Fletcher Tamara L, Moss Patrick T, Salisbury Steven W
Department of Ecosystem and Conservation Sciences, University of Montana, Missoula, MT, United States of America.
Department of Geography, University of Nevada-Reno, Reno, United States of America.
PeerJ. 2018 Sep 7;6:e5513. doi: 10.7717/peerj.5513. eCollection 2018.
The Winton Formation is increasingly recognised as an important source of information about the Cretaceous of Australia, and, more broadly, the palaeobiogeographic history of eastern Gondwana. With more precise dating and stratigraphic controls starting to provide temporal context to the geological and palaeontological understanding of this formation, it is timely to reassess the palaeoenvironment in which it was deposited. This new understanding helps to further differentiate the upper, most-studied portion of the formation (Cenomanian-Turonian) from the lower portions (Albian-Cenomanian), allowing a coherent picture of the ecosystem to emerge. Temperatures during the deposition of the Upper Cretaceous portion of the Winton Formation were warm, with high, seasonal rainfall, but not as extreme as the modern monsoon. The landscape was heterogeneous, a freshwater alluvial plain bestrode by low energy, meandering rivers, minor lakes and mires. Infrequent, scouring flood events were part of a multi-year cycle of drier and wetter years. The heavily vegetated flood plains supported abundant large herbivores. This was the final infilling of the great Eromanga Basin.
温顿组越来越被认为是澳大利亚白垩纪，更广泛地说是东冈瓦纳古生物地理历史的重要信息来源。随着更精确的年代测定和地层控制开始为对该地层的地质和古生物学理解提供时间背景，重新评估其沉积时的古环境恰逢其时。这种新的认识有助于进一步区分该地层上部（森诺曼阶-土伦阶）和下部（阿尔比阶-森诺曼阶），后者是研究最多的部分，从而形成一个连贯的生态系统图景。温顿组上白垩统沉积期间温度温暖，季节性降雨量高，但不像现代季风那样极端。地貌多样，是一个淡水冲积平原，有低能量的蜿蜒河流、小型湖泊和泥潭。罕见的冲刷洪水事件是多年干湿交替周期的一部分。植被茂密的洪泛平原上有大量大型食草动物。这是巨大的伊罗曼加盆地的最后充填阶段。
