于推断化石森林的气候和环境。这种组合代表了一种近地生物化石植物群落，它们要么生活在河道边缘，要么生活在排水良好的土壤中，可能是热带红壤，靠近它们的沉积环境（潮汐通道和河口的堤坝）。温暖潮湿的条件和多孔的主岩有利于木材的硅化和铁的着色，从而产生黄橙色和绿色的化石木材。我们将年轮分析应用于针叶林。对于双子叶植物，分析了受环境影响的木材解剖特征，并使用脆弱性和中形态指数。这些方法与现存森林和沉积学进行比较，表明 Las Violetas Fossil Forest 是一个常绿森林，生长季节突然结束，具有丰富的供水和高年平均气温。导致黄橙色和绿色化石木材。我们将年轮分析应用于针叶林。对于双子叶植物，分析了受环境影响的木材解剖特征，并使用脆弱性和中形态指数。这些方法与现存森林和沉积学进行比较，表明 Las Violetas Fossil Forest 是一个常绿森林，生长季节突然结束，具有丰富的供水和高年平均气温。导致黄橙色和绿色化石木材。我们将年轮分析应用于针叶林。对于双子叶植物，分析了受环境影响的木材解剖特征，并使用脆弱性和中形态指数。这些方法与现存森林和沉积学进行比较，表明 Las Violetas Fossil Forest 是一个常绿森林，生长季节突然结束，具有丰富的供水和高年平均气温。